Schiff Bases of Pioglitazone Provide Better Antidiabetic and Potent Antioxidant Effect in a Streptozotocin-Nicotinamide-Induced Diabetic Rodent Model

3,5-Disubstituted-thiazolidine-2,4-dione hybrids as antidiabetic agents: Design, synthesis, in-vitro and In vivo evaluation

Diabetes is one of the fastest-growing metabolic disorders, nearly doubling the number of patients each year. There are different treatment approaches available for the management of diabetes, which lacks due to their side effects. The inhibition of enzymes involved in the metabolism of complex polysaccharides to monosaccharides has proven beneficial in patients with type 2 diabetes mellitus. Two enzymes, α-amylase and α-glucosidase, have emerged as potential drug targets and are widely explored for drug development against type 2 diabetes mellitus. In this context, thiazolidine-2,4-diones (TZDs) have emerged as potential drug candidates for developing newer molecules against α-amylase and α-glucosidase. Nineteen TZD-hybrids were synthesized and evaluated in vitro α-amylase and α-glucosidase inhibitory activity. The compounds 7i, 7k, and 7p have emerged as the best dual inhibitors with IC50 of 10.33 ± 0.11-20.94 ± 0.76 μM and 10.19 ± 0.25-24.07 ± 1.56 μM against α-glucosidase and α-amylase, respectively. The derivatives had good anti-oxidant activity, displaying IC50 = 14.95 ± 0.65-23.27 ± 0.99 μM. The compounds 7k and 7p showed the best inhibition of reactive oxygen species in the PNAC-1 cells. The molecules exhibit good binding within the active site of α-amylase (PDB id: 1B2Y) and α-glucosidase (PDB id: 3W37), displaying binding energies of -7.5 to -10.7 kcal/mol and -7.4 to -10.3 kcal/mol, respectively. Further, the compounds were nontoxic (LD50 = 500-1311 mg/kg) and possessed good GI absorption. The compounds 7i, 7k, and 7p were evaluated in vivo antidiabetic activity in an STZ-induced diabetic model in Wistar rats. The compound 7p emerged as the best compound in the in vivo studies; however, the activity was lesser than that of the standard drug pioglitazone.

Antidiabetes and antioxidant potential of Schiff bases derived from 2-naphthaldehye and substituted aromatic amines: Synthesis, crystal structure, Hirshfeld surface analysis, computational, and invitro studies

Three Schiff bases were synthesised by the condensation reaction between 2-napthaldehyde and aromatic amines to afford (E)-N-mesityl-1-(naphthalen-2-yl)methanimine (L1), (E)-N-(2,6-dimethylphenyl)-1-(naphthalen-2-yl)methanimine (L2) and (E)-N-(2,6-diisopropylphenyl)-1-(naphthalen-2-yl)methanimine (L3). The synthesised compounds were characterised using UV-visible, NMR (13C & 1H), and Fourier transform infrared spectroscopic methods while their purity was ascertained by elemental analysis. Structural analysis revealed that the naphthalene ring is almost coplanar with the imine functional group as evident by C1-C10-C11-N1 torsion angles of 176.4(2)° and 179.4(1)° in L2 and L3, respectively. Of all the various intermolecular contacts, H⋯H interactions contributed mostly towards the Hirshfeld surfaces of both L2 (58.7 %) and L3 (69.7 %). Quantum chemical descriptors of L1 - L3 were determined using Density Functional Theory (DFT) and the results obtained showed that the energy band gap (ΔE) for L1, L2 and L3 are 3.872, 4.023 and 4.004 eV respectively. The antidiabetic potential of the three compounds were studied using α-amylase and α-glucosidase assay. Compound L1 showed very promising antidiabetic activities with IC50 values of 58.85 μg/mL and 57.60 μg/mL while the reference drug (Acarbose) had 405.84 μg/mL and 35.69 μg/mL for α-amylase and α-glucosidase respectively. In-silico studies showed that L1 docking score as well as binding energies are higher than that of acarbose, which are recognized inhibitors of α-amylase together with α-glucosidase. Further insight from the RMSF, RMSD and RoG analysis predicted that, throughout the simulation L1 showcased evident influence on the structural stability of α-amylase. The antioxidant potential of the compounds was carried out using nitric oxide (NO), ferric reducing ability power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The compounds exhibited good to fairly antioxidant properties with L1 as well as L3 having IC50 values of 70.91 and 91.21 μg/mL respectively for NO scavenging activities assay, which comparatively outshined acarbose (reference drug) with IC50 value of 109.95 μg/mL. Pharmacology and pharmacokinetics approximations of L1 - L3 showed minimal violation of Lipinski's Ro5 and this projects them to be less toxic and orally bioavailable as potential templates for the design of therapeutics with antioxidant and antidiabetic activities.

