262863-44-5Relevant articles and documents
Structure-activity relationships of pyridoxal phosphate derivatives as potent and selective antagonists of P2X1 receptors
Kim,Brown,Harden,Boyer,Dubyak,King,Burnstock,Jacobson
, p. 340 - 349 (2001)
Novel analogues of the P2 receptor antagonist pyridoxal-5′-phosphate 6-azophenyl-2′,5′ disulfonate (2) were synthesized and studied as antagonists in functional assays at recombinant rat P2X1, P2X2, and P2X3 receptors expressed in Xenopus oocytes (ion flux stimulation) and at turkey erythrocyte P2Y1 receptors (phospholipase C activation). Selected compounds were also evaluated as antagonists of ion flux and the opening of a large pore at the recombinant human P2X7 receptor. Modifications were made in the 4-aldehyde and 5′-phosphate groups of the pyridoxal moiety: i.e. a CH2OH group at the 4-position in pyridoxine was either condensed as a cyclic phosphate or phosphorylated separately to form a bisphosphate, which reduced potency at P2 receptors. 5-Methylphosphonate substitution, anticipated to increase stability to hydrolysis, preserved P2 receptor potency. At the 6-position, halo, carboxylate, sulfonate, and phosphonate variations made on the phenylazo ring modulated potency at P2 receptors. The p-carboxyphenylazo analogue, 4, of phosphate 2 displayed an IC50 value of 9 nM at recombinant P2X1 receptors and was 1300-, 16-, and > 10000-fold selective for P2X1 versus P2X2, P2X3, and P2Y1 subtypes, respectively. The corresponding 5-methylphosphonate was equipotent at P2X1 receptors. The 5-methylphosphonate analogue containing a 6-[3,5-bis(methylphosphonate)]phenylazo moiety, 9, had IC50 values of 11 and 25 nM at recombinant P2X1 and P2X3 receptors, respectively. The analogue containing a phenylazo 4-phosphonate group, 11, was also very potent at both P2X1 and P2X3 receptors. However, the corresponding 2,5-disulfonate analogue, 10, was 28-fold selective for P2X1 versus P2X3 receptors. None of the analogues were more potent at P2X7 and P2Y1 receptors than 2, which acted in the micromolar range at these two subtypes.
Optimization of a synthetic arginine receptor. Systematic tuning of noncovalent interactions
Rensing,Arendt,Springer,Grawe,Schrader
, p. 5814 - 5821 (2007/10/03)
The simple arginine binder 1 could be optimized by strengthening π-cation as well as electrostatic interactions. Electron-donating or -withdrawing substituents in the 5-position provide experimental evidence for π-cation interactions, because binding energies increase by up to 0.6 kcal/mol due to a single benzene-guanidinium interaction. Even more effective is the introduction of a third phosphonate functionality at the correct distance, so that the guanidinium cation is recognized by optimal electrostatic and hydrogen bond interactions. Monte Carlo simulations and NOESY experiments confirm the expected complex geometries. The optimized host molecule 8 binds arginine half an order of magnitude more efficiently than the parent molecule.
