Investigation on 2′,3′-O-Substituted ATP Derivatives and Analogs as Novel P2X3 Receptor Antagonists

Abstract

Antagonists of the purinergic P2X3 receptors represent promising drugs for the treatment of inflammation and pain. The ATP derivative 2′,3′-O-(2,4,6-trinitrophenyl)-ATP (TNP-ATP) has been described as a potent competitive inhibitor of this receptor. In this work, the design and synthesis of novel TNP-ATP analogues bearing alkyl groups in the 2′,3′-position are reported. These compounds were biologically evaluated as P2X3 antagonists using the patch clamp recording technique on mouse trigeminal ganglionic sensory neurons. Some of the compounds showed nanomolar inhibitory potency for the P2X3 receptor. Further modification of these derivatives was made by substitution of the triphosphate chain with different acidic groups. All compounds were additionally tested at five human P2X receptor subtypes stably expressed in 1321N1 astrocytoma cells to evaluate their potency and P2X3 selectivity. Results confirmed the P2X3 antagonist potency for some derivatives.

Update of P2X receptor properties and their pharmacology: IUPHAR Review 30

“…They are of limited use and should be replaced by more potent and selective antagonists that are now available. The ATP derivative TNP-ATP ( 7 ) is very potent at P2X1 and P2X3 receptors (low nanomolar IC 50 values), much less potent at P2X2 and P2X4 receptors, and virtually inactive at P2X7 receptors ( Dal Ben et al, 2019 ). Ip 5 I ( 10 ) is most potent as a P2X1 receptor antagonist and also blocks P2X3 receptors, but not the heteromeric P2X2/3 receptors, while it potentiates P2X4 receptors ( Lambertucci et al, 2015 ).…”

“…It displays low peroral and CNS bioavailability and high plasma–protein binding. 2′,3′-Benzylidene-ATP ( 8 ) and related ATP derivatives have submicromolar potency and some P2X3 receptor selectivity ( Dal Ben et al, 2019 ). The 3′-benzamido-ATP derivative, DT-0111 ( 9 ), was developed as a water-soluble P2X2/3 receptor antagonist suitable for administration by inhalation ( Pelleg, Xu, Zhuang, Undem, & Burnstock, 2019 ).…”

A review of TNP-ATP in protein binding studies: benefits and pitfalls

“…In addition to using TNP-ATP as part of determining the K d for ligand binding, TNP-ATP has been used to study other aspects of binding, including kinetics (on and off rates), inhibitory block (K i and IC50) ( 107 ), and the Michaelis constant (K m ), for example. Another common use of TNP-ATP is as an antagonist of P2X receptors, as reviewed in ( 108 ) (see also ( 17 , 18 , 109 , 110 )), and it continues to inspire the design of new P2X receptor antagonists ( 111 ). TNP-ATP is also useful in screening proteins for ATP binding ( 97 , 112 , 113 , 114 , 115 ).…”

Identification of a novel P2X7 antagonist using structure-based virtual screening

“…Indeed, the binding pose of ATP in the pocket is strikingly similar in Danio rerio P2X4, human P2X3, gulf coast tick P2X and rat P2X7, adopting a U-shaped conformation where conserved lysine and arginine residues coordinate the phosphates. The presence of the gamma phosphate is crucial for agonist activity, as well as the conformation of the ribose moiety and the localization of the adenine moiety into a relatively hydrophobic pocket ( Dal Ben et al, 2019 ; Gasparri et al, 2019 ; Grimes et al, 2020 ). We chose a model of human P2X4 based on the ATP-bound structure of Danio rerio P2X4 for virtual screening and validated our docking algorithms using ATP (in a model where the bound ATP was removed prior to docking).…”