Design, Synthesis, and Biological Evaluation of Novel Quercetin Derivatives as PPAR-γ Partial Agonists by Modulating Epithelial-Mesenchymal Transition in Lung Cancer Metastasis

Epithelial-to-mesenchymal transition (EMT) is responsible for driving metastasis of multiple cancer types including lung cancer. Peroxisome proliferator-activated receptor (PPAR)-γ, a ligand-activated transcription factor, controls expression of variety of genes involved in EMT. Although several synthetic compounds act as potent full agonists for PPAR-γ, their long term application is restricted due to serious adverse effects. Therefore, partial agonists involving reduced and balanced PPAR-γ activity are more effective and valued. A previous study discerned the efficacy of quercetin and its derivatives to attain favorable stabilization with PPAR-γ. Here this work is extended by synthesizing five novel quercetin derivatives (QDs) namely thiosemicarbazone (QUETSC)) and hydrazones (quercetin isonicotinic acid hydrazone (QUEINH), quercetin nicotinic acid hydrazone (QUENH), quercetin 2-furoic hydrazone (QUE2FH), and quercetin salicyl hydrazone (QUESH)) and their effects are analyzed in modulating EMT in lung cancer cell lines via PPAR-γ partial activation. QDs-treated A549 cells diminish cell proliferation strongly at nanomolar concentration compared to NCI-H460 cells. Of the five screened derivatives, QUETSC, QUE2FH, and QUESH exhibit the property of partial activation as compared to the overexpressive level of rosiglitazone. Consistently, these QDs also suppress EMT process by markedly downregulating the levels of mesenchymal markers (Snail, Slug, and zinc finger E-box binding homeobox 1) and concomitant upregulation of epithelial marker (E-cadherin).

Synthesis, Spectral Characterization, Thermal Investigation, Computational Studies, Molecular Docking, and In Vitro Biological Activities of a New Schiff Base Derived from 2-Chloro Benzaldehyde and 3,3'-Dimethyl-[1,1'-biphenyl]-4,4'-diamine

The current research involves the synthesis of a new Schiff base through the reaction between 2-chlorobenzaldehyde and 3,3'-dimethyl-[1,1'-biphenyl]-4,4'-diamine by using a natural acid catalyst and a synthesized compound physicochemically characterized by X-ray diffraction, Fourier transform infrared spectroscopy, 1H- and 13C-nuclear magnetic resonance, and liquid chromatography-mass spectrometry. Thermal studies were conducted using thermogravimetric, differential thermal analysis, and differential thermogravimetric curves. These curves were obtained in an inert nitrogen environment from ambient temperature to 1263 K using heating rates of 10, 15, and 20 K·min-1. Using thermocurve data, model-free isoconversional techniques such as Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, and Friedman are used to determine kinetic parameters. These parameters include activation energy, phonon frequency factor, activation enthalpy, activation entropy, and Gibb's free energy change. All of the results have been thoroughly investigated. The molecule's anti-inflammatory and antidiabetic properties were also examined. To learn more about the potential of the Schiff base and how successfully it can suppress the amylase enzyme, a molecular docking experiment was also conducted. For in silico research, the Swiss Absorption, Distribution, Metabolism, Excretion, and Toxicity algorithms were used to calculate the theoretical pharmacokinetic properties, oral bioavailability, toxic effects, and biological activities of the synthesized molecule. Moreover, the cytotoxicity tests against a human lung cancer cell line (A549) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay demonstrated that the synthesized Schiff base exhibited significant anticancer properties.

Step-Economical Mechanosynthesis of Hybrid Azoles: Deciphering Their π-Orbital and Pharmacological Characteristics

A hybrid pharmacophore strategy for unifying 1,2,3-triazole with 1,2,4-triazole cores to prepare mixed triazoles was accomplished by a ball-milling approach. The developed chemistry works under the catalysis of cupric oxide nanoparticles with salient features like one-jar operation, lower number of synthetic steps, catalyst recyclability, time-dependent product control, and good overall yields. π-Orbital properties based on theoretical calculations supported the suitability of these molecules for pharmacological screening. Therefore, the biological potency of the synthesized molecules was evaluated for antioxidant, anti-inflammatory, and anti-diabetic activities. By virtue of their proton-donating tendency, all compounds showed promising radical-scavenging activity with the inhibition level reaching up to 90 %. These molecular hybrids also exhibited anti-inflammatory and anti-diabetic potencies similar to those of standard compounds, owing to their electron-rich nature. Finally, α-amylase inhibitory potential was demonstrated in silico; significant regions necessary for enzyme inhibition were identified by hydrogen bonding interactions.

