Cytotoxic terpenoids from the fruits of Vitex trifolia L.

Two new labdane-type diterpenoids vitetrifolin H (1) and vitetrifolin I (2), and one new monoterpenoid vitexoid (3), were isolated from the fruits of Vitex trifolia L., together with seven known diterpenoids. Structures of all compounds were elucidated by extensive spectroscopic methods. All these compounds exhibited inhibition of Hela cell proliferation, with IC50 values in the range of 4-28 microM. In addition, vitetrifolin I (2) induced cell cycle G0/G1 phase arrest and apoptosis of Hela cells.