Novel cytotoxic 1H-cyclopenta[b]benzofuran lignans from Aglaia elliptica

Bioassay-guided fractionation of the stems and fruits of Aglaia elliptica using human oral epidermoid carcinoma (KB) cells, led to the isolation of five cyclopenta[b]benzofurans, constituted by methyl rocaglate (1) and four novel compounds (2-5), along with three known dammarane triterpenoids. Compound 5 possesses an unusual formyl ester substituent at the C-l position. The structures of the novel compounds were established on the basis of spectroscopic methods. Compounds 1-5 were found to be very potent cytotoxic substances when evaluated against a panel of human cancer cell lines. (C) 1997 Elsevier Science Ltd.