Compounds used extensively as acetylation, oxidation and dehydrating agents and in the modification of proteins and enzymes.
Chemical compounds derived from acids by the elimination of a molecule of water.
A subclass of anhydrides with the general structure of dihydrofurandione. They can be substituted on any carbon atom. They modify and inhibit proteins and enzymes and are used in the acylation of amino- and hydroxyl groups.
Phthalic acid anhydrides. Can be substituted on any carbon atom. Used extensively in industry and as a reagent in the acylation of amino- and hydroxyl groups.
Used in copolymerization reactions, in the Diels-Alder(diene)synthesis, in the preparation of resins, pharmaceuticals and agricultural chemicals. It is a powerful irritant and causes burns.
Formation of an acetyl derivative. (Stedman, 25th ed)
A subclass of GLYCOSPHINGOLIPIDS containing one or more sugars within their head group connected directly to a ceramide moiety. They consist of monoglycosyl-, and oligoglycosylsphingoids and monoglycosyl- and oligoglycosylceramides.
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
Methylmaleic anhydrides.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
An essential amino acid. It is often added to animal feed.
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)
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Tritium is a radioactive isotope of hydrogen used in medical applications such as radiation therapy and as a tracer in diagnostic imaging.

Characterisation of the conformational and quaternary structure-dependent heparin-binding region of bovine seminal plasma protein PDC-109. (1/78)

PDC-109, the major heparin-binding protein of bull seminal plasma, binds to sperm choline lipids at ejaculation and modulates capacitation mediated by heparin. Affinity chromatography on heparin-Sepharose showed that polydisperse, but not monomeric, PDC-109 displayed heparin-binding capability. We sought to characterise the surface topology of the quaternary structure-dependent heparin-binding region of PDC-109 by comparing the arginine- and lysine-selective chemical modification patterns of the free and the heparin-bound protein. A combination of reversed-phase peptide mapping of endoproteinase Lys-C-digested PDC-109 derivatives and mass spectrometry was employed to identify modified and heparin-protected residues. PDC-109 contains two tandemly arranged fibronectin type II domains (a, Cys24-Cys61; b, Cys69-Cys109). The results show that six basic residues (Lys34, Arg57, Lys59, Arg64, Lys68, and Arg104) were shielded from reaction with acetic anhydride and 1,2-cyclohexanedione in heparin-bound PDC-109 oligomers. In the 1H-NMR solution structures of single fibronectin type II domains, residues topologically equivalent to PDC-109 Arg57 (Arg104) and Lys59 lay around beta-strand D on the same face of the domain. In full-length PDC-109, Arg64 and Lys68 are both located in the intervening polypeptide between domains a and b. Our data suggest possible quaternary structure arrangements of PDC-109 molecules to form a heparin-binding oligomer.  (+info)

Chemical modification of lysine side chains of cyclodextrin glycosyltransferase from Thermoanaerobacter causes a shift from cyclodextrin glycosyltransferase to alpha-amylase specificity. (2/78)

Cyclodextrin glycosyltransferases and alpha-amylases are two groups of enzymes with related secondary structures. However, cyclodextrin glycosyltransferases display transferase activities not present in alpha-amylases, probably derived from the existence of two more domains and different amino acid sequences. The hydrolytic activity of cyclodextrin glycosyltransferases is generally quite low, except for two cyclodextrin glycosyltransferases from termophiles. In this work, we have carried out the chemical modification (with acetic anhydride) of the amino groups of cyclodextrin glycosyltransferase from Thermoanaerobacter to assess their contributions to protein function. The acetylated cyclodextrin glycosyltransferase showed a significant reduction of its cyclization, coupling and disproportionation activities. Surprisingly, the hydrolytic (saccharifying) activity was slightly enhanced. These results suggest the participation of one or more lysine side chains in the interactions contributing to the transferase activity, either in any of the S11 subsites or in the acceptor binding site.  (+info)

Induction and suppression of endothelial cell apoptosis by sphingolipids: a possible in vitro model for cell-cell interactions between platelets and endothelial cells. (3/78)

