Hydroquinones are chemical compounds that function as potent depigmenting agents, inhibiting the enzymatic conversion of tyrosine to melanin, used topically in the treatment of various dermatological disorders such as melasma, freckles, and hyperpigmentation.
Toxic, volatile, flammable liquid hydrocarbon byproduct of coal distillation. It is used as an industrial solvent in paints, varnishes, lacquer thinners, gasoline, etc. Benzene causes central nervous system damage acutely and bone marrow damage chronically and is carcinogenic. It was formerly used as parasiticide.
Arbutin is a natural derivative of hydroquinone, found in the leaves of some plant species, which exhibits skin lightening properties by inhibiting tyrosinase activity and reducing melanin production.
Benzene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
An antiseptic and disinfectant aromatic alcohol.
Substances used to obtain a lighter skin complexion or to treat HYPERPIGMENTATION disorders.
A flavoprotein that reversibly catalyzes the oxidation of NADH or NADPH by various quinones and oxidation-reduction dyes. The enzyme is inhibited by dicoumarol, capsaicin, and caffeine.
A low-molecular-weight (16,000) iron-free flavoprotein containing one molecule of flavin mononucleotide (FMN) and isolated from bacteria grown on an iron-deficient medium. It can replace ferredoxin in all the electron-transfer functions in which the latter is known to serve in bacterial cells.
A group of 1,2-benzenediols that contain the general formula R-C6H5O2.
Chemicals that are used to oxidize pigments and thus effect whitening.
Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance.
Injectable form of VITAMIN B 12 that has been used therapeutically to treat VITAMIN B 12 DEFICIENCY.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.
Hydrocarbon rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
Disorders of increased melanin pigmentation that develop without preceding inflammatory disease.
An oral anticoagulant that interferes with the metabolism of vitamin K. It is also used in biochemical experiments as an inhibitor of reductases.
A plant genus of the family ROSACEAE. The common names of chokeberry or chokecherry are also used for some species of PRUNUS.
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
The yellowish discoloration of connective tissue due to deposition of HOMOGENTISIC ACID (a brown-black pigment). This is due to defects in the metabolism of PHENYLALANINE and TYROSINE. Ochronosis occurs in ALKAPTONURIA, but has also been associated with exposure to certain chemicals (e.g., PHENOL, trinitrophenol, BENZENE DERIVATIVES).
Xanthene dye used as a bacterial and biological stain. Synonyms: Pyronin; Pyronine G; Pyronine Y. Use also for Pyronine B. which is diethyl-rather than dimethylamino-.
Mold and yeast inhibitor. Used as a fungistatic agent for foods, especially cheeses.
Enzymes that catalyze the joining of two molecules by the formation of a carbon-carbon bond. These are the carboxylating enzymes and are mostly biotinyl-proteins. EC 6.4.
Methyl, propyl, butyl, and ethyl esters of p-hydroxybenzoic acid. They have been approved by the FDA as antimicrobial agents for foods and pharmaceuticals. (From Hawley's Condensed Chemical Dictionary, 11th ed, p872)
A genus of SPONGES in the family Dysideidae, in which all skeletal fibers are filled with detritus.
A genus of basidiomycetous fungi, family POLYPORACEAE, order POLYPORALES, that grows on logs or tree stumps in shelflike layers. The species P. ostreatus, the oyster mushroom, is a choice edible species and is the most frequently encountered member of the genus in eastern North America. (Alexopoulos et al., Introductory Mycology, 4th ed, p531)
Phenols substituted with one or more chlorine atoms in any position.
A family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.
A genus of gram-negative, aerobic, rod-shaped bacteria characterized by an outer membrane that contains glycosphingolipids but lacks lipopolysaccharide. They have the ability to degrade a broad range of substituted aromatic compounds.
Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
A genus of anaerobic, gram-positive bacteria in the family Peptococcaceae, that reductively dechlorinates CHLOROPHENOLS.
An insecticide and herbicide that has also been used as a wood preservative. Pentachlorphenol is a widespread environmental pollutant. Both chronic and acute pentachlorophenol poisoning are medical concerns. The range of its biological actions is still being actively explored, but it is clearly a potent enzyme inhibitor and has been used as such as an experimental tool.
A family of gram-negative bacteria, in the phylum FIRMICUTES.
The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
A broad-spectrum antibiotic that is being used as prophylaxis against disseminated Mycobacterium avium complex infection in HIV-positive patients.
A group of compounds that are derivatives of methoxybenzene and contain the general formula R-C7H7O.
Facial dermatoses refers to various skin conditions that affect the face, causing symptoms such as redness, inflammation, papules, pustules, scaling, or pigmentation changes, which can be caused by a range of factors including genetics, infections, allergies, and environmental factors.
A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.
Negative ions or salts derived from bromic acid, HBrO3.
**Maleates** are organic compounds that contain a carboxylic acid group and a hydroxyl group attached to adjacent carbon atoms, often used as intermediates in the synthesis of pharmaceuticals and other chemicals, or as drugs themselves, such as maleic acid or its salts.
NAD(P)H:(quinone acceptor) oxidoreductases. A family that includes three enzymes which are distinguished by their sensitivity to various inhibitors. EC (NAD(P)H DEHYDROGENASE (QUINONE);) is a flavoprotein which reduces various quinones in the presence of NADH or NADPH and is inhibited by dicoumarol. EC (NADH dehydrogenase (quinone)) requires NADH, is inhibited by AMP and 2,4-dinitrophenol but not by dicoumarol or folic acid derivatives. EC (NADPH dehydrogenase (quinone)) requires NADPH and is inhibited by dicoumarol and folic acid derivatives but not by 2,4-dinitrophenol.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.
Flavoproteins that serve as specific electron acceptors for a variety of DEHYDROGENASES. They participate in the transfer of electrons to a variety of redox acceptors that occur in the respiratory chain.

Multiple oligodeoxyribonucleotide syntheseson a reusable solid-phase CPG support via the hydroquinone-O,O'-diacetic acid (Q-Linker) linker arm. (1/775)

A strategy for oligodeoxyribonucleotide synthesis on a reusable CPG solid-phase support, derivatized with hydroxyl groups instead of amino groups, has been developed. Ester linkages, through a base labile hydroquinone- O, O '-diacetic acid ( Q-Linker ) linker arm, were used to couple the first nucleoside to the hydroxyl groups on the support. This coupling was rapidly accomplished (10 min) using O -benzotriazol-1-yl- N, N, N ', N '-tetramethyluronium hexafluorophosphate (HBTU) and 1-hydroxybenzotriazole as the activating reagents. Oligodeoxyribonucleotide synthesis was performed using existing procedures and reagents, except a more labile capping reagent, such as chloro-acetic anhydride, methoxyacetic anhydride or t-butylphenoxyacetic anhydride, was used instead of acetic anhydride. After each oligodeoxyribonucleotide synthesis, the product was cleaved from the support with ammonium hydroxide (3 min) and deprotected as usual. Residual linker arms or capping groups were removed by treatment with ammonium hydroxide/methylamine reagent and the regenerated support was capable of reuse. Up to six different oligodeoxyribonucleotide syntheses or up to 25 cycles of nucleoside derivatization and cleavage were consecutively performed on the reusable support. This method may provide a significant cost advantage over conventional single-use solid supports currently used for the manufacture of antisense oligodeoxyribonucleotides.  (+info)

Effects of pyrogallol, hydroquinone and duroquinone on responses to nitrergic nerve stimulation and NO in the rat anococcygeus muscle. (2/775)

1. The hypothesis that endogenous superoxide dismutase (SOD) protects the nitrergic transmitter from inactivation by superoxide and that this explains the lack of sensitivity of the transmitter to superoxide generators was tested in the rat isolated anococcygeus muscle. 2. Responses to nitrergic nerve stimulation or to NO were not significantly affected by exogenous SOD or by the Cu/Zn SOD inhibitor diethyldithiocarbamic acid (DETCA). 3. Hydroquinone produced a concentration-dependent reduction of responses to NO with an IC50 of 27 microM, and higher concentrations reduced relaxant responses to nitrergic nerve stimulation with an IC50 of 612 microM. The effects of hydroquinone were only slightly reversed by SOD, so it does not appear to be acting as a superoxide generator. 4. Pyrogallol produced a concentration-dependent reduction in responses to NO with an IC50 value of 39 microM and this effect was reversed by SOD (100-1000 u ml(-1)). Pyrogallol did not affect responses to nitrergic nerve stimulation. Treatment with DETCA did not alter the differentiating action of pyrogallol. 5. Duroquinone produced a concentration-dependent reduction of relaxations to NO with an IC50 value of 240 microM and 100 microM slightly decreased nitrergic relaxations. After treatment with DETCA, duroquinone produced greater reductions of relaxant responses to NO and to nitrergic stimulation, the IC50 values being 8.5 microM for NO and 40 microM for nitrergic nerve stimulation: these reductions were reversed by SOD. 6. The findings do not support the hypothesis that the presence of Cu/Zn SOD explains the greater susceptibility of NO than the nitrergic transmitter to the superoxide generator pyrogallol, but suggest that it may play a role in the effects of duroquinone.  (+info)

8-(N,N-diethylamino)-n-octyl-3,4,5-trimethoxybenzoate actions on calcium dynamics in cultured vascular smooth muscle cells. (3/775)

AIM: To study 8-(N,N-Diethylamino)n-octyl-3,4,5-trimethoxybenzoate (TMB), a potent Ca(2+)-antagonist, actions on cellular calcium dynamics in vascular smooth muscle cell (VSMC) cultures. METHODS: A7r5 VSMC were cultured with Fura-2 measurements of intracellular Ca2+ concentration, [Ca2+]i. RESULTS: TMB reduced [Ca2+]i from control levels and blocked [Ca2+]i increase caused by norepinephrine (NE) and 2,5-di (t-butyl)-1,4-benzohydroquinone (BHQ). [Ca2+]i reduction by TMB was further enhanced by ryanodine. CONCLUSION: TMB is an effective agent for blocking the [Ca2+]i increase caused by NE and BHQ and for enhancing the [Ca2+]i reduction caused by ryanodine.  (+info)

Biodegradative mechanism of the brown rot basidiomycete Gloeophyllum trabeum: evidence for an extracellular hydroquinone-driven fenton reaction. (4/775)

We have identified key components of the extracellular oxidative system that the brown rot fungus Gloeophyllum trabeum uses to degrade a recalcitrant polymer, polyethylene glycol, via hydrogen abstraction reactions. G. trabeum produced an extracellular metabolite, 2,5-dimethoxy-1,4-benzoquinone, and reduced it to 2,5-dimethoxyhydroquinone. In the presence of 2,5-dimethoxy-1,4-benzoquinone, the fungus also reduced extracellular Fe3+ to Fe2+ and produced extracellular H2O2. Fe3+ reduction and H2O2 formation both resulted from a direct, non-enzymatic reaction between 2,5-dimethoxyhydroquinone and Fe3+. Polyethylene glycol depolymerization by G. trabeum required both 2,5-dimethoxy-1,4-benzoquinone and Fe3+ and was completely inhibited by catalase. These results provide evidence that G. trabeum uses a hydroquinone-driven Fenton reaction to cleave polyethylene glycol. We propose that similar reactions account for the ability of G. trabeum to attack lignocellulose.  (+info)

Bioavailability and metabolism of hydroquinone after intratracheal instillation in male rats. (5/775)

