New antimicrobial and cytotoxic acylated triterpenoidal saponins from Gleditsia aquatica

Phytochemical investigation on the fruits of Gleditsia aquatica resulted in the isolation and identification of two new bisdesmosidic triterpenoidal saponins, aquaticasaponin A (1) and aquaticasaponin B (2) acylated with two and one monoterpenic acids, respectively, and one known cytokinin, aquaticine C (3). The structural elucidation of isolated metabolites was established on the basis of 1D, 2D NMR, and MS spectral analyses. The antimicrobial activity of the isolated compounds [1–3] was evaluated. Compound 1 exhibited the highest degree of activity against Syncephalastrum racemosum with an MIC value of 9.2 μM, whereas compound 2 exhibited the highest degree of activity against Escherichia coli with an MIC value of 67.3 μM. The isolated compounds also exhibited good cytotoxic activity against human breast cancer (MCF-7) and human colon cancer (HCT-116) cell lines with values of IC50 from 0.5 to 1.0 μM. Compound 1 was found to be the most active against colon cancer HCT-116 cell line with IC50 value of 0.5 μM.