Acid induced decomposition of coenzyme B12 and variants

✍ Scribed by L. E. H. Gerards; S. Balt

• Book ID: 104589447
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 181 KB
• Volume: 111
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19921110906

✦ Synopsis

Abstract

The acid catalyzed heterolytic cleavage of the CoC bond in coenzyme B~12~ (1) was studied using the ‘excess acidity’ functions of Cox and Yates. The results are compared to the acid induced decomposition of (methyl‐5‐deoxy‐ribofuranosyl)‐(2) and (2‐ethoxyethyl)cobalamin (3). Evidence is presented to view the CoC bond cleavage in the compounds (1) and (2) as an A~2~ mechanism with water as the nucleophile or as an I~a~ substitution at Co^3+^, and in (3) as an A~1~ mechanism. Volumes of activation are consistent with the proposed mechanism.