Design, synthesis, spectroscopic characterization, single crystal X-ray analysis, in vitro α-amylase inhibition assay, DPPH free radical evaluation and computational studies of naphtho[2,3-d]imidazole-4,9-dione appended 1,2,3-triazoles

Heterologous Expression and Biochemical Characterization of a New α-Amylase from Nocardiopsis aegyptia HDN19-252 of Antarctic Animal Origin

α-Amylases, catalyzing starch degradation, serve as vital biocatalysts in industrial and pharmaceutical applications. This study identified a new α-amylase, Alphaz, from Nocardiopsis aegyptia HDN19-252 of Antarctic animal origin, achieving heterologous expression in Escherichia coli. Phylogenetic analysis confirmed its classification into the GH13_5 subfamily of glycoside hydrolases. Recombinant Alphaz exhibited optimal activity at 40 °C/pH 8.0 while maintaining stability across 0-30 °C and pH 6.6-9.6. Its distinctive halotolerant properties included full activity retention in 0.6 M NaCl and >60% efficiency in salt-free conditions. The enzyme exhibits tolerance to K+, Ca2+, and Fe³+ while demonstrating specific inhibition by Cu2+/Zn2+. With its heterologously validated functional properties, Alphaz emerges as a programmable enzymatic tool offering advantages in sustained-release formulation quality control, targeted prodrug modification, and precision medicine applications, thereby enabling sustainable biomanufacturing solutions that harmonize process reliability with environmental compatibility.

Eco-friendly Synthesis of Iron Oxide Nanoparticles Using Parietaria alsinifolia Extracts and Evaluation of Biological Applications

The current research was conducted to synthesize Parietaria alsinifolia-mediated iron oxide nanoparticles (P.A@FeONPs) using the green and eco-friendly protocol. The biosynthesized P.A@FeONPs were characterized using various approaches like UVs, FTIR, SEM, EDX, and DLS. The mean crystallite size was calculated to be ~ 21.48 nm using the Debye-Scherrer equation. Further, various in vitro biological assays were performed to analyze the therapeutic potentials of FeONPs. 2,2-Diphenyl-1-picrylhydrazy (DPPH) antioxidant activity was performed to reveal the DPPH radical scavenging potential of P.A@FeONPs and was calculated as 72%. Similarly, the total reducing power was determined as 65.45 ± 1.77%. In addition, P.A@FeONPs exhibited a significant total antioxidant capacity of 87 ± 4.8%. Antibacterial and antifungal assays were performed using the disc diffusion method. Among the different bacterial strains accession (EFB-10-2023 M.B), Rhodococcus jostii has shown the highest zone of inhibition (23.9 mm at 1000 μg/mL), while Escherichia coli displayed a 22.65 mm zone of inhibition at (1000 μg/mL). Similarly, Aspergillus niger exhibited a substantial zone of inhibition (28.75 mm). A brine shrimp cytotoxicity assay revealed the cytotoxicity potential (LC50 244.92 μg/mL). P.A@FeONPs were also tested against red blood cells, HEK-293, and VERO cell lines (< 200 μg/mL) to validate their biocompatibility. An alpha-amylase inhibition assay demonstrated 68.66% inhibition and substantial cytotoxicity against Hep-2 liver cancer cells (IC50 100 μg/mL). In conclusion, P.A@FeONPs have shown significant bioactivities. In the future, we recommend other biological and catalytic activities using different animal models to explore its potential further.

Key molecular scaffolds in the development of clinically viable α-amylase inhibitors

The escalating cases of type II diabetes combined with adverse side effects of current antidiabetic drugs spurred the advancement of innovative approaches for the management of postprandial glucose levels. α-Amylase is an endoamylase responsible for the breakdown of internal α-1,4-glycosidic linkages in dietary starch, producing oligosaccharides. Subsequently, α-glucosidase degraded these oligosaccharides to monosaccharides, which are absorbed into the bloodstream and become available to the body. The inhibitors of α-amylase reduced the digestibility of carbohydrates accompanied by delayed glucose absorption, leading to decreased blood glucose levels after meals and thus, inhibition of the enzyme seems to be a crucial strategy for diabetes management and improving overall glycemic control in diabetic patients. The present review article emphasizes the therapeutic promise of recently discovered potential α-amylase inhibitors, highlighting their in vitro, in silico and in vivo profiles. Ultimately, we addressed the contemporary challenges and potential routes ahead in the search for safe and reliable α-amylase inhibitors for clinical use, summarizing the most recent research in the field.