The purpose of this study was to investigate the rate and extent of hydroquinone (HQ) absorption and first pass metabolism in the lungs of male rats in vivo. [14C]HQ in physiological saline was administered intratracheally via an indwelling endotracheal tube to simulate inhalation exposure to HQ dust. The bioavailability of HQ was determined by blood sampling simultaneously at arterial and venous sites beginning immediately after administration to conscious rats. Pulmonary absorption and metabolism, and systemic metabolism and elimination were determined by chromatographic analysis of parent compound and metabolites in blood samples after intratracheal administration of [14C]HQ at 0.1, 1.0, and 10 mg/kg. Pulmonary absorption of HQ was found to be very rapid with [14C]HQ detectable in arterial blood, and to a lesser extent in venous blood, within 5 to 10 s after dose administration. Only [14C]HQ was detected in the initial (5-10 s) arterial blood samples at all dose levels, indicating that pulmonary metabolism of HQ was not extensive. However, later blood samples (45-720 s) indicated rapid metabolism and elimination of the parent compound and metabolites after intratracheal absorption. The elimination half-life from the 0.1 mg/kg dose was allometrically scaled to human proportions and used to estimate the steady-state (maximum) human blood concentrations of HQ resulting from presupposed workplace exposures. The estimates indicated minimal levels of HQ in human blood after respiratory exposures of greater than 1 h at 0.1 or 2.0 mg/m3; these levels were less than background concentrations of HQ detected in human blood in previous studies.  (+info)

Antioxidants reversibly inhibit the spontaneous resumption of meiosis. (6/775)

We previously showed that the cell-permeant antioxidant 2(3)-tert-butyl-4-hydroxyanisole (BHA) inhibited germinal vesicle breakdown (GVBD) in oocyte-cumulus complexes (OCC) of the rat. The objective of the present studies was to assess other antioxidants and whether such inhibition was reversible. Spontaneous GVBD in OCC incubated for 2 h was significantly inhibited (P < 0.005) by nordihydroguaiaretic acid (NDGA; GVBD = 19.4%), BHA (GVBD = 25.7%), octyl gallate (OG; GVBD = 52.2%), ethoxyquin (EQ; GVBD = 58.8%), 2, 6-di-tert-butyl-hydroxymethyl phenol (TBHMP; GVBD = 59%), butylated hydroxytoluene (BHT; GVBD = 59.5%), and tert-butyl hydroperoxide (TBHP; GVBD = 60.0%). Other antioxidants that produced lower but significant (P < 0.05) inhibition of oocyte maturation included propyl gallate (PG; GVBD = 70.3%), 2,4,5-trihydroxybutrophenone (THBP; GVBD = 71.4%), and lauryl gallate (LG; GVBD = 71.4%). Antioxidants that had no effect on oocyte maturation at the same concentration (100 microM) included ascorbic acid, vitamin E, and Trolox. Inhibition of GVBD was evident for up to 8 h of incubation of OCC and denuded oocytes (DO) with BHA or NDGA and was reversed by washing. NDGA was less potent than BHA for inhibition of GVBD in DO, unlike that seen with OCC. Oocyte maturation was induced by incubation of follicles for 3 h with human chorionic gonadotropin (hCG), and this response was inhibited by BHA or NDGA. These findings support the conclusion that cell-permeant antioxidants inhibit spontaneous resumption of meiosis, which may implicate a role of oxygen radicals in oocyte maturation.  (+info)

Determination of hydroquinone in air by high performance liquid chromatography. (7/775)

A method for measuring hydroquinone in air was evaluated, both in the laboratory and in the workplace. The method involved sampling the inhalable fraction onto a filter contained in a multi-holed sampler with a back-up of Tenax TA, followed by desorption into acetonitrile and analysis by High Performance Liquid Chromatography. It was shown to be effective at measuring hydroquinone over the range 0.1 to 2 times a concentration of 0.5 mg/m3 for 8 h.  (+info)

Induction of human UDP glucuronosyltransferases (UGT1A6, UGT1A9, and UGT2B7) by t-butylhydroquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin in Caco-2 cells. (8/775)

Human colon carcinoma Caco-2 cells were used to study the induction of UDP glucuronosyltransferase (UGT) isoforms UGT1A6, UGT1A9, and UGT2B7 by aryl hydrocarbon receptor agonists and by antioxidant-type inducers with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and t-butylhydroquinone (TBHQ), respectively. Early- (PF11) and late-passage clones (TC7) of Caco-2 cells, which show low and high constitutive UGT1A6 expression, respectively, were selected. The following results were obtained: 1) In Caco-2 cells UGT activity (4-methylumbelliferone as substrate) was significantly enhanced by 10 nM TCDD or 40 to 80 microM TBHQ and 2) duplex reverse-transcription-polymerase chain reaction analysis showed for the first time that the expression of human UGT1A6, UGT1A9, and UGT2B7 was enhanced by 40 to 80 microM TBHQ; both UGT1A6 and UGT1A9 were induced by 10 nM TCDD, whereas UGT2B7 was not induced by TCDD. The results suggest that at least two human UGTs (UGT1A6 and UGT1A9) are inducible by aryl hydrocarbon receptor agonists and even more isoforms (UGT1A6, UGT1A9, and UGT2B7) are inducible by antioxidant-type inducers in Caco-2 cells.  (+info)

Hydroquinones are a type of chemical compound that belong to the group of phenols. In a medical context, hydroquinones are often used as topical agents for skin lightening and the treatment of hyperpigmentation disorders such as melasma, age spots, and freckles. They work by inhibiting the enzyme tyrosinase, which is necessary for the production of melanin, the pigment that gives skin its color.

It's important to note that hydroquinones can have side effects, including skin irritation, redness, and contact dermatitis. Prolonged use or high concentrations may also cause ochronosis, a condition characterized by blue-black discoloration of the skin. Therefore, they should be used under the supervision of a healthcare provider and for limited periods of time.

Benzene is a colorless, flammable liquid with a sweet odor. It has the molecular formula C6H6 and is composed of six carbon atoms arranged in a ring, bonded to six hydrogen atoms. Benzene is an important industrial solvent and is used as a starting material in the production of various chemicals, including plastics, rubber, resins, and dyes. It is also a natural component of crude oil and gasoline.

In terms of medical relevance, benzene is classified as a human carcinogen by the International Agency for Research on Cancer (IARC) and the Environmental Protection Agency (EPA). Long-term exposure to high levels of benzene can cause various health effects, including anemia, leukemia, and other blood disorders. Occupational exposure to benzene is regulated by the Occupational Safety and Health Administration (OSHA) to protect workers from potential health hazards.

It's important to note that while benzene has legitimate uses in industry, it should be handled with care due to its known health risks. Exposure to benzene can occur through inhalation, skin contact, or accidental ingestion, so appropriate safety measures must be taken when handling this chemical.

Arbutin is a natural compound found in the leaves of some plants, such as bearberry (Arctostaphylos uva-ursi), cranberry, and blueberry. It is a glycoside of hydroquinone, which means it consists of a molecule of hydroquinone attached to a sugar molecule.

Arbutin has been used in some skincare products as a skin-lightening agent because it inhibits the production of melanin, the pigment that gives skin its color. When applied to the skin, arbutin is broken down into hydroquinone, which has been shown to have skin-lightening effects by interfering with the enzyme tyrosinase, which is involved in melanin production.

However, it's important to note that the use of hydroquinone in skincare products is controversial due to concerns about its potential toxicity and side effects, such as skin irritation and discoloration. Therefore, arbutin may be a safer alternative for those looking for a natural skin-lightening ingredient, but more research is needed to confirm its safety and effectiveness.

Benzoquinones are a type of chemical compound that contain a benzene ring (a cyclic arrangement of six carbon atoms) with two ketone functional groups (-C=O) in the 1,4-positions. They exist in two stable forms, namely ortho-benzoquinone and para-benzoquinone, depending on the orientation of the ketone groups relative to each other.

Benzoquinones are important intermediates in various biological processes and are also used in industrial applications such as dyes, pigments, and pharmaceuticals. They can be produced synthetically or obtained naturally from certain plants and microorganisms.

In the medical field, benzoquinones have been studied for their potential therapeutic effects, particularly in the treatment of cancer and infectious diseases. However, they are also known to exhibit toxicity and may cause adverse reactions in some individuals. Therefore, further research is needed to fully understand their mechanisms of action and potential risks before they can be safely used as drugs or therapies.

Phenol, also known as carbolic acid, is an organic compound with the molecular formula C6H5OH. It is a white crystalline solid that is slightly soluble in water and has a melting point of 40-42°C. Phenol is a weak acid, but it is quite reactive and can be converted into a variety of other chemicals.

In a medical context, phenol is most commonly used as a disinfectant and antiseptic. It has a characteristic odor that is often described as "tarry" or " medicinal." Phenol is also used in some over-the-counter products, such as mouthwashes and throat lozenges, to help kill bacteria and freshen breath.

However, phenol is also a toxic substance that can cause serious harm if it is swallowed, inhaled, or absorbed through the skin. It can cause irritation and burns to the eyes, skin, and mucous membranes, and it can damage the liver and kidneys if ingested. Long-term exposure to phenol has been linked to an increased risk of cancer.

Because of its potential for harm, phenol is regulated as a hazardous substance in many countries, and it must be handled with care when used in medical or industrial settings.

Skin lightening preparations are topical products or cosmetic treatments that contain ingredients intended to reduce the melanin concentration or inhibit its production in the skin, leading to a lighter skin tone. These products often include active ingredients such as hydroquinone, corticosteroids, retinoic acid, kojic acid, arbutin, or vitamin C. They work by suppressing tyrosinase, an enzyme responsible for melanin production, or causing skin cell turnover to decrease melanin-rich cells' appearance on the surface of the skin. It is essential to use these products under medical supervision and follow recommended guidelines, as improper usage can lead to skin irritation, allergic reactions, or other adverse effects.

Flavodoxin is not strictly a medical term, but it is a term used in biochemistry and molecular biology. Flavodoxins are small electron transfer proteins that contain a non-heme iron atom bound to a organic molecule called flavin mononucleotide (FMN). They play a role in various biological processes such as photosynthesis, nitrogen fixation and respiration where they function as electron carriers. Flavodoxins can undergo reversible oxidation and reduction, and this property allows them to transfer electrons between different enzymes during metabolic reactions. They are not specific to human physiology, but can be found in various organisms including bacteria, algae, and plants.

Catechols are a type of chemical compound that contain a benzene ring with two hydroxyl groups (-OH) attached to it in the ortho position. The term "catechol" is often used interchangeably with "ortho-dihydroxybenzene." Catechols are important in biology because they are produced through the metabolism of certain amino acids, such as phenylalanine and tyrosine, and are involved in the synthesis of various neurotransmitters and hormones. They also have antioxidant properties and can act as reducing agents. In chemistry, catechols can undergo various reactions, such as oxidation and polymerization, to form other classes of compounds.

Bleaching agents are substances that are used to remove color or whiten a variety of materials, including teeth, hair, and fabrics. In the medical field, bleaching agents are often used in dermatology to lighten or eliminate unwanted pigmentation in the skin, such as age spots, sun damage, or melasma.

The most common type of bleaching agent used in dermatology is hydroquinone, which works by inhibiting the production of melanin, the pigment that gives skin its color. Other bleaching agents include retinoic acid, corticosteroids, and kojic acid.

