Studies on the biosynthesis of corrinoids and porphyrinoids. I. The labeling of oxygen of vitamin B12.
- 1 January 1989
- journal article
- research article
- Published by Pharmaceutical Society of Japan in CHEMICAL & PHARMACEUTICAL BULLETIN
- Vol. 37 (5) , 1151-1154
- https://doi.org/10.1248/cpb.37.1151
Abstract
Recently the amide-oxygen has been suggested to participate in the formation of the corrin ring of vitamin B12. To confirm this hypothesis, 17O-labeled aminolevulinic acid (ALA) was prepared and administered to Propionibacterium shermanii. The isolated vitamin B12 showed only broad 17O signals in the oxygen-17 nuclear magnetic resonance (17O-NMR) spectrum. However, distinct isotope-shifted peaks were observed in the 13C-NMR spectrum of vitamin B12 isolated after incorporation of [1-13C:1,4-18O2]-ALA. Of these shifted peaks, one peak (C27) showed every very low intensity. This indicates that dilution of 18O occurred at the acetyl chain of the A ring of vitamin B12. This result supports the assumption that the lactone formation of the A ring promotes the ring contraction, as proposed by Eschenmoser.This publication has 2 references indexed in Scilit:
- Biosynthesis of vitamin B12: concerning the origin of the methine protons of the corrin nucleus.Proceedings of the National Academy of Sciences, 1987
- Carbon-13 nuclear magnetic resonance studies of cyanocobalamin and several of its analogsBiochemistry, 1982