The vitamin B12 group. Presence of 2-methyl purines in factors A and H and isolation of new factors

Abstract

By suitable fractionation procedures a number of red cobalt-containing substances other than vitamin B12 were isolated from pig and calf manure. These are factors A, B and C of Ford and Porter (1952) and -vitamin B12 of Dion, Calkins and Pfiffner (1952). Others are designated Factors D, E, F, G, H and I. Factor A of Ford and Porter (1952) differs from vitamin B12 only in having 2-methyladenine in place of 5:6-dimethylbenziminazole. On deamination, factor A is converted into a naturally occurring factor H, which yields 2-methylhypoxanthine on mild hydrolysis. Similarily, -vitamin B12 is deaminated to a naturally occurring hypoxanthine containing factor G. -Vitamin B12 and factors A, G and H resemble vitamin B12 in yielding one fundamental cobalt-containing substance, factor B, on removal of their nucleotides with warm concentrated HCL.