New eudesmane-type sesquiterpenoid from Solanum lyratum with cytotoxic activity

In our continuing effort to discover more new cytotoxic sesquiterpenoids from Solanum lyratum, one new eudesmane-type sesquiterpenoid (1, 3-keto-eudesm-9β,11-diol, named lyratol G), together with one known eudesmane-type sesquiterpenoid (2, 1β-hydroxy-1,2-dihydro-α-santonin), was obtained. The structure of the new sesquiterpenoid was elucidated on the basis of integrated spectroscopic techniques, mainly HR-FAB-MS, 1D and 2D NMR (1H–1H COSY, HMQC, HMBC and ROESY). In vitro, two sesquiterpenoids were found to exhibit significant cytotoxicity against three cancer cell lines (P-388, HONE-1 and HT-29), and gave IC50 values in the range of 3.1–6.9 μM.