Stereochemistry of .DELTA.1,4 unsaturation in microbial transformation of cholesterol.

Abstract

The stereochemistry of H loss from C-2 and C-4 in cholesterol during microbial degradation into androstra-1,4-diene-3,17-dione was studied. Each of the substrates, epimeric 2- and 4-deuteriocholesterols was incubated with respiring cultures of Arthrobacter simplex. Determination of the labeled isotope retained in the biotransformation products revealed that metabolic transformation of cholesterol into .DELTA.1,4-3-ketosteroid proceeds by a stereospecific removal of 4.beta.- and 2.beta.-H''s.