ENANTIOTOPIC SELECTIVITY IN MONODEMETHYLATION OF FENITROTHION BY RAT-LIVER GLUTATHIONE-S-TRANSFERASE ISOENZYMES AND MOUSE-LIVER CYTOSOL

Monodemethylation of fenitrothion catalyzed by any of five purified gl utathione S-transferases from rat liver predominantly produced the (S) (P)-(-)-enantiomer of desmethyl fenitrothion. Mouse liver cytosolic fr action demethylated fenitrothion in the presence of glutathione to pro duce predominantly the (R)(P)-(+)-isomer. The absolute configuration o f the (+)-desmethyl fenitrothion was determined as (R)(P) by X-ray cry stallography of its brucine salt.