Thus synthesized thienopyrimidine derivatives were evaluated
Thus synthesized thienopyrimidine derivatives were evaluated in vitro for GPR119 agonistic activity, and the results are summarized in , , . First, we fixed the 4-methylsulfonylphenyl substituent at the R position on the thienopyrimidine ring, and derivatized at the R position. As shown in , and showed weak agonistic activities; however, the introduction of a Boc-protected -methylpiperidine to thienopyrimidine exhibited good in vitro activity with an EC value of 39nM. Also, pyrimidine substituted -methylpiperidine derivative displayed moderate potency (EC=1200nM). 4-Oxypiperidine derivatives and also activated GPR119 with EC values of 100nM and 240nM, respectively.
Based on the data shown in , we further derivatized the R position with an -methylaminopiperidine group. As shown in , isopropyl carbamate was also active with an EC value of 82nM. Amide derivatives ( and ) were weaker than carbamate derivatives ( and ). Introduction of an isopropyl urea moiety resulted in loss of activity (). Also, isopropyl sulfonamide () showed moderated GPR119 agonistic activity.
Diverse substituted aryl and heteroaryl groups were introduced at the R position of the thienopyrimidine ring. As expected, methylsulfonyl substituted aryl or heteroaryl derivatives showed good in vitro activity (data not shown). Therefore, we focused on R modification with 2-fluoro-4-methylsulfonylphenyl group, and the results were summarized in . -Butyl and isopropyl carbamate () showed good in vitro potency with EC value of 3nM. However, the introduction of an ethyl group resulted in loss of activity (compound ). Methylcyclopropyl carbamate () exhibited good activity (EC=26nM), whereas other amides ( and ) and oxadiazole () resulted in a loss of activity.
From the results of our in vitro data, was selected as a prototype compound. Next, PCI-34051 mg was investigated for its stability, ability to induce/inhibit CYP, Herg binding and cytotoxicity. As shown in , compound is metabolically stable in human and rat liver microsomes, with over 95% of the parent compound remaining after 30min incubation. In CYP inhibition/induction assays with several CYP subtypes, compound did not significantly inhibit or induce CYP. Compound showed no Herg binding (13% inhibition at 10μM) and mutagenic potential in the AMES assay.
To evaluate that has direct effects on beta cells, insulin secretion was measured in the pancreatic beta cell line, TC-6. As can be seen in , exposure to at concentrations ranging from 10nM to 100nM increased glucose-stimulated insulin secretion (GSIS) in a dose-dependent manner in TC-6 cells.
To evaluate in vivo efficacy, oral glucose tolerance tests (OGTT) were performed using compound . Plasma glucose levels were determined based on the AUC of the glucose concentration, and they were significantly reduced at 15mg/kg dose ().
In conclusion, we identified a series of thienopyrimidine derivatives as GPR119 agonists. Several thienopyrimidine derivatives with R and R substituents were found to be potent GPR119 agonists. Among them, compound was the most active with an EC value of 3nM and showed good human and rat liver microsomal stability. Compound exhibited no CYP inhibition and induction, hERG binding, or mutagenic potential. Compound induced increased insulin secretion from beta cell and reduced the AUC of glucose in vivo OGTT. We are currently producing further modification of this prototype that will be examined in the near future.
This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2012-0019773) and a grant of the Korea Health technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare (A111345).
Introduction Type 2 diabetes mellitus (T2DM) is a metabolic disease of staggering proportions in the twenty-first century, with an estimated 439 million cases worldwide by 2030 . T2DM is mainly characterized by insulin resistance and insulin deficiency. Recently, the therapy of glucagon-like peptide-1 (GLP-1), an incretin hormone, has been emerged as a new therapeutic option for T2DM. The active form of GLP-1 plays an important role in glucose-dependent insulin biosynthesis and secretion from pancreatic β-cells , , . However, active GLP-1 is rapidly degraded by dipeptidyl peptidase IV (DPP-IV) , which is a serine protease to produce a dipeptide and an inactive GLP-1 , . DPP-IV inhibition increases the plasma concentration of active GLP-1 and causes the secretion of insulin in response to increased blood glucose level , , , . GLP-1 is important in glucose homeostasis and energy metabolism. Accordingly, inhibiting GLP-1 degradation and increasing the release of GLP-1 are both effective strategies for GLP-1-based T2DM treatment .