Because sphingosine (Sph) is actively incorporated into platelets and rapidly converted to sphingosine 1-phosphate (Sph-1-P), which is then released extracellularly, it is important to study the effects of Sph and Sph-1-P on endothelial cells from the viewpoint of platelet-endothelial cell interaction. In this study, we found that Sph, as well as ceramide, induces apoptosis in human umbilical vein endothelial cells (HUVECs). In contrast, Sph-1-P acts as a HUVEC survival factor; this bioactive lipid was shown to protect HUVECs from apoptosis induced by the withdrawal of growth factors and to stimulate HUVEC DNA synthesis. In metabolic studies, [3H]Sph, incorporated into HUVECs, was converted to [3H]Cer and further to [3H]sphingomyelin in a time-dependent manner, whereas [3H]Sph-1-P formation from [3H]Sph was weak and transient. These findings in HUVECs are very different from those of platelets, which possess a highly active Sph kinase but lack Sph-1-P lyase. As a result, platelets abundantly store Sph-1-P, whereas HUVECs contain much less Sph-1-P. Finally, HUVECs, in contrast to platelets, failed to release Sph-1-P extracellularly, indicating that HUVECs themselves are not able to supply the survival factor Sph-1-P, but receive it from activated platelets. Our results suggest that platelets may maintain the integrity of endothelial cells by incorporating Sph and releasing Sph-1-P.  (+info)

Distinguishing between luminal and localized proton buffering pools in thylakoid membranes. (4/78)

The dual gradient energy coupling hypothesis posits that chloroplast thylakoid membranes are energized for ATP formation by either a delocalized or a localized proton gradient geometry. Localized energy coupling is characterized by sequestered domains with a buffering capacity of approximately 150 nmol H(+) mg(-1) chlorophyll (Chl). A total of 30 to 40 nmol mg(-1) Chl of the total sequestered domain buffering capacity is contributed by lysines with anomolously low pK(a)s, which can be covalently derivatized with acetic anhydride. We report that in thylakoid membranes treated with acetic anhydride, luminal acidification by a photosystem I (duraquinol [DQH(2)] to methyl viologen [MV]) proton pumping partial reaction was nearly completely inhibited, as measured by three separate assays, yet surprisingly, H(+) accumulation still occurred to the significant level of more than 100 nmol H(+) mg Chl(-1), presumably into the sequestered domains. The treatment did not increase the observed rate constant of dark H(+) efflux, nor was electron transport significantly inhibited. These data provide support for the existence of a sequestered proton translocating pathway linking the redox reaction H(+) ion sources with the CF(0) H(+) channel. The sequestered, low-pK(a) Lys groups appear to have a role in the H(+) diffusion process and chemically modifying them blocks the putative H(+) relay system.  (+info)

Novel mechanism of surface catalysis of protein adduct formation. NMR studies of the acetylation of ubiquitin. (5/78)

Reactivity of surface lysyl residues of proteins with a broad range of chemical agents has been proposed to be dependent on the catalytic microenvironment of the residue. We have investigated the acetylation of wild type ubiquitin and of the UbH68N mutant to evaluate the potential contribution of His-68 to the reactivity of Lys-6, which is about 4 A distant. These studies were performed using [1-(13)C]acetyl salicylate or [1,1'-(13)C(2)]acetic anhydride, and the acetylated products were detected by two-dimensional heteronuclear multiple quantum coherence spectroscopy. The results demonstrate that His-68 makes a positive contribution to the rate of acetylation of Lys-6 by labeled aspirin. Additionally, a pair of transient resonances is observed after treatment of wild type ubiquitin with the labeled acetic anhydride but not upon treatment of the H68N mutant. These resonances are assigned to the acetylated His-68 residue. The loss of intensity of the acetylhistidine resonances is accompanied by an increase in intensity of the acetyl-Lys-6 peak, supporting the existence of a transacetylation process between the acetylhistidine 68 and lysine 6 residues located on the protein surface. Hence, this may be the first direct demonstration of a catalytic intermediate forming on the protein surface.  (+info)

Intramolecular capture of pummerer reaction intermediates by an aromatic nucleophile: selective construction of 1,4-benzothiazine and indole ring systems. (6/78)

The simple alkyl sulfoxide 6 carrying two aromatic nucleophiles, when treated with trifluoroacetic anhydride at room temperature (Pummerer reaction conditions), underwent an intramolecular aromatic sulfenylation of the 6-exo-tet process in an exclusive manner to yield two regioisomeric 1,4-benzothiazine derivatives, 8 and 9. On the other hand, a similar reaction of the alpha-acyl sulfoxide 7, possessing identical aromatic nucleophiles, caused an intramolecular aromatic alkylation of the 5-exo-trig process to produce the 3-oxo-indole derivative 14 in a quantitative yield. These results demonstrate that the construction of 1,4-benzothiazine and indole ring systems can be achieved in a selective manner by proper choice of the sulfoxide side chain.  (+info)

Trifluoromethyl ketone-based inhibitors of apoptosis in cerebellar granule neurons. (7/78)

