Chemical constituents and biological activity from the stem barks of Croton oblongifolius Roxb. from Amphoe Muang, Udon Thani province

Abstract

Two new labdane diterpenoid compounds, labda-7,13(Z)-diene-17,12-olide and labda-7,13(Z)-diene-17,12-olide-15-ol, one new clerodane diterpenoid compound, (-)-20-benzyloxyhardwickiic acid, and hardwickiic acid, which was the main product of the crude hexane, were isolated from the stem barks of Croton oblongifolius Roxb., which were collected from Amphur Muang, Udonthani Province. The structures of the new compounds were established by spectroscopic data including IR, MS spectra, X-ray diffraction, 1D and 2D NMR techniques (DEPT, COSY, NOESY, HMBC and HMQC) and chemical transformation. All of the compounds, both natural and synthetic, were subjected to biological activity test against a panel of six cell lines including HS 27 (fibroblast), KATO (gastric), BT 474 (breast), CHAGO (lung), SW 620 (colon) and HEP-G2 (hepatoma). Labda-7,13(Z)-diene-17,12-olide-15-o1 exhibited cytotoxic activity against the HEP-G2 (hepatoma) cell, CHAGO (lung) cell, SW 620 (colon) cell and KATO (gastric) cell, in vitro, with IC50 values of 5,6.4, 6.5, and 7.1 ug/ml, respectively.