Small molecule ago-allosteric modulators of the human glucagon-like peptide-1 (hGLP-1) receptor.

Following our previous publication describing the biological profiles, we herein describe the structure-activity relationships of a core set of quinoxalines as the hGLP-1 receptor agonists. The most potent and efficacious compounds are 6,7-dichloroquinoxalines bearing an alkyl sulfonyl group at the C-2 position and a secondary alkyl amino group at the C-3 position. These findings serve as a valuable starting point for the discovery of more drug-like small molecule agonists for the hGLP-1 receptor.

Small-molecule agonists for the glucagon-like peptide 1 receptor.

The peptide hormone glucagon-like peptide (GLP)-1 has important actions resulting in glucose lowering along with weight loss in patients with type 2 diabetes. As a peptide hormone, GLP-1 has to be administered by injection. Only a few small-molecule agonists to peptide hormone receptors have been described and none in the B family of the G protein coupled receptors to which the GLP-1 receptor belongs.

New beta-alanine derivatives are orally available glucagon receptor antagonists.

A weak human glucagon receptor antagonist with an IC50 of 7 microM was initially found by screening of libraries originally targeted to mimic the binding of the glucagon-like peptide (GLP-1) hormone to its receptor. Optimization of this hit for binding affinity for the glucagon receptor led to ligands with affinity in the nanomolar range. In addition to receptor binding, optimization efforts were made to stabilize the molecules against fast metabolic turnover.

Optimization of alkylidene hydrazide based human glucagon receptor antagonists. Discovery of the highly potent and orally available 3-cyano-4-hydroxybenzoic acid [1-(2,3,5,6-tetramethylbenzyl)-1H-indol-4-ylmethylene]hydrazide.

Highly potent human glucagon receptor (hGluR) antagonists have been prepared employing both medicinal chemistry and targeted libraries based on modification of the core (proximal) dimethoxyphenyl group, the benzyl ether linkage, as well as the (distal) benzylic aryl group of the lead 2, 3-cyano-4-hydroxybenzoic acid (3,5-dimethoxy-4-isopropylbenzyloxybenzylidene)hydrazide. Electron-rich proximal aryl moieties such as mono- and dimethoxy benzenes, naphthalenes, and indoles were found to be active. The SAR was found to be quite insensitive regarding the linkage to the distal aryl group, since long and short as well as polar and apolar linkers gave highly potent compounds.

Human glucagon receptor antagonists based on alkylidene hydrazides.

A series of alkylidene hydrazide derivatives containing an alkoxyaryl moiety was optimized. The resulting hydrazide-ethers were competitive antagonists at the human glucagon receptor. Pharmacokinetic experiments showed fast clearance of most of the compounds tested.