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 to 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).