GLYCEROPHOSPHOLIPIDS in which one of the two acyl chains is attached to glycerol with an ether alkenyl linkage instead of an ester as with the other glycerophospholipids.
Compounds in which one or more of the three hydroxyl groups of glycerol are in ethereal linkage with a saturated or unsaturated aliphatic alcohol; one or two of the hydroxyl groups of glycerol may be esterified. These compounds have been found in various animal tissue.
An autosomal recessive form of CHONDRODYSPLASIA PUNCTATA characterized by defective plasmalogen biosynthesis and impaired peroxisomes. Patients have shortened proximal limbs and severely disturbed endochondral bone formation. The metabolic defects associated with the impaired peroxisomes are present only in the rhizomelic form of chondrodysplasia punctata. (From Scriver et al, Metabolic Basis of Inherited Disease, 6th ed, p1497)
Vinyl compounds, in the context of medical materials, refer to synthetic polymers made from vinyl chloride or vinyl acetate monomers, which are used in the production of various medical devices and supplies such as blood bags, intravenous (IV) bags, tubing, and gloves due to their flexibility, transparency, and resistance to chemicals and heat.
A halogen with the atomic symbol Br, atomic number 36, and atomic weight 79.904. It is a volatile reddish-brown liquid that gives off suffocating vapors, is corrosive to the skin, and may cause severe gastroenteritis if ingested.
Acetals are chemical compounds formed when a carbonyl group (aldehyde or ketone) reacts with two equivalents of alcohol in the presence of a strong acid, resulting in the formation of a stable carbon-carbon bond and producing water as a byproduct.
Organic compounds containing a carbonyl group in the form -CHO.
Usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4 carbons, derived from natural fats and oils, including lauryl, stearyl, oleyl, and linoleyl alcohols. They are used in pharmaceuticals, cosmetics, detergents, plastics, and lube oils and in textile manufacture. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
A component of PHOSPHATIDYLCHOLINES or LECITHINS, in which the two hydroxy groups of GLYCEROL are esterified with fatty acids. (From Stedman, 26th ed) It counteracts the effects of urea on enzymes and other macromolecules.
'Ethers' in a medical context are a class of organic compounds used as medication, particularly as an inhalational agent to induce and maintain general anesthesia, characterized by their ability to produce a state of unconsciousness while providing muscle relaxation and analgesia.
Phospholipids which have an alcohol moiety in ethereal linkage with a saturated or unsaturated aliphatic alcohol. They are usually derivatives of phosphoglycerols or phosphatidates. The other two alcohol groups of the glycerol backbone are usually in ester linkage. These compounds are widely distributed in animal tissues.
The conformation, properties, reaction processes, and the properties of the reactions of carbon compounds.
Six-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives. Various polyneuropathies are caused by hexane poisoning.
Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Derivatives of phosphatidic acid in which the hydrophobic regions are composed of two fatty acids and a polar alcohol is joined to the C-3 position of glycerol through a phosphodiester bond. They are named according to their polar head groups, such as phosphatidylcholine and phosphatidylethanolamine.
A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.
An autosomal recessive disorder due to defects in PEROXISOME biogenesis which involves more than 13 genes encoding peroxin proteins of the peroxisomal membrane and matrix. Zellweger syndrome is typically seen in the neonatal period with features such as dysmorphic skull; MUSCLE HYPOTONIA; SENSORINEURAL HEARING LOSS; visual compromise; SEIZURES; progressive degeneration of the KIDNEYS and the LIVER. Zellweger-like syndrome refers to phenotypes resembling the neonatal Zellweger syndrome but seen in children or adults with apparently intact peroxisome biogenesis.
Salts of hydrobromic acid, HBr, with the bromine atom in the 1- oxidation state. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A 66-kDa peroxidase found in EOSINOPHIL granules. Eosinophil peroxidase is a cationic protein with a pI of 10.8 and is comprised of a heavy chain subunit and a light chain subunit. It possesses cytotoxic activity towards BACTERIA and other organisms, which is attributed to its peroxidase activity.

Plasmalogens as endogenous antioxidants: somatic cell mutants reveal the importance of the vinyl ether. (1/244)

Exposure of plasmalogen-deficient variants of the murine cell line RAW 264.7 to short-term (0-100 min) treatment with electron transport inhibitors antimycin A or cyanide (chemical hypoxia) resulted in a more rapid loss of viability than in the parent strain. Results suggested that plasmalogen-deficient cells were more sensitive to reactive oxygen species (ROS) generated during chemical hypoxia; the mutants could be rescued from chemical hypoxia by using the antioxidant Trolox, an alpha-tocopherol analogue, and they were more sensitive to ROS generation by plumbagin or by rose bengal treatment coupled with irradiation. In addition, the use of buffers containing 2H2O greatly enhanced the cytotoxic effect of chemical hypoxia, suggesting the involvement of singlet oxygen. We used the unique enzymic deficiencies displayed by the mutants to differentially restore either plasmenylethanolamine (the major plasmalogen species normally found in this cell line) or its biosynthetic precursor, plasmanylethanolamine. Restoration of plasmenylethanolamine, which contains the vinyl ether, resulted in wild-type-like resistance to chemical hypoxia and ROS generators, whereas increasing levels of its precursor, which bears the saturated ether, had no effect on cell survival. These findings identify the vinyl ether double bond as a crucial element in cellular protection under these conditions and support the hypothesis that plasmalogens, through the vinyl ether, act as antioxidants to protect cells against ROS. These phospholipids might protect cells from ROS-mediated damage during events such as chemical hypoxia.  (+info)

