Two new stilbene trimers from Cynodon dactylon

Many naturally occurring oligostilbenes have drawn considerable attention because of their intricate structures and diverse bioactivities. Two new stilbene trimers, cystibenetrimerol A (1) and cystibenetrimerol B (2) were isolated from the dried grass of Cynodon dactylon (L.) Pers. The planar structures and stereo configurations of them were elucidated by spectroscopic and spectrometric methods. The isolation and structures elucidation of two new stilbene trimers suggested the ordinary grass belonging to the family Poaceae may be a rich source of stilbene oligomers.