抄録
In order to obtain further informations on the mechanism of the decomposition of the cobalt-carbon bond of acetylcobalamin by nucleophilic agents, the reaction was carried out using an appropriate apparatus under either aerobic or anaerobic conditions.
By time-course study of the spectral changes, direct spectrophotometric evidence was presented for the formation of vitamin B12S as the initial intermediate in these reactions. Formation of acetic acid was also detected in the case of alkaline cyanidedecomposition. These facts indicate that the cleavage of the cobalt-carbon bond of acetylcobalamin by alkaline cyanide is caused by OH- ion generated from the hydrolysis of the cyanide in a similar way as in the case of β-cyanoethylcobalamin. Discussions on the mechanism of the conversion of vitamin B12S into dicyanocobalamin were described.
