The methanol soluble portion of black cumin oil, which is prepared by compr
ession of seeds of Nigella saliva L., showed inhibitory effects on arachido
nic acid (AA)-induced platelet aggregation and blood coagulation. By bioact
ive assay of AA-induced platelet aggregation, the methanol soluble part was
purified to isolate a new compound 2-(2-methoxypropyl)-5-methyl-1,4-benzen
ediol (1) and two known compounds, thymol (2), carvacrol (3), having ver?;
strong inhibitory activity. Further, we then examined the isolated compound
s (1-3) and eight related compounds by the screening test for AA-induced pl
atelet aggregation. Compounds possessing aromatic hydroxyl and acetoxyl gro
up had more potent activity than aspirin, which is well known as a remedy f
or thrombosis.