Structure–activity relationships of chalcone analogs as potential inhibitors of ADP- and collagen-induced platelet aggregation

In an effort to develop potent antiplatelet agents, 12 O-prenylated (2–13) and 10 O-allylated (14–23) chalcones were synthesized and screened for in vitro inhibitory effects on aggregation of washed rabbit platelets induced by ADP (20μM) and collagen (10μg/mL). In addition, the platelet aggregation activity of previously synthesized Mannich bases of heterocyclic chalcones (MBHC) (24–62) was evaluated. The preliminary structure–activity relationships suggested that the antiplatelet activity was governed to a great extent by the presence of a pyridyl ring-B and a hydroxy group at position C-3′ in ring-A of the MBHC templates.