A variety of aromatic trifluoromethyl ketone derivatives has been studied as inhibitors of apoptosis in cerebellar granule neurons (CGNs). Among them, alpha-trifluoromethyl diketone (2) and benzyl trifluoromethyl ketone (11) were found to be apoptosis inhibitors which can prevent a neurodegenerative disease. Compounds 2 and 11 showed neuroprotection effect on low K+-induced apoptosis in CGNs. Furthermore, these compounds effectively suppressed DNA fragmentation accompanied with apoptosis. The neuroprotection mode of 2 and 11 was not related to inhibition of caspase-3.  (+info)

Scandium(III) trifluoromethanesulfonate catalyzed aromatic nitration with inorganic nitrates and acetic anhydride. (8/78)

The rare earth metal(III) trifluoromethanesulfonate (rare earth metal(III) triflate, RE(OTf)3) was found to be an efficient catalyst for aromatic nitration with carboxylic anhydride-inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)3, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifluoromethanesulfonate (scandium(III) triflate, Sc(OTf)3) is the most active catalyst among our tested Lewis acids. It was also found that acetic anhydride-Al(NO3).9H2O is the most active nitrating agent in this system.  (+info)

Acetic anhydride is a chemical compound with the formula CH3COOCO2H. It is a colorless, oily liquid with a strong, unpleasant smell. In the medical field, acetic anhydride is used as a reagent in the synthesis of various drugs and other chemical compounds. It is also used as a local anesthetic and as an antiseptic. However, it is important to note that acetic anhydride is highly toxic and can cause serious harm if not used properly. It is therefore important to use it only under the supervision of a qualified healthcare professional.

In the medical field, anhydrides refer to compounds that do not contain water molecules. Anhydrides can be found in various forms, including organic and inorganic compounds. One example of an anhydride in the medical field is acetylsalicylic acid, also known as aspirin. Aspirin is an organic anhydride that is commonly used as a pain reliever and anti-inflammatory medication. Another example of an anhydride in the medical field is sulfuric acid, which is an inorganic anhydride. Sulfuric acid is used in various medical applications, including as a preservative for vaccines and as a component in some medications. Overall, anhydrides play important roles in the medical field and are used in a variety of applications, from pain relief to vaccine preservation.

Succinic anhydride is a chemical compound that is used in the production of various pharmaceuticals and other chemicals. It is a white, crystalline solid that is soluble in organic solvents but not in water. In the medical field, succinic anhydride is used as a starting material for the synthesis of a number of drugs, including antibiotics, anticonvulsants, and analgesics. It is also used as a solvent and a chemical intermediate in the production of other chemicals.

Phthalic anhydrides are a class of organic compounds that are commonly used as intermediates in the production of various chemicals, including plastics, dyes, and pharmaceuticals. In the medical field, phthalic anhydrides are used as starting materials for the synthesis of a variety of drugs and other therapeutic agents. One example of a drug that is derived from phthalic anhydrides is diethyl phthalate (DEP), which is used as a solvent and plasticizer in medical devices and pharmaceuticals. DEP has been shown to have estrogenic effects in animal studies, which has raised concerns about its potential impact on human health. Other phthalic anhydrides that are used in the medical field include isophthalic anhydride, which is used as a starting material for the synthesis of certain antibiotics, and terephthalic anhydride, which is used in the production of resins and plastics that are used in medical devices. It is important to note that the use of phthalic anhydrides in the medical field is regulated by various government agencies, including the U.S. Food and Drug Administration (FDA), to ensure that they are safe and effective for their intended uses.

Maleic anhydride is a chemical compound that is not commonly used in the medical field. It is a white, crystalline solid that is used primarily as a chemical intermediate in the production of other chemicals, such as polymers and dyes. It is not used as a medication or for any medical purpose.

Neutral glycosphingolipids (NGSs) are a type of glycosphingolipid that do not contain charged groups on their sugar moieties. They are composed of a sphingosine backbone, a fatty acid chain, and a sugar moiety. NGSs are found in all mammalian cells and are important components of the cell membrane, playing roles in cell signaling, cell adhesion, and membrane trafficking. They are also involved in the pathogenesis of various diseases, including cancer, neurodegenerative disorders, and autoimmune diseases.

