Triterpenoid saponins from the fruit pulp of Tetrapleura tetraptera (Fabaceae).

Tetrapleura tetraptera fruit, used as spice in West Africa was studied chemically; five previously undescribed triterpenoid saponins 1-5 and four known compounds 6-9 were isolated from the n-Butanol fraction. The chemical structures of all nine isolates were determined by comprehensive analysis of HRMS, 1D & 2D NMR experiments and by comparison with data in the literature. All nine compounds were evaluated for antibacterial activity by the broth microdilution through the rapid p-iodonitrotetrazolium chloride (INT) colorimetric technique. The results showed that only compounds 5 (MIC = 64 µg/mL against P. aeruginosa and P. stuartii) and 8 (MIC = 64 µg/mL against E. coli) exhibited moderate antibacterial activity. The rest of the compounds displayed weak antibacterial activity against the tested organisms. Molecular docking studies was used to comprehend antibacterial activities.