Chen, Ching-YuChing-YuChenCheng, Yuan-BinYuan-BinChengChen, Shun-YingShun-YingChenChien, Ching-TeChing-TeChienKuo, Yao-HaurYao-HaurKuoGuh, Jih-HwaJih-HwaGuhKhalil, Ashraf TahaAshraf TahaKhalilShen, Ya-ChingYa-ChingShen2009-11-182018-07-132009-11-182018-07-132008http://ntur.lib.ntu.edu.tw//handle/246246/173126Bioassay-guided fractionation of the acetone extract of the roots of Casearia membranacea furnished three new clerodane diterpenes, caseamembrins S-U (1-3) and the known caseamembrin Q (4). Their structures were established by extensive spectroscopic analyses, especially 2D-NMR. Compounds 1-4 were tested against human tumor cells, including HeLa ( cervical epitheloid carcinoma), DLD-1 (colon carcinoma), Daoy ( medulloblastoma), and KB (oral epidermoid carcinoma) cell lines. Caseamembrin T (2) exhibited the most potent activity against Daoy cells ( ED50 = 10 ng/ml), superior to that of the standard drug mitomycin.application/pdf177131 bytesapplication/pdfen-UShttp://ntur.lib.ntu.edu.tw/bitstream/246246/173126/1/145.pdf