In the medical field, acetates refer to compounds that contain the acetate ion (CH3COO-). Acetates are commonly used in the treatment of various medical conditions, including: 1. Hyperkalemia: Acetate is used to treat high levels of potassium (hyperkalemia) in the blood. It works by binding to potassium ions and preventing them from entering cells, which helps to lower potassium levels in the blood. 2. Acidosis: Acetate is used to treat acidosis, a condition in which the blood becomes too acidic. It works by increasing the production of bicarbonate ions, which helps to neutralize excess acid in the blood. 3. Respiratory failure: Acetate is used to treat respiratory failure, a condition in which the lungs are unable to provide enough oxygen to the body. It works by providing an alternative source of energy for the body's cells, which helps to support the respiratory system. 4. Metabolic acidosis: Acetate is used to treat metabolic acidosis, a condition in which the body produces too much acid. It works by increasing the production of bicarbonate ions, which helps to neutralize excess acid in the body. 5. Hyperammonemia: Acetate is used to treat hyperammonemia, a condition in which the blood contains too much ammonia. It works by providing an alternative source of energy for the body's cells, which helps to reduce the production of ammonia. Overall, acetates are a useful tool in the treatment of various medical conditions, and their use is closely monitored by healthcare professionals to ensure their safe and effective use.

Citraconic anhydrides are a class of organic compounds that are used in various medical applications. They are typically derived from citric acid, which is a naturally occurring organic acid found in citrus fruits. One common use of citraconic anhydrides in medicine is as a preservative in pharmaceuticals and other medical products. They are also used as a stabilizer in certain types of medical devices, such as catheters and implants. Citraconic anhydrides are also used as a chelating agent, which means they can bind to certain metals and help to remove them from the body. This can be useful in the treatment of certain types of metal poisoning, such as lead poisoning. In addition to their medical uses, citraconic anhydrides are also used in a variety of other industries, including the food and beverage industry, where they are used as a flavor enhancer and preservative.

Lysine is an essential amino acid that is required for the growth and maintenance of tissues in the human body. It is one of the nine essential amino acids that cannot be synthesized by the body and must be obtained through the diet. Lysine plays a crucial role in the production of proteins, including enzymes, hormones, and antibodies. It is also involved in the absorption of calcium and the production of niacin, a B vitamin that is important for energy metabolism and the prevention of pellagra. In the medical field, lysine is used to treat and prevent various conditions, including: 1. Herpes simplex virus (HSV): Lysine supplements have been shown to reduce the frequency and severity of outbreaks of HSV-1 and HSV-2, which cause cold sores and genital herpes, respectively. 2. Cold sores: Lysine supplements can help reduce the frequency and severity of cold sore outbreaks by inhibiting the replication of the herpes simplex virus. 3. Depression: Lysine has been shown to increase levels of serotonin, a neurotransmitter that regulates mood, in the brain. 4. Hair loss: Lysine is important for the production of hair, and deficiency in lysine has been linked to hair loss. 5. Wound healing: Lysine is involved in the production of collagen, a protein that is important for wound healing. Overall, lysine is an important nutrient that plays a crucial role in many aspects of human health and is used in the treatment and prevention of various medical conditions.

Tritium is a radioactive isotope of hydrogen with the atomic number 3 and the symbol T. It is a beta emitter with a half-life of approximately 12.3 years. In the medical field, tritium is used in a variety of applications, including: 1. Medical imaging: Tritium is used in nuclear medicine to label molecules and track their movement within the body. For example, tritium can be used to label antibodies, which can then be injected into the body to track the movement of specific cells or tissues. 2. Radiation therapy: Tritium is used in radiation therapy to treat certain types of cancer. It is typically combined with other isotopes, such as carbon-14 or phosphorus-32, to create a radioactive tracer that can be injected into the body and targeted to specific areas of cancerous tissue. 3. Research: Tritium is also used in research to study the behavior of molecules and cells. For example, tritium can be used to label DNA, which can then be used to study the process of DNA replication and repair. It is important to note that tritium is a highly radioactive isotope and requires careful handling to minimize the risk of exposure to radiation.