Plasmalogen status influences docosahexaenoic acid levels in a macrophage cell line. Insights using ether lipid-deficient variants. (2/244)

Previously, this laboratory reported the isolation of variants, RAW. 12 and RAW.108, from the macrophage-like cell line RAW 264.7 that are defective in plasmalogen biosynthesis [Zoeller, R.A. et al. 1992. J. Biol. Chem. 267: 8299-8306]. Fatty acid analysis showed significant changes in the mutants in the ethanolamine phospholipids (PE), the only phospholipid class in which the plasmalogen species, plasmenylethanolamine, contributes significantly. Within the PE fraction, docosapentaenoic (DPA; 22:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids were reduced by approximately 50% in the variants while the levels of arachidonic acid (AA; 20:4n-6) remained unaffected. The decrease in DHA was accompanied by a 50% decrease in labeling PE with [3H]DHA over a 90-min period. Restoration of plasmenylethanolamine by supplementing the growth medium with sn -1-hexadecylglycerol (HG) completely reversed these changes in RAW. 108. Pre-existing pools of plasmenylethanolamine were not required for restoration of normal [3H]DHA labeling; addition of HG only during the labeling period was sufficient. Due to the loss of Delta1'-desaturase in RAW.12, HG supplementation resulted in the accumulation of plasmenylethanolamine's immediate biosynthetic precursor, plasmanylethanolamine. Even though this latter phospholipid contained only the ether functionality (lacking the vinyl ether double bond) it was sufficient to restore wild type-like fatty acid composition and DHA labeling of the ethanolamine phospholipids, identifying the ether bond as a structural determinant for this specificity. In summary, we have used these mutants to establish that the plasmalogen status of a cell can influence the levels of certain polyunsaturated fatty acids. These results support the notion that certain polyunsaturated fatty acids, such as DHA, can be selectively targeted to plasmalogens and that this targeting occurs during de novo biosynthesis, or shortly thereafter, through modification of nascent plasmalogen pools.  (+info)

Purification and characterization from rat kidney membranes of a novel platelet-activating factor (PAF)-dependent transacetylase that catalyzes the hydrolysis of PAF, formation of PAF analogs, and C2-ceramide. (3/244)

We have previously identified two enzyme activities that transfer the acetyl group from platelet-activating factor (PAF) in a CoA-independent manner to lysoplasmalogen or sphingosine in HL-60 cells, endothelial cells, and a variety of rat tissues. These were termed as PAF:lysoplasmalogen (lysophospholipid) transacetylase and PAF:sphingosine transacetylase, respectively. In the present study, we have solubilized and purified this PAF-dependent transacetylase 13,700-fold from rat kidney membranes (mitochondrial plus microsomal membranes) based on the PAF:lysoplasmalogen transacetylase activity. The mitochondria and microsomes were prepared and washed three times, then solubilized with 0.04% Tween 20 at a detergent/protein (w/w) ratio of 0.1. The solubilized fractions from mitochondria and microsomes were combined and subjected to sequential column chromatographies on DEAE-Sepharose, hydroxyapatite, phenyl-Sepharose, and chromatofocusing. The enzyme was further purified by native-polyacrylamide gel electrophoresis (PAGE) and affinity gel matrix in which the competitive inhibitor of the enzyme, 1-O-hexadecyl-2-N-methylcarbamyl-sn-glycero-3-phosphoethanolamine was covalently attached to the CH-Sepharose. On SDS-PAGE, the purified enzyme showed a single homogeneous band with an apparent molecular mass of 40 kDa. The purified enzyme catalyzed transacetylation of the acetyl group not only from PAF to lysoplasmalogen forming plasmalogen analogs of PAF, but also to sphingosine producing N-acetylsphingosine (C2-ceramide). In addition, this enzyme acted as a PAF-acetylhydrolase in the absence of lipid acceptor molecules. These results suggest that PAF-dependent transacetylase is an enzyme that modifies the cellular functions of PAF through generation of other diverse lipid mediators.  (+info)

Total plasmalogens and O-(acylalkylglycerophosphoryl) ethanolamine from labelled hexadecanol and palmitate during hypoxia and anoxia in rat heart. (4/244)

