T. Watabe, N. Ozawa, A. Hiratsuka
Mar 1, 1983
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0
Influential Citations
42
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Rat liver cytosol converted phenyloxirane enantiomers regioselectively to glutathione S-conjugates. R-(+)-Phenyloxirane was converted to S-(1-phenyl-2-hydroxyethyl)glutathione (conjugate 1) and S-(2-phenyl-2-hydroxyethyl)glutathione (conjugate 2) (ratio 6.1:1), and S-(-)-phenyloxirane to conjugates 1 and 2 (ratio 1:32). Racemic phenyloxirane was converted to conjugates 1 and 2 (ratio 1.8:1). The conjugates were separated by HPLC on an octadecylsilicone column and identified with synthetic specimens whose structures were assigned by 13C NMR spectrometry. R-(+)-, S-(-)- and racemic phenyloxiranes were hydrolyzed to R-(-)-, S-(+)- and racemic phenylethanediols by microsomal epoxide hydrolase without inversion of absolute configurations of their benzylic carbons. R-(+)-Phenyloxirane had much smaller Km and Vmax than the S-(-)-oxirane did. The R-(+)-oxirane potentially inhibited the microsomal hydrolysis of the S-(-)-oxirane and was preferentially hydrolyzed when the racemic oxirane was used as the substrate. Microsomal monooxygenase oxidized styrene to R-(+)- and S-(-)-phenyloxiranes (ratio 1.3:1), and the ratio was little changed by the pretreatment of the animal with phenobarbital, 3-methylcholanthrene and polychlorinated biphenyls.