Mechanistic studies on pregnene side-chain cleavage enzyme (17α-hydroxylase-17,20-lyase) using18O

Abstract
In the conversion of pregnenolone 1 into dehydroisoandrosterone 3 and 3β-hydroxyandrosta-5,16-diene 5 an atom of oxygen from O2 is incorporated into the side chain released as acetate; during the conversions the C-21 methyl hydrogens of the precursor are not disturbed, the status of 16α and 17α hydrogen atoms during the conversions is also defined.