Discovery and computational studies of 2-phenyl-benzoxazole acetamide derivatives as promising P2YR antagonists with anti-gout potential.

The P2Y nucleotide receptor, a subtype of P2Y receptors, is implicated in many human inflammatory diseases. Based on the identification of favorable residues of two screening hits in the almost symmetrical P2Y binding domain, we describe the structural optimization of previously identified virtual screening hits 6 and 7 that result in the development of P2YR antagonists with a novel 2-phenyl-benzoxazole acetamide chemical scaffold. Notably, compound 52 showed potent P2YR antagonistic activity (IC = 2 nM), and a stronger inhibitory effect on MSU-induced inflammatory in vitro, better than a previously described P2YR antagonist PPTN. In vivo evaluation demonstrated that compound 52 also had satisfactory inhibitory activity on the inflammatory response of gout flares in mice. Moreover, P2YR antagonist 52 decreased paw swelling and inflammatory cell infiltration through cAMP/NLRP3/GSDMD signaling pathways in MSU-induced acute gouty arthritis mice. The discussions on the binding mechanism that employ MM/GBSA free energy calculations/decompositions also provide some useful clues for further structural designing of compound 52. Taken together, 2-phenyl-benzoxazole acetamide derivative 52 with potent P2YR antagonistic activity and in vivo potency could be a promising strategy for gout therapy and deserves further optimization.