Efficient synthesis of promising antidiabetic triazinoindole analogues via a solvent-free method: investigating the reaction of 1,3-diketones and 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole-3-thione

Diabetes poses a significant global health challenge, driving the search for effective management strategies. In the past years, α-amylase inhibitors have emerged as promising candidates for regulating blood sugar levels. In this concern, we have synthesized a series of novel 3-methyl-2-aroylthiazolo[3',2':2,3][1,2,4]triazino[5,6-b]indole derivatives via the regioselective reaction of 2,5-dihydro-3H-[1,2,4]triazino[5,6-b]indole-3-thione and 1,3-diketones in the presence of NBS under solvent-free conditions. Subsequently, the inhibitory potential of the newly synthesized 3-methyl-2-aroylthiazolo[3',2':2,3][1,2,4]triazino[5,6-b]indole derivatives was assessed against the α-amylase enzyme to probe their antidiabetic properties. In vitro studies revealed moderate to excellent α-amylase inhibitory activity, with IC50 values ranging from 16.14 ± 0.41 to 27.69 ± 0.58 μg ml-1. Furthermore, SAR analysis showed that compounds containing halogen groups exhibited superior inhibition potential, surpassing the standard drug Acarbose (IC50 = 18.64 ± 0.42 μg ml-1), particularly derivatives substituted with 4-fluoro and 2,4-dichloro groups, with IC50 values of 16.14 ± 0.41 μg ml-1 and 17.21 ± 0.15 μg ml-1, respectively. Additionally, molecular docking unveiled the binding modes of ligands with the active site of A. oryzae α-amylase. Encouragingly, the theoretical analyses closely mirrored the experimental findings, further underlining the promise of these synthetic molecules as potent α-amylase inhibitors.

Identification of 3-methyl-1-(3-methylpyridin-2-yl)-1H-pyrazol-5-ol as promising neuroprotective agent

Pyrazolol derivatives are gaining significant attention for their diverse pharmacological effects, such as analgesic, anti-inflammatory, antioxidant, and anticancer activities. In this study, 20 pyrazolol derivatives were designed and synthesized to develop an anti-ischemic stroke formulation with free radical scavenging activity. Most of these synthesized compounds demonstrated antioxidant capabilities in DPPH, ABTS radical scavenging, and ORACFL assays. The methyl-substituted compound Y12, in particular, showed exceptional antioxidant capacity. Additionally, these compounds showed excellent neurocytoprotective effects in the SH-SY5Y cell injury model subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). Notably, Y12 exhibited significant metal chelating activity with Cu2+. In vivo studies confirmed that compound Y12 has neuroprotective effects and can significantly reduce the infarct area in a mouse model of focal cerebral ischemia induced by transient middle cerebral artery occlusion (tMCAO).

Naphthoquinone fused diazepines targeting hyperamylasemia: potential therapeutic agents for diabetes and cancer

Aim: Elevated levels of amylase in the blood, known as hyperamylasemia, have been correlated with diabetes and cancer. To investigate the impact of hyperamylasemia on cellular proliferation, it is imperative to design dual inhibitors targeting both α-amylase activity and cancer progression.Materials & methods: Naphthoquinone fused diazepines have been synthesized using multicomponent reaction with high Eco-score of 87 and evaluated for bio efficacy using antioxidant and α-amylase inhibition assay. A correlation between diabetes and cancer has been established via preliminary screening against A549 based lung cancer cell line at 5 μM.Results & conclusion: Compound 4b exhibited superior anti-oxidant and α-amylase inhibitory potential over butylated hydroxytoluene (BHT) and acarbose, respectively with uncompetitive mode of inhibition. Compounds possessing more than 50 % inhibition were then investigated for their IC50 against A549 (Lung cancer), and Breast cancer (MCF-7 and MDA-MB-231) cells. Among all, compound 4p has been selected for further studies, as it demonstrated significant cytotoxicity, while compound 4b showed no effect on AKT gene expression but upregulated IGF-1R gene expression, suggesting a role in managing diabetes. Compound 4p exhibited the ability to decrease AKT expression and increase IGF-1R expression, indicating its potential for treating both diabetes and cancer.

