F. Kiuchi, D. Thibaut, L. Debussche, F. J. Leeper, F. Blanche and A. R. Battersby
"Biosynthesis of Vitamin B12: Stereochemistry of Transfer of a Hydride Equivalent from NADPH by Precorrin-6x Reductase"
J. Chem. Soc., Chem. Commun.,1992, 306-308. Full Text
Deuterium labelling with NMR analysis demonstrates that the enzyme precorrin-6x reductase transfers HR from C-4 of the pyridine residue of NADPH as the first step in the sequence leading from precorrin-6x to hydrogenobyrinic acid.
Department of Chemistry
University of Cambridge