We recently established that drugs used for the treatment and the prophylaxis of breast cancers, such as tamoxifen, were potent inhibitors of cholesterol-5,6-epoxide hydrolase (ChEH), which led to the accumulation of 5,6α-epoxy-cholesterol (5,6α-EC) and 5,6β-epoxy-cholesterol (5,6β-EC). This could be considered a paradox because epoxides are known as alkylating agents with putative carcinogenic...

The stereoselective synthesis of â-D-glucopyranosiduronic, R-L-idopyranosiduronic, and R-L-altropyranosiduronic acids has been performed from different ∆4-uronate monosaccharides. Bromination of the C-4,5 double bond provided the trans-diaxial bromohydrin derivatives, which were converted to the corresponding epoxides in high yields. Direct reduction of the epoxides using boranetetrahydrofuran ...

Four benzo-ring epoxides of the environmental carcinogen benzo(a)pyrene (BP) were tested for mutagenic and cytotoxic activity in 3 strains of Salmonella typhimurium (TA1538, TA98, and TA100) and in Chinese hamster V79 cells. Although very unstable in aqueous solution, 7beta,8alpha-dihydroxy-0beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (diol epoxide 1), with the 7-hydroxyl group on the s...

K-region epoxides of dibenz(a,h)anthracene and benz(a)anthracene were more active in producing malignant transforma tion of hamster embryo cells than the corresponding hydrocarbons, K-regions CMand frans-dihydrodiols and phenols. The cytotoxicity exerted by epoxides, relative to the other derivatives, varied among those tested. The 8,9-epoxide (non-K-region) of benz(a)anthracene was less active...

Four aliphatic epoxides, 1-naphthyl glycidyl ether (NGE), 1-naphthylpropylene oxide (NPO), 4-nitrophenyl glycidyl ether (NPGE), 3,3,3-trichloropropylene oxide (TCPO) and two of their precursors, 1-allylnaphthalene (AN) and 3,3,3-trichloropropylene (TCP), were selected for DNA strand-break analysis in liver in vivo with mice. The four epoxides selected were among the most mutagenic aliphatic epo...

Nuclear magnetic resonance techniques were used to study the kinetics and products of the reaction of a variety of epoxides with various amines under varying pH conditions. In agreement with a previous finding, the amine-epoxide reactions were found to be water-catalyzed and not directly dependent on the pH of the reaction environment. At pH values higher than the pK(a) of the particular amine,...

Olefins and their corresponding epoxide derivatives are extensively used in industrial processes. Many epoxides are used as intermediates in organic synthesis as well as in surfactants, fumigants, industrial sterilants, cosmetics, and pharmaceuticals. These compounds pose potential hazards for biological systems where 1,2-epoxides are able to cause adverse biological effects through genetic int...

Clinical studies suggest that diets rich in ω-3 polyunsaturated fatty acids (PUFAs) provide beneficial anti-inflammatory effects, in part through their conversion to bioactive metabolites. Here we report on the endogenous production of a previously unknown class of ω-3 PUFA-derived lipid metabolites that originate from the crosstalk between endocannabinoid and cytochrome P450 (CYP) epoxygenase ...

[reaction: see text] Treatment of hydroxy-substituted silyl epoxides with Grignard reagents induces a 1,2-carbon shift to reveal alpha-silyl aldehydes, which are trapped by highly diastereoselective addition reactions of the Grignard reagent. The starting epoxides are readily accessible from propargylic alcohols by regio- and diastereoselective hydrosilylation and epoxidation reactions. In addi...

OBJECTIVE Enzymatic metabolism of polyunsaturated fatty acids leads to formation of bioactive lipid metabolites (LMs). Previous studies have shown that obesity leads to deregulation of LMs in adipose tissues. However, most previous studies have focused on a single or limited number of LMs, and few systematical analyses have been carried out. METHODS A LC-MS/MS-based lipidomics approach was us...