By the use of the Langendorff technique, surviving isolated rat hearts were perfused with [1-14 C] palmitate, [1-14C] hexadecanol or [1-14C,1-3H] hexadecanol under normal or anoxic conditions. After perfusion for 30min with either precursor, when oxygenated or in an hypoxic condition, or when 1mM-KCN was included in the system, the heart tissues showed no significant chemical changes in their content of total lipids, total phospholipids or total ethanolamine-containing phospholipids. Changes were observed in the ratio of alkyl-to alk-1-enyl-glycerophosphorylethanolamine in the tissue perfused with N2+CO1 plus CN-. A slight increase from 4.0+/-0.3 to 4.9+/-0.2% in alkyl derivatives and a decrease from 11.2+/-0.4 to 9.4+/-0.3% in alk-1-enyl derivatives was observed. The incorporation of the [14C] palmitate and the [14C] hexadecanol into the recovered phospholipids and plasmalogens was severely decreased in the tissues perfused with CN-: in the hypoxic state only a mild inhibition was observed compared with the oxygenated systems. Considerable 3H from [1-14C, 1-3H] hexadecanol was retained (25-35%) in the alk-1-enylether chains of plasmalogens under both the oxygenated conditions and with CN-, suggesting that the same mechanism of incorporation is operational at high or low O2 concentrations. The results are consistent with an O2-dependent, CN-sensitive step in the biosynthesis of plasmalogens in the rat heart.  (+info)

Contribution of copper binding to the inhibition of lipid oxidation by plasmalogen phospholipids. (5/244)

The role of plasmalogen phospholipids for copper-induced lipid oxidation was evaluated. Using 1H-NMR we observed that the copper (CuSO4)-promoted oxidative degradation of polyunsaturated fatty acids in micellar solution was dose-dependently attenuated by the plasmalogen lysoplasmenylethanolamine from bovine brain (lysoBP-PtdEtn). This was due to a direct interaction of copper ions with the plasmalogen-specific enol ether double bond. The enol ether methine 1H signal decreased on the addition of copper, saturation being reached at a molar ratio of lysoBP-PtdEtn to copper of 1:1. The original 1H signal was recovered almost completely after the addition of EDTA. Enrichment of micelles and low-density lipoproteins (LDLs) with plasmalogen phospholipids led to a decrease in the Cu(II) concentration in the aqueous media. After loading of LDLs in vitro with BP-PtdEtn, the LDL-dependent formation of Cu(I) was decreased, in particular in particles experimentally supplemented with alpha-tocopherol. The suppression of copper-promoted lipid oxidation that was observed in the presence of plasmalogen phospholipids plus alpha-tocopherol was greater than the sum of the protective effects elicited by the two substances alone. In conclusion, the formation of a complex between copper ions and the plasmalogens accounts partly for their inhibition of copper-induced lipid oxidation.  (+info)

Synthesis of plasmalogens in eye lens epithelial cells. (6/244)

The present paper describes cloning and sequencing of the mouse cDNA encoding dihydroxyacetonephosphate acyltransferase (DAPAT), the peroxisomal key enzyme of plasmalogen (PM) biosynthesis. Using monospecific antibodies, we localized DAPAT and alkyl dihydroxyacetonephosphate synthase to peroxisomes of mouse lens epithelial cells (LECs) and determined their enzymatic activity. By electrospray ionization mass spectrometry of mouse lens lipid extracts, we identified phosphatidyl ethanolamine including plasmenyl ethanolamine species as major constituents. Our data demonstrate the capacity of LECs to synthesize PMs and the high coincidence between deficiency of PM and early manifestation of cataract in patients with peroxisomal disorders suggests that ether-bonded lipids may play an important role in maintaining lens transparency.  (+info)

Role of plasmalogens in the enhanced resistance of LDL to copper-induced oxidation after LDL apheresis. (7/244)

Extracorporeal reduction of plasma low density lipoproteins (LDLs) by LDL apheresis was shown to attenuate the proatherogenic influences of LDL, such as impairment of vasodilation and increased monocyte adhesion to the endothelium. In 16 patients with familial hypercholesterolemia, we analyzed whether LDL apheresis by the heparin precipitation procedure affected the oxidative resistance of LDL. Plasma LDL cholesterol concentrations were reduced by 65% after the apheresis. The lag time of copper-mediated LDL oxidation was increased from 103 to 117 minutes (P<0.0005). The LDL contents of alpha-tocopherol and beta-carotene, as well as the ratio of monounsaturated to polyunsaturated fatty acids in LDL, were not altered. However, the LDL apheresis induced a 15% increase in the LDL contents of plasmalogen phospholipids (P<0.0005), a class of ether phospholipids that were recently shown to prevent lipid oxidation. The phosphatidylcholine (PC) to lysoPC ratio was elevated by 16% after the apheresis (P<0.0005). The percent increase in LDL plasmalogen phospholipids showed a close association with the increased lag time after apheresis (P<0.0005). The LDL plasmalogen contents of the blood samples from patients and from normolipidemic donors were also positively related to the lag time (P<0.005). In vitro loading of LDL with plasmalogen phospholipids resulted in a prolongation of the lag time and an increase in the PC/lysoPC ratio. In conclusion, the rapid rise in LDL contents of plasmalogen phospholipids most probably causes the increase in lag time after LDL apheresis. Plasmalogens appear to play an important role in the oxidation resistance of LDL in vivo.  (+info)

Ether lipid biosynthesis: alkyl-dihydroxyacetonephosphate synthase protein deficiency leads to reduced dihydroxyacetonephosphate acyltransferase activities. (8/244)

