Chapter 6.1: Six-Membered Ring Systems: Pyridine and Benzo Derivatives

Synthesis, in vitro and in silico screening of 2-amino-4-aryl-6-(phenylthio) pyridine-3,5-dicarbonitriles as novel α-glucosidase inhibitors

Inhibition of α-glucosidase enzyme is of prime importance for the treatment of diabetes mellitus (DM). Apart of many organic scaffolds, pyridine based compounds have previously been reported for wide range of bioactivities. The current study reports a series of pyridine based synthetic analogues for their α-glucosidase inhibitory potential assessed by in vitro, kinetics and in silico studies. For this purpose, 2-amino-4-aryl-6-(phenylthio)pyridine-3,5-dicarbonitriles 1-28 were synthesized and subjected to in vitro screening. Several analogs, including 1-3, 7, 9, 11-14, and 16 showed many folds increased inhibitory potential in comparison to the standard acarbose (IC₅₀ = 750 ± 10 µM). Interestingly, compound 7 (IC₅₀ = 55.6 ± 0.3 µM) exhibited thirteen-folds greater inhibition strength than the standard acarbose. Kinetic studies on most potent molecule 7 revealed a competitive type inhibitory mechanism. In silico studies have been performed to examine the binding mode of ligand (compound 7) with the active site residues of α-glucosidase enzyme.

Significance and biological importance of pyrimidine in the microbial world

Microbes are unique creatures that adapt to varying lifestyles and environment resistance in extreme or adverse conditions. The genetic architecture of microbe may bear a significant signature not only in the sequences position, but also in the lifestyle to which it is adapted. It becomes a challenge for the society to find new chemical entities which can treat microbial infections. The present review aims to focus on account of important chemical moiety, that is, pyrimidine and its various derivatives as antimicrobial agents. In the current studies we represent more than 200 pyrimidines as antimicrobial agents with different mono-, di-, tri-, and tetrasubstituted classes along with in vitro antimicrobial activities of pyrimidines derivatives which can facilitate the development of more potent and effective antimicrobial agents.