GB766749A - Benzimidazole cobalamines and process for their preparation and separation - Google Patents

Abstract

The invention comprises benzimidazole cobalamines (i.e complete cobalamines in which the nucleotide component is constituted by benzimidazole or substituted benzimidazoles and which are characterized by certain specified properties), other than Vitamin B12 (5 : 6-dimethylbenzimidazole cobalamine), and the biosynthetic production of benzimidazole cobalamines (including Vitamin B12) by the action of E. coli strains on an aqueous nutrient medium (e.g. a modified Davis-medium) containing phosphates and if necessary carbohydrates (e.g. d-ribose) together with etiocobalamine and an unsubstituted or substituted benzimidazole or an unsubstituted or substituted o-phenylenediamine, followed if desired by isolation of the product by known selective extraction, adsorption and chromatographic techniques (several of which are described and exemplified). The biosynthesis may be effected by (a) growing the micro-organisms (e.g. E. coli mutant 113-3 or a wild strain of E. coli) in the medium above defined; or (b) first growing the micro-organisms in a known nutrient and thereafter causing them to act on the etiocobalamine and benzimidazole or derivative thereof. The process may be carried out continuously, and the etiocobalamine (or crude solution containing it) and/or the benzimidazole or derivative may be added in alcoholic solution (thereby making sterilization unnecessary). In examples, in which (1)-(4) employ method (a) and the rest method (b), the following benzimidazoles and o-phenylenediamines are employed; (1), (2) and (6) 5 : 6-dimethylbenzimidazole; (3) benzimidazole; (4) and (5) 5-methylbenzimidazole; (7) 4 : 6-dimethylbenzimidazole; (8) and (12) 5 : 6-diethylbenzimidazole; (9) 5-chloro-6-methylbenzimidazole; (10) and (13) benzimidazole-5-carboxamide; (11) and (14) 1 : 2-diamino-4 : 5-dimethylbenzene; (15) 5 : 6-dichlorobenzimidazole; (16) 2-hydroxymethylbenzimidazole or benzimidazole-2-carboxylic acid or its amide; (17) the 5-methyl derivatives of the compounds used in (16); (18) the 5 : 6-dimethyl derivatives of the compounds used in (16); (19) 5-methylbenzimidazole-2 : 6-dicarboxylic acid amide; (20) 1 : 2-diamino-3 : 4-dimethylbenzene.