Triterpene glycosides from the aerial parts of Gouania longipetala.

Six previously undescribed triterpenoid saponins, gouaniaside I-VI, were isolated from the aerial parts of Gouania longipetala Hemsl. (Rhamnaceae), in addition to four known triterpenes. The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D- and 2D-NMR and HR-ESI-MS techniques. The inhibitory activity of isolated compounds against promyelocytic leukemia HL60 and human erythromyeloblastoid leukemia K562 cell lines was evaluated and jujuboside I exhibited moderate cytotoxicity, with IC50 values of 13.5 and 21.0 μM, respectively. Among the isolated triterpenes, alphitolic acid exhibited moderate antibacterial activity against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli (MICs 32, 64 and 128 μg/mL, respectively).