Five new compounds including two tetrahydrofuran-type lignans, beilschmin A and beilschmin B, a dihydrofuran-type lignan, beilschmin C, and two 1-phenylbutyl benzoates, tsangin A and tsangin B, together with thirteen known compounds have been isolated from the stem of Beilschmiedia tsangii. The structures of these new compounds were determined through spectral analyses. Among the isolates, beilschmin A (1), beilschmin B (2), beilschmin C (3), tsangin A (4), tsangin B (5), 2,6,11-trimethyldodeca-2,6,10-triene (14), alpha-tocopherylquinone (17), and alpha-tocospiro B (18) were cytotoxic (IC (50) values < 4 microg/mL) in P-388 and/or HT-29 cell lines in vitro.

Three new epoxyfuranoid lignans, 4alpha,5alpha-epoxybeilschmin A (1), 4alpha,5alpha-epoxybeilschmin B (2), and beilschmin D (3), together with nine known compounds have been isolated from the leaves of Beilschmiedia tsangii. The structures of these new compounds were determined through spectral analyses. Among the isolates, beilschmin A (4) and beilschmin B (5) exhibited potent antitubercular activities (MICs = 2.5 and 7.5 microg/mL, respectively) against Mycobacterium tuberculosis 90 - 221387 in vitro.