α-(5,6-Dimethylbenzimidazolyl)hydrogenobamide and Its Copper and Zinc Analogues

Chromatium (ATCC 17899), when grown in the presence of 5,6-dimethylbenzimidazole, produces α-(5,6-dimethylbenzimidazolyl)hydrogenobamide as the principal descobaltocorrinoid rather then phenylhydrogenobamide. Insertion of cobalt under neutral conditions converts it into hydroxocobalamin. Methods for the preparation of the corresponding copper and zinc analogues are described. The hydrogeno, copper, and zinc analogues are characterized by their spectral and electrophoretic properties. All three analogues are active as antimetabolites to vitamin B 12 in suppressing the growth of Lactobacillus leichmanii (ATCC 7830).