Due to its low cost, acetic anhydride is usually purchased, not prepared, for use in research laboratories. Acetic anhydride is ... "Acid Anhydrides", Understanding Chemistry, retrieved 2006-03-25. Shakhashiri, Bassam Z., "Acetic Acid & Acetic Anhydride", ... acetic anhydride is listed as a U.S. DEA List II precursor, and restricted in many other countries. Acetic anhydride is an ... The route from acetic acid to acetic anhydride via ketene was developed by Wacker Chemie in 1922, when the demand for acetic ...
... was conjectured to be an intermediate in the decomposition of anhydrous oxalic acid by acetic anhydride ... Oxalic anhydride W. R. Edwards and Walter M. Henley (1953), Acetic Oxalic Anhydride. J. Am. Chem. Soc., volume 75, issue 14, ... Unlike some other anhydrides, Acetic oxalic anhydride cannot be obtained directly from the acids. It was synthesized in 1953 by ... C into acetic anhydride (H 3C-(C=O)-)2O, carbon dioxide (CO 2) and carbon monoxide (CO). It is hydrolyzed by water into acetic ...
Formic anhydride Acetic anhydride Acetic oxalic anhydride Strazzolini, Paolo; Giumanini, Angelo G.; Cauci, Sabina (1990). " ... Acetic formic anhydride is an organic compound with the, which can be viewed as the mixed anhydride of acetic acid and formic ... It can also be prepared by the reaction of acetic anhydride and formic acid at 0 °C. While more stable than formic anhydride, ... Acetic formic anhydride is a formylation agent for amines, amino acids, and alcohols. It is also a starting material for other ...
Reaction with acetic anhydride gave CID:22741820 (4). Catalytic hydrogenation removal of the benzyl protecting group gave N- ...
Acetic formic anhydride Acetic anhydride Formaldehyde "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations ... It can also be obtained by disproportionation of acetic formic anhydride. Formic anhydride is a liquid with boiling point 24 °C ... Formic anhydride, also called methanoic anhydride, is an organic compound with the chemical formula C 2H 2O 3 and a structural ... It can be viewed as the anhydride of formic acid (HCOOH). Formic anhydride can be obtained by reaction of formyl fluoride with ...
Similar to acetic anhydride, trifluoroacetic anhydride can be used as a dehydrating agent and as an activator for the Pummerer ... Trifluoroacetic anhydride (TFAA) is the acid anhydride of trifluoroacetic acid. It is the perfluorinated derivative of acetic ... Trifluoroacetic anhydride is the recommended desiccant for trifluoroacetic acid. Sigma-Aldrich Co., Trifluoroacetic Anhydride. ... "Dimethyl Sulfoxide-Trifluoroacetic Anhydride. New Reagent for Oxidation of Alcohols to Carbonyls". J. Org. Chem. 41 (6): 957- ...
Thus, (CH3CO)2O is called acetic anhydride. Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see ... of acetic anhydride makes it a common choice for acetylation reactions. Illustrative acid anhydrides Acetic anhydride is ... benzoic propanoic anhydride. Organic acid anhydrides are prepared in industry by diverse means. Acetic anhydride is mainly ... An organic acid anhydride is an acid anhydride that is also an organic compound. An acid anhydride is a compound that has two ...
The product of the condensation of two molecules of acetic acid is acetic anhydride. The worldwide production of acetic ... Acetic anhydride is also a reagent for the production of heroin and other compounds. As a polar protic solvent, acetic acid is ... The largest single use of acetic acid is in the production of vinyl acetate monomer, closely followed by acetic anhydride and ... "Acetic Anhydride and Mixed Fatty Acid Anhydrides". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi: ...
Acetic anhydride is produced by carbonylation of methyl acetate in a process that was inspired by the Monsanto acetic acid ... "Eastman Chemical Company Acetic Anhydride Process". Catalysis Today. 13: 73-91. doi:10.1016/0920-5861(92)80188-S. (CS1 maint: ... Methyl acetate also arises by esterification of acetic acid with methanol in the presence of strong acids such as sulfuric acid ... Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula ...
Related carbonylation reactions afford acetic anhydride. Carbon monoxide-releasing molecules are metal carbonyl complexes that ... Metal carbonyls are soluble in nonpolar and polar organic solvents such as benzene, diethyl ether, acetone, glacial acetic acid ... acetic acid is produced from methanol, carbon monoxide, and water using hydrogen iodide as well as rhodium and iridium carbonyl ...
Acetic anhydride is produced by carbonylation of methyl acetate in a process that is similar to the Monsanto acetic acid ... Because acetic anhydride hydrolyzes, the conversion is conducted under anhydrous conditions in contrast to the Monsanto acetic ... Acetyl iodide reacts with acetate salts or acetic acid to give the anhydride. Rhodium iodides and lithium salts are employed as ... The Monsanto process is an industrial method for the manufacture of acetic acid by catalytic carbonylation of methanol. The ...
