A new lignan glycoside from Trigonostemon heterophyllus.

Phytochemical investigation on the stems of Trigonostemonheterophyllus led to the isolation of a new lariciresinol-based lignan glycoside, trigonoheteran (1), together with a known lignan glycoside, aviculin (2). Their structures were elucidated by spectroscopic methods including 1D and 2D NMR (HMQC, H-1-H-1 COSY, HMBC, and NOESY).