Dihydrobenzofuran Norlignans from the Leaves of Cedrela sinensis A. Juss

Two new norlignans, cedralins A (1) and B (2), were isolated from the leaves of Cedrela sinensis. Their structures were established by extensive spectroscopic studies and chemical evidence. The absolute configurations of these compounds were determined by comparing their CD spectra with those of known compounds. In addition, their in vitro cytotoxic activity against two human-cancer cell lines was evaluated.