... prevent the supply of acetic anhydride; and prohibit aircraft to land, take off or overfly their territory if it had taken off ...
... which convert methanol to acetic acid. In another major industrial process, acetic anhydride is prepared by a related ... "Eastman Chemical Company Acetic Anhydride Process". Catalysis Today. 13: 73-91. doi:10.1016/0920-5861(92)80188-S. Takashi Ohara ... Large-scale applications of carbonylation are the Monsanto acetic acid process and Cativa process, ...
The related Tennessee Eastman acetic anhydride process affords acetic anhydride by carbonylation of methyl acetate. CH3CO2CH3 ... "Eastman Chemical Company Acetic Anhydride Process". Catalysis Today. 13 (1): 73-91. doi:10.1016/0920-5861(92)80188-S. Cornils, ... The Monsanto process is an industrial method for the making of acetic acid by catalytic carbonylation of methanol, although it ... Hosea Cheung, Robin S. Tanke, G. Paul Torrence "Acetic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH ...
... was prepared in the 19th century from glycerol and acetic acid. Its synthesis from acetic anhydride and glycerol is ... the triester of glycerol with acetic acid. It is a colorless, viscous, and odorless liquid with a high boiling point and a low ...
Dimethyl sulfoxide/acetic anhydride serves as oxidizing agent. The reaction does not proceed further to the carboxylic acid. ... The following figure shows the reaction mechanism: First, dimethyl sulfoxide (1) reacts with acetic anhydride to form a ... Furthermore, acetic acid is cleaved, so that intermediate 2 is formed. The latter reacts upon elimination of acetic acid and ... 33-36, ISBN 978-0-470-28662-3 J. Donald Albright, Leon Goldman (1967), "Dimethyl sulfoxide-acid anhydride mixtures for the ...
Haque, M.N. (1997). The Chemical Modification of Wood with Acetic Anhydride. MSc Dissertation. The University of Wales, Bangor ... wood modification with acetic anhydride has been noted for the high anti-shrink or anti-swell efficiency (ASE) attainable ... However, acetylation of wood has been slow to be commercialised due to the cost, corrosion and the entrapment of the acetic ...
Moreau P, Finiels A, Meric P (20 March 2000). "Acetylation of dimethoxybenzenes with acetic anhydride in the presence of acidic ...
Acetic anhydride is mainly produced by the carbonylation of methyl acetate. Acetic anhydride is used industrially for preparing ... Technologies were developed for producing acetic anhydride, used in producing rayon and film. The Tennessee Eastman division of ... Under Landau's direction, Scientific Design also developed processes and sold licenses to make maleic anhydride, acetic ... In 1955, Scientific Design licensed an improved catalyst for oxidizing benzene to produce maleic anhydride. Maleic anhydride is ...
ISBN 978-0-471-28250-1. "Chemical of the Week -- Acetic Acid and Acetic Anhydride". www.eng.uwaterloo.ca. Archived from the ... Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid's ... Reaction between acetic acid and salicylic acid can also form aspirin but this esterification reaction is reversible and the ... It is stable in dry air, but gradually hydrolyses in contact with moisture to acetic and salicylic acids. In solution with ...
Treatment with acetic anhydride yielded 133 in quantitative yield. The cyclic enol ether 134 was formed through oxidative ...
Treatment with acetic anhydride results in the Polonovski reaction. Saponification followed by treatment with thionyl chloride ...
SAIB can be prepared by esterification of sucrose with acetic and isobutyric anhydride. Beverage emulsions - weighting agent ...
The first intentional synthesis involved dehydration of phthalamide by boiling in acetic anhydride. Another synthesis of ... Products of the Action of Acetic Anhydride on Phthalamide)" Berichte der Deutschen Chemischen Gesellschaft 1907, volume 40, pp ...
C2H6 Synthesis by oxidation of acetic anhydride by peroxides, is conceptually similar. The chemistry of ethane involves chiefly ... Similarly, the Saudi Arabian firm SABIC has announced construction of a 30,000 t/a plant to produce acetic acid by ethane ...
Methanesulfonyl chloride Disulfuric acid Sodium pyrosulfate Acetic anhydride Trifluoromethanesulfonic anhydride Wachtmeister, C ... Methanesulfonic anhydride (Ms2O) is the acid anhydride of methanesulfonic acid. Like methanesulfonyl chloride (MsCl), it may be ... 2-Naphthyl acetate was prepared from 2-naphthol and glacial (anhydrous) acetic acid in the presence of Ms2O. Both alcohols on ... Field, Lamar; Settlage, Paul H. (January 1955). "Reaction of Methanesulfonic Anhydride with Hydrogen Halides 1". Journal of the ...