Recent studies have indicated that two peroxisomal enzymes involved in ether lipid synthesis, i.e., dihydroxyacetonephosphate acyltransferase and alkyl-dihydroxyacetonephosphate synthase, are directed to peroxisomes by different targeting signals, i.e., peroxisomal targeting signal type 1 and type 2, respectively. In this study, we describe a new human fibroblast cell line in which alkyl-dihydroxyacetonephosphate synthase was found to be deficient both at the level of enzyme activity and enzyme protein. At the cDNA level, a 128 base pair deletion was found leading to a premature stop. Remarkably, dihydroxyacetonephosphate acyltransferase activity was strongly reduced to a level comparable to the activities measured in fibroblasts from patients affected by the classical form of rhizomelic chondrodysplasia punctata (caused by a defect in peroxisomal targeting signal type 2 import). Dihydroxyacetonephosphate acyltransferase activity was completely normal in another alkyl-dihydroxyacetonephosphate synthase activity-deficient patient. Fibroblasts from this patient showed normal levels of the synthase protein and inactivity results from a point mutation leading to an amino acid substitution. These results strongly suggest that the activity of dihydroxyacetonephosphate acyltransferase is dependent on the presence of alkyl-dihydroxyacetonephosphate synthase protein. This interpretation implies that the deficiency of dihydroxyacetonephosphate acyltransferase (targeted by a peroxisomal targeting signal type 1) in the classic form of rhizomelic chondrodysplasia punctata is a consequence of the absence of the alkyl-dihydroxyacetonephosphate synthase protein (targeted by a peroxisomal targeting signal type 2).  (+info)

Plasmalogens are a type of complex lipid called glycerophospholipids, which are essential components of cell membranes. They are characterized by having a unique chemical structure that includes a vinyl ether bond at the sn-1 position of the glycerol backbone and an ester bond at the sn-2 position, with the majority of them containing polyunsaturated fatty acids. The headgroup attached to the sn-3 position is typically choline or ethanolamine.

Plasmalogens are abundant in certain tissues, such as the brain, heart, and skeletal muscle. They have been suggested to play important roles in cellular functions, including membrane fluidity, signal transduction, and protection against oxidative stress. Reduced levels of plasmalogens have been associated with various diseases, including neurological disorders, cardiovascular diseases, and aging-related conditions.

Glyceryl ethers, also known as glycerol ethers or alkyl glycosides, are a class of compounds formed by the reaction between glycerol and alcohols. In the context of medical definitions, glyceryl ethers may refer to a group of naturally occurring compounds found in some organisms, including humans.

These compounds are characterized by an ether linkage between the glycerol molecule and one or more alkyl chains, which can vary in length. Glyceryl ethers have been identified as components of various biological tissues, such as lipid fractions of human blood and lung surfactant.

In some cases, glyceryl ethers may also be used as pharmaceutical excipients or drug delivery systems due to their unique physicochemical properties. For example, they can enhance the solubility and bioavailability of certain drugs, making them useful in formulation development. However, it is important to note that specific medical applications and uses of glyceryl ethers may vary depending on the particular compound and its properties.

Chondrodysplasia punctata, rhizomelic is a rare genetic disorder that affects the development of bones and cartilage. The condition is characterized by shortened limbs (rhizomelia), particularly the upper arms and thighs, and multiple small punctate calcifications in the cartilage of the body, including the ears, nose, and other areas.

The disorder is caused by mutations in the gene PEX7, which is involved in the transport of enzymes to peroxisomes, cellular organelles that break down fatty acids and other substances. Without functional PEX7, these enzymes cannot reach the peroxisomes, leading to abnormal accumulation of lipids and other substances in various tissues, including bone and cartilage.

Chondrodysplasia punctata, rhizomelic is typically diagnosed in infancy or early childhood based on clinical features and imaging studies. The condition can be associated with a range of complications, including developmental delays, respiratory problems, hearing loss, and visual impairment. There is no cure for the disorder, and treatment is focused on managing symptoms and addressing specific complications as they arise.

"Vinyl compounds" is not a term used in medical definitions. It is a term used in chemistry and materials science to refer to a group of chemicals that contain carbon-based molecules with a vinyl group, which is a functional group consisting of a double bond between two carbon atoms, with one of the carbons also being bonded to a hydrogen atom (-CH2=CH-).

Vinyl compounds are used in various industrial and consumer products, including plastics, resins, adhesives, and coatings. Some vinyl compounds, such as polyvinyl chloride (PVC), have been used in medical devices and supplies, such as intravenous (IV) bags, tubing, and blood vessel catheters. However, the use of PVC and other vinyl compounds in medical applications has raised concerns about potential health risks due to the release of toxic chemicals, such as phthalates and dioxins, during manufacturing, use, and disposal. Therefore, alternative materials are being developed and used in medical devices and supplies.

Bromine is a chemical element with the symbol "Br" and atomic number 35. It belongs to the halogen group in the periodic table and is a volatile, reddish-brown liquid at room temperature that evaporates easily into a red-brown gas with a strong, chlorine-like odor.

Bromine is not found free in nature, but it is present in many minerals, such as bromite and halite. It is produced industrially through the treatment of brine with chlorine gas. Bromine has a wide range of uses, including as a disinfectant, fumigant, flame retardant, and intermediate in the production of various chemicals.

In medicine, bromine compounds have been used historically as sedatives and anticonvulsants, although their use has declined due to the availability of safer and more effective drugs. Bromine itself is not used medically, but some of its compounds may have therapeutic applications in certain contexts. For example, bromide salts have been used as a mild sedative and anticonvulsant in veterinary medicine. However, their use in humans is limited due to the risk of toxicity.

