Bligha sapida (family Sapindaceae) is a plant widely used in ethnomedicine for the treatment of dysentery, dental decay and whitlow. Qualitative and quantitative analysis of the 50% ethanol extract of the plant (B) revealed a rich presence of saponins. Extraction and acid hydrolysis of the crude saponins (Bs) yielded crude sapogenins (Bss) which was fractionated using various chromatographic techniques to afford five pentacyclic triterpenes (coded Bss1- Bss5) whose structures were elucidated using physical, chemical and spectroscopic data in comparison with literature data. B, Bs, Bss and Bss1- Bss5 were evaluated for their antibacterial potentials against three Gram-positive and three Gram-negative bacterial strains in comparison with Erythromycin using the agar dilution method. The isolated compounds were characterized as friedelin (Bss1), friedelinol (Bss2), β-amyrin (Bss3), oleanolic acid (Bss4) and hederagenin (Bss5) respectively. The crude extract, B, crude sapogenins, Bss and isolated compounds (Bss1 - Bss4) were moderately active against all test strains, while, the crude saponins, Bs was only active against Gram-positive strains, all at different concentrations in comparison with Erythromycin. The results of these findings justify the strong presence of pentacyclic triterpenes in the seed pods of Bligha sapida, as well as their contributions to the antibacterial efficacy of the plant.
