Discovery of hydroxy pyrimidine Factor IXa inhibitors.

The synthesis and structure activity relationship development of a pyrimidine series of heterocyclic Factor IXa inhibitors is described. Increased selectivity over Factor Xa inhibition was achieved through SAR expansion of the P1 element. Select compounds were evaluated in vivo to assess their plasma levels in rat.

Discovery of nor-seco himbacine analogs as thrombin receptor antagonists.

Discovery of a novel nor-seco himbacine analog as potent thrombin receptor (PAR-1) antagonist is described. Despite low plasma level, these new analogs showed excellent ex vivo efficacy in the monkey platelet aggregation assay. A potent hydroxy metabolite generated in vivo was identified as the agent responsible for the ex vivo efficacy. Following this discovery, the metabolite series was optimized to obtain analogs that showed very good ex vivo efficacy along with excellent pharmacokinetic profile in c. monkey.

Heterotricyclic himbacine analogs as potent, orally active thrombin receptor (protease activated receptor-1) antagonists.

Pursuing our earlier efforts in the himbacine-based thrombin receptor antagonist area, we have synthesized a series of compounds that incorporate heteroatoms in the C-ring of the tricyclic motif. This effort has resulted in the identification of several potent heterocyclic analogs with excellent affinity for the thrombin receptor. Several of these compounds demonstrated robust inhibition of platelet aggregation in an ex vivo model in cynomolgus monkeys following oral administration. A detailed profile of 28b, a benchmark compound in this series, with a Ki of 4.3 nM, is presented.

Design, Synthesis, and Evaluation of Novel and Selective G-protein Coupled Receptor 120 (GPR120) Spirocyclic Agonists.

Type 2 diabetes mellitus (T2DM) is an ever increasing worldwide epidemic, and the identification of safe and effective insulin sensitizers, absent of weight gain, has been a long-standing goal of diabetes research. G-protein coupled receptor 120 (GPR120) has recently emerged as a potential therapeutic target for treating T2DM. Natural occurring, and more recently, synthetic agonists have been associated with insulin sensitizing, anti-inflammatory, and fat metabolism effects. Herein we describe the design, synthesis, and evaluation of a novel spirocyclic GPR120 agonist series, which culminated in the discovery of potent and selective agonist 14. Furthermore, compound 14 was evaluated in vivo and demonstrated acute glucose lowering in an oral glucose tolerance test (oGTT), as well as improvements in homeostatic measurement assessment of insulin resistance (HOMA-IR; a surrogate marker for insulin sensitization) and an increase in glucose infusion rate (GIR) during a hyperinsulinemic euglycemic clamp in diet-induced obese (DIO) mice.

Himbacine-derived thrombin receptor antagonists: c7-aminomethyl and c9a-hydroxy analogues of vorapaxar.

We have synthesized several C7-aminomethyl analogues of vorapaxar that are potent PAR-1 antagonists. Many of these analogues showed excellent in vitro binding affinity and pharmacokinetics profile in rats. Compound 6a from this series showed excellent PAR-1 activity (K i = 5 nM). We have also synthesized a C9a-hydroxy analogue of vorapaxar, which showed very good PAR-1 affinity (K i = 19.5 nM) along with excellent rat pharmacokinetic profile and ex vivo efficacy in the cynomolgus monkey.

Himbacine-derived thrombin receptor antagonists: c7-spirocyclic analogues of vorapaxar.

We have synthesized several C7-spirocyclic analogues of vorapaxar and evaluated their in vitro activities against PAR-1 receptor. Some of these analogues showed activities and rat plasma levels comparable to vorapaxar. Compound 5c from this series showed excellent PAR-1 activity (K i = 5.1 nM). We also present a model of these spirocyclic compounds docked to the PAR-1 receptor based on the X-ray crystal structure of vorapaxar bound to PAR-1 receptor. This model explains some of the structure-activity relationships in this series.