Cytotoxic phenolic glycosides from <Emphasis Type="Italic">Boschniakia himalaica</Emphasis>

A new lignan glycoside, 9-acetyl lanicepside B (1), was isolated from the whole plant of Boschniakia himalaica, along with five known compounds, lanicepside A (2), plantainoside D (3), plantamajoside (4), (–)-woonenoside XI (5), and syringin (6). The new compound's structure was established on the basis of detailed 1D and 2D NMR spectroscopic analysis and chemical evidence. 9-Acetyl lanicepside B (1) showed weak in vitro cytotoxic activities against A549 and P388 with IC₅₀ values of 64.7 μM and 72.5 μM, respectively. Syringin (6) showed moderate in vitro cytotoxic activities against A549 and HL-60 with IC₅₀ values of 32.5 μM and 41.8 μM, respectively.