Synthesis of thiazolidine-2,4-dione tethered 1,2,3-triazoles as α-amylase inhibitors: In vitro approach coupled with QSAR, molecular docking, molecular dynamics and ADMET studies

A new series of thiazolidine-2,4-dione tethered 1,2,3-triazole derivatives were designed, synthesized and screened for their α-amylase inhibitory potential employing in vitro and in silico approaches. The target compounds were synthesized with the help of Cu (I) catalyzed [3 + 2] cycloaddition of terminal alkyne with numerous azides, followed by unambiguously characterizing the structure by employing various spectroscopic approaches. The synthesized derivatives were assessed for their in vitro α-amylase inhibition and it was found that thiazolidine-2,4-dione derivatives 6e, 6j, 6o, 6u and 6x exhibited comparable inhibition with the standard drug acarbose. The compound 6e with a 7-chloroquinolinyl substituent on the triazole ring exhibited significant inhibition potential with IC50 value of 0.040 μmol mL-1 whereas compound 6c (IC50 = 0.099 μmol mL-1) and 6h (IC50 = 0.098 μmol mL-1) were poor inhibitors. QSAR studies revealed the positively correlating descriptors that aid in the design of novel compounds. Molecular docking was performed to investigate the binding interactions with the active site of the biological receptor and the stability of the complex over a period of 100 ns was examined using molecular dynamics studies. The physiochemical properties and drug-likeliness behavior of the potent derivatives were investigated by carrying out the ADMET studies.

Pyrano[2,3-c]pyrazole fused spirooxindole-linked 1,2,3-triazoles as antioxidant agents: Exploring their utility in the development of antidiabetic drugs via inhibition of α-amylase and DPP4 activity

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.

A New Avenue for Enhanced Treatment of Hyperuricemia and Oxidative Stress: Design, Synthesis and Biological Evaluation of Some Novel Mutual Prodrugs Involving Febuxostat Conjugated with Different Antioxidants

Febuxostat (FEB) is the first non-purine xanthine oxidase inhibitor (XOI) used for the treatment of hyperuricemia and gout. The oxidative stress induced by reactive oxygen species (ROS) which accompany purine metabolism by XO, could contribute to cellular damage and several pathological conditions. In this view, the present work addresses the evaluation of combining the hypouricemic effect of FEB and the free radical scavenging potential of various natural antioxidants in a single chemical entity by implementing the "mutual prodrug" strategy. Accordingly, a series of five ester prodrugs containing FEB together with different naturally occurring antioxidants namely, thioctic acid (4), thymol (5), menthol (6), vanillin (7), and guaiacol (8) was synthesized. Prominently, all the chemically conjugated prodrugs (4 - 8) revealed an obvious increase in the hypouricemic and antioxidant potentials when compared with their corresponding promoieties and physical mixtures. Moreover, they showed a potential protective effect against CCl4-induced hepatotoxicity and oxidative stress, together with no cytotoxicity on normal breast cells (MCF10A). Furthermore, the in vitro chemical and enzymatic stability studies of the prodrugs (4 - 8) using a developed HPLC method, verified their stability in different pHs, and rapid hydrolysis in rabbit plasma and liver homogenate to their parent metabolites. Moreover, the prodrugs (4 - 8) showed higher lipophilicity and lower aqueous solubility when compared to the parent drugs. Finally, the obtained merits from the implementation of the mutual prodrug strategy would encourage further application in the development of promising candidates with high therapeutic efficacy and improved safety profiles.

Novel dihydrobenzofuran derivatives: design, synthesis, cytotoxic activity, apoptosis, molecular modelling and DNA binding studies

Pyrazoline derivatives (3a-3e) and (4a-4e) were designed and synthesized through chalcones (2a-2e) cyclization with NH2NH2/HCOOH and NH2CSNHNH2/CH3COOH, respectively. The molecular structures were elucidated by using various techniques such as UV-visible, FT-IR, 1H, 13C NMR spectroscopy and mass spectrometry. The purity of all synthesized compounds was checked by the