- New highly active antiplatelet agents with dual specificity for platelet P2Y1 and P2Y12 adenosine diphosphate receptors
-
Currently approved platelet adenosine diphosphate (ADP) receptor antagonists target only the platelet P2Y12 receptor. Moreover, especially in patients with acute coronary syndromes, there is a strong need for rapidly acting and reversible antiplatelet agents in order to minimize the risk of thrombotic events and bleeding complications. In this study, a series of new P1,P4-di(adenosine-5′) tetraphosphate (Ap4A) derivatives with modifications in the base and in the tetraphosphate chain were synthesized and evaluated with respect to their effects on platelet aggregation and function of the platelet P2Y1, P2Y12, and P2X1 receptors. The resulting structure-activity relationships were used to design Ap4A analogs which inhibit human platelet aggregation by simultaneously antagonizing both P2Y1 and P2Y12 platelet receptors. Unlike Ap4A, the analogs do not activate platelet P2X1 receptors. Furthermore, the new compounds exhibit fast onset and offset of action and are significantly more stable than Ap4A to degradation in plasma, thus presenting a new promising class of antiplatelet agents.
- Yanachkov, Ivan B.,Chang, Hung,Yanachkova, Milka I.,Dix, Edward J.,Berny-Lang, Michelle A.,Gremmel, Thomas,Michelson, Alan D.,Wright, George E.,Frelinger, Andrew L.
-
supporting information
p. 204 - 218
(2015/11/24)
-
- Nucleoside-5′-monophosphates as prodrugs of adenosine A2A receptor agonists activated by ecto-5′-nucleotidase
-
Prodrugs of adenosine A2A receptor agonists were developed that are activated by ecto-5′-nucleotidase (ecto-5′-NT,CD73). Because ecto-5′-NT is upregulated in inflamed tissue, the A2A agonists are expected to be released from their prodrug form at the sites of inflammation. 2-(Ar)alkyl-substituted AMP derivatives were synthesized and investigated. Certain 2-substituted AMP derivatives, including 2-hexylthio-AMP, 2-cyclopentylthio-AMP, 2-cyclohexylmethylthio-AMP, and 2-cyclohexylethylthio-AMP were accepted as substrates by ecto-5′-NT and readily converted to the corresponding 2-substituted adenosine derivatives. The 2-cyclohexylethylthio substitution was a good compromise between the requirements of the ecto-5′-NT and the adenosine A2A receptor. The corresponding AMP derivative (12g) was a similarly good substrate as AMP itself, while the resulting adenosine derivative (11g) was a relatively potent A2A agonist (radioligand binding to rat brain striatal membranes: Ki=372 nM; inhibition of anti-CD3/anti-CD28-induced IFN-γ release in mouse CD4+ cells: EC50=50 nM). Compound 11g was released from 12g by incubation with CD4+ cells isolated from wild-type mice but only to a much smaller extent by cells from ecto-5′-NT knockout mice. Compound 12g will be a new lead structure for the development of more potent and selective ecto-5′-NT- activated prodrugs of selective anti-inflammatory A2A receptor agonists.
- El-Tayeb, Ali,Iqbal, Jamshed,Behrenswerth, Andrea,Romio, Michael,Schneider, Marion,Zimmermann, Herbert,Schrader, Jürgen,Müller, Christa E.
-
supporting information; experimental part
p. 7669 - 7677
(2010/09/03)
-
- Antagonists of the platelet P(2t) receptor: A novel approach to antithrombotic therapy
-
The platelet P(2T) receptor plays a major role in platelet aggregation, and its antagonists are predicted to have significant therapeutic potential as antithrombotic agents. We have explored analogues of adenosine triphosphate (ATP), which is a weak, nonselective but competitive P(2T), receptor antagonist. Modification of the polyphosphate side chain to prevent breakdown to the agonist adenosine diphosphate (ADP) and substitution of the adenine moiety to enhance affinity and selectivity for the P(2T) receptor led to the identification of 10e (AR-C67085MX), having an IC50 of 2.5 nM against ADP-induced aggregation of human platelets. Compound 10e was the first very potent antagonist of the P(2T) receptor, with a selectivity for that subtype of the P2 receptor family of > 1000-fold. Further modification of the structure produced compound 101 (AR-C69931MX) having an IC50 of 0.4 nM. In vivo, at maximally effective antithrombotic doses, there is little prolongation of bleeding time (1.4-fold), which is in marked contrast to the 5-6 fold found with GPIIb/IIIa antagonists.
- Ingall, Anthony H.,Dixon, John,Bailey, Andrew,Coombs, Mandy E.,Cox, David,McInally, Judith I.,Hunt, Simon F.,Kindon, Nicholas D.,Teobald, Barry J.,Willis, Paul A.,Humphries, Robert G.,Leff, Paul,Clegg, Jane A.,Smith, James A.,Tomlinson, Wendy
-
p. 213 - 220
(2007/10/03)
-
- ADP and ATP analogues, process for making and administration to inhibit ADP-induced platelet aggregation
-
There are disclosed compounds of formula I, STR1 wherein Q represents CR 1 R 2,R represents O or CR 3 R 4,W represents O or CH 2,R 1, R 2, R 3 and R 4 independently represent hydrogen or halogen,X represents S(O) n R 5, alkyl C 1-6 alkoxy C 1-6, acylamino C 1-6, CONR 6 R 7, NR 8 R 9, halogen, a 5- or 6-membered S containing heterocycle, or phenyl optionally substituted by alkyl C 1-6,n represents 0, 1 or 2,R 5 represents aryl or alkyl C 1-6 optionally substituted by one or more substituents selected from hydroxy, alkoxy C 1-6, halogen and aryl;R 6, R 7, R 8 and R 9 independently represent hydrogen or alkyl C 1-6,Y represents NH 2 or alkoxy C 1-6, andZ represents an acidic moiety,in addition, when R represents CR 3 R 4, then --Q--Z may also represent hydroxy or --OP(O)(OH) 2,and pharmaceutically acceptable salts thereof, with certain provisos, for use as pharmaceuticals.
- -
-
-