Cytotoxic Effects of Oleanane-type Saponins from Lysimachia laxa

Phytochemical investigation of the methanol extract of the aerial parts of Lysimachia laxa led to the isolation of four new oleanane-type saponins, lysimosides A-D (1-4) and one known compound, lysimachigenoside B (5). Their structures were elucidated using a combination of HR-ESI-MS, 1D and 2D-NMR spectral data, chemical methods, and comparison with previous literature. The cytotoxic activity of these compounds was evaluated against human lung cancer (A-549) and human breast cancer (MCF-7) cell lines. All compounds exhibited cytotoxic activity against A-549 and MCF-7 cell lines with IC₅₀ values ranging from 6.1-16.0 μM, comparable to the positive control, mitoxantrone. Interestingly, oleanane-type saponins with an acetyl group (2-4) exhibited increased cytotoxic activities compared to those without an acetyl group (1).