Organocatalyzed Solvent Free and Efficient Synthesis of 2,4,5-Trisubstituted Imidazoles as Potential Acetylcholinesterase Inhibitors for Alzheimer's Disease

Biological Evaluation of Anti-Cholinesterase Activity, in Silico Molecular Docking Studies, and DFT Calculations of Green Synthesized Thiadiazolo[3,2-a]pyrimidine Derivatives

A series of [1,3,4] thiadiazolo[3,2-a]pyrimidine-6-carboxylate derivatives 4(a-n) have been designed and synthesized as inhibitors of acetylcholinesterase (AChE). Synthesizing of thiadiazolo[3,2-a] pyrimidines was carried out in a single step, one-pot reaction using aromatic aldehydes, ethyl acetoacetate and different derivatives of 1,3,4-thiadiazoles (with molar ratio of 1 : 2 : 1, respectively) in conjunction with the catalyst, anhydrous iron(III) chloride by a grinding method under solvent-free conditions at room temperature. The in-vitro studies exhibited good potency for inhibiting AChE comparable with donepezil as the reference drug. The best results were obtained by Ethyl 2-(4-nitroophenyl)-7-methyl-5-(pyridin-3-yl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidine-6-carboxylate 4n with IC50 value of 0.082±0.001 μM which was comparable with AChE inhibitory effects of donepezil (IC50 =0.079 μM).

Investigations of Electronic, Structural, and In Silico Anticancer Potential of Persuasive Phytoestrogenic Isoflavene-Based Mannich Bases

Isoflavenes have received the greatest research attention among the many groups of phytoestrogens. In this study, various isoflavene-based Mannich bases were selected for their theoretical studies. The purpose of this research was to discover the binding potential of all the designated Mannich bases acting as inhibitors against cancerous proteins EGFR, cMet, hTrkA, and HER2 (PDB codes: 5GTY, 3RHK, 6PL2, and 7JXH, respectively). For their virtual screening, DFT calculations and molecular docking studies were undertaken using in silico software. Docking studies predicted that ligands 5 and 15 exhibited the highest docking score by forming hydrogen bonds within the active pocket of protein 6PL2, ligands 1 and 15 both with protein 3RHK, and 7JXH, 12, and 17 with protein 5GTY. Rendering to the trends in polarizability and dipole moment, the energy gap values (0.2175 eV, 0.2106 eV) for the firm conformers of Mannich bases (1 and 4) replicate the increase in bioactivity and chemical reactivity. The energy gap values (0.2214 eV and 0.2172 eV) of benzoxazine-substituted isoflavene-based Mannich bases (9 and 10) reflect the increase in chemical potential due to the most stable conformational arrangements. The energy gap values (0.2188 eV and 0.2181 eV) of isoflavenes with tertiary amine-based Mannich bases (14 and 17) reflect the increase in chemical reactivity and bioactivity due to the most stable conformational arrangements. ADME was also employed to explore the pharmacokinetic properties of targeted moieties. This study revealed that these ligands have a strong potential to be used as drugs for cancer treatment.

Synthesis, in vitro cholinesterase inhibition, molecular docking, DFT and ADME studies of novel 1,3,4-oxadiazole 2-thiol derivatives

A sequence of 1,3,4-oxadiazole 2-thiol derivatives bearing various alkyl or aryl moieties was designed, synthesized, and characterized by modern spectroscopic methods to yield 17 compounds ( 6a - 6q ) which were screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in search of 'lead' compounds for the treatment of Alzheimer disease (AD). The compounds 6q, 6p, 6k, 6o, and 6l showed inhibitory capability against AChE and BChE, with IC 50 values ranging from 11.730.49 to 27.360.29 µM for AChE and 21.830.39 to 39.430.44 µM for BChE, inhibiting both enzymes within a limited range. The SAR ascertained that the substitution of the aromatic moiety had a profound effect on the AChE and BChE inhibitory potential as compared to the aliphatic substitutions which were supported by the molecular docking studies. In silico ADME studies reinforced the drug-likeness of most of the synthesized molecules. These results were additionally supplemented by the molecular orbital analysis (HOMO-LUMO) and electrostatic potential maps got from DFT calculations. ESP maps expose that on all structures, there are two potential binding sites conquered by the most positive and most negative districts.