An acetal is a chemical compound that contains two ether functional groups (-O-) bonded to two carbon atoms, which in turn are bonded to two other carbon atoms forming a six-membered ring. Acetals are formed by the reaction of an aldehyde with two equivalents of an alcohol under acid catalysis, followed by removal of water. They are stable compounds that do not easily hydrolyze back to their starting materials, making them useful in various chemical and industrial applications. In the context of organic chemistry, acetals are a subclass of hemiacetals, which contain only one ether functional group bonded to a carbon atom that is also bonded to another oxygen-containing group.

Aldehydes are a class of organic compounds characterized by the presence of a functional group consisting of a carbon atom bonded to a hydrogen atom and a double bonded oxygen atom, also known as a formyl or aldehyde group. The general chemical structure of an aldehyde is R-CHO, where R represents a hydrocarbon chain.

Aldehydes are important in biochemistry and medicine as they are involved in various metabolic processes and are found in many biological molecules. For example, glucose is converted to pyruvate through a series of reactions that involve aldehyde intermediates. Additionally, some aldehydes have been identified as toxicants or environmental pollutants, such as formaldehyde, which is a known carcinogen and respiratory irritant.

Formaldehyde is also commonly used in medical and laboratory settings for its disinfectant properties and as a fixative for tissue samples. However, exposure to high levels of formaldehyde can be harmful to human health, causing symptoms such as coughing, wheezing, and irritation of the eyes, nose, and throat. Therefore, appropriate safety measures must be taken when handling aldehydes in medical and laboratory settings.

Fatty alcohols, also known as long-chain alcohols or long-chain fatty alcohols, are a type of fatty compound that contains a hydroxyl group (-OH) and a long alkyl chain. They are typically derived from natural sources such as plant and animal fats and oils, and can also be synthetically produced.

Fatty alcohols can vary in chain length, typically containing between 8 and 30 carbon atoms. They are commonly used in a variety of industrial and consumer products, including detergents, emulsifiers, lubricants, and personal care products. In the medical field, fatty alcohols may be used as ingredients in certain medications or topical treatments.

Lysophosphatidylcholines (LPCs) are a type of glycerophospholipids, which are major components of cell membranes. They are formed by the hydrolysis of phosphatidylcholines, another type of glycerophospholipids, catalyzed by the enzyme phospholipase A2. LPCs contain a single fatty acid chain attached to a glycerol backbone and a choline headgroup.

In medical terms, LPCs have been implicated in various physiological and pathological processes, such as cell signaling, membrane remodeling, and inflammation. Elevated levels of LPCs have been found in several diseases, including cardiovascular disease, neurodegenerative disorders, and cancer. They can also serve as biomarkers for the diagnosis and prognosis of these conditions.

Phosphatidylethanolamines (PE) are a type of phospholipid that are abundantly found in the cell membranes of living organisms. They play a crucial role in maintaining the structural integrity and functionality of the cell membrane. PE contains a hydrophilic head, which consists of an ethanolamine group linked to a phosphate group, and two hydrophobic fatty acid chains. This unique structure allows PE to form a lipid bilayer, where the hydrophilic heads face outwards and interact with the aqueous environment, while the hydrophobic tails face inwards and interact with each other.

PE is also involved in various cellular processes, such as membrane trafficking, autophagy, and signal transduction. Additionally, PE can be modified by the addition of various functional groups or molecules, which can further regulate its functions and interactions within the cell. Overall, phosphatidylethanolamines are essential components of cellular membranes and play a critical role in maintaining cellular homeostasis.

Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.

Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.

Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.

Glycerylphosphorylcholine (GPC) is not typically considered a medical term, but it is a choline-containing phospholipid that can be found in various tissues and fluids within the human body. It is also available as a dietary supplement. Here's a definition of Glycerylphosphorylcholine:

Glycerylphosphorylcholine (GPC) is a natural choline-containing compound that is present in various tissues and fluids within the human body, including neural tissue, muscle, and blood. It plays an essential role in the synthesis of the neurotransmitter acetylcholine, which is involved in memory, learning, and other cognitive functions. GPC can also be found in some foods, such as egg yolks and soybeans, and is available as a dietary supplement. In the body, GPC can be converted to phosphatidylcholine, another important phospholipid that is necessary for maintaining cell membrane structure and function.

In medical or clinical terms, "ethers" do not have a specific relevance as a single medical condition or diagnosis. However, in a broader chemical context, ethers are a class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups. Ethers are not typically used as therapeutic agents but can be found in certain medications as solvents or as part of the drug's chemical structure.

An example of a medication with an ether group is the antihistamine diphenhydramine (Benadryl), which has a phenyl ether moiety in its chemical structure. Another example is the anesthetic sevoflurane, which is a fluorinated methyl isopropyl ether used for inducing and maintaining general anesthesia during surgeries.

It's important to note that 'ethers' as a term primarily belongs to the field of chemistry rather than medicine.