It's important to note that while bleaching agents can be effective in reducing the appearance of unwanted pigmentation, they can also cause side effects such as skin irritation, redness, and dryness. Therefore, it's essential to follow the instructions carefully and consult with a healthcare professional before using any bleaching agent.

Hyperpigmentation is a medical term that refers to the darkening of skin areas due to an increase in melanin, the pigment that provides color to our skin. This condition can affect people of all races and ethnicities, but it's more noticeable in those with lighter skin tones.

Hyperpigmentation can be caused by various factors, including excessive sun exposure, hormonal changes (such as during pregnancy), inflammation, certain medications, and underlying medical conditions like Addison's disease or hemochromatosis. It can also result from skin injuries, such as cuts, burns, or acne, which leave dark spots known as post-inflammatory hyperpigmentation.

There are several types of hyperpigmentation, including:

1. Melasma: This is a common form of hyperpigmentation that typically appears as symmetrical, blotchy patches on the face, particularly the forehead, cheeks, and upper lip. It's often triggered by hormonal changes, such as those experienced during pregnancy or while taking birth control pills.
2. Solar lentigos (age spots or liver spots): These are small, darkened areas of skin that appear due to prolonged sun exposure over time. They typically occur on the face, hands, arms, and decolletage.
3. Post-inflammatory hyperpigmentation: This type of hyperpigmentation occurs when an injury or inflammation heals, leaving behind a darkened area of skin. It's more common in people with darker skin tones.

Treatment for hyperpigmentation depends on the underlying cause and may include topical creams, chemical peels, laser therapy, or microdermabrasion. Preventing further sun damage is crucial to managing hyperpigmentation, so wearing sunscreen with a high SPF and protective clothing is recommended.

Hydroxocobalamin is a form of vitamin B12 that is used in medical treatments. It is a synthetic version of the naturally occurring compound, and it is often used to treat vitamin B12 deficiencies. Hydroxocobalamin is also used to treat poisoning from cyanide, as it can bind with the cyanide to form a non-toxic compound that can be excreted from the body.

In medical terms, hydroxocobalamin is defined as: "A bright red crystalline compound, C21H30CoN4O7·2H2O, used in the treatment of vitamin B12 deficiency and as an antidote for cyanide poisoning. It is converted in the body to active coenzyme forms."

It's important to note that hydroxocobalamin should only be used under the supervision of a medical professional, as improper use can lead to serious side effects or harm.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

Phenols, also known as phenolic acids or phenol derivatives, are a class of chemical compounds consisting of a hydroxyl group (-OH) attached to an aromatic hydrocarbon ring. In the context of medicine and biology, phenols are often referred to as a type of antioxidant that can be found in various foods and plants.

Phenols have the ability to neutralize free radicals, which are unstable molecules that can cause damage to cells and contribute to the development of chronic diseases such as cancer, heart disease, and neurodegenerative disorders. Some common examples of phenolic compounds include gallic acid, caffeic acid, ferulic acid, and ellagic acid, among many others.

Phenols can also have various pharmacological activities, including anti-inflammatory, antimicrobial, and analgesic effects. However, some phenolic compounds can also be toxic or irritating to the body in high concentrations, so their use as therapeutic agents must be carefully monitored and controlled.

Quinones are a class of organic compounds that contain a fully conjugated diketone structure. This structure consists of two carbonyl groups (C=O) separated by a double bond (C=C). Quinones can be found in various biological systems and synthetic compounds. They play important roles in many biochemical processes, such as electron transport chains and redox reactions. Some quinones are also known for their antimicrobial and anticancer properties. However, some quinones can be toxic or mutagenic at high concentrations.

Melanosis is a general term that refers to an increased deposit of melanin, the pigment responsible for coloring our skin, in the skin or other organs. It can occur in response to various factors such as sun exposure, aging, or certain medical conditions. There are several types of melanosis, including:

1. Epidermal melanosis: This type of melanosis is characterized by an increase in melanin within the epidermis, the outermost layer of the skin. It can result from sun exposure, hormonal changes, or inflammation.
2. Dermal melanosis: In this type of melanosis, there is an accumulation of melanin within the dermis, the middle layer of the skin. It can be caused by various conditions such as nevus of Ota, nevus of Ito, or melanoma metastasis.
3. Mucosal melanosis: This type of melanosis involves an increase in melanin within the mucous membranes, such as those lining the mouth, nose, and genitals. It can be a sign of systemic disorders like Addison's disease or Peutz-Jeghers syndrome.
4. Lentigo simplex: Also known as simple lentigines, these are small, benign spots that appear on sun-exposed skin. They result from an increase in melanocytes, the cells responsible for producing melanin.
5. Labial melanotic macule: This is a pigmented lesion found on the lips, typically the lower lip. It is more common in darker-skinned individuals and is usually benign but should be monitored for changes that may indicate malignancy.
6. Ocular melanosis: An increase in melanin within the eye can lead to various conditions such as ocular melanocytosis, oculodermal melanocytosis, or choroidal melanoma.

It is important to note that while some forms of melanosis are benign and harmless, others may indicate an underlying medical condition or even malignancy. Therefore, any new or changing pigmented lesions should be evaluated by a healthcare professional.

Dicumarol is an anticoagulant medication that belongs to a class of compounds known as coumarins. It works by inhibiting the action of vitamin K, which is necessary for the production of certain clotting factors in the liver. This results in a decrease in blood clotting ability and helps prevent the formation of harmful blood clots.

Dicumarol is primarily used to treat and prevent deep vein thrombosis (DVT), pulmonary embolism, and other conditions that may require anticoagulation therapy. It is also used in the management of atrial fibrillation, valvular heart disease, and certain types of heart attacks.

It's important to note that dicumarol has a narrow therapeutic index, meaning that the difference between an effective dose and a toxic dose is relatively small. Therefore, it requires careful monitoring of blood clotting times (INR) to ensure that the drug is working effectively without causing excessive bleeding.

Dicumarol is available in oral form and is typically taken once or twice daily. Common side effects include nausea, vomiting, diarrhea, skin rash, and abnormal liver function tests. Rare but serious side effects include severe bleeding, necrosis of the skin and other tissues, and allergic reactions.

Dicumarol is a prescription medication that should only be used under the guidance of a healthcare professional. It interacts with many other medications and foods, so it's important to inform your doctor about all the drugs you are taking and any dietary changes you may make while on this medication.

I'm sorry for any confusion, but "Photinia" is not a medical term. It is a genus of shrubs and small trees in the rose family, Rosaceae. The most commonly cultivated species is Photinia x fraseri, also known as Fraser photinia or Red Robin, which is often used in landscaping due to its attractive, glossy green leaves and clusters of white flowers followed by bright red berries.

If you have any medical concerns or questions, I would be happy to try to help with those.

Mutagens are physical or chemical agents that can cause permanent changes in the structure of genetic material, including DNA and chromosomes, leading to mutations. These mutations can be passed down to future generations and may increase the risk of cancer and other diseases. Examples of mutagens include ultraviolet (UV) radiation, tobacco smoke, and certain chemicals found in industrial settings. It is important to note that not all mutations are harmful, but some can have negative effects on health and development.

Ochronosis is a medical condition characterized by the accumulation of a dark pigment called homogentisic acid in various connective tissues, such as the skin, tendons, and cartilage. This accumulation results in a bluish-black or grayish discoloration of the affected tissues, which can lead to stiffness, pain, and limited mobility. Ochronosis is often associated with alkaptonuria, a rare inherited metabolic disorder that affects the breakdown of certain amino acids. However, it can also occur as a result of exposure to certain chemicals or medications.

I'm sorry for any confusion, but "Pyronine" is not a medical term. It is a type of basic dye that is often used in histology (the study of the microscopic structure of tissues) and cytology (the study of individual cells). Pyronin Y, a specific type of pyronine dye, is sometimes used to stain acidic components within cells, such as DNA and RNA. However, it is not a term that is typically used in clinical medicine to describe diseases or conditions.

Sorbic acid is a chemical compound that is commonly used as a preservative in various food and cosmetic products. Medically, it's not typically used as a treatment for any specific condition. However, its preservative properties help prevent the growth of bacteria, yeast, and mold, which can improve the safety and shelf life of certain medical supplies such as ointments and eye drops.

The chemical structure of sorbic acid is that of a carboxylic acid with two double bonds, making it a unsaturated fatty acid. It's naturally found in some fruits like rowanberries and serviceberries, but most commercial sorbic acid is synthetically produced.

Food-grade sorbic acid is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA), and it has a wide range of applications in food preservation, including baked goods, cheeses, wines, and fruit juices. In cosmetics, it's often used to prevent microbial growth in products like creams, lotions, and makeup.

It is important to note that some people may have allergic reactions to sorbic acid or its salts (sorbates), so caution should be exercised when introducing new products containing these substances into personal care routines or diets.

Carbon-carbon ligases are a type of enzyme that catalyze the formation of carbon-carbon bonds between two molecules. These enzymes play important roles in various biological processes, including the biosynthesis of natural products and the metabolism of carbohydrates and lipids.

Carbon-carbon ligases can be classified into several categories based on the type of reaction they catalyze. For example, aldolases catalyze the condensation of an aldehyde or ketone with another molecule to form a new carbon-carbon bond and a new carbonyl group. Other examples include the polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs), which are large multienzyme complexes that catalyze the sequential addition of activated carbon units to form complex natural products.

Carbon-carbon ligases are important targets for drug discovery and development, as they play critical roles in the biosynthesis of many disease-relevant molecules. Inhibitors of these enzymes have shown promise as potential therapeutic agents for a variety of diseases, including cancer, infectious diseases, and metabolic disorders.

Parabens are a group of synthetic preservatives that have been widely used in the cosmetics and personal care product industry since the 1920s. They are effective at inhibiting the growth of bacteria, yeasts, and molds, which helps to prolong the shelf life of these products. Parabens are commonly found in shampoos, conditioners, lotions, creams, deodorants, and other personal care items.

The most commonly used parabens include methylparaben, ethylparaben, propylparaben, and butylparaben. These compounds are often used in combination to provide broad-spectrum protection against microbial growth. Parabens work by penetrating the cell wall of microorganisms and disrupting their metabolism, which prevents them from multiplying.

Parabens have been approved for use as preservatives in cosmetics and personal care products by regulatory agencies around the world, including the U.S. Food and Drug Administration (FDA) and the European Commission's Scientific Committee on Consumer Safety (SCCS). However, there has been some controversy surrounding their safety, with concerns raised about their potential to mimic the hormone estrogen in the body and disrupt normal endocrine function.

While some studies have suggested that parabens may be associated with health problems such as breast cancer and reproductive toxicity, the evidence is not conclusive, and more research is needed to fully understand their potential risks. In response to these concerns, many manufacturers have begun to remove parabens from their products or offer paraben-free alternatives. It's important to note that while avoiding parabens may be a personal preference for some individuals, there is currently no scientific consensus on the need to avoid them entirely.

Dysidea is a genus of sponge in the family Dysideidae. It is a common and widely distributed marine sponge, found in tropical and subtropical waters around the world. Dysidea species are known for their soft, flexible bodies and their ability to filter water for food particles. They often have a pale or cream color and may be covered with small, hard spicules. Some species of Dysidea contain chemicals that have potential medicinal uses.

