Proof that the biosynthesis of vitamin B12 involves a reduction step in an anaerobic as well as an aerobic organism
Abstract
Labelling experiments with 2H and 3H prove that as cobyrinic acid is biosynthesised by the anaerobic bacterium Propionibacterium shermanii, its H–19 is derived from HR(and not HS) at C-4 of a reduced nicotinamide cofactor, so demonstrating that the biosynthetic pathway involves a reduction step.