Antibacterial activity and QSAR of homoisoflavanones isolated from six Hyacinthaceae species

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 (R2 = 0.81, p < 0.003), depicting logP 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.