Vitamin B₁₂. XIII. Additional Data on Vitamin B_12a

Abstract

Additional Data on Vitamin B]2a 335 with hydrobromic acid. The hydrogenation of apo-and isoapo-5-erythroidine yielded the same compound, octahydro-apo-/3-erythroidine. Oxidation of apo-/3-erythroidine gave formic acid.Interpretation of these reactions and degradation products of ß-erythroidine allows one to formulate tentative structures for these products. Rahway, N. J.

The Chemistry of the Vitamin B12 Group.

“…This has a spectrum (Table V) with no strong -band, and may, therefore, have suffered reduction in the conjugated system. Aerial oxidation, which appears to be complex (116), furnishes aquocobalamin (198). That vitamin Bi2r contains divalent cobalt is suggested by titrimetric and polarographic evidence (108,188).…”

Chemical Studies on Vitamin B12 and Its Related Compounds

“…(OH-B12) was isolated by Pierce et al (l) in a crystalline form from the culture of Streptoinyces aureofaciens and was designated as vitamin B12b, which was soon ascertained to be the same as B12a obtainable by catalytic reduction of cyanocobalamin (CN-B12) using platinum as a catalyst (3,4). It was also found that OH-B12 was formed by irradiation of CN-B12 in an acidic solution and that it was converted to CN-B12 by treatment with cyanide in a neutral medium (5).…”

Fermentation

“…Several reviews of the early chemical developments have been published (206,371,396). A number of papers have discussed the relationships of vitamin Bis to Bi2", Bm, and (107,116,207,208,369,370,480) and it appears that vitamins Bi2a, Bi2¡), and Bim are identical. Some actinomycetes and bacteria produce a form of vitamin Bi2 (perhaps the hj'droxo form) capable of forming stable cyanide and dicyanide complexes.…”