13c nmr spectroscopy has been used to locate six deuterium atoms incorporated biosynthetically on the periphery of the corrin nucleus of vitamin b12 ( cyanocobalamin ) derived from cells of propionibacterium shermanii grown in a medium containing 50 % 2h2o and 13c-enriched delta-aminolevulinic acid .
C0007610
nucleus
C0007634
cells