2-Chloroadenosine-5'-O-diphosphate, a purine nucleotide adenosine 5'diphosphate (ADP) derivative, demonstrates multiple biological activities. It promotes aggregation and inhibits cyclic AMP (cAMP) production, triggered by prostaglandin E2 (PGE2), in a concentration-dependent manner within isolated human platelet-rich plasma. Additionally, this compound facilitates the relaxation of precontracted isolated guinea pig taenia coli strips (pD2 = 6.74) and reduces arterial blood pressure in rats. Moreover, 2-Chloroadenosine-5'-O-diphosphate significantly inhibits the ATPase activity of mortalin, a member of the heat shock protein 70 (Hsp70) family, with an apparent Ki of 45.05 uM for the human enzyme.