Solution conformation of virginiamycins (staphylomycins).

The 1H (at 300 MHz) and 13C nuclear magnetic resonance spectra of virginiamycins S and S4 and vernamycin Balpha have been unravelled and analyzed. Together with model building and theoretical considerations, this allows the detailed description of their solution conformations. The depside bond can rotate and gives to the backbone some conformational mobility. The orientation of the depsicarbonyl bond depends on the surrounding. Apparent discrepancies between the different methods that are applicable for the disclosure of the nature of peptide H-bonding, have found a rational explanation.