title: Phenolic and antibacterial constituents of Vahlia capensis.
abstract: The n-butanol fraction of Vahlia capensis yielded kaempferol, quercetin, afzelin, astragalin, quercitrin, isoquercitrin, rutin, gallic acid, chiro-inositol, dulcitol, and a novel biflavonoid, VC-15B (vahlia biflavone). The compounds were identified using 1D and 2D NMR techniques and FABMS. Vahlia biflavone and gallic acid were isolated, using bioassay-guided procedure and identified as the antibacterial components. Both compounds showed activity against Gram positive Staphylococcus aureus and Bacillus subtilis. Vahlia biflavone gave MIC values of 15.3 micrograms/ml and 30.6 micrograms/ml against S. aureus and B. subtilis, respectively while gallic acid gave a value of 71.3 micrograms/ml for both organisms.
authors.forename: R R
authors.initials: RR
authors.lastname: Majinda
authors.forename: M
authors.initials: M
authors.lastname: Motswaledi
authors.forename: R D
authors.initials: RD
authors.lastname: Waigh
authors.forename: P G
authors.initials: PG
authors.lastname: Waterman
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects*; D001902:Botswana; D002701:Chloramphenicol / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010946:Plants, Medicinal; D013211:Staphylococcus aureus / Q000187:drug effects*; D015030:Zimbabwe
chemical_list: D000900:Anti-Bacterial Agents; D005419:Flavonoids; D010636:Phenols; D002701:Chloramphenicol