OBJECTIVETo investigate the constituents of the Annona squamosa and evaluate their anti-tumor activity.

METHODThe compounds were isolated and purified by various column chromatography. Their structures were elucidated by spectral data analysis. Their anti-tumor activity was assayed by SRB method.

RESULTEleven compounds were obtained from the 95% EtOH extract. The structures were determined as: annosquamosin C(1),15, 16-epoxy-17-hydroxy-ent-kau-ran-19-oic acid (2),16,17-dihydroxy-ent-kau-ran-19-oic acid(3), annosquamosin A(4), ent-kaur-16-en-19-oic acid (5), 19-nor-ent-kauran4-ol-17-oic acid (6),16-hydroxy ent-kau ran-19-oic acid (7), ent-15beta-hydroxy-kaur-16-en-19-oic acid (8), annosquamosin B (9), ent-16beta, 17-dihydroxykauran-19-al (10), 16, 17-dihydroxy-ent-kauran-19-oic acid me thyl ester (11). Compounds 1,2,3,5,9 showed different inhibitory activities against 95-D lung cancer cells,the effect of compound 5 was strongest with the IC50 value 7.78 micromol x L(-1); Compounds 2, 5, 9 showed inhibitory activities against A2780 ovarian cancer cells, the effects of compounds 2 and 9 were strong with the IC50 values being 0.89, 3.10 micromol x L(-1), respectively.

CONCLUSIONCompound 2 was firstly isolated from this family, while compound 8 and 10 were first found from this genus and the title species, respectively. The in vitro anti-tumor test showed compound 5 significantly inhibited 95-D lung cancer cells and compounds 2 and 9 exhibited remarkbale activity against A2780 ovarian cancer cells.