A new hexenol glycoside from leaves of Smallanthus sonchifolius.

A new hexenol glycoside with two known compounds was isolated from the leaves of Smallanthus sonchifolius. The structure of the new compound was elucidated as Z-hex-3-en-1-ol O-alpha-L-arabinopyransyl (1''-2')-beta-D-glucopyranoside (1) on the basis of spectroscopic analysis and chemical evidence. The two known compounds were identified as ent-15β-hydroxy-kaur-16-en-19-oic acid (2) and ent-18-hydroxy-kaur-16-en-19-oic acid (3) by comparison of their spectral data with the reported data. Compounds 2 and 3 were isolated for the first time from the title plant.