Abstract: Born turbidimetry was used to evaluate the aggregation inhibition rate and the half-inhibition concentration.The phenolic acid compounds in Echinacea and its extracts were resistant to platelet aggre-gation induced by 4,5-adenosine diphosphate (ADP).Using molecular docking method,coagulation factor V (F5),factor VIII (F8) and factor XI (F11) were selected for virtual docking with phenolic compounds to study their molecular targets for anti-platelet aggregation.The results showed that the 60% ethanol ext-ract of Echinacea had inhibitory effect on ADP-induced platelet aggregation in vitro,and the inhibition rate was concentration-dependent.The chemically synthesized phenolic compounds all have anti-ADP-in duced platelet aggregation activity,and the anti-platelet aggregation effects of three compounds were similar to those off ASA against platelet aggregation.Molecular docking studies showed that all compounds can be hydrogen bonded to the target compound,wherein the binding energy of the target to some of the co-mpounds can be higher than 50% of the positive control.It was suggested that these may participate in the process of platelet aggregation and exert an inhibitory effect.Compound S-6 had more binding site with the target,more tight binding,stronger binding ability and better selectivity,and was expected to be a lead against platelet aggregation.The phenolic acids and their extracts in Echinacea showed anti-ADP-induced platelet aggregation activity in vitro,which provided a basis for the in vivo study of Echinacea.

Key words: Echinacea purpurea, phenolic compounds, coagulation factor, virtual molecular docking, antiplatelet aggregation