"Pleurotus" is not a medical term, but a genus of fungi commonly known as oyster mushrooms. These mushrooms are often consumed for their nutritional and potential medicinal benefits. However, in a medical context, if someone is referring to "pleural," it relates to the pleura, which is the double-layered serous membrane that surrounds the lungs and lines the inside of the chest wall. Any medical condition or disease affecting this area may be described as "pleural."

Chlorophenols are a group of chemical compounds that consist of a phenol ring substituted with one or more chlorine atoms. They are widely used as pesticides, disinfectants, and preservatives. Some common examples of chlorophenols include pentachlorophenol, trichlorophenol, and dichlorophenol.

Chlorophenols can be harmful to human health and the environment. They have been linked to a variety of adverse health effects, including skin and eye irritation, respiratory problems, damage to the liver and kidneys, and an increased risk of cancer. Exposure to chlorophenols can occur through contact with contaminated soil, water, or air, as well as through ingestion or absorption through the skin.

It is important to handle chlorophenols with care and to follow proper safety precautions when using them. If you are concerned about exposure to chlorophenols, it is recommended that you speak with a healthcare professional for further guidance.

Vitamin K1, also known as phylloquinone, is a type of fat-soluble vitamin K. It is the primary form of Vitamin K found in plants, particularly in green leafy vegetables such as kale, spinach, and collard greens. Vitamin K1 plays a crucial role in blood clotting and helps to prevent excessive bleeding by assisting in the production of several proteins involved in this process. It is also essential for maintaining healthy bones by aiding in the regulation of calcium deposition in bone tissue. A deficiency in Vitamin K1 can lead to bleeding disorders and, in some cases, osteoporosis.

Sphingomonas is a genus of gram-negative, aerobic bacteria that are widely distributed in the environment. They are known for their ability to degrade various organic compounds and are often found in water, soil, and air samples. The cells of Sphingomonas species are typically straight or slightly curved rods, and they do not form spores.

One distinctive feature of Sphingomonas species is the presence of a unique lipid called sphingolipid in their cell membranes. This lipid contains a long-chain base called sphingosine, which is not found in the cell membranes of other gram-negative bacteria. The genus Sphingomonas includes several species that have been associated with human infections, particularly in immunocompromised individuals. These infections can include bacteremia, pneumonia, and urinary tract infections. However, Sphingomonas species are generally considered to be of low virulence and are not typically regarded as major pathogens.

Naphthoquinones are a type of organic compound that consists of a naphthalene ring (two benzene rings fused together) with two ketone functional groups (=O) at the 1 and 2 positions. They exist in several forms, including natural and synthetic compounds. Some well-known naphthoquinones include vitamin K1 (phylloquinone) and K2 (menaquinone), which are important for blood clotting and bone metabolism. Other naphthoquinones have been studied for their potential medicinal properties, including anticancer, antibacterial, and anti-inflammatory activities. However, some naphthoquinones can also be toxic or harmful to living organisms, so they must be used with caution.

'Desulfitobacterium' is a genus of anaerobic, gram-positive bacteria that are capable of dehalogenating and reducing chlorinated organic compounds. These organisms play a significant role in the bioremediation of contaminated environments, as they can transform harmful pollutants into less toxic forms. The name 'Desulfitobacterium' is derived from the Latin words "de," meaning "from," "sulfur," referring to the sulfur-containing compounds these bacteria use for energy, and "bacterium," meaning "rod" or "staff."

Some notable species within this genus include:

* Desulfitobacterium dehalogenans: This species is well-known for its ability to reductively dechlorinate a wide range of chlorinated organic compounds, including polychlorinated biphenyls (PCBs) and trichloroethylene (TCE).
* Desulfitobacterium hafniense: This species is capable of reducing various halogenated compounds, such as tetrachloroethene (PCE), TCE, and polychlorinated phenols. It can also use nitrate, sulfate, or metal ions as electron acceptors for energy metabolism.
* Desulfitobacterium frappieri: This species is known to dechlorinate chlorinated ethenes, such as PCE and TCE, and can also reduce iron(III) and manganese(IV) compounds.

These bacteria are typically found in anaerobic environments, such as soil, groundwater, sediments, and the gastrointestinal tracts of animals. They play a crucial role in maintaining the balance of these ecosystems by breaking down complex organic compounds and contributing to nutrient cycling.

Pentachlorophenol is not primarily a medical term, but rather a chemical compound with some uses and applications in the medical field. Medically, it's important to understand what pentachlorophenol is due to its potential health implications.

Pentachlorophenol (PCP) is an organochlorine compound that has been widely used as a pesticide, wood preservative, and disinfectant. Its chemical formula is C6HCl5O. It is a white crystalline solid with a distinct, somewhat unpleasant odor. In the environment, pentachlorophenol can be found in soil, water, and air as well as in various organisms, including humans.

Pentachlorophenol has been associated with several potential health risks. It is classified as a probable human carcinogen by the International Agency for Research on Cancer (IARC) and as a possible human carcinogen by the United States Environmental Protection Agency (EPA). Exposure to pentachlorophenol can occur through inhalation, skin contact, or ingestion. Potential health effects include irritation of the skin, eyes, and respiratory tract; damage to the liver and kidneys; neurological issues; and reproductive problems.

In a medical context, pentachlorophenol might be relevant in cases where individuals have been exposed to this compound through occupational or environmental sources. Medical professionals may need to assess potential health risks, diagnose related health issues, and provide appropriate treatment.

Veillonellaceae is a family of Gram-negative, anaerobic bacteria found in various environments, including the human mouth and gut. The bacteria are known for their ability to produce acetic and lactic acid as end products of their metabolism. They are often part of the normal microbiota of the body, but they can also be associated with certain infections, particularly in individuals with weakened immune systems.

It's important to note that while Veillonellaceae bacteria are generally considered to be commensal organisms, meaning they exist harmoniously with their human hosts, they have been implicated in some disease states, such as periodontitis (gum disease) and bacterial pneumonia. However, more research is needed to fully understand the role of these bacteria in health and disease.

Biotransformation is the metabolic modification of a chemical compound, typically a xenobiotic (a foreign chemical substance found within an living organism), by a biological system. This process often involves enzymatic conversion of the parent compound to one or more metabolites, which may be more or less active, toxic, or mutagenic than the original substance.

In the context of pharmacology and toxicology, biotransformation is an important aspect of drug metabolism and elimination from the body. The liver is the primary site of biotransformation, but other organs such as the kidneys, lungs, and gastrointestinal tract can also play a role.

Biotransformation can occur in two phases: phase I reactions involve functionalization of the parent compound through oxidation, reduction, or hydrolysis, while phase II reactions involve conjugation of the metabolite with endogenous molecules such as glucuronic acid, sulfate, or acetate to increase its water solubility and facilitate excretion.

Rifabutin is an antibiotic drug that belongs to the class of rifamycins. According to the Medical Subject Headings (MeSH) database of the National Library of Medicine, Rifabutin is defined as: "A semi-synthetic antibiotic produced from Streptomyces mediterranei and related to rifamycin B. It has iron-binding properties and is used, usually in combination with other antibiotics, to treat tuberculosis. Its antibacterial action is due to inhibition of DNA-dependent RNA polymerase activity."

Rifabutin is primarily used to prevent and treat Mycobacterium avium complex (MAC) infections in people with human immunodeficiency virus (HIV) infection or acquired immune deficiency syndrome (AIDS). It may also be used off-label for other bacterial infections, such as tuberculosis, atypical mycobacteria, and Legionella pneumophila.

Rifabutin has a unique chemical structure compared to other rifamycin antibiotics like rifampin and rifapentine. This structural difference results in a longer half-life and better tissue distribution, allowing for once-daily dosing and improved penetration into the central nervous system (CNS).

As with any medication, Rifabutin can have side effects, including gastrointestinal disturbances, rashes, and elevated liver enzymes. Additionally, it is known to interact with several other medications, such as oral contraceptives, anticoagulants, and some anti-seizure drugs, which may require dose adjustments or monitoring for potential interactions.

Anisoles are organic compounds that consist of a phenyl ring (a benzene ring with a hydroxyl group replaced by a hydrogen atom) attached to a methoxy group (-O-CH3). The molecular formula for anisole is C6H5OCH3. Anisoles are aromatic ethers and can be found in various natural sources, including anise plants and some essential oils. They have a wide range of applications, including as solvents, flavoring agents, and intermediates in the synthesis of other chemicals.

Facial dermatoses refer to various skin conditions that affect the face. These can include a wide range of disorders, such as:

1. Acne vulgaris: A common skin condition characterized by the formation of comedones (blackheads and whiteheads) and inflammatory papules, pustules, and nodules. It primarily affects the face, neck, chest, and back.
2. Rosacea: A chronic skin condition that causes redness, flushing, and visible blood vessels on the face, along with bumps or pimples and sometimes eye irritation.
3. Seborrheic dermatitis: A common inflammatory skin disorder that causes a red, itchy, and flaky rash, often on the scalp, face, and eyebrows. It can also affect other oily areas of the body, like the sides of the nose and behind the ears.
4. Atopic dermatitis (eczema): A chronic inflammatory skin condition that causes red, itchy, and scaly patches on the skin. While it can occur anywhere on the body, it frequently affects the face, especially in infants and young children.
5. Psoriasis: An autoimmune disorder that results in thick, scaly, silvery, or red patches on the skin. It can affect any part of the body, including the face.
6. Contact dermatitis: A skin reaction caused by direct contact with an allergen or irritant, resulting in redness, itching, and inflammation. The face can be affected when allergens or irritants come into contact with the skin through cosmetics, skincare products, or other substances.
7. Lupus erythematosus: An autoimmune disorder that can cause a butterfly-shaped rash on the cheeks and nose, along with other symptoms like joint pain, fatigue, and photosensitivity.
8. Perioral dermatitis: A inflammatory skin condition that causes redness, small bumps, and dryness around the mouth, often mistaken for acne. It can also affect the skin around the nose and eyes.
9. Vitiligo: An autoimmune disorder that results in the loss of pigmentation in patches of skin, which can occur on the face and other parts of the body.
10. Tinea faciei: A fungal infection that affects the facial skin, causing red, scaly, or itchy patches. It is also known as ringworm of the face.

These are just a few examples of skin conditions that can affect the face. If you experience any unusual symptoms or changes in your skin, it's essential to consult a dermatologist for proper diagnosis and treatment.

Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting and bone metabolism. It is essential for the production of several proteins involved in blood clotting, including factor II (prothrombin), factor VII, factor IX, and factor X. Additionally, Vitamin K is necessary for the synthesis of osteocalcin, a protein that contributes to bone health by regulating the deposition of calcium in bones.

There are two main forms of Vitamin K: Vitamin K1 (phylloquinone), which is found primarily in green leafy vegetables and some vegetable oils, and Vitamin K2 (menaquinones), which is produced by bacteria in the intestines and is also found in some fermented foods.

Vitamin K deficiency can lead to bleeding disorders such as hemorrhage and excessive bruising. While Vitamin K deficiency is rare in adults, it can occur in newborns who have not yet developed sufficient levels of the vitamin. Therefore, newborns are often given a Vitamin K injection shortly after birth to prevent bleeding problems.

Bromates are chemical compounds that contain the bromate ion (BrO3-). The most common bromate is potassium bromate, which is used as a flour improver in some bread making processes. However, its use has been restricted or banned in many countries due to concerns about its potential carcinogenicity.

