The global reaction between acetic anhydride and a fatty acid yields, at equilibrium, an asymmetric acetic-aliphatic anhydride in a medium containing finally: acetic-fatty anhydride, acetic anhydride, fatty acid, acetic acid and fatty anhydride. No solvent or catalyst was used to evaluate the impact of the actual reactivity of the anhydrides. The competition between the formation of acetyl and ...

BACKGROUND Increased levels of reactive oxygen species during and after surgery may affect inflammatory response, post-operative adhesion molecule formation, and hemodynamic stability. The glutathione redox cycle is an important regulator in oxidative stress and its reduced forms scavenge free radicals. N-acetyl cysteine, a precursor of reduced glutathione, is considered as a potentially therap...

Treatment of acetyl- 1,4-benzoquinone with isoprene gave the corresponding regioselective adduct (I). Rearrangement of the adduct (1) in pyridine and methanol gave 2-acetyl-5, 8-dihydro-6-methyl- 1,4-dihydroxynaphthalene (2). Silver oxide oxidation of the rearranged product (2) gave 2-acetyl-5,8-dihydro- 6-methyl- 1,4naphthalenedione (3). Regioselective addition of trans-piperylene to this...

1. A method is described for the estimation of thiol ester groups. The thiol ester is converted into the corresponding thiol by reaction with ammonia; the thiol is then titrated amperometrically with mercuric chloride. 2. The method may be used in the presence of SH and S.S groups. The SH groups are titrated at pH3 in the presence of excess of chloride; under these conditions thiol esters do no...

Xylan is a major acetylated polymer in plant lignocellulosic biomass and it can be mono- and di-acetylated at O-2 and O-3 as well as mono-acetylated at O-3 of xylosyl residues that is substituted with glucuronic acid (GlcA) at O-2. Based on the finding that ESK1, an Arabidopsis thaliana DUF231 protein, specifically mediates xylan 2-O- and 3-O-monoacetylation, we previously proposed that differe...

By comparative analysis of the hemagglutinin-esterase (HE) protein of mouse hepatitis virus strain S (MHV-S) and the HE protein of influenza C virus, we found major differences in substrate specificities. In striking contrast to the influenza C virus enzyme, the MHV-S esterase was unable to release acetate from bovine submandibulary gland mucin. Furthermore, MHV-S could not remove influenza C v...

In the title compound, C11H9FN2O2S, the 2-sulfanylideneimidazolidin-4-one moiety is essentially planar, with a maximum deviation of 0.0183 (14) Å. The mean plane of this moiety is approximately coplanar with the attached acetyl group and perpendicular to the benzene ring, making dihedral angles of 9.70 (14) and 86.70 (6)°, respectively. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bo...

Pyruvic acid and O-acetyl groups are the major noncarbohydrate substituents in exopolysaccharides (EPS) produced by fast-growing species of Rhizobium. EPS substituent variations were observed among strains of the same species. The amounts of these substituents also varied with culture age; pyruvic acid increased in the EPS of all four species, whereas O-acetyl increased in Rhizobium trifolii an...

Three lectins have been isolated from an extract of mistletoe (Viscum album) by affinity chromatography on partially hydrolysed Sepharose and human immunoglobulin- Sepharose. The lectins differ in molecular weight and sugar specificity (lectin I, mol.wt. 11500, D-galactose-specific; lectin II, mol.wt. 60000, both D-galactose- and N-acetyl-D-galactosamine-specific; lectin III, mol. wt. 50000, N-...

The comparative carcinogenicities of N-hydroxy-N-acetyl-1-aminopyrene, N-acetyl-1-aminopyrene, and 1-, 2-, and 4-nitropyrene were determined following i.p. injection into weaning female CD rats (67 mumol/kg body weight in dimethyl sulfoxide; 3 times/week for 4 weeks). At sacrifice 61 weeks after the first injection the incidences of malignant mammary tumors were increased significantly to 45 an...