Effect of Certain Cobalamin Acids and Their Derivatives on Embryonic Development and Growth in the Chick

Mono-, di- and tricarboxylic acids of cyanocobalamin (CCB) prepared by hydrolysis of the propionamide side chains were isolated by ion exchange chromatography, purified and identified. When a mixture of the monocarboxylic acid isomers (MCA) was injected into eggs containing 7-day-old embryos from cobalamin-deficient hens, embryonic survival and hatchability increased although the vitamin potency of mixed MCA for hatchability was 1/16 that of CCB. Two MCA isomers showed vitamin activity while a third isomer was inactive. Early growth of chicks fed a cobalamin-deficient diet was improved by CCB treatment of the egg, while mixed MCA failed to improve growth when given in similar amounts. The dicarboxylic acids (Di CA) had little vitamin activity and the tricarboxylic acid (Tri CA) had no vitamin activity. The methylamide of MCA had slight vitamin activity and the anilide of MCA had no activity. The MCA mixture and two of the MCA isomers used in these studies were assayed with an E. coli mutant and were found to be inhibitory.