Cisapride is a chiral molecule that is marketed as a racemate consisting of two optical isomers, but little is known about its stereoselective metabolism. Studies with (-)-, (+)-, and (+/-)-cisapride were undertaken in human liver microsomes (HLMs) and recombinant cytochrome P450s (P450s) to determine the stereoselective metabolism and enantiomer-enantiomer interaction. Each enantiomer and race...

The reactions with DNA and mutagenic activities toward Salmonella typhimurium TA 100 of the R,S,S,R and S,R,R,S enantiomers of antil,2,-dihydroxy-3,4-epoxy-l,2,3,4-tetrahydro-5-methylchrysene (anti5-MeC-l,2-diol-3,4-epoxide), an»i-5-MeC-7,8-diol-9,10-epoxide, and «nf/-6-MeC-l,2-diol-3,4-epoxide were compared because among these compounds only the H,S,S,K enantiomer of anri-5-MeC-l,2-diol-3,4e...

The front cover picture illustrates a rhodium-catalyzed enantioselective hydroacylation of racemic alkynals having substituent at the α-position carbonyl group. Mechanistic studies revealed that occurs preferentially from one enantiomer substrate via dynamic kinetic resolution (DKR) process. shows an outline DKR process by using illustration soccer, in which player getting good ball (i. e., ena...

Racemic 2'-deoxy-3'-thiacytidine (BCH 189) is a dideoxycytidine analog having a sulfur atom in place of the 3' carbon. The enantiomers of BCH 189 have been resolved and found to be equipotent in antiviral activity against human immunodeficiency virus types 1 and 2. However, the (-)-enantiomer (3TC) is considerably less cytotoxic than the (+)-enantiomer.

An enantioselective synthesis of the (1S,5R)-enantiomer of litseaverticillols A and B was accomplished in line with our previously reported synthetic pathway for their (1R,5S)-enantiomer. The use of "EtSCeCl2" prepared from EtSLi and CeCl3, instead of previously employed EtSLi itself, for the formation of thiol ester intermediates prevented any undesirable epimerization occurring in the process.

Using a new sensitive reverse-phase HPLC assay relying on UV detection at 344 nm, the capacity of 18 human liver microsomal samples to support NADPH-dependent, cytochrome P450-mediated oxidation and arachidonic acid-dependent oxidation of the enantiomers of trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (B[a]P-7,8-DHD) was determined. The (-)-7R,8R-enantiomer, the preferred substrate of cytochro...

The enantioselective tuning of two columns coupled in series is investigated in chiral high-resolution gas chromatography. Two columns with opposite enantioselectivities (Chirasil-L-Val and Chirasil-D-Val) are coupled in series via a T connector, and the relative retention of enantiomers chromatographed on the system is changed by varying the individual carrier gas flow rates in the coupled col...

The enantiomeric resolution of the fungicides uniconazole and diniconazole was performed using electrokinetic chromatography with cyclodextrins as pseudostationary phase (CD-EKC). A systematic evaluation of several chiral selectors was made. The anionic derivative carboxymethylated-gamma-cyclodextrin (CM-gamma-CD) was found to be the most appropriate for the enantioseparation of fungicides amon...

A directed manipulation of the functional groups at C3 and C4 of D-glucose was demonstrated to synthesize naturally occurring (2S,3R)-α-hydroxy-β-aminodecanoic acid (AHDA, 2a) and its enantiomer 2b. The enantiomer of 2a is the N-terminal part of the natural linear pentapeptide microginin, which is used as an antihypertensive agent.