Synthesis and evaluation of cyclohexane carboxylic acid head group containing isoxazole and thiazole analogs as DGAT1 inhibitors.

Abstract Diacylglycerol acyltransferase 1 (DGAT1) is known to play an important catalytic role in the final step of triglyceride biosynthesis. High fat diet fed DGAT1 knockout mice were resistant to weight gain and exhibited increased insulin and leptin sensitivity thereby indicating a plausible role for DGAT1 inhibitors in the treatment of obesity. 4-Phenylpiperidine-1-carbonyl cyclohexanecarboxylic acid (compound 6 , DGAT1 IC 50  = 57 nM) has been lately reported as a potent DGAT1 inhibitor. In our search for newer scaffolds possessing potent DGAT1 activity we undertook a systematic diversification of compound 6 to identify a 4-(5-phenylthiazole-2-carboxamido)cyclohexanecarboxylic acid scaffold. Further linker optimization of this scaffold identified compound 9e (DGAT1 IC 50  = 14.8 nM) as a potent DGAT1 inhibitor. Coupled with its in vitro potency, compound 9e also exhibited 112 percent plasma triglyceride reduction at a 3 mpk dose in an oral fat tolerance test (FTT) when studied in Swiss mice.