Discovery of novel enasidenib analogues targeting inhibition of mutant isocitrate dehydrogenase 2 as antileukaemic agents

Mutant isocitrate dehydrogenase (IDH) 2 "IDH2m" acquires a neo-enzymatic activity reducing α-ketoglutarate to an oncometabolite, D-2-hydroxyglutarate (2-HG). Three s-triazine series were designed and synthesised using enasidenib as a lead compound. In vitro anticancer screening via National Cancer Institute "NCI" revealed that analogues 6a, 6c, 6d, 7g, and 7l were most potent, with mean growth inhibition percentage "GI%" = 66.07, 66.00, 53.70, 35.10, and 81.15, respectively, followed by five-dose screening. Compounds 6c, 6e, and 7c were established as the best IDH2^R140Q inhibitors compared to enasidenib, reporting IC₅₀ = 101.70, 67.01, 88.93, and 75.51 nM, respectively. More importantly, 6c, 6e, and 7c displayed poor activity against the wild-type IDH2, IC₅₀ = 2928, 2295, and 3128 nM, respectively, which implementing high selectivity and accordingly safety. Furthermore, 6c was screened for cell cycle arrest, apoptosis induction, and western blot analysis. Finally, computational tools were applied to predict physicochemical properties and binding poses in IDH2^R140Q allosteric site.

Thiopyrano[2,3-d]Thiazoles as New Efficient Scaffolds in Medicinal Chemistry

This review presents the up to date development of fused thiopyranothiazoles that comprise one of the thiazolidine derivatives classes. Thiazolidine and thiazolidinone-related compounds belong to the widely studied heterocycles from a medicinal chemistry perspective. From the chemical point of view, they are perfect heterodienes to undergo hetero-Diels–Alder reaction with a variety of dienophiles, yielding regio- and diastereoselectively thiopyranothiazole scaffolds. The annealing of thiazole and thiopyran cycles in condensed heterosystem is a precondition for the “centers conservative” creation of the ligand-target binding complex and can promote a potential selectivity to biotargets. The review covers possible therapeutic applications of thiopyrano[2,3-d]thiazoles, such as anti-inflammatory, antibacterial, anticancer as well as aniparasitic activities. Thus, thiopyrano[2,3-d]thiazoles may be used as powerful tools in the development of biologically active agents and drug-like molecules.

Tandem hetero-Diels–Alder-hemiacetal reaction in the synthesis of new chromeno[4′,3′:4,5]thiopyrano[2,3-d]thiazoles

Novel rel-(5aR,6R,11bS)-6-hydroxy-3,5a,6,11b-tetrahydro-2H,5H-chromeno[4′,3′:4,5]thiopyrano[2,3-d][1,3]thiazole-2-ones were synthesized via tandem hetero-Diels-Alder-hemiacetal reaction of 5-(2-hydroxybenzylidene)-4-thioxo-2-thiazolidinones and α,β-unsaturated aldehydes. The stereochemistry of cycloadditions was confirmed by NMR spectra and a single crystal X-ray diffraction analysis.