Isolation and properties of crystalline cobamide coenzymes containing benzimidazole or 5, 6-dimethylbenzimidazole.

The isolation of three cobamide coenzymes has been briefly reported (1, 2). Methods used in the assay and purificat.ion of the adenylcobamide coenzyme have been described in some detail (3). This paper describes methods used in the isolation of the benzimidazolylcobamide and 5,6-dimethylbenzimidazolylcobamide coenzymes, both of which have been obtained as crystalline products. Some properties of the coenzymes are also reported.