Bromates can form in drinking water supplies that are treated with ozone or chlorine in the presence of bromide ions. This can occur during water treatment or as a result of contamination from natural sources or industrial waste. Exposure to high levels of bromates has been linked to an increased risk of cancer, particularly thyroid and kidney cancer. Therefore, regulatory agencies have set limits on the amount of bromates that are allowed in drinking water and other consumer products.

"Maleate" is not a medical term in and of itself, but it is a chemical compound that can be found in some medications. Maleic acid or its salts (maleates) are used as a keratolytic agent in topical medications, which means they help to break down and remove dead skin cells. They can also be used as a preservative or a buffering agent in various pharmaceutical preparations.

Maleic acid is a type of organic compound known as a dicarboxylic acid, which contains two carboxyl groups. In the case of maleic acid, these carboxyl groups are located on a single carbon atom, which makes it a cis-conjugated diacid. This structural feature gives maleic acid unique chemical properties that can be useful in various pharmaceutical and industrial applications.

It's worth noting that maleic acid and its salts should not be confused with "maleate" as a gender-specific term, which refers to something related to or characteristic of males.

Quinone reductases are a group of enzymes that catalyze the reduction of quinones to hydroquinones, using NADH or NADPH as an electron donor. This reaction is important in the detoxification of quinones, which are potentially toxic compounds produced during the metabolism of certain drugs, chemicals, and endogenous substances.

There are two main types of quinone reductases: NQO1 (NAD(P)H:quinone oxidoreductase 1) and NQO2 (NAD(P)H:quinone oxidoreductase 2). NQO1 is a cytosolic enzyme that can reduce a wide range of quinones, while NQO2 is a mitochondrial enzyme with a narrower substrate specificity.

Quinone reductases have been studied for their potential role in cancer prevention and treatment, as they may help to protect cells from oxidative stress and DNA damage caused by quinones and other toxic compounds. Additionally, some quinone reductase inhibitors have been developed as chemotherapeutic agents, as they can enhance the cytotoxicity of certain drugs that require quinone reduction for activation.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Mixed Function Oxygenases (MFOs) are a type of enzyme that catalyze the addition of one atom each from molecular oxygen (O2) to a substrate, while reducing the other oxygen atom to water. These enzymes play a crucial role in the metabolism of various endogenous and exogenous compounds, including drugs, carcinogens, and environmental pollutants.

MFOs are primarily located in the endoplasmic reticulum of cells and consist of two subunits: a flavoprotein component that contains FAD or FMN as a cofactor, and an iron-containing heme protein. The most well-known example of MFO is cytochrome P450, which is involved in the oxidation of xenobiotics and endogenous compounds such as steroids, fatty acids, and vitamins.

MFOs can catalyze a variety of reactions, including hydroxylation, epoxidation, dealkylation, and deamination, among others. These reactions often lead to the activation or detoxification of xenobiotics, making MFOs an important component of the body's defense system against foreign substances. However, in some cases, these reactions can also produce reactive intermediates that may cause toxicity or contribute to the development of diseases such as cancer.

Electron-transferring flavoproteins (ETFs) are small protein molecules that play a crucial role in the electron transport chain in cells. They are responsible for accepting and donating electrons during various metabolic processes, particularly in the oxidation of fatty acids and amino acids.

ETFs contain a cofactor called flavin adenine dinucleotide (FAD), which can accept two electrons and two protons to form a reduced form of FAD (FADH2). When ETFs receive electrons from other molecules, they transfer these electrons to another protein called electron-transferring flavoprotein dehydrogenase (ETFDH), which then donates the electrons to the main electron transport chain.

Defects in ETFs or ETFDH can lead to serious metabolic disorders, such as multiple acyl-CoA dehydrogenase deficiency (MADD), also known as glutaric acidemia type II. This disorder affects the body's ability to break down certain fats and amino acids, leading to a buildup of toxic compounds in the body and potentially causing serious health problems.

