Synthesis and biological evaluation of novel potent FFA1 agonists containing 2,3-dihydrobenzo[b][1,4]dioxine

FFA1 (free fatty acid receptor 1) has emerged as an attractive antidiabetic target due to its role in mediating the enhancement of glucose-stimulated insulin secretion in pancreatic β cells with a low risk of hypoglycemia. Many reported FFA1 agonists possessed somewhat pharmacokinetic and/or safety issues. Herein, we describe the identification of 2,3-dihydrobenzo[b][1,4]dioxine as a novel scaffold for FFA1 agonists. Comprehensive structure-activity relationship study based on this scaffold led to the discovery of (S)-3-(4-(((S)-7-(4-methoxyphenyl)-2,3-dihydrobenzo [b][1,4]dioxin-2-yl)methoxy) phenyl)hex-4-ynoic acid (26k), which displayed a potent FFA1 agonistic activity and good pharmacokinetic profiles. Subsequent in vivo studies demonstrated that compound 26k significantly improved the glucose tolerance in ICR mice. In summary, compound 26k is a promising drug candidate for further investigation.