Total assignment of 1H and 13C NMR spectra of a prenylated oxanthrone from Vismia latifolia.

Abstract

New prenylated oxanthrones, vismianol A and vismianol B [(1,3,8,10-tetrahydroxy-6-methyl-4,5-bis(3- methylbut-2-enyl)anthracen-9(10H)-one) (3a and 3c)] were isolated from the roots of Vismia latifolia (Clusiaceae) as a mixture of two enantiomers, in addition to two other known anthraquinones (chrisophanol and physcion). The structures were established by 2D NMR spectroscopic techniques (HMQC, HMBC and NOESY).