Oleanane-typesaponins from Lysimachia laxaBaudo and their antibacterial activities

Seven new oleanane-typetriterpene saponins, lysimaponins A-G, were isolated from aerial parts of Lysimachia laxaBaudo. Their chemical structures have been elucidated by analysis of spectroscopic and chemical methods. All compounds were evaluated for their antibacterial effects against Microcystis aeruginosa, Vibrio parahaemolyticus, V. harveyi, V. vulinificus, V. cholerae, and V. alginolyticus. All compounds showed potent antibacterial activities against the cyanobacteria M. aeruginosawith IC50values ranging from 14.4 ± 1.2 to 35.3 ± 2.2 µg/mL. Compounds 1, 2, 4-7inhibited V. parahaemolyticuswith MIC values ranging from 64 to 256 µg/mL. The results suggested that saponins from L. laxacould be potential anti-cyanobacteria agents.Graphical AbstractAntibacterial oleanane-typesaponins from Lysimachia laxa