... is thought to be the active toxin in Agaricus hondensis mushrooms. Hydroquinone has been shown to be one of the ... The name "hydroquinone" was coined by Friedrich Wöhler in 1843. Hydroquinone is produced industrially in two main ways. The ... under the name of colorless hydroquinone, further below in more detail.) [Note: Wöhler's empirical formula for hydroquinone (p ... The useful dye quinizarin is produced by diacylation of hydroquinone with phthalic anhydride. Hydroquinone undergoes oxidation ...
... hydroquinone-O-beta-D-glucopyranoside Thus, the two substrates of this enzyme are UDP-glucose and hydroquinone, whereas its two ... In enzymology, a hydroquinone glucosyltransferase (EC is an enzyme that catalyzes the chemical reaction UDP-glucose ... The systematic name of this enzyme class is UDP-glucose:hydroquinone-O-beta-D-glucosyltransferase. Other names in common use ... Arend J, Warzecha H, Stockigt J (2000). "Hydroquinone: O-glucosyltransferase from cultivated Rauvolfia cells: enrichment and ...
... (EC, hydroquinone dioxygenase) is an enzyme with systematic name benzene-1,4-diol: ... Hydroquinone+1,2-dioxygenase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology (EC 1.13. ... "Hydroquinone dioxygenase from pseudomonas fluorescens ACB: a novel member of the family of nonheme-iron(II)-dependent ...
"Hydroquinones". Phenols-Advances in Research and Application: 2013 Edition. Scholastic. 2013. p. 76. (Articles without InChI ... Among several chemicals known to inhibit tyrosinase production, such as hydroquinone, arbutin, and kojic acid, 4- ...
H2O Both hydroquinone and catechol are produced. Subsequent oxidation of the hydroquinone gives the quinone. Quinone was ... Oxidation of hydroquinone is facile. One such method makes use of hydrogen peroxide as the oxidizer and iodine or an iodine ... Quinone is mainly used as a precursor to hydroquinone, which is used in photography and rubber manufacture as a reducing agent ... It is excreted in its original form and also as variations of its own metabolite, hydroquinone. 1,4-Benzoquinone is able to ...
SnCl2 also reduces quinones to hydroquinones. Stannous chloride is also added as a food additive with E number E512 to some ...
Phosphoramidates, the most commonly used in agriculture (see above). Hydroquinone and quinones. In medicine, the most ...
"Hydroquinone". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_499. Komen L, ... US 4933504, Correale M, Panseri P, Romano U, Minisci F, "Process for the preparation of mono-ethers of hydroquinones" "4- ... Gambarotti C, Melone L, Punta C, Shisodia SU (2013). "Selective Monoetherification of 1,4-Hydroquinone Promoted by NaNO2". ... Monobenzone (benzyloxyphenol) Hydroquinone Guaiacol 2-Hydroxy-5-methoxybenzaldehyde Stiefel Laboratories, Inc. "Full ...
Hydroquinone is superadditive with metol, meaning that it acts to "recharge" the metol after it has been oxidised in the ... Hydroquinone can also be toxic to the human operator as well as environment; some modern developers replace it with ascorbic ... Developers for high contrast work have higher concentrations of hydroquinone and lower concentrations of metol and tend to use ... However, the staining effect only appears in solutions with very little sulfite, and most hydroquinone developers contain ...
Other hydrogen-bonded networks are derived from hydroquinone, urea, and thiourea. A much studied host molecule is Dianin's ... Birchall, T.; Frampton, C. S.; Schrobilgen, G. J.; Valsdóttir, J. (1989). "Β-Hydroquinone xenon clathrate". Acta ...
"FDA Proposes Hydroquinone Ban". Archived from the original on 2007-07-03.FDA bans hydroquinone in skin whitening products "NYC ...
In 1880, he introduced hydroquinone. Abney also introduced new and useful types of photographic paper, including in 1882 a ...
In the EU hydroquinone was banned from cosmetic applications. According to leading Celebrity Dermatologist Dr. Chytra Anand, ... Hydroquinone was the most commonly prescribed hyperpigmentation treatment before the long-term safety concerns were raised, and ... "Hydroquinone - Substance evaluation - CoRAP - ECHA". echa.europa.eu. Retrieved 2017-02-12. "Glow Brite Beauty Box - Best Kit ... Several are prescription only in the US, especially in high doses, such as hydroquinone, azelaic acid, and kojic acid. Some are ...
Hydroquinone is generally well-tolerated; side effects are typically mild (e.g., skin irritation) and occur with the use of a ... Hydroquinone is ineffective for hyperpigmentation affecting deeper layers of skin such as the dermis. The use of a sunscreen ... Hydroquinone lightens the skin when applied topically by inhibiting tyrosinase, the enzyme responsible for converting the amino ... In extremely rare cases, the frequent and improper application of high-dose hydroquinone has been associated with a systemic ...
Hydroxylated diterpenoid-hydroquinones can be isolated from C. elegans. Hydroxylated diterpenoid-hydroquinones from cystoseira ...
Other synthetically useful products of the Dakin oxidation include guaiacol, a precursor of several flavorants; hydroquinone, a ...
Hydroquinone is more commonly used today. Its use is largely historical except for special purpose applications. It was still ...
... are oxidized to hydroquinones in the Elbs persulfate oxidation. Reaction of naphtols and hydrazines and sodium ...
Jovel E, Kroeger P, Towers N (1996). "Hydroquinone: the toxic compound of Agaricus hondensis". Planta Medica. 62 (2): 195. doi: ... Relatively high levels of the chemical hydroquinone are present in fruit bodies. Fungi portal List of Agaricus species Zeller ...
Hydroquinone et potasse, nouvelle méthode de développement... Paris: Gauthier-Villars, 1889. Traité de photographie par les ...
with 90ppm hydroquinone - HDODA - 43203 - Alfa Aesar". www.alfa.com. Retrieved 2020-02-27. Ohara, Takashi; Sato, Takahisa; ... Like other acrylate monomers it is usually supplied with a radical inhibitor such as hydroquinone added. The material is ...
A 1996 review claimed 20% AzA is as potent as 4% hydroquinone after a period of application of three months without the ... It has been recommended as an alternative to hydroquinone. As a tyrosinase inhibitor, azelaic acid reduces synthesis of melanin ... Draelos, Z. (Sep-Oct 2007). "Skin lightening preparations and the hydroquinone controversy". Dermatologic Therapy. 20 (5): 308- ...
Vitamin K hydroquinone serves as a cofactor for vitamin K γ‐carboxylase that catalyzes γ‐carboxylation of specific glutamic ... NQO1 catalyzes the reduction of vitamin K1, K2 and K3 into their hydroquinone form, but it only has a high affinity for Vitamin ... A possible explanation is the accumulation of phenols and hydroquinone in the target organ-the bone marrow-and subsequent ... This enzyme facilitates the two electron reduction of quinone to hydroquinone. NQO1-mediated two electron reduction of quinone ...
The larger of the pair, the storage chamber or reservoir, contains hydroquinones and hydrogen peroxide, while the smaller, the ... The oxygen oxidizes the hydroquinones and also acts as the propellant. The oxidation reaction is very exothermic (ΔH = −202.8 ...
ISBN 978-0-85404-182-4. Lander, John J.; Svirbely, W. J. (1945). "The Dipole Moments of Catechol, Resorcinol and Hydroquinone ...
... phenol to hydroquinone, and hydroquinone to both benzenetriol and catechol. Hydroquinone, benzenetriol and catechol are ... hydroquinone and 1,2,4-trihydroxybenzene. Most of these metabolites have some value as biomarkers of human exposure, since they ... hyperdiploidy and chromosome breakage in interphase human lymphocytes following exposure to the benzene metabolite hydroquinone ...
... is produced by carboxylation of hydroquinone. C6H4(OH)2 + CO2 → C6H3(CO2H)(OH)2 This conversion is an example of ... Hudnall, Phillip M. (2005) "Hydroquinone" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. Wiley- ... maleylpyruvate As a hydroquinone, gentisic acid is readily oxidised and is used as an antioxidant excipient in some ... Hydroquinones, Salicylic acids, Dihydroxybenzoic acids, Phenolic human metabolites, Human drug metabolites). ...
In 2006, the FDA removed previous advice that stated hydroquinone was considered generally safe, as hydroquinone has been ... All over-the-counter (OTC) sales over hydroquinone were banned in the US with the CARES Act of 2020 and a prescription is now ... "Hydroquinone Studies Under The National Toxicology Program (NTP)". Food and Drug Administration. "CARES Act Legislation Halting ... The process performed with creams containing hydroquinone is banned in some countries, such as the member states of the EU. ...
Bleach Traditional bleach contains chlorine and/or hydroquinone. Chlorine can irritate and burn skin, as can skin-bleaching ...
... is an organic compound with the formula C6H4(COH)2(CH)(CH3). It is formally a derivative of p-hydroquinone. The name ...
Hydroquinone is thought to be the active toxin in Agaricus hondensis mushrooms. Hydroquinone has been shown to be one of the ... The name "hydroquinone" was coined by Friedrich Wöhler in 1843. Hydroquinone is produced industrially in two main ways. The ... under the name of colorless hydroquinone, further below in more detail.) [Note: Wöhlers empirical formula for hydroquinone (p ... The useful dye quinizarin is produced by diacylation of hydroquinone with phthalic anhydride. Hydroquinone undergoes oxidation ...
Hydroquinone, an ingredient in skin lightening agents worldwide, is linked with increased risk for skin cancer, researchers ... "Because hydroquinone exposure is not defined, it is unclear how TriNetX identified the hydroquinone exposure cohort," she ... "This study is a wonderful starting point to further investigate the hydroquinone exposure cohort to determine if hydroquinone ... "Given the global consumption of hydroquinone, multinational collaboration investigating hydroquinone and cancer data will ...
HYDROQUINONE (UNII: XV74C1N1AE) (HYDROQUINONE - UNII:XV74C1N1AE) HYDROQUINONE. 10 mL in 500 mL. ... CLEAR ACTION- hydroquinone cream. To receive this label RSS feed. Copy the URL below and paste it into your RSS Reader ... CLEAR ACTION- hydroquinone cream. If this SPL contains inactivated NDCs listed by the FDA initiated compliance action, they ... Caution: For external use only - It contains Hydroquinone - Keep away from eyes - Apply on small surfaces only - In case of ...
... well go through the uses for Hydroquinone, the side effects, the way it works, and results of taking it, and the safety ... Safety of Hydroquinone. In the 1980s, the FDA stated that Hydroquinone was a safe product to use. Hydroquinone started getting ... Results of Taking Hydroquinone. You may not see the results of Hydroquinone until a couple of weeks after starting. Each body ... How Does Hydroquinone Work?. Hydroquinone works in a way to lighten the skin that may have darkened due to Melasma. ...
Hydroquinone) drug information. Find its price or cost, dose, when to use, how to use, side effects, adverse effects, ... Hydroquinone (Hancro-HT) is a local cream prescribed for dark or hyper-pigmented skin marks such as freckles (small flat brown ... Hydroquinone cream should not be used during pregnancy or in patients allergic to the drug. It is not recommended for children ... Hydroquinone should be avoided with: • Hydrogen peroxide ,benzoyl peroxide or other peroxide containing products,since it can ...
... contains hydroquinone as stabilizer; CAS Number: 84508-46-3; find Sigma-Aldrich-492612 MSDS, related peer-reviewed papers, ...
... mono t-butyl hydroquinone) is a light tan solid. Eastman MTBHQ is used primarily as a polymerization inhibitor and industrial ... Eastman™ MTBHQ (mono t-butyl hydroquinone) is a light tan solid. Eastman™ MTBHQ is used primarily as a polymerization inhibitor ... increased potency at higher temperartures combine to make it more useful in many applications than unsubstituted hydroquinone. ...
CIL) offers product CLM-721-0.5 Benzaldehyde (carbonyl-¹³C, 99%) + 0.1% hydroquinone ...
Find out if you can buy Hydroquinone Cream 4%-30g for humans online without a prescription discount Price and low cost in our ... How will Generic for Hydroquinone work on my body? *How can the drug interactions and side effects of Generic for Hydroquinone ... Hydroquinone Cream 4%-30g. $20.70. - $25.30. Hydroquinone is a depigmenting cream used to lighten dark skin spots such as age ... What does Generic for Hydroquinone Cream 4%-30g treat?. Generic for Hydroquinone Cream 4%-30g is prescribed to treat ...
... Trends in Applied Sciences Research, 6: 622-639. URL: ... of the emulsions contained hydroquinone having concentration ranging from 9.50-50.35 mg g-1 showing that hydroquinone present ... In conclusion most of the emulsions do not contain hydroquinone or heavy metals at levels that are detrimental to human health ... Hydroquinone and Heavy Metals Levels in Cosmetics Marketed in Nigeria table, th, td { border: 0px solid #ececec; border- ...
View our Hydroquinones products at Fisher Scientific. ...
Hydroquinone has proven to be quite a controversial skincare ingredient in recent years, but is its reputation valid? Lets ... How does hydroquinone work?. asiandelight/Shutterstock Hydroquinone is a valuable ally in our quest for perfect skin. After all ... Enter hydroquinone. Hydroquinone is a chemical compound used in skincare regimes as early as the 1800s, as plastic surgeon ... How to use hydroquinone cream. Prostock-studio/Getty Images To avoid these side effects, dermatologist Purvisha Patel M.D., the ...
Hydroquinone, like so many things, is composed of hydrogen, oxygen and carbon. Its a simple structure - a benzine ring with ... Hydroquinone also pops up elsewhere in nature. Its found in certain types of mushrooms and in propolis, the glue bees make to ... As you may expect from a ping-pong ball with arms, hydroquinone is pretty reactive. Its also slightly acidic and, on a non- ... Hydroquinone reduces silver halides to make fine particles of silver, these look black and so develop a photograph. ...
What is Hydroquinone, and what is it used for?. Hydroquinone is among the most commonly-used topical agents used to correct ... How does Hydroquinone work?. Hydroquinones lightening ability was first reported in 1936, when a German doctor noticed that ... What skin conditions can benefit from Hydroquinone?. Hydroquinone is often used to treat a number of skin discoloration ... Are there other alternatives to Hydroquinone?. The increased scrutiny on the potential side effects of Hydroquinone, as well as ...
