Synthesis and potency of novel uracil nucleotides and derivatives as P2Y2 and P2Y6 receptor agonists Original Research Article

The phosphate, uracil, and ribose moieties of uracil nucleotides were varied structurally for evaluation of agonist activity at the human P2Y2, P2Y4, and P2Y6 receptors. The 2-thio modification, found previously to enhance P2Y2 receptor potency, could be combined with other favorable modifications to produce novel molecules that exhibit high potencies and receptor selectivities. Phosphonomethylene bridges introduced for stability in analogues of UDP, UTP, and uracil dinucleotides markedly reduced potency. Truncation of dinucleotide agonists of the P2Y2 receptor, in the form of Up4-sugars, indicated that a terminal uracil ring is not essential for moderate potency at this receptor and that specific SAR patterns are observed at this distal end of the molecule. Key compounds reported in this study include 9, α,β-methylene-UDP, a P2Y6 receptor agonist; 30, Up4-phenyl ester and 34, Up4-[1]glucose, selective P2Y2 receptor agonists; dihalomethylene phosphonate analogues 16 and 41, selective P2Y2 receptor agonists; 43, the 2-thio analogue of INS37217 (P1-(uridine-5′)-P4-(2′-deoxycytidine-5′)tetraphosphate), a potent and selective P2Y2 receptor agonist.