Citrate is a key regulatory metabolic intermediate as it facilitates the integration of the glycolysis and lipid synthesis pathways. Inhibition of hepatic extracellular citrate uptake, by blocking the sodium-coupled citrate transporter (NaCT or SLC13A5), has been suggested as a potential therapeutic approach to treat metabolic disorders. NaCT transports citrate from the blood into the cell coupled to the transport of sodium ions. The studies herein report the identification and characterization of a novel small dicarboxylate molecule (compound 2) capable of selectively and potently inhibiting citrate transport through NaCT, both in vitro and in vivo. Binding and transport experiments indicate that 2 specifically binds NaCT in a competitive and stereosensitive manner, and is recognized as a substrate for transport by NaCT. The favorable pharmacokinetic properties of 2 permitted in vivo experiments to evaluate the effect of inhibiting hepatic citrate uptake on metabolic endpoints.

The medicinal chemistry and preclinical biology of imidazopyridine-based inhibitors of diacylglycerol acyltransferase 2 (DGAT2) is described. A screening hit 1 with low lipophilic efficiency (LipE) was optimized through two key structural modifications: (1) identification of the pyrrolidine amide group for a significant LipE improvement, and (2) insertion of a sp(3)-hybridized carbon center in the core of the molecule for simultaneous improvement of N-glucuronidation metabolic liability and off-target pharmacology. The preclinical candidate 9 (PF-06424439) demonstrated excellent ADMET properties and decreased circulating and hepatic lipids when orally administered to dyslipidemic rodent models.

Inhibition of the sodium-coupled citrate transporter (NaCT or SLC13A5) has been proposed as a new therapeutic approach for prevention and treatment of metabolic diseases. In a previous report, we discovered dicarboxylate 1a (PF-06649298) which inhibits the transport of citrate in in vitro and in vivo settings via a specific interaction with NaCT. Herein, we report the optimization of this series leading to 4a (PF-06761281), a more potent inhibitor with suitable in vivo pharmacokinetic profile for assessment of in vivo pharmacodynamics. Compound 4a was used to demonstrate dose-dependent inhibition of radioactive [(14)C]citrate uptake in liver and kidney in vivo, resulting in modest reductions in plasma glucose concentrations.

Takeda G-protein-coupled receptor 5 (TGR5) represents an exciting biological target for the potential treatment of diabetes and metabolic syndrome. A new class of high-throughput screening (HTS)-derived tetrahydropyrido- [4,3-d]pyrimidine amide TGR5 agonists is disclosed. We describe our effort to identify an orally available agonist suitable for assessment of systemic TGR5 agonism. This effort resulted in identification of 16, which had acceptable potency and pharmacokinetic properties to allow for in vivo assessment in dog. A key aspect of this work was the calibration of human and dog in vitro assay systems that could be linked with data from a human ex vivo peripheral blood monocyte assay that expresses receptor at endogenous levels. Potency from the human in vitro assay was also found to correlate with data from an ex vivo human whole blood assay. This calibration exercise provided confidence that 16 could be used to drive plasma exposures sufficient to test the effects of systemic activation of TGR5. KEYWORDS: GPCR, TGR5, agonist, diabetes, GLP-1 T GR5 (Takeda G-protein-coupled receptor 5) is a class A G-protein-coupled receptor (GPCR) expressed in liver, skeletal muscle, intestine, brown adipose tissues, and monocytes. 1−4 Activation of the TGR5 receptor upon ligand binding results in Gα s -coupled activation of adenylate cyclase. The subsequent downstream signaling cascade is believed to drive multiple effects that are cell type-dependent including (1) enhanced glucagon-like peptide-1 (GLP-1) release from intestinal cells potentially offering improved glycemic control through potentiation of glucose-dependent insulin secretion; 5 (2) nuclear effects, such as endothelial nitric oxide synthase activation and increased nitric oxide production in liver cells; 6 and (3) reduction of macrophage inflammation and lipid loading leading to inhibition of atherosclerosis. 7,8 Activation of TGR5 can also induce type 2 iodothyronine deiodinase in brown adipose tissue. In mice, this leads to increased energy expenditure, but the picture is less clear for humans. 9,10 For these reasons, TGR5 agonists may be useful agents to not only treat diabetes with concurrent management of glucose levels and body weight but also potentially address other aspects of metabolic syndrome.Bile acids are the purported endogenous agonists for TGR5. Of the several bile acids that act as ligands, taurine-conjugated lithocholic acid, lithocholic acid, deoxycholic acid, chenodeoxycholic acid, and cholic acid have all been shown to dose dependently induce accumulation of cyclic adenosine 5′-monophosphate (cAMP) in TGR5-transfected Chinese hamster ovary (CHO) cells. 11 Significant effort has been devoted to synthetic bile acids, such as INT-777 (1). 12,13 In addition, several other nonbile acid agonists have been reported in the literature (2−4), 14−16 which offer the potential for higher selectivity over other bile acid-mediated pathways (Figure 1). Previous work with 1 demonstrated in vivo modulation of

Organozinc reagents react with the SO2 surrogate DABSO, and the resulting zinc sulfinate salts are alkylated in situ to afford sulfones. This transformation has a broad scope and is compatible with a wide range of structural motifs of medicinal chemistry relevance including nitrile, secondary carbamates, and nitrogen-containing heterocycles.