DFT calculations, molecular docking, in vitro antimicrobial and antidiabetic studies of green synthesized Schiff bases: as Covid-19 inhibitor

In this investigation, we synthesized Schiff bases 2-(2-methoxyphenoxy)-N-(4-methylbenzylidene)ethanamine, N-(4-methoxybenzylidene)-2-(2-methoxyphenoxy)ethanamine and 2-(2-methoxyphenoxy)-N-(4-nitrobenzylidene)ethanamine from 2-(2-methoxyphenoxy)ethanamine and various aromatic aldehydes by the environmentally friendly sonication method. The B3LYP method with a 6-311++G (d, p) basis set was used in the DFT calculation to obtain the optimized structure of the Schiff base MPEA-NIT. The compounds were tested in vitro for inhibition of bacterial growth (disc well method) and inhibition of α-amylase (starch-iodine method). The compounds tested showed inhibitory activities. In addition, they were subjected to PASS analysis, drug likeness, and bioactivity score predictions using online software. To confirm the experimental findings, molecular docking analyses of synthesized compounds on α-amylase (PDB ID: 1SMD), tRNA threonylcarbamoyladenosine (PDB ID: 5MVR), glycosyl transferase (PDB ID: 6D9T), and peptididoglycan D,D-transpeptidase (PDB ID: 6HZQ) were performed. The emergence of a new coronavirus epidemic necessitates the development of antiviral medications (SARS-CoV-2). Docking active site interactions were investigated to predict compounds' activity against COVID-19 by binding with the SARS-CoV-2 (PDB ID: 6Y84).Communicated by Ramaswamy H. Sarma.

Anticancer heterocyclic hybrids: design, synthesis, molecular docking and evaluation of new thiazolidinone-pyrazoles

In order to obtain potential anticancer agents, hybrid compounds have been synthesized by coupling thiazolidinone and pyrazole scaffolds. Among the synthesized compounds, 2-(1,3-diphenyl-1H-pyrazol-4-yl)-3-phenyl thiazolidin-4-one (4a) was found to be the most potent based on a docking (−9.307) and binding scores (−66.46), along with good ADME parameters. In vitro anticancer activity of compound 4a shows a maximum inhibition against lung cancer (NCI-H23) cell lines with a moderate inhibition rate of 31.01%. Molecular docking studies revealed that these hybrid compounds bind well to the active site of peroxisome proliferator-activated receptors-gamma (PPAR-gamma). Doxorubicin was used as a positive control. It can be concluded that 4a having pyrazole-thiazolidinone ring systems has the potential to be developed as an anticancer agent.

Metal Complexes with Schiff Bases: Data Collection and Recent Studies on Biological Activities

Metal complexes play a crucial role in pharmaceutical sciences owing to their wide and significant activities. Schiff bases (SBs) are multifaceted pharmacophores capable of forming chelating complexes with various metals in different oxidation states. Complexes with SBs are extensively studied for their numerous advantages, including low cost and simple synthetic strategies. They have been reported to possess a variety of biological activities, including antimicrobial, anticancer, antioxidant, antimalarial, analgesic, antiviral, antipyretic, and antidiabetic ones. This review summarizes the most recent studies on the antimicrobial and antiproliferative activities of SBs-metal complexes. Moreover, recent studies regarding mononuclear and binuclear complexes with SBs are described, including antioxidant, antidiabetic, antimalarial, antileishmanial, anti-Alzheimer, and catecholase activities.

The Nicotinamide/Streptozotocin Rodent Model of Type 2 Diabetes: Renal Pathophysiology and Redox Imbalance Features

Diabetic nephropathy (DN) is a common complication of diabetes mellitus. While there has been a great advance in our understanding of the pathogenesis of DN, no effective managements of this chronic kidney disease are currently available. Therefore, continuing to elucidate the underlying biochemical and molecular mechanisms of DN remains a constant need. In this regard, animal models of diabetes are indispensable tools. This review article highlights a widely used rodent model of non-obese type 2 diabetes induced by nicotinamide (NA) and streptozotocin (STZ). The mechanism underlying diabetes induction by combining the two chemicals involves blunting the toxic effect of STZ by NA so that only a percentage of β cells are destroyed and the remaining viable β cells can still respond to glucose stimulation. This NA-STZ animal model, as a platform for the testing of numerous antidiabetic and renoprotective materials, is also discussed. In comparison with other type 2 diabetic animal models, such as high-fat-diet/STZ models and genetically engineered rodent models, the NA-STZ model is non-obese and is less time-consuming and less expensive to create. Given that this unique model mimics certain pathological features of human DN, this model should continue to find its applications in the field of diabetes research.