8-Epi-cyanocobalamin (Crude)

8-Epi-cyanocobalamin (Crude) is a stereoisomeric variant of cyanocobalamin, featuring an inverted hydroxyl configuration at the C8 position of the corrin macrocycle. This structural modification alters the spatial orientation of the adjacent methyl group while retaining the cyanide-ligated cobalt center and the 5,6-dimethylbenzimidazole nucleotide. The compound arises via epimerization under specific synthetic or degradation conditions, distinguishing itself from the parent vitamin B12 derivative. It serves as a critical reference standard for detecting epimeric impurities in cyanocobalamin formulations via chiral HPLC analysis.