Cytotoxic dihydrobenzofuran neolignans from Mappianthus iodoies.

Three new dihydrobenzofuran neolignans, mappiodoinins A-C (1-3), together with nine known analogues (4 -12) were isolated from the stems and leaves of Mappianthus iodoies. Their structures with the absolute configurations were elucidated by extensive spectroscopic methods. This is the first time to find dihydrobenzofuran neolignans from the genus Mappianthus. All isolated compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW-480 in vitro. Neolignans 1-12 showed significant cytotoxic effects against various human cancer cell lines with IC50 values ranging from 0.16 to 18.62 μM.