Unusual Flavonoids, an Antifungal Heptenolide

This book reports on phytochemical investigations and antimicrobial assays of two plant species of the family Annonaceae, namely Uvaria species (Boza) and Monanthotaxis fornicata. Plant species from the genus Uvaria are widely used in indigenous therapies while a crude extract from M. fornicata is used as an antivenin as well as for the treatment of stomach ailments. The stem bark of the hitherto univestigated Uvaria species (Boza) yielded the C-benzyldihydrochalcones uvaretin, isouvaretin, their O-methylated derivatives 4'-O-methylisouvaretin and 4'-O-methyluvaretin, chamuvaritin, diuvaretin and angoluvarin, and benzoic acid, some of which occurred as inseparable mixtures. Establishment of the structures of the pure compounds was based on extensive analysis of spectroscopic data, viz 1H NMR, 13C NMR, MS, COSY, HMQC, and HMBC. All the compounds showed in vitro inhibitory effects whereby the activity of uvaretin against Staphylococcus aureus, Bacillus anthracis and Streptococcus faecalis were almost equal to the standard drugs (Ampicillin and Chloramphenicol) used as positive controls in these investigations.