Ford S H, Nichols A, Shambee M
Department of Chemistry and Physics, Chicago State University, Illinois 60628.
J Inorg Biochem. 1991 Mar;41(4):235-44. doi: 10.1016/0162-0134(91)80015-a.
The preparation of the diaquo- forms of the incomplete corrinoids, cobyric acid, cobinamide, and three isomeric cobinic acid pentaamides, from the corresponding aquocyanocorrinoids has been accomplished. The compounds were characterized by electronic absorption spectra, pka values, and HPLC/TLC behavior. Upon titration, the acids exhibited three pKa values, but only the pKa corresponding to the carboxylic acid involved the transfer of a full equivalent of protons. In addition, the progress of diaquo- to dihydroxo-titration, and the spectrum of the final products indicated a complex process. These diaquocorrinoids appear to be unstable, and should be stored in solution, frozen, under an inert atmosphere.
已完成从不完全类咕啉的相应水合氰基咕啉制备二水合形式的钴胺酸、辅酶酰胺以及三种异构的钴胺酸五酰胺。这些化合物通过电子吸收光谱、pKa值以及HPLC/TLC行为进行表征。滴定过程中，这些酸呈现出三个pKa值，但只有对应羧酸的pKa涉及一整当量质子的转移。此外，二水合到二羟基滴定的过程以及最终产物的光谱表明这是一个复杂的过程。这些二水合类咕啉似乎不稳定，应在惰性气氛下冷冻保存在溶液中。