Phospholipid ethers are a type of phospholipid in which the traditional fatty acid chains are replaced by alkyl or alkenyl groups linked to the glycerol backbone via an ether bond. They are a significant component of lipoproteins and cell membranes, particularly in archaea, where they contribute to the stability and rigidity of the membrane at extreme temperatures and pressures.

The two main types of phospholipid ethers are plasmalogens and diether lipids. Plasmalogens contain a vinyl ether bond at the sn-1 position, while diether lipids have an ether bond at both the sn-1 and sn-2 positions. These unique structures give phospholipid ethers distinct chemical and biological properties compared to conventional phospholipids with ester-linked fatty acids.

I believe there may be some confusion in your question as "Organic chemistry phenomena" is a broad term and not a medical definition. However, I can provide you with an explanation of organic chemistry phenomena in a general context.

Organic chemistry is the study of carbon-containing compounds, their synthesis, reactions, properties, and structures. The term "organic" was originally used to describe biological materials, but now it refers to any compound that contains carbon atoms bonded to hydrogen atoms, except for some simple oxides, sulfides, and halides.

Organic chemistry phenomena encompass a wide range of processes and events related to organic compounds. These can include:

1. Structural properties: Understanding the arrangement of atoms in organic molecules and how they influence chemical behavior and reactivity.
2. Stereochemistry: The study of three-dimensional spatial arrangements of atoms in organic molecules, which can significantly impact their properties and biological activity.
3. Functional groups: Recognizing and understanding the behavior of specific groupings of atoms within organic molecules that determine their chemical reactivity.
4. Reaction mechanisms: Investigating and describing the step-by-step processes by which organic reactions occur, including the movement of electrons, formation and breaking of bonds, and energy changes.
5. Synthetic methodologies: Developing strategies and techniques for creating complex organic molecules from simpler precursors, often involving multiple steps and protecting group strategies.
6. Physical properties: Examining how factors such as molecular weight, polarity, solubility, and melting/boiling points affect the behavior of organic compounds in various conditions.
7. Spectroscopic analysis: Utilizing techniques like NMR (Nuclear Magnetic Resonance), IR (Infrared) spectroscopy, and mass spectrometry to analyze the structure and composition of organic molecules.
8. Biochemistry and medicinal chemistry: Exploring how organic compounds interact with biological systems, including drug design, development, and delivery.

While not a medical definition per se, understanding organic chemistry phenomena is crucial for many areas within medicine, such as pharmaceutical research, toxicology, and biochemistry.

Heptanes are a group of hydrocarbons that are composed of straight-chain or branched arrangements of six carbon atoms and are commonly found in gasoline. They are colorless liquids at room temperature with a characteristic odor. In a medical context, exposure to heptanes can occur through inhalation, skin contact, or ingestion, and can cause symptoms such as headache, dizziness, nausea, and irritation of the eyes, nose, and throat. Chronic exposure has been linked to more serious health effects, including neurological damage and cancer. Proper handling and use of heptanes, as well as adequate ventilation, are important to minimize exposure and potential health risks.

Thin-layer chromatography (TLC) is a type of chromatography used to separate, identify, and quantify the components of a mixture. In TLC, the sample is applied as a small spot onto a thin layer of adsorbent material, such as silica gel or alumina, which is coated on a flat, rigid support like a glass plate. The plate is then placed in a developing chamber containing a mobile phase, typically a mixture of solvents.

As the mobile phase moves up the plate by capillary action, it interacts with the stationary phase and the components of the sample. Different components of the mixture travel at different rates due to their varying interactions with the stationary and mobile phases, resulting in distinct spots on the plate. The distance each component travels can be measured and compared to known standards to identify and quantify the components of the mixture.

TLC is a simple, rapid, and cost-effective technique that is widely used in various fields, including forensics, pharmaceuticals, and research laboratories. It allows for the separation and analysis of complex mixtures with high resolution and sensitivity, making it an essential tool in many analytical applications.

Glycerophospholipids, also known as phosphoglycerides, are a major class of lipids that constitute the structural components of biological membranes. They are composed of a glycerol backbone to which two fatty acid chains and a phosphate group are attached. The phosphate group is esterified to an alcohol, typically choline, ethanolamine, serine, or inositol, forming what is called a phosphatidyl headgroup.

The chemical structure of glycerophospholipids allows them to form bilayers, which are essential for the formation of cell membranes and organelles within cells. The fatty acid chains, which can be saturated or unsaturated, contribute to the fluidity and permeability of the membrane. Glycerophospholipids also play important roles in various cellular processes, including signal transduction, cell recognition, and metabolism.

Chlorine is a chemical element with the symbol Cl and atomic number 17. It is a member of the halogen group of elements and is the second-lightest halogen after fluorine. In its pure form, chlorine is a yellow-green gas under standard conditions.

Chlorine is an important chemical compound that has many uses in various industries, including water treatment, disinfection, and bleaching. It is also used in the production of a wide range of products, such as plastics, solvents, and pesticides.

In medicine, chlorine compounds are sometimes used for their antimicrobial properties. For example, sodium hypochlorite (bleach) is a common disinfectant used to clean surfaces and equipment in healthcare settings. Chlorhexidine is another chlorine compound that is widely used as an antiseptic and disinfectant in medical and dental procedures.

