Lignans from Bark of Larix olgensis var. koreana

Six new lignans (2-7) were isolated from the bark of Larix olgensis var. koreana, and their structures were determined on the basis of their spectroscopic data. Seven known lignans were also obtained and identified as (+)-lariciresinol 9'-p-coumarate (1), (+)-lariciresinol, (-)-secoisolariciresinol, (+)-isolariciresinol, vladinol D, sesquipinsapol B, and ehletianol C. Compound 1 showed weak inhibition against K562, SHG44, HCT-8, A549, and PC-3M tumor cells with IC50 values of 2.9, 21.4, 32.9, 33.8, and 28.0 mu g/mL, respectively.