Four new ursane-type triterpenoid saponins, clinopoursaponins A-D (1-4), six new oleanane-type triterpenoid saponins, clinopodiside VII-XII (5-10), as well as eight known triterpene analogues (11-18), were isolated from the aerial parts of Clinopodium chinense (Benth.) O. Kuntze. The structures of the new compounds were determined based on extensive spectral analyses, including 1D (1H and 13C) and 2D NMR experiments (COSY, NOESY, HSQC, 2D TOCSY, HSQC-TOCSY and HMBC), HR-ESI-MS and chemical methods. Compounds 1-18 were evaluated for their protective effects against anoxia/reoxygenation-induced apoptosis in H9c2 cells and cytotoxicities against murine mammary carcinoma cell line 4T1. Compounds 8, 9 and 18 exhibited significant protective effects, while compound 1 exhibited cytotoxic activity with IC50 value of 7.4 μm compared to 7.6 μm for the positive control 10-hydroxycamptothecin.
Keywords: Clinopodium chinense; Cytotoxic activity; Lamiaceae; Ursane-type triterpenoid saponins.