A new diarylheptanoid, 1,7-bis(4-hydroxyphenyl)-3-hydroxy-1,3-(1), alo
ng with seven other known compounds, were isolated from the seeds of A
lpinia blepharocalyx. Of these, compounds 1 and 3 showed strong inhibi
tion of collagen-induced, arachidonic acid-induced, and adenosine diph
osphate-induced platelet aggregation of human whole blood. Compound 3
also strongly inhibited ristocetin-induced platelet aggregation. Struc
tures of these compounds were elucidated by spectroscopic and chemical
means.