Thesis (M.Sc. in Pharm.)--Chulalongkorn University, 2006

The chemical study of the fruits of Trichosanthes cucumerina L. (Buap khom) led to the isolation of a triterpenoid saponin. The structure determination of this compound was accomplished by spectroscopic analyses (UV, IR, MS and NMR) and by comparison with previously reported data of the known compound cucurbitacin B, C[subscript 32]H[subscript 46]O[subscript 8], 25-acetoxy-2B, 16a,20B-trihydroxy-9B-methyl-19-nor-10a-lanosta-5,23-diene-3,11,12-trione. Cucurbitacin B showed molluscicidal activity against Pomacea canaliculata Lamarck (2.0-2.5 cm, in diameter) with LC[subscript 50] value of 9.02 ppm and LC[subscript 90] value of 17.67 ppm after 24 h at 95% confidence interval. Assays by MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric method with 5 cancer cell lines including human colon adenocarcinoma (SW620), human liver hepatoblastoma (HEP-G2), human gastric carcinoma (KATO-III), human breast ductal carcinoma (BT474) and human undifferentiated lung carcinoma (CHAGO) revealed that cucurbitacin B has strong cytotoxic activity against human colon adenocarcinoma (SW620) and human liver carcinoma (HEP-G2) with IC[subscript 50] values of 0.06 and 0.09 ug/mL, respectively. It appears that T. cucumerina L. (Buap khom) has potential to be used as a molluscicide substitute for toxic chemicals.