1H and 13C resonance designation of antimycin A1 by two-dimensional NMR spectroscopy

Abstract

Complete 1 H and 13 C resonance assignments of antimycin A 1 were accomplished by two-dimensional NMR techniques, viz. 1 H homonuclear COSY correlation, heteronuclear 13 C- 1 H chemical shift correlation and long-range heteronuclear 13 C- 1 H COLOC correlation. Antimycin A 1 was found to consist of two isomeric components in a 2:1 ratio based on NMR spectroscopic evidence. The structure of the major component was newly assigned as the 8-isopentanoic acid ester. The spectra of the minor component were consistent with the known structure of antimycin A 1 .