Biological activity of synthesized 5-{1-[(4-chlorophenyl)sulfonyl]piperidin-4-yl}-2-mercapto-1,3,4-oxadiazole derivatives demonstrated by in silico and BSA binding studies

Synthesis, Characterization, and Enzyme Inhibition Properties of 1,2,4-Triazole Bearing Azinane Analogues

Considering the importance of acetylcholine esterase (AChE, BchE) and α-glucosidase in the treatment of Alzheimer's disease and diabetes mellitus, the synthesis of novel azinane triazole-based derivatives as effective acetylcholinesterase (AchE), α-glucosidase, urease, lipoxygenase (LOX), and butyrylcholinesterase (BChE) inhibitors is described. Azinane analogue (2) was merged with 1,2,4-triazole to acquire 1-(4-toluenesulfonyl)-4-(3-mercapto-4-methyl-4H-1,2,4-triazol-5-yl) piperidine (8) through a list of intermediates including 1-(4-toluenesulfonyl)-4-(ethoxycarbonyl) piperidine (3), 1-(4-toluenesulfonyl)-4-(2-hydrazinocarbonyl)piperidine (5), and 1-(4-toluenesulfonyl)-4-[1-(methyl amino thiocarbonyl)-2-hydrazinocarbonyl]piperidine (7). The target molecules, 1-(4-toluenesulfonyl)-4-[3-(N-alkyl/phenyl/aryl-2-ethanamoyl thio)-4-methyl-4H-1,2,4-triazol-5-yl] piperidine (12a-o), were achieved through the reaction of 8 with N-alkyl/phenyl/aryl-2-bromo ethanamides (11a-o) as electrophiles. These electrophiles were accomplished by a benign reaction of alkyl/phenyl/aryl amines (9a-o) and 2-bromo ethanoyl bromide (10). The spectral study of IR, 1D-NMR, and EI-MS corroborated the synthesized compounds. Methyl phenyl and methyl phenyl-substituted derivatives 12d and 12m with IC₅₀ = 0.73 ± 0.54; 36.74 ± 1.24; 19.35 ± 1.28; 0.017 ± 0.53; and 0.038 ± 0.50 μM are found to be the most potent AChE, α-glucosidase, urease, and BChE inhibitors. The high inhibition potential of synthesized molecules against AChE, α-glucosidase, urease, and BChEenzymes inferred their role in enzyme inhibition properties.

Synthesis, anticholinesterase activity, molecular docking, and molecular dynamic simulation studies of 1,3,4-oxadiazole derivatives

Two new series of 1,3,4-oxadiazoles bearing pyridine and thiazole heterocycles (4a-h and 5a-h) were synthesized (2,5-disubstituted-1,3,4-oxadiazoles). The structures of these newly synthesized compounds were confirmed by ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, high-resolution mass spectrometric and Fourier transform infrared spectroscopic methods. All these compounds were evaluated for their enzyme inhibitory activities against two cholinesterase enzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the studies, we identified compounds 4a, 4h, 5a, 5d, and 5e as selective AChE inhibitors, with IC₅₀ values ranging from 0.023 to 0.037 μM. Furthermore, docking studies of these compounds were performed at the active sites of their target enzymes. The molecular docking study showed that 5e possessed an ideal docking pose with interactions inside AChE.