一种新型辅酶B12类似物——3'-脱氧-2',3'-脱水胸苷钴胺素的合成、光谱表征、轴向碱基配位平衡及光解动力学研究

Synthesis, spectroscopic characterization, axial base coordination equilibrium and photolytic kinetics studies of a new coenzyme B12 analogue-3'-deoxy-2',3'-anhydrothymidylcobalamin.

作者信息

Zhang Xin, Shen Xujie, Yan Hong, Chen Huilan

机构信息

Stake Key laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China.

出版信息

Dalton Trans. 2007 Jun 14(22):2336-42. doi: 10.1039/b701845b. Epub 2007 Mar 30.

DOI:10.1039/b701845b

PMID:17534495

Abstract

A new coenzyme B12 (AdoCbl) analogue, 3'-deoxy-2',3'-didehydrothymidylcobalamin (2',3'-anThyCbl) was prepared by the reaction of 5'-iodo-3'-deoxy-2',3'-dihydrothmidine with reduced B12a, and characterized by UV-Vis, CD, ESI-MS and NMR spectroscopies. Its axial base (dbzm) coordination equilibria with pH's and temperatures were investigated and showed similar features to those of coenzyme B12. Photolytic dynamics studies under homolytic and heterolytic conditions demonstrated that the Co-C bond of the analogue is slightly more photolabile relative to coenzyme B12.

摘要

一种新的辅酶B12（腺苷钴胺素，AdoCbl）类似物，3'-脱氧-2',3'-二脱氢胸苷钴胺素（2',3'-anThyCbl），通过5'-碘-3'-脱氧-2',3'-二氢胸苷与还原型B12a反应制备而成，并通过紫外可见光谱、圆二色光谱、电喷雾电离质谱和核磁共振光谱进行了表征。研究了其轴向碱基（二苯并咪唑，dbzm）在不同pH值和温度下的配位平衡，结果显示其与辅酶B12具有相似的特征。在均裂和异裂条件下的光解动力学研究表明，该类似物的Co-C键相对于辅酶B12在光解方面略显不稳定。