抄録
A green substance whose visible absorption spectrum was similar to that of vitamin B_<12s> was obtained by heating cyanocobalamin in 30% NaOH at 120℃ for 1 hour, and when oxidized by air it turned via brown to red and yielded 8-aminocobyrinic acid-c-lactam as a main product. The latter compound also turned green by the same alkali treatment. The green substance reacted with methyl iodide to give mainly Co-methyl-8-aminocobyrinic acid-c-lactam, which was identified by paper chromatography, paper electrophoresis, ultraviolet, visible and infrared absorption spectra. Thus, it was shown that the cobalt atom in a corrinoid compound was reduced to the same state as in vitamin B_<12s> by a vigorous alkali-treatment, and a reduction mechanism of cobalt atom by the action of hydroxyl ion was discussed.
