Antibacterial activity and QSAR of homoisoflavanones isolated from six Hyacinthaceae species

Abstract Antibacterial activity, as detected in the bioautographic and microplate assays against Staphylococcus aureus , was shown for thirteen homoisoflavanones isolated from six Hyacinthaceae species. Four of these homoisoflavanones were isolated from Eucomis comosa , one from Eucomis schijffii , one from Albuca fastigiata , one from Drimia delagoensis , five from Drimiopsis maculata and one from Drimiopsis burkei . Extracts from most of these plants are employed as traditional medicines in South Africa. Biological screening was followed by a computer-based quantitative structure–activity relationship (QSAR) study. Stepwise multiple linear regression analysis of the data yielded a statistically significant two-component model ( R 2  = 0.81, p P and electron potential at O-1 as effective descriptors of antimicrobial activity against S. aureus . The derived model provides valuable parameter guidelines for those properties influencing the antibacterial activity of these homoisoflavanones.