hydroquinone, A.R. Grade, 620.000/500g, đã bao gồm VAT. kojic acid, 1.300.000 /25 g, đã bao gồm VAT. Số lượng lớn hơn thì có ...
Eastman hydroquinone and derivatives are industrial grade reaction inhibitors and stabilizers. Explore the product catalog. ... Eastman Hydroquinone and Derivatives Articles Eastman Hydroquinone For Water Treatment Innovation in oxygen scavenging ... Eastman Hydroquinone for Oilfield Applications Hydroquinone plays an important role as an oxygen scavenger in oilfield ... Hydroquinone and its derivatives are practical storage and in-process inhibitors. They function primarily as antioxidants for ...
Although numerous hydroquinone-free compounds for skin lightening are available, their effectiveness depends on the severity of ... I use hydroquinone on my patients every single day and we have no trouble, Dr. Rendon says. I do not see any carcinogenic ... For example, hydroquinone is combined with retinoic acid, retinols, or in combination with vitamin C or glycolic acid. ... Although numerous hydroquinone-free compounds for skin lightening are available, their effectiveness depends on the severity of ...
Tags: Le Traitement du mélasma de triple combinaison (cortisone - vitamine A - hydroquinone) est loin de marcher toujours. ... Triple Combination Creams in Melasma (Steroid - Vitamin A - Hydroquinone) Dont Always Work. Friday, May 10th, 2013 ... Posts Tagged Le Traitement du mélasma de triple combinaison (cortisone - vitamine A - hydroquinone) est loin de marcher ... Triple Combination Creams (Triluma) In Melasma (Hydroquinone, Fluocinolone, Tretinoin) Dont Always Work. Triple combination ...
Quinone/hydroquinone redox couple. *Šebojka Komorsky-Lovrić* and Milivoj Lovrić. Electrode Reaction of Adriamycin Interpreted ...
Clear Essence® Exclusive Hydroquinone-Free Skin Beautifying Milk is a hydroquinone-free all over body moisturizing complexion ... The Clear Essence® Exclusive Hydroquinone-Free Skin Beautifying Milk is now prepared in a completely new avatar infused with ... Clear Essence® Exclusive Hydroquinone-Free Skin Beautifying Milk - Maxi Tone (10 oz.) ... Exclusive Hydroquinone-Free Skin Beautifying Milk – Maxi Tone (10 oz.),/a,,/blockquote,,iframe sandbox=allow-scripts ...
Magnalyte Cream 15gm, Lumacip Plus (Flucinolone Acetonide/Hydroquinone/Tretinoin) is a triple combination cream which works for ... Magnalyte Cream is a combination of three medicines: Hydroquinone, Tretinoin and Fluocinolone acetonide which treat melasma ( ... dark spots on skin). Hydroquinone is a skin lightening medicine. It reduces the amount of a skin pigment (melanin) that reason ...
View our Hydroquinones products at Fisher Scientific. ...
Categories: Acne, Hyperpigmentation, Melasma, Skin Care Tag: Eukroma Plus Cream 20gm (Hydroquinone /Tretinoin /Mometasone) ...
... GUARANTEED ANALYSIS CAS#: Synonym: FORMULA: PRODUCT TYPE: 123-31-9 Benzene-1,4-diol; 1,4-Benzenediol; Hydroquinone ... Hydroquinone is a water soluble reducing agent used in the development in black and white photos. Hydroquinone is used in the ...
... Synonym(s). 1,4-Benzenediol , 1,4-Dihydroxybenzene , 4-Hydroxyphenol , Arctuvin , Benzohydroquinone , Benzoquinol ...
Time is of the essence! A 4% hydroquinone cream applied about 2 weeks before a laser treatment can drastically improve the ...
It is a natural alternative to hydroquinone and is generally safe for all skin types. bearberry extract is antioxidant, anti- ... Natural skin lightener that turns into hydroquinone in the skin. corrector. Bearberry - From an evergreen plant with red ...
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  • Ava Shamban, a board-certified dermatologist, suggests to Byrdie that better results can be achieved when choosing a cream with 4% hydroquinone, 0.25 % tretinoin, and "mild over-the-counter cortisone. (glam.com)
  • Triple Combination Creams (Triluma) In Melasma (Hydroquinone, Fluocinolone, Tretinoin) Don't Always Work. (globale-dermatologie.com)
  • Magnalyte Cream 15gm, Lumacip Plus (Flucinolone Acetonide/Hydroquinone/Tretinoin) is a triple combination cream which works for melasma by lightening the skin, reducing inflammation and increasing exfoliation. (genericday.com)
  • Magnalyte Cream is a combination of three medicines: Hydroquinone, Tretinoin and Fluocinolone acetonide which treat melasma (dark spots on skin). (genericday.com)
  • A dark spot hyperpigmentation treatment recommended for acne prone skin, the dark spot corrector cream contains 0.1% Tretinoin and 0.1% Dexamethasone acne medications in addition to 5% Hydroquinone spot lightener. (beautesolutions.shopping)
  • Hydroquinone + Mometasone + Tretinoin is a composition used in the dermatology cream by Cosmederma that is known to provide protection against melasma which is mentioned as the occurrence of the dark patch on the face generally due to pregnancy. (cosmederma.in)
  • The pharmaceutical aid is composed using three different types of salt Hydroquinone, Mometasone, and Tretinoin and each one has its own effect on the skin. (cosmederma.in)
  • There are some of the required precautions which is needed to be taken care of while using the Hydroquinone + Mometasone + Tretinoin Composition ointment. (cosmederma.in)
  • Note- Hydroquinone + Mometasone + Tretinoin Ointment is only for external use. (cosmederma.in)
  • The combination of tretinoin and hydroquinone can be used as a skin lightening agent. (medscape.com)
  • Tretinoin may help lighten lentigines, particularly when used in combination with hydroquinone. (medscape.com)
  • Only one hydroquinone-containing medication - Tri-Luma at 4% concentration, used to treat melasma - is currently FDA-approved, she said. (medscape.com)
  • Hydroquinone is a skin bleaching product that helps relieve the symptoms of those with Melasma or hyperpigmentation. (ncddr.org)
  • While there are home treatments (such as the over the counter Hydroquinone dose) and doctor-prescribed options, Melasma is technically incurable. (ncddr.org)
  • Hydroquinone works well for conditions other than Melasma. (ncddr.org)
  • While Hydroquinone is a skin lightening product regarding hyperpigmentation and Melasma, it works well to fix simple dark spots that anyone can experience due to sun exposure or age. (ncddr.org)
  • If you find that you don't suffer from Melasma but have begun noticing dark spots due to age or sun exposure, over the counter Hydroquinone doses may help even your skin tone. (ncddr.org)
  • Hydroquinone can work well for Ochronosis in the same way it works for Melasma. (ncddr.org)
  • Hydroquinone works in a way to lighten the skin that may have darkened due to Melasma. (ncddr.org)
  • Following the directions on your Hydroquinone package is the best option, as you don't want to lighten any areas of your skin that aren't affected by Melasma. (ncddr.org)
  • Hydroquinone (Hancro-HT) is a local cream prescribed for dark or hyper-pigmented skin marks such as freckles (small flat brown marks on the face and sun exposed areas), melasma (brown patches on skin), age spots, and dark spots due to acne, pregnancy-related scars, skin trauma or use of birth control pills. (medindia.net)
  • Hydroquinone is a depigmenting cream used to lighten dark skin spots such as age spots, freckles, melasma, and chloasma. (internationaldrugmart.com)
  • Nevertheless, hydroquinone - albeit efficient in treating melasma - is not a treatment that should be taken lightly and is not for everyone. (glam.com)
  • Hydroquinone is often used to treat various skin conditions like melasma, age spots and post-inflammatory hyperpigmentation. (glaminc.com)
  • Hydroquinone effectively lightens and fades dark spots, melasma, age spots and post-inflammatory hyperpigmentation for a more even skin tone. (glaminc.com)
  • Hydroquinone, which I talk about all the time, is a topical skin-lightening agent that is used to treat various forms of hyperpigmentation, including age spots, melasma, and post-inflammatory hyperpigmentation. (alottaskin.com)
  • It doubles as a medicated acne cream and skin lightening hydroquinone cream for dark spots, age spots, sun spots, acne scars and melasma. (beautesolutions.shopping)
  • Hydroquinone is a viable treatment of choice for those suffering from pigmentary problems such as melasma, sun spots, age spots, post-inflammatory hyperpigmentation and more. (slclinic.com.sg)
  • Hydroquinone, a skin-lightening product used for hyperpigmentation and other skin conditions, can even reduce dark patches. (ncddr.org)
  • We'll also discuss hyperpigmentation and the causes for the condition, as well as other conditions that may benefit from using Hydroquinone . (ncddr.org)
  • Hydroquinone lightens the skin as hyperpigmentation can cause dark spots and patches. (ncddr.org)
  • Those with hyperpigmentation may be looking to lessen the darkness of their hyperpigmentation, and Hydroquinone can do that. (ncddr.org)
  • Generic for Hydroquinone Cream 4%-30g is prescribed to treat hyperpigmentation due to various causes like pregnancy, birth control, injury to the skin, hormone medication, age and so on. (internationaldrugmart.com)
  • Firstly, hydroquinone lightens dark spots and is considered "the topical gold standard in dermatology for reducing hyperpigmentation," as Ee Ting Ng, a cosmetic chemist and the founder of hop&cotton, tells Byrdie . (glam.com)
  • However, you can get prescribed hydroquinone to treat things like hyperpigmentation. (chemistryworld.com)
  • At SL Aesthetic Clinic, we prefer using hydroquinone as a concentrated treatment to address an immediate hyperpigmentation concern. (slclinic.com.sg)
  • Many skincare products are available with Hydroquinone added to eliminate or reduce dark spots on the skin. (ncddr.org)
  • What Is The Controversial Skincare Ingredient Hydroquinone? (glam.com)
  • Hydroquinone is a chemical compound used in skincare regimes as early as the 1800s, as plastic surgeon David Shafer, M.D., tells Byrdie . (glam.com)
  • Given the benefits of hydroquinone on your skin, this chemical compound is solidly gaining ground as a staple in skincare routines. (glam.com)
  • Hydroquinone is a chemical compound that's commonly used in skincare and cosmetic products for its skin-lightening properties. (glaminc.com)
  • It is required to have a skincare virtual consultation before purchasing the Hydroquinone Program Kit. (antiagingvancouver.com)
  • Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. (wikipedia.org)
  • The most widely used industrial methods of producing Hydroquinone are hydroxylation of phenol and cumene process. (byjus.com)
  • This is also known as methoxy phenol, monomethyl ether with hydroquinone, and p-hydroxyanisole. (byjus.com)
  • Exogenous ochronosis, in which bluish black pigmentation of cartilage is noted iatrogenically by exogenous agents, has been seen after exposure to noxious substances, including phenol, trinitrophenol, benzene, and hydroquinone. (medscape.com)
  • Clear Essence® Exclusive Hydroquinone-Free Skin Beautifying Milk is a hydroquinone-free all over body moisturizing complexion lotion fortified with botanical licorice extracts to effectively fade away skin discolorations, dark spots, freckles, uneven skin tone unveiling a smooth brighter glowing complexion. (clearessence.com)
  • Hydrating formula in our proprietary fiam delivery contains 2% hydroquinone plus 9 complementary ingredients that even the appearance of skin tone and dark spots for more luminous-looking skin. (vivatiaskincare.com)
  • Their deterrent is a mixture of hydroquinone and hydrogen peroxide - well known for its use in hair dye. (chemistryworld.com)
  • However, the Buckingham Center for Facial Plastic Surgery cautions that results are not permanent, and interrupting hydroquinone will result in the skin's natural pigmentation resurfacing. (glam.com)
  • Hydroquinone can be found in over-the-counter products as well as prescription-strength formulas, with various concentrations depending on the severity of the pigmentation concern. (glaminc.com)
  • Hydroquinone minimizes the appearance of irregular pigmentation to promote a clearer and more uniform complexion. (glaminc.com)
  • Whiten unwanted pigmentation with hydroquinone in Singapore. (slclinic.com.sg)
  • Hoshaw RA, Zimmerman KG, Menter A. Ochronosislike pigmentation from hydroquinone bleaching creams in American blacks. (medscape.com)
  • People who use skin lightening products that contain hydroquinone may be at an increased risk for skin cancers, an analysis of records from a large research database suggests. (medscape.com)
  • In conclusion most of the emulsions do not contain hydroquinone or heavy metals at levels that are detrimental to human health and the manufacturers are likely to have used utility water during production. (scialert.net)
  • Hydroquinone is the aromatic organic compound that conforms to the formula: C 6 H 6 O 2 . (productingredients.com)
  • Hydroquinone is an aromatic organic compound with a chemical formula C 6 H 6 O 2 . (byjus.com)
  • Eighty cosmetic emulsions were purchased from a whole sale supermarket in Ibadan, Nigeria with the aim of finding out if the creams contained hydroquinone and heavy metals at levels which were harmful to the populace. (scialert.net)
  • Skin-lightening creams typically include hydroquinone as a primary ingredient. (glam.com)
  • Over-the-counter skin whitening creams containing hydroquinone are banned in Europe, however the UK is seeing an increase in illegal imports. (chemistryworld.com)
  • Exogenous ochronosis and pigmented colloid milium from hydroquinone bleaching creams. (medscape.com)
  • In April, the FDA issued warning letters to 12 companies that sold hydroquinone in concentrations not generally recognized as safe and effective, because of other concerns including rashes, facial swelling, and ochronosis (skin discoloration). (medscape.com)
  • Ochronosis is the most prevalent clinical condition associated with long-term hydroquinone use. (byjus.com)
  • Ochronosis is generally seen in cases where a high percentage of hydroquinone was used for a prolonged period and seems to be seen in individuals with a deeper complexion. (amelia-technologies.com)