This dihydrate can be dehydrated to anhydration using acetic anhydride. A solution of tin(II) chloride containing a little ...
At one time acetic anhydride was prepared by the reaction of ketene with acetic acid: H2C=C=O + CH3CO2H → (CH3CO)2O Δ H = − 63 ... Acetic anhydride. This reagent is common in the laboratory; its use cogenerates acetic acid. Acetyl chloride. This reagent is ... which is achieved using acetic anhydride. Acetylation disrupts hydrogen bonding, which otherwise dominates the properties of ... In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical ...
The capping step is performed by treating the solid support-bound material with a mixture of acetic anhydride and 1- ... The remaining unreacted amino groups are capped with acetic anhydride. Typically, three conceptually different groups of solid ... the solid support may contain the residual acetic anhydride and N-methylimidazole left after the capping step. The capping ... On small scale (less than 0.01-0.02 mmol), the treatment with 80% aqueous acetic acid for 15-30 min at room temperature is ...
... is synthesized using hydrogen fluoride and acetic anhydride. Acetic acid is produced as a byproduct. HF + (CH ...
Acetic acid anhydride,Acetyl acetate,Acetyl anhydride,Ethanoic anhydride; Linear Formula: (CH3CO)2O; find Sigma-Aldrich-242845 ... Acetic anhydride ACS reagent, ≥98.0%; CAS Number: 108-24-7; EC Number: 203-564-8; Synonyms: Acetanhydride, ... Acetic anhydride is an organic solvent. On dissolution in water it undergoes solvolysis to afford acetic acid. It is widely ... Acetic anhydride has been used as one of the reaction components in the preparation of:. *2-acetylamino-5-aminobenzenesulfonic ...
Acetic anhydride. C 5 ppm (20 mg/m 3 ). Acetone. TWA 750 ppm (1800 mg/m 3 ). ST 1000 ppm (2400 mg/m 3 ). ...
Users can register to get a Free Trial of Acetic Anhydride Tenders Online. ... Get latest updates on Acetic Anhydride Tenders from various Indian Government organizations. ... The information on Acetic Anhydride online tenders is sourced from various sources like: State Government Eproc Portals, ... In this section the users can find latest Acetic Anhydride tenders and eProcurement notices from various tendering authorities ...
This study aimed to introduce a new method based on Hollow Fiber in order to determination of acetic anhydride (AA) in the air ... This study aimed to introduce a new method based on Hollow Fiber in order to determination of acetic anhydride (AA) in the air ... Mollabahrami, F., Bahrami, A., Taheri, E., Farhadian, M. Fast and Sensitive Determination of Acetic Anhydride in the Air Using ... Mollabahrami, F., Bahrami, A., Taheri, E., & Farhadian, M. (2020). Fast and Sensitive Determination of Acetic Anhydride in the ...
Alternative to Acetic Anhydride. Industry need to find alternative solvent to acetic anhydride in determination of Hydroxyl ... As acetic anhydride is banned item. There is need to technology to find alternative to serve the testi.... Petrochemicals from ...
Acetic anhydride and butan-1-ol for industrial use - Determination of bromine number ... Acetic anhydride and butan-1-ol for industrial use - Determination of bromine number. ...
adipic anhydride and 5.5 per cent. acetic anhydride. Native starch was used as control. Caloric values were determined from a ... acetic anhydride resulting in 3.1 per cent. of acetyl groups being present (Oser, 1964). Long-term studies None available. ... acetic anhydride and a maximum of 0.12 per cent. adipic acid, the latter acting as cross-linking agent. The maximum number of ...
Acetic Anhydride. *Acetone *Amyl Acetate (primary). *Amyl Alcohol (primary). *Aromatic 150. *Aromatic 200 ...
The extracts were derivatized with acetic anhydride and excess reagent was removed with phosphate buffer and sodium sulfate ... Acetic anhydride; Reagents; Phosphates; Sampling; Biomarkers; Workers; Work environment ...
Industry uses carbon monoxide to manufacture compounds such as acetic anhydride, polycarbonates, acetic acid and polyketone. ...
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"DMF in Acetic Anhydride: a Useful Reagent for Multiple-Component Syntheses of Merocyanine Dyes." ... Synthesis of cis-5-Amidino-pyrrolidine-2-acetic Acid Derivatives". ...
With acetic anhydride In pyridine for 5h; Ambient temperature;. 2766-43-0 N-(tert-butoxycarbonyl)-L-serine methyl ester ... With dihydrogen peroxide; acetic acid at 25℃; for 0.0166667h;. 90%. With 3,3-dimethyldioxirane In methanol; acetone at 25℃; ... Imidazole is formed by reacting glyoxal with formaldehyde in the presence of ammonium acetate in acetic acid. The driving ... With ammonium acetate; acetic acid at 106℃; for 0.0583333h; Microwave irradiation;. 78%. ...
