Discovery of novel benzomorpholine derivatives as potent URAT1 inhibitors with hypouricemic effects

Urate transporter 1 (URAT1) is a clinically validated therapeutic target for hyperuricemia and gout. To obtain structurally novel URAT1 inhibitors, a series of benzomorpholine derivatives were designed by adopting a pharmacophore guided molecular hybridization strategy. Most compounds potently inhibit the human URAT1 in HEK293 cells, and the most active compound 7 exhibited an IC₅₀ of 0.72 μM, which was much more potent than Lesinurad and comparable to Benzbromarone. The possible interaction mode of compound 7 with URAT1 was revealed by molecular modeling. Cell viability assays indicated that compound 7 was less cytotoxic than Benzbromarone in Hep-G2 cells. The urate-lowering effects of compounds 1 and 7 were confirmed in two different hyperuricemia mouse models, and no obvious toxicity was observed in the treated mice. The results provide new chemical prototypes for urate-lowering drug discovery targeting URAT1.