However, it's important to note that exposure to high concentrations of chlorine gas can be harmful to human health, causing respiratory irritation, coughing, and shortness of breath. Long-term exposure to chlorine can also lead to more serious health effects, such as damage to the lungs and other organs.

Zellweger Syndrome is a rare genetic disorder that affects the development and function of multiple organ systems in the body. It is part of a group of conditions known as peroxisome biogenesis disorders (PBDs), which are characterized by abnormalities in the structure and function of peroxisomes, which are cellular structures that break down fatty acids and other substances in the body.

Zellweger Syndrome is caused by mutations in one or more genes involved in the formation and maintenance of peroxisomes. As a result, people with this condition have reduced levels of certain enzymes that are necessary for normal brain development, as well as for the breakdown of fats and other substances in the body.

Symptoms of Zellweger Syndrome typically appear within the first few months of life and may include:

* Severe developmental delays and intellectual disability
* Hypotonia (low muscle tone) and poor motor skills
* Vision and hearing problems
* Facial abnormalities, such as a high forehead, wide-set eyes, and a prominent nasal bridge
* Liver dysfunction and jaundice
* Seizures
* Feeding difficulties and failure to thrive

There is no cure for Zellweger Syndrome, and treatment is focused on managing the symptoms of the condition. The prognosis for people with this disorder is generally poor, with most individuals not surviving beyond the first year of life. However, some individuals with milder forms of the condition may live into early childhood or adolescence.

In medical terms, "bromides" refer to salts or compounds that contain bromine, a chemical element. Historically, potassium bromide was used as a sedative and anticonvulsant in the 19th and early 20th centuries. However, its use has largely been discontinued due to side effects such as neurotoxicity and kidney damage.

In modern medical language, "bromides" can also refer to something that is unoriginal, dull, or lacking in creativity, often used to describe ideas or expressions that are trite or clichéd. This usage comes from the fact that bromide salts were once commonly used as a sedative and were associated with a lack of excitement or energy.

Eosinophil peroxidase (EPO) is an enzyme that is primarily found in the granules of eosinophils, which are a type of white blood cell that plays a role in the immune response. EPO is involved in the destruction of certain types of parasites and also contributes to the inflammatory response in allergic reactions and other diseases.

EPO catalyzes the conversion of hydrogen peroxide to hypochlorous acid, which is a potent oxidizing agent that can kill or inhibit the growth of microorganisms. EPO also plays a role in the production of other reactive oxygen species, which can contribute to tissue damage and inflammation in certain conditions.

Elevated levels of EPO in tissues or bodily fluids may be indicative of eosinophil activation and degranulation, which can occur in various diseases such as asthma, allergies, parasitic infections, and some types of cancer. Measuring EPO levels can be useful in the diagnosis and monitoring of these conditions.

