CONFORMATIONAL-ANALYSIS OF ASPERLIN BY NMR-SPECTROSCOPY AND MOLECULARMODELING

NOESY experiments and computerised molecular modeling have been employ ed to examine the configuration and conformation of the epoxypropyl si de chain of asperlin in benzene solution. The data support the conclus ion that the oxirane ring in this molecule has the 6S,7R configuration . Moreover, the (3)J(H-5,H-6) coupling constant about the C-5-C-6 bond has been calculated using an equation suitable for the H-5-C-5-C-6-H- 6 segment. This value does not support a single conformation, but rath er conformational averaging that provides good agreement between the t heoretical and experimental parameters. (C) 1996 Elsevier Science Ltd.