TWO NEW CLERODANE DITERPENOIDS FROM CROTON CRASSIFOLIUS

摘要

The root of Croton crassifolius was evaluated for its anti-angiogenic properties and anti-angiogenic components. The ethanol extract of the herb and its successive four subtractions were investigated in zebrafish model by quantitative endogenous alkaline phosphatase assay. Both petroleum ether (PE) and ethyl acetate fractions (EtOAc) showed potent anti-angiogenic activities. Two new clerodane diterpenoids, crassifolin I (1) and crassifolin H (2) were isolated from EtOAc fraction. Their structures were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, ID and 2D NMR), and compound 1 was confirmed by single-crystal X-ray diffraction analysis. The further activities study showed that crassifolin H possessed anti-angiogenic activity by reducing vessel formation to 59.3% of the control value at concentrations of 15 μg/mL.