Plasmalogens are classified according to their head group, mainly as PC plasmalogens (plasmenylcholines) and PE plasmalogens ( ... Plasmalogens are commonly found in cell membranes in the nervous, immune, and cardiovascular systems. Plasmalogens are found in ... Deficits in plasmalogen levels contribute to pathology in Zellweger syndrome. Plasmalogen-knockout mice show similar ... The lack of good methods to assay plasmalogen has created difficulties for scientists to assess how plasmalogen might be ...
In enzymology, a plasmalogen synthase (EC 2.3.1.25) is an enzyme that catalyzes the chemical reaction acyl-CoA + 1-O-alk-1-enyl ... 1-alkenyl-glycero-3-phosphorylcholine acyltransferase action in plasmalogen biosynthesis". J. Biol. Chem. 243 (10): 2654-9. ...
His work on phospholipids resulted in his proposed structure for plasmalogens: these are not - as Robert Feulgen called them - ... Klenk, E.; Debuch, H. (1963). "Plasmalogens". Progress in the Chemistry of Fats and Other Lipids. 6: 1-29. doi:10.1016/0079- ... plasmalogens, and polyene fatty acids. By elucidating the structure of the glucocerebrosides, he pioneered the field of ...
Paltauf F, Holasek A (March 1973). "Enzymatic synthesis of plasmalogens. Characterization of the 1-O-alkyl-2-acyl-8n-glycero-3- ... Mice lacking plasmanylethanolamine desaturase lack plasmalogens in their tissues and have reduced body weight. Werner, Ernst R ... "A novel assay for the introduction of the vinyl ether double bond into plasmalogens using pyrene-labeled substrates". Journal ... "Evidence for a mixed function oxidase in the biosynthesis of ethanolamine plasmalogens from 1-alkyl-2-acyl-sn-glycero-3- ...
Plasmalogens Plasmalogens are a type of phosphoglyceride. The first carbon of glycerol has a hydrocarbon chain attached via an ... There are three major classes namely; 1-alkyl-2-acyl glycerophospholipid, 1,2-diacyl glycerophospholipid and plasmalogen. The ... Plasmalogens and phosphatidates are examples. In general, glycerophospholipids use an "sn" notation, which stands for ...
Wood, Randall; Healy, Kathleen (1970). "Tumor lipids: Biosynthesis of plasmalogens". Biochemical and Biophysical Research ... and hexadecyl glyceryl ether participates in the biosynthesis of plasmalogens. Cetane index Isocetane Higher alkanes CID 11006 ...
"Impaired Plasmalogens in Patients with Schizophrenia". Psychiatry Research. 198 (3): 347-52. doi:10.1016/j.psychres.2012.02.019 ...
Plasmalogens as well as some 1-O-alkyl lipids are ubiquitous and sometimes major parts of the cell membranes in mammals and ... Another possible function of the plasmalogen ether lipids is as antioxidants, as protective effects against oxidative stress ... Brosche T, Platt D (August 1998). "The biological significance of plasmalogens in defense against oxidative damage". ... Christie W. "Ether lipids - glyceryl ethers, plasmalogens, aldehydes, structure, biochemistry, composition and analysis". www. ...
Warner HR; Lands WEM (1961). "The metabolism of plasmalogen: enzymatic hydrolysis of the vinyl ether" (PDF). J. Biol. Chem. 236 ... Ellingson JS; Lands WEM (1968). "Phospholipid reactivation of plasmalogen metabolism". Lipids. 3 (2): 111-120. doi:10.1007/ ...
Plasmalogen is the most abundant phospholipid in myelin. Deficiency of plasmalogens causes profound abnormalities in the ... Peroxisomes also interact with the endoplasmic reticulum (ER) and cooperate in the synthesis of ether lipids (plasmalogens) ... The first reactions in the formation of plasmalogen in animal cells also occur in peroxisomes. ... and the biosynthesis of plasmalogens, i.e., ether phospholipids critical for the normal function of mammalian brains and lungs ...
The cause is a genetic mutation that results in low levels of plasmalogens, which are a type of lipid found in cell membranes ... Plasmalogen Peroxisomal disorder "Rhizomelic chondrodysplasia punctata type 1". Genetic and Rare Diseases Information Center ( ... catalyzes plasmalogen biosynthesis) PhYH (catalyzes catabolism of phytanic acid) ACAA1 (catalyzes beta-oxidation of VLCFA - ...
... also reacts with a subclass of glycerophospholipids called plasmalogens, yielding chlorinated fatty aldehydes ... "Reactive Chlorinating Species Produced by Myeloperoxidase Target the Vinyl Ether Bond of Plasmalogens". Journal of Biological ...
Sphinganine (dihydrosphingosine), an effective donor of the alk-1-enyl chain of plasmalogens". Hoppe-Seyler's Z. Physiol. Chem ...
"Incorporation of Isobutyrate and Valerate into Cellular Plasmalogen by Bacteroides succinogenes". Journal of Bacteriology. 85: ...
D-BP can be distinguished from Zellweger Syndrome by normal plasmalogen synthesis. Recent studies in D-BP knockout mice show ...
In addition, PBD-ZSD patients show deficient levels of plasmalogens, ether-phospholipids necessary for normal brain and lung ... and show reduced levels of plasmalogens. Peroxisomal disorders also include: Wanders, R. J. A.; Waterham, H. R. (2006). " ...
... a critique of the hypothesis relating to plasmalogen depletion and cardiovascular disease". Am. J. Clin. Nutr. 38 (2): 327-332 ...
... the xanthine oxidase/plasmalogen depletion hypothesis." Mercola.com has featured positive presentations of the claims of AIDS ... a critique of the hypothesis relating to plasmalogen depletion and cardiovascular disease". Am. J. Clin. Nutr. 38 (2): 327-32. ...
In addition, these individuals can show deficient levels of plasmalogens, ether-phospholipids that are especially important for ... and plasmalogen biosynthesis. The nutrient malabsorption resulting from a lack of bile acids has resulted in elemental formula ...
In addition, these individuals can show deficient levels of plasmalogens, ether-phospholipids that are especially important for ... and plasmalogen biosynthesis. Currently, there is no cure for infantile Refsum disease syndrome, nor is there a standard course ...
October 2011). "Enzymatic formation of N-acylethanolamines from N-acylethanolamine plasmalogen through N- ...
Calcium Independent Phospholipase A2 and Plasmalogen Selective Phospholipase A2 in Neurodegenerative and Neuropsychiatric ...
"Enzymatic formation of N-acylethanolamines from N-acylethanolamine plasmalogen through N-acylphosphatidylethanolamine- ...
Heymans HS, Schutgens RB, Tan R, van den Bosch H, Borst P. Severe plasmalogen deficiency in tissues of infants without ...
Many strictly anoxic bacteria and a few aerobic species contain plasmalogens (Pla), which has an alkyl chain bound to sn-1 ...
Lee TC, Uemura Y, Snyder F (1992). "A novel CoA-independent transacetylase produces the ethanolamine plasmalogen and acyl ...
... and biosynthesis of plasmalogens, ether phospholipids, which are found in mammalian brains and lungs. They produce hydrogen ...
... plasmalogens MeSH D10.570.755.375.760.400.985.910 - platelet activating factor MeSH D10.570.755.375.760.550 - lysophospholipids ...
... plasmalogen) glycerophospholipids, as well as dialkylether variants in archaebacteria. Sphingolipids are a complicated family ...
... plasmalogen synthase EC 2.3.1.26: sterol O-acyltransferase EC 2.3.1.27: cortisol O-acetyltransferase EC 2.3.1.28: ...

No FAQ available that match "plasmalogens"

No images available that match "plasmalogens"