A new antiplatelet diarylheptanoid from Alpinia blepharocalyx.

A new diarylheptanoid, 1,7-bis(4-hydroxyphenyl)-3-hydroxy-1,3-heptadien-5-one (1), along with seven other known compounds, were isolated from the seeds of Alpinia blepharocalyx. Of these, compounds 1 and 3 showed strong inhibition of collagen-induced, arachidonic acid-induced, and adenosine diphosphate-induced platelet aggregation of human whole blood. Compound 3 also strongly inhibited ristocetin-induced platelet aggregation. Structures of these compounds were elucidated by spectroscopic and chemical means.