The structural features of polycyclic polyether natural products can, in some cases, be traced to their biosynthetic origin. However in case that are less well understood, only biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades are proposed. We summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers (see s...

Enantiomers of the diastereomeric pair of bay-region benz(a)anthracene 3,4-diol-1,2-epoxides in which the benzylic 4-hydroxyl group and epoxide oxygen are either cis (isomer 1) or trans (isomer 2) were evaluated for mutagenic activity in two histidine-dependent strains of Salmonella typhimurium, as well as in an 8-azaguanine-sensitive Chinese hamster cell line. In strain TA 98 of S. typhimurium...

CD-1 female mice were initiated with a single topical application of 500 nmol dibenz[a,h]acridine (DB[a,h]Acr), its racemic trans-1,2-, 3,4-, 8,9- and 10,11-dihydrodiols, racemic DB[a,h]Acr 3,4-diol 1,2-epoxide-1 and -2 or racemic DB[a,h]Acr 10,11-diol 8,9-epoxide-1 and -2, where the benzylic hydroxyl group is either cis (isomer 1) or trans (isomer 2) to the epoxide oxygen. The mice were subseq...

The effects of a wide variety of chemical modification reagents on the activity of purified rat liver microsomal epoxide hydrase have been investigated. Alkylating agents, such as the phenacyl bromides and benzyl bromide are potent inhibitors of epoxide hydrase. Z-Bromo-4’-nitroacetophenone @-nitrophenacyl bromide) specifically and irreversibly inactivates epoxide hydrase. Pseudo-first order ki...

Epoxide-opening cascades offer the potential to construct complex polyether natural products expeditiously and in a manner that emulates the biogenesis proposed for these compounds. Herein we provide a full account of our development of a strategy that addresses several important challenges of such cascades. The centerpiece of the method is a trimethylsilyl (SiMe(3)) group that serves several p...

poly (n-bromosuccinimide) (pnbs) as a mild, efficient, non-acidic, polymeric and heterogeneous catalyst was applied for simple conversion of epoxides into thiiranes by treatment with kscn or (nh2)2cs at room temperature. aliphatic and aromatic epoxides converted into their corresponding thiiranes under mild conditions. all reactions proceeded in short reaction times and afforded the correspondi...

The mutagenic activities of the enantiomers of the pair of diastereomeric bay-region benzo(c)phenanthrene 3,4-diol-1,2epoxides were evaluated in histidine-dependent strains of Sal monella typhimurium and in an 8-azaguanine-sensitive Chinese hamster Å“il line. In strains TA 98 and TA 100 of S. typhimurium, the range in mutagenic activity observed for the four optically active isomers was less th...

BACKGROUND The aim of this study was to investigate the effect of two genetic polymorphisms in the coding regions (exon 3 and exon 4) of the EPHX1 gene, ie, 337T>C and 416A>G, respectively, on the metabolism of carbamazepine (CBZ) 10,11-epoxide (the active metabolite of CBZ) by evaluating the variation in serum CBZ 10,11-epoxide levels 4 hours after administration of the drug. Moreover, we repo...

A series of acceptor-substituted epoxide derivatives is scrutinized by means of experimental and theoretical electron-density investigations. Due to the possibility of nucleophilic ring-opening, the epoxide ring is not only a very useful functional group in organic synthesis, but acceptor-substituted epoxides are valuable building blocks for the design of protease inhibitors. Therefore, the ele...

Soluble epoxide hydrolase enzyme is a promising therapeutic target for hypertension, vascular inflammation, pain and some other risk factors of cardiovascular diseases. The most potent sEH inhibitors reported in the literature are urea-based ones which often have poor bioavailability. In this study, in a quest for finding potent inhibitors of soluble epoxide hydrolase, some 4,6-disubstituted py...