  • With exogenous cutaneous ochronosis induced by topical hydroquinones, carbon dioxide lasers and dermabrasion have been reported to be helpful. (medscape.com)
  • Hydroquinone and its derivatives can also be prepared by oxidation of various phenols. (wikipedia.org)
  • Hydroquinone undergoes oxidation under mild conditions to give benzoquinone. (wikipedia.org)
  • The cell-toxic activity of hydroquinone is caused by a free-radical oxidation mechanism. (shields.pharmacy)
  • 4. Protects hydroquinone from oxidation. (cosmederma.in)
  • Hydroquinone has two hydroxyl groups binding to a benzene ring in the para position. (byjus.com)
  • The companies are trying to potentiate the effects of hydroquinone by adding in other ingredients, but the basic one is hydroquinone,' Dr. Rendon says. (dermatologytimes.com)
  • Beyond ethical considerations associated with whitening treatments, the active ingredients themselves, particularly hydroquinone, have more recently come under intense scrutiny regarding overall safety. (amelia-technologies.com)
  • Hydroquinone is used in the production of skin bleaching cream used to lighten dark patches of skin. (chemstock.com)
  • Hydroquinone works by stopping the production of melanocytes present. (ncddr.org)
  • Hydroquinone interacts with the melanin-producing melanocytes and interferes with melanin production. (glam.com)
  • Hydroquinone works by inhibiting melanocytes in the skin. (slclinic.com.sg)
  • While it has been believed that hydroquinone achieves skin lightening by destroying melanocytes, the actual mechanism of hydroquinone involves inhibiting the synthesis of new melanin production. (amelia-technologies.com)
  • Hydroquinone is a potent melanin inhibitor that works by inhibiting the activity of tyrosinase and reducing the production of melanin. (alottaskin.com)
  • For example, hydroquinone is combined with retinoic acid, retinols, or in combination with vitamin C or glycolic acid. (dermatologytimes.com)
  • Hydroquinone can lose a hydrogen cation from both hydroxyl groups to form a diphenolate ion. (wikipedia.org)
  • As it stands, hydroquinone is not known and/or has not been proven to be carcinogenic to humans when applied topically. (amelia-technologies.com)
  • Hydroquinone (multiple brand names), a tyrosinase inhibitor used worldwide for skin lightening due to its inhibition of melanin production, was once considered "generally safe and effective" by the FDA, the authors write. (medscape.com)
  • Hydroquinone will block the enzyme tyrosinase, which is responsible for the first step in the melanin production pathway. (amelia-technologies.com)
  • Hydroquinone preparations in higher concentrations are unfortunately also available in the United States," added Thomas, who was not involved in the study and referred to the FDA warning letter issued in April. (medscape.com)
  • Hydroquinone can be well-tolerated on skin when used as directed and under the supervision of a healthcare professional, but it may cause skin irritation, redness and other side effects in some, particularly when used in higher concentrations or for extended periods. (glaminc.com)
  • Prescribe concentrations of hydroquinone not more than 4 per cent. (byjus.com)
  • However, there have been studies that claim hydroquinone is carcinogenic in rats, although this testing of hydroquinone was through oral administration and at relatively high concentrations. (amelia-technologies.com)
  • Valencia D. Thomas, MD , professor in the Department of Dermatology of the University of Texas MD Anderson Cancer Center in Houston, said in an email that over-the-counter skin lightening products containing low-concentration hydroquinone are in widespread use and are commonly used in populations of color. (medscape.com)
  • Dermatologist Sharon Garcia advises that residual light marks left by acne breakouts should be treated with mild brightening washes combined with a sunscreen with a high SPF instead of hydroquinone (via Advanced Dermatology and Skin Cancer Associates ). (glam.com)
  • C6H4(OH)2 + H2O}}} Other, less common methods include: A potentially significant synthesis of hydroquinone from acetylene and iron pentacarbonyl has been proposed Iron pentacarbonyl serves as a catalyst, rather than as a reagent, in the presence of free carbon monoxide gas. (wikipedia.org)
  • Synthesis of antiplatelet ortho-carbonyl hydroquinones with differential action on platelet aggregation stimulated by collagen or TRAP-6. (bvsalud.org)
  • Substituted derivatives of this parent compound are also referred to as hydroquinones. (wikipedia.org)
  • Some naturally occurring hydroquinone derivatives exhibit this sort of reactivity, one example being coenzyme Q. Industrially this reaction is exploited both with hydroquinone itself but more often with its derivatives where one OH has been replaced by an amine. (wikipedia.org)
  • An important reaction is the conversion of hydroquinone to the mono- and diamine derivatives. (wikipedia.org)
  • Eastman™ hydroquinone and derivatives are photographic- and industrial-grade reaction inhibitors and stabilizers that react with free radicals in polymerization reactions to form stable compounds in the presence of oxygen. (chempoint.com)
  • Hydroquinone and its derivatives are practical storage and in-process inhibitors. (chempoint.com)
  • In this work , we evaluate the antiplatelet effect of a series of ortho-carbonyl hydroquinone derivatives on cytotoxicity and function of human platelets , using collagen and thrombin receptor activator peptide 6 (TRAP-6) as agonists . (bvsalud.org)
  • Exposures to glutaraldehyde (111308), acetic-acid (64197), hydroquinone (123319), ethylene- oxide (75218), formaldehyde (50000), xylene (1330207), and volatile organic compounds were all well below any evaluation criteria. (cdc.gov)
  • As a polymerisation inhibitor, exploiting its antioxidant properties, hydroquinone prevents polymerization of acrylic acid, methyl methacrylate, cyanoacrylate, and other monomers that are susceptible to radical-initiated polymerization. (wikipedia.org)
  • Although numerous hydroquinone-free compounds for skin lightening are available, their effectiveness depends on the severity of the condition, according to Marta Rendon, M.D., who practices in Boca Raton, Fla. (dermatologytimes.com)
  • Although some hydroquinone scaffold-containing compounds have known antiplatelet activities, currently there is a lack of evidence on the antiplatelet activity of hydroquinones carrying electron attractor groups. (bvsalud.org)
  • 3. Enhances hydroquinone penetration through the stratum. (cosmederma.in)
  • Another study found that topical application of hydroquinone caused thinning of the stratum corneum in rats. (amelia-technologies.com)
  • Hydroquinone is a lotion that can be applied multiple times daily in order to help lighten the affected areas. (ncddr.org)
  • The name "hydroquinone" was coined by Friedrich Wöhler in 1843. (wikipedia.org)
  • The name Hydroquinone was coined in the year 1843 by Friedrich Wohler. (byjus.com)
  • However, this all changed after hydroquinone was stripped of its generally regarded as safe and effective (GRASE) ranking in 2020 following the CARES act. (amelia-technologies.com)
  • In 2020, under the Coronavirus Aid, Relief, and Economic Security (CARES) Act, hydroquinone was stripped of its GRASE ranking due to the side effects discussed above and was no longer allowed to be legally sold OTC. (amelia-technologies.com)
  • Current or past use of monobenzyl ether or hydroquinone (Benoquin) to depigment the skin. (who.int)
  • Hydroquinone is available in prescription-strength formulas as part of tailored treatment plans for specific skin concerns. (glaminc.com)
  • The hydrogen peroxide decomposes and the hydroquinone oxidises - forming, among other things, benzoquinone - which is an irritant to most vertebrate eyes and lungs. (chemistryworld.com)
  • When colorless hydroquinone and benzoquinone, a bright yellow solid, are cocrystallized in a 1:1 ratio, a dark-green crystalline charge-transfer complex (melting point 171 °C) called quinhydrone (C6H6O2·C6H4O2) is formed. (wikipedia.org)
  • Does 'exposure' count prescriptions written and potentially not used, the use of hydroquinone products of high concentration not approved by the FDA, or the use of over-the-counter hydroquinone products? (medscape.com)
  • Are there certain foods, beverages and products to be avoided while on Generic for Hydroquinone? (internationaldrugmart.com)
  • The Local Government Authority declared it 'the biological equivalent of paint stripper' after a swell in seizures of products containing hydroquinone, often at very unsafe levels. (chemistryworld.com)
  • The regulatory status of over-the-counter (OTC) skin bleaching drug products containing hydroquinone, a popular agent for skin lightening, is pending. (dermatologytimes.com)
  • Newer prescription skin lightening products on the market are often combination products with hydroquinone. (dermatologytimes.com)
  • The products that worked best were 4% hydroquinone, but I never felt good when having to use such a strong product in my face for a long period of time. (vivatiaskincare.com)
  • Currently hydroquinone is not able to be legally sold OTC in the Unites States, and all OTC skin lightening products require an FDA approved new drug application before they can legally begin marketing in the US. (amelia-technologies.com)
  • As for alternatives to hydroquinone, antioxidants like vitamin C have been widely used for brightening/evening the skin tone with prolonged use, alpha-hydroxy acids and beta-hydroxy acids such as glycolic and salicylic are used as mild chemical exfoliants that help with removing dead skin cells, and lastly, the use of a retinoid will aid in increasing cell turnover which may enhance the benefits of the other products. (amelia-technologies.com)
  • Eastman™ MTBHQ (mono t-butyl hydroquinone) is a light tan solid. (eastman.com)
  • How can Eastman® Hydroquinone improve the life of your water system? (chempoint.com)
  • The data in the study do not show an increased risk for skin cancer with hydroquinone exposure, but do show "an increased risk of cancer in the TriNetX medication code 5509 hydroquinone exposure group, which does not prove causation," Thomas commented. (medscape.com)
  • Because 'hydroquinone exposure' is not defined, it is unclear how TriNetX identified the hydroquinone exposure cohort," she noted. (medscape.com)
  • This study is a wonderful starting point to further investigate the 'hydroquinone exposure' cohort to determine if hydroquinone is a driver of cancer, or if hydroquinone is itself a confounder. (medscape.com)
  • Generally, we recommend applying hydroquinone to the affected area 1 to 2 times a day for 3 to 6 months. (slclinic.com.sg)
  • Coming in lotion form, Hydroquinone will be applied two or more times daily to the skin unless otherwise directed. (ncddr.org)
  • What does Generic for Hydroquinone Cream 4%-30g treat? (internationaldrugmart.com)
  • Generic for Hydroquinone Cream 4%-30g might have some side effects but it's not possible to anticipate them. (internationaldrugmart.com)
  • Follow the Generic for Hydroquinone dosage prescribed by your physician. (internationaldrugmart.com)
  • Drug interactions might happen either when Generic for Hydroquinone is used along with another drug or with particular foods. (internationaldrugmart.com)
  • To prevent any kind of negative interaction, make sure you inform your doctor of any drugs you are taking including non-prescription medication, OTCs, health supplements like vitamins, minerals, herbal medicine, drinks with caffeine and alcohol, illegal drugs, smoking habits and so on which may increase or interfere with the effect of Generic for Hydroquinone. (internationaldrugmart.com)
  • Check with your physician on drugs that Generic for Hydroquinone could interact with. (internationaldrugmart.com)
  • What to ask your doctor before you start on Generic for Hydroquinone Cream 4%-30g tube? (internationaldrugmart.com)
  • Can I use Generic for Hydroquinone along with other drugs? (internationaldrugmart.com)
  • What is the dosage of Generic for Hydroquinone to be used? (internationaldrugmart.com)
  • How should I use Generic for Hydroquinone? (internationaldrugmart.com)
  • The most common side effects of regular hydroquinone use are skin irritation, allergic contact dermatitis, inflammation, and stinging of the skin. (amelia-technologies.com)
  • The US market for skin lightening agents was approximately 330 million dollars in 2021, and 330,000 prescriptions containing hydroquinone were dispensed in 2019," Miles said. (medscape.com)
  • Hence, by limiting melanocyte activity in the treated area, hydroquinone allows your skin to become more even-toned over time. (slclinic.com.sg)
  • Caution: For external use only - It contains Hydroquinone - Keep away from eyes - Apply on small surfaces only - In case of allergic symptoms, immediately suspend the application - Do not use on children under 12. (nih.gov)
  • Hydroquinone cream should not be used during pregnancy or in patients allergic to the drug. (medindia.net)
  • A very serious allergic reaction to hydroquinone is rare. (slclinic.com.sg)
  • Hydroquinone is used as a topical application in skin whitening to reduce the color of skin. (wikipedia.org)
  • About 51.25% of the emulsions contained hydroquinone having concentration ranging from 9.50-50.35 mg g -1 showing that hydroquinone present are within, usual limit in most cases. (scialert.net)
  • Hydroquinone (up to 4 percent concentration) can only be prescribed by a licensed doctor as a cream, emulsion, gel, or solution. (slclinic.com.sg)
  • But the U.S. Food and Drug Administration confirmed that hydroquinone only be prescribed by a doctor at a maximum of 4 percent concentration. (slclinic.com.sg)
  • When used effectively, Hydroquinone works to eliminate the dark patches that many find on their skin. (ncddr.org)
  • How Does Hydroquinone Work? (ncddr.org)
  • Another study suggests that people who work in the manufacture and use of hydroquinone are actually less likely to suffer from cancer than the general population, although why this is is a big question mark. (chemistryworld.com)
  • How does hydroquinone work at lightening the skin? (amelia-technologies.com)
  • 2% hydroquinone creme that lessens the appearance of discolouration for a more even skin tone. (antiagingvancouver.com)