Acetic acid-d4 (D, 99.5%). DLM-1556. Acetic acid (OD, 98%). DLM-1162. Acetic anhydride (D6, 98%). ... Cyanamide (13C, 99%; 15N2, 98%) (stabilized with ,0.1% acetic acid). ...
Facile, high yield, N1-acetylation is achieved by reaction with acetic anhydride. ...
Miller and co-workers combined acetic anhydride with vanillin - a by-product in the manufacture of paper from lignin - to form ... Biorenewable polyethylene terephthalate mimics derived from lignin and acetic acid. Laurent Mialon, Alexander G. Pemba and ...
The samples were acetylated with 0.25% acetic anhydride in 0.1 M triethanolamine/HCl (Nacalai Tesque) (pH 8.0) for 10 min. ...
... acetic anhydride in 100 mM triethanolamine, then washed 2 × 2 min in 10% 20× saline-sodium citrate buffer. Prior to ...
The residue was acetylated with acetic anhydride-pyridine 95:5 (v/v) and fractionated by preparative TLC (CHCl3/MeOH 98:2) to ...
Acetaldehyde, Acetic Acid, Acetic Anhydride, Vinyl Acetate Ethylene Oligomers (Alpha Olefins) And Linear Primary Alcohols ... Phthalic Anhydride. Isophthalic Acid. Naphtalene Derivatives. 6. Paint, Varnishes, Resins. Butyl Acetate. N-Butyl Acetate. Iso- ... Maleic Anhydride. Detergent Alkylate. Nitrobenzene (Aniline). Chlorobenzenes. Derivatives Of Toluene. Toluene Diisocyanate (Tdi ... Xylene use depends on the isomer, para-xylene going into polyester and ortho-xylene going into phthalic anhydride. Both are ...
Acetylation was performed for 10 min with 0.25% acetic anhydride in 100 mM triethanolamine, pH 8.0, and slides were rinsed ...
p-TsOH and sodium metabisulphite or thiosulphate and chlorination (modification of the acetic anhydride patent, which replaces ...
The difference between the volumes used ggbp the titrations represents the amount of acetic anhydride required for the ...
... acetic anhydride, amines, paper, and wood. Shelf life: Fair. See Section 7 for further information. ...
Blocks were treated with uncatalyzed acetic anhydride for different lengths of time and exposed to Tyromyces palustris, Serpula ...
Using such hazardous materials as acetic anhydride, anhydrous ammonia, iodine and butane to manufacture illicit drugs, these ...
... more typical and high-boiling acetic anhydride. The (3,4-dimethoxylphenyl)benzyl (DMPBn) protecting group, which is removed (cf ...
In this solution for hydroxyl group esterification in cellular wall acetic anhydride is used what results in resistance to ... Basic acetylation process relies on using acetic anhydride for changing basic chemistry of cellular wall polymers. In ...
  • 2-Butoxyethanol is acid, acetic acid anhydride, or acetic acid chloride. (cdc.gov)
  • Urine samples collected from 15 exposed workers (N = 111) were subjected to acid hydrolysis and extracted with dichloromethane, then derivatized with acetic anhydride. (nih.gov)
  • [ 48 , 49 ] Acetic anhydride derivatization is best utilized if a deuterated version is used, as shown previously to quantify the acetylation isomers on histone H4 and developmental changes of core histones from Drosophila melanogaster . (medscape.com)
  • The chips were reacted with acetic, succinic, maleic and phthalic anhydride at constant temperature for 3 hours then, hot pressed at 150 °C by using phenol for. (irg-wp.com)
  • Ethanol ignites and then explodes on contact with acetic anhydride + sodium hydrosulfate (ignites and may explode), disulfuric acid + nitric acid, phosphorous(III) oxide platinum, potassium-tert-butoxide+ acids. (libertynatural.com)
  • Genetic Toxicity Evaluation of Acetic Anhydride in Salmonella/E.coli Mutagenicity Test or Ames Test. (nih.gov)
  • The extracts were derivatized with acetic anhydride and excess reagent was removed with phosphate buffer and sodium sulfate before sample was dried and reconstituted with water for analysis. (cdc.gov)
  • Prior to proteolysis, the highly charged histones may be chemically derivatized using acetic or propionic anhydride. (medscape.com)
  • Intriguingly, methods have been refined to include the use of isotopically labeled propionic anhydride to compare PTM abundances between multiple sample types. (medscape.com)
  • Another series of 2,3-disubstituted-4(3 H )-quinazolinones has been also obtained from reactions of a 3-aminoquinazolin-4(3 H )-one derivative with other carbon electrophiles, such as chloroacetamide, acetic anhydride, phenyl isocyanate, and ethyl chloroacetate. (heterocycles.jp)
  • Industry uses carbon monoxide to manufacture compounds such as acetic anhydride, polycarbonates, acetic acid and polyketone. (cdc.gov)
  • It is it may also be made by the reaction of ethylene prepared by reacting 2-butoxyethanol with acetic glycol with dibutyl sulfate. (cdc.gov)
  • Reacts with water to form acetic acid. (cdc.gov)