New phosphinic and phosphonic acids: Synthesis, antidiabetic, anti-Alzheimer, antioxidant activity, DFT study and SARS-CoV-2 inhibition

Synthesis, Theoretical, in Silico and in Vitro Biological Evaluation Studies of New Thiosemicarbazones as Enzyme Inhibitors

Eleven new thiosemicarbazone derivatives (1-11) were designed from nine different biologically and pharmacologically important isothiocyanate derivatives containing functional groups such as fluorine, chlorine, methoxy, methyl, and nitro at various positions of the phenyl ring, in addition to the benzyl unit in the molecular skeletal structure. First, their substituted-thiosemicarbazide derivatives were synthesized from the treatment of isothiocyanate with hydrazine to synthesize the designed compounds. Through a one-step easy synthesis and an eco-friendly process, the designed compounds were synthesized with yields of up to 95 % from the treatment of the thiosemicarbazides with aldehyde derivatives having methoxy and hydroxy groups. The structures of the synthesized molecules were elucidated with elemental analysis and FT-IR, 1 H-NMR, and 13 C-NMR spectroscopic methods. The electronic and spectroscopic properties of the compounds were determined by the DFT calculations performed at the B3LYP/6-311++G(2d,2p) level of theory, and the experimental findings were supported. The effects of some global reactivity parameters and nucleophilic-electrophilic attack abilities of the compounds on the enzyme inhibition properties were also investigated. They exhibited a highly potent inhibition effect on acetylcholinesterase (AChE) and carbonic anhydrases (hCAs) (KI values are in the range of 23.54±4.34 to 185.90±26.16 nM, 103.90±23.49 to 325.90±77.99 nM, and 86.15±18.58 to 287.70±43.09 nM for AChE, hCA I, and hCA II, respectively). Furthermore, molecular docking simulations were performed to explain each enzyme-ligand complex's interaction.

A Combined Experimental and Computational Study of Novel Benzotriazinone Carboxamides as Alpha-Glucosidase Inhibitors

Diabetes is a chronic metabolic disorder of the endocrine system characterized by persistent hyperglycemia appears due to the deficiency or ineffective use of insulin. The glucose level of diabetic patients increases after every meal and medically recommended drugs are used to control hyperglycemia. Alpha-glucosidase inhibitors are used as antidiabetic medicine to delay the hydrolysis of complex carbohydrates. Acarbose, miglitol, and voglibose are commercial drugs but patients suffer side effects of flatulence, bloating, diarrhea, and loss of hunger. To explore a new antidiabetic drug, a series of benzotriazinone carboxamides was synthesized and their alpha-glucosidase inhibition potentials were measured using in vitro experiments. The compounds 14k and 14l were found to be strong inhibitors compared to the standard drug acarbose with IC50 values of 27.13 ± 0.12 and 32.14 ± 0.11 μM, respectively. In silico study of 14k and 14l was carried out using molecular docking to identify the type of interactions developed between these compounds and enzyme sites. Both potent compounds 14k and 14l exhibited effective docking scores by making their interactions with selected amino acid residues. Chemical hardness and orbital energy gap values were investigated using DFT studies and results depicted affinity of 14k and 14l towards biological molecules. All computational findings were found to be in good agreement with in vitro results.

Halogen substituted aurones as potential apoptotic agents: synthesis, anticancer evaluation, molecular docking, ADMET and DFT study

A series of halogen-substituted aurone derivatives (2a-k) were synthesized and evaluated for an anti-proliferative study against NCI 60 cancer cell line panel and showed that most of the compounds predominantly exhibited promising activity against MCF-7. Compound 2e exhibited promising anticancer activity against the MCF-7 cancer cell line with 84.98% percentage growth inhibition in a single dose assay of 10 μM with an IC₅₀ value of 8.157 ± 0.713 μM. In apoptotic assay, the effect of compound 2e on the cell cycle progression indicated that exposure of MCF-7 cells to compound 2e induced a significant disruption in the cell cycle profile including a time-dependent decrease in the cell population at G0/G1 and G2/M phase and arrests the cell cycle at the S phase. In silico, molecular docking ADME and toxicity studies of all compounds were also carried out. The docking study revealed that all the aurone derivatives displayed good docking scores ranging from -7.066 to -8.573. The results of Molecular Electrostatic Potential Mapping (MESP) and Density Functional Theory (DFT) studies of the most active compound 2e and least active compound 2k also favoured the experimental results.

Design, synthesis, anti-acetylcholinesterase evaluation and molecular modelling studies of novel coumarin-chalcone hybrids

The major enzyme responsible for the hydrolytic breakdown of the neurotransmitter acetylcholine (ACh) is acetylcholinesterase (AChE). Acetylcholinesterase inhibitors (AChEIs) are the most prescribed class of medications for the treatment of Alzheimer's disease (AD) and dementia. The limitations of available therapy, like side effects, drug tolerance, and inefficacy in halting disease progression, drive the need for better, more efficacious, and safer drugs. In this study, a series of fourteen novel chalcone-coumarin derivatives (8a-n) were designed, synthesized and characterized by spectral techniques like FT-IR, NMR, and HR-MS. Subsequently, the synthesized compounds were tested for their ability to inhibit acetylcholinesterase (AChE) activity by Ellman's method. All tested compounds showed AChE inhibition with IC50 value ranging from 0.201 ± 0.008 to 1.047 ± 0.043 μM. Hybrid 8d having chloro substitution on ring-B of the chalcone scaffold showed relatively better potency, with IC50 value of 0.201 ± 0.008 μM compared to other members of the series. The reference drug, galantamine, exhibited an IC50 at 1.142 ± 0.027 μM. Computational studies revealed that designed compounds bind to the peripheral anionic site (PAS), the catalytic active site (CAS), and the mid-gorge site of AChE. Putative binding modes, ligand-enzyme interactions, and stability of the best active compound are studied using molecular docking, followed by molecular dynamics (MD) simulations. The cytotoxicity of the synthesised derivatives was determined using the MTT test at three concentrations (100 g/mL, 500 g/mL, and 1 mg/mL). None of the chemicals had a significant effect on the body at the highest dose of 1 mg/mL.Communicated by Ramaswamy H. Sarma.