In-silico and in-vitro hybrid approach to identify glucagon-like peptide-1 receptor agonists from anti-diabetic natural products

Natural products have contributed immensely towards the treatment of various diseases including diabetes. Here, a database of small molecules from nature possessing antidiabetic properties was analysed and shortlisted according to their structural diversity. Later, those structures were screened by in-silico docking studies to understand their affinity towards glucagon-like peptide-1 (GLP-1) receptor. The selected molecules were isolated and investigated further by integrated in-vitro and in-silico approaches. Alpha-mangostin was found to be suitable due to its excellent docking score and isolation yield. A pancreatic beta cell line was used to test the activity of alpha-mangostin and observed a 3-fold increase in insulin secretion compared to 15 mM glucose control. Further, in-silico molecular dynamics simulations studies have validated its target by showing conformational changes at the functionally active part of the GLP-1 receptor. This screening strategy can be applied to identify pertinent natural products rapidly for various therapeutic targets.

From Vietnamese plants to a biflavonoid that relieves inflammation by triggering the lipid mediator class switch to resolution

Chronic inflammation results from excessive pro-inflammatory signaling and the failure to resolve the inflammatory reaction. Lipid mediators orchestrate both the initiation and resolution of inflammation. Switching from pro-inflammatory to pro-resolving lipid mediator biosynthesis is considered as efficient strategy to relieve chronic inflammation, though drug candidates exhibiting such features are unknown. Starting from a library of Vietnamese medical plant extracts, we identified isomers of the biflavanoid 8-methylsocotrin-4'-ol from Dracaena cambodiana, which limit inflammation by targeting 5-lipoxygenase and switching the lipid mediator profile from leukotrienes to specialized pro-resolving mediators (SPM). Elucidation of the absolute configurations of 8-methylsocotrin-4'-ol revealed the 2S,γS-isomer being most active, and molecular docking studies suggest that the compound binds to an allosteric site between the 5-lipoxygenase subdomains. We identified additional subordinate targets within lipid mediator biosynthesis, including microsomal prostaglandin E2 synthase-1. Leukotriene production is efficiently suppressed in activated human neutrophils, macrophages, and blood, while the induction of SPM biosynthesis is restricted to M2 macrophages. The shift from leukotrienes to SPM was also evident in mouse peritonitis in vivo and accompanied by a substantial decrease in immune cell infiltration. In summary, we disclose a promising drug candidate that combines potent 5-lipoxygenase inhibition with the favorable reprogramming of lipid mediator profiles.

Synthesis of 1,2,4-Trisubstituted-(1H)-imidazoles through Cu(OTf)2-/I2-Catalyzed C-C Bond Cleavage of Chalcones and Benzylamines

1,2,4-Trisubstituted-(1H)-imidazoles have been synthesized by the Cu(OTf)₂- and I₂-catalyzed unusual C-C bond cleavage of chalcones and benzylamines. After the α,β-unsaturated C-C bond cleavage, the β-portion is eliminated from the reaction. Various aryl- and heteroaryl-substituted chalcones and benzylamines were well tolerated in this unusual transformation to yield the trisubstituted-(1H)-imidazoles.