Pyrimidine ribonucleotides with enhanced selectivity as P2Y(6) receptor agonists: novel 4-alkyloxyimino, (S)-methanocarba, and 5'-triphosphate gamma-ester modifications

J Med Chem. 2010 Jun 10;53(11):4488-501. doi: 10.1021/jm100287t.


The P2Y(6) receptor is a cytoprotective G-protein-coupled receptor (GPCR) activated by UDP (EC(50) = 0.30 microM). We compared and combined modifications to enhance P2Y(6) receptor agonist selectivity, including ribose ring constraint, 5-iodo and 4-alkyloxyimino modifications, and phosphate modifications such as alpha,beta-methylene and extension of the terminal phosphate group into gamma-esters of UTP analogues. The conformationally constrained (S)-methanocarba-UDP is a full agonist (EC(50) = 0.042 microM). 4-Methoxyimino modification of pyrimidine enhanced P2Y(6), preserved P2Y(2) and P2Y(4), and abolished P2Y(14) receptor potency, in the appropriate nucleotide. N(4)-Benzyloxy-CDP (15, MRS2964) and N(4)-methoxy-Cp(3)U (23, MRS2957) were potent, selective P2Y(6) receptor agonists (EC(50) of 0.026 and 0.012 microM, respectively). A hydrophobic binding region near the nucleobase was explored with receptor modeling and docking. UTP-gamma-aryl and cycloalkyl phosphoesters displayed only intermediate P2Y(6) receptor potency but had enhanced stability in acid and cell membranes. UTP-glucose was inactive, but its (S)-methanocarba analogue and N(4)-methoxycytidine 5'-triphospho-gamma-[1]glucose were active (EC(50) of 2.47 and 0.18 microM, respectively). Thus, the potency, selectivity, and stability of pyrimidine nucleotides as P2Y(6) receptor agonists may be enhanced by modest structural changes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Cell Line, Tumor
  • Dinucleoside Phosphates / chemistry*
  • Dinucleoside Phosphates / pharmacology*
  • Esters / chemistry*
  • Humans
  • Imines / chemistry*
  • Models, Molecular
  • Polyphosphates / chemistry*
  • Protein Conformation
  • Purinergic P2 Receptor Agonists*
  • Pyrimidines / chemistry*
  • Receptors, Purinergic P2 / chemistry
  • Ribonucleotides / chemistry*
  • Ribonucleotides / pharmacology*
  • Structure-Activity Relationship
  • Substrate Specificity


  • Dinucleoside Phosphates
  • Esters
  • Imines
  • P1-(5'-uridine)-P3-(5'-N4-methoxycytidine)triphosphate
  • Polyphosphates
  • Purinergic P2 Receptor Agonists
  • Pyrimidines
  • Receptors, Purinergic P2
  • Ribonucleotides
  • purinoceptor P2Y6
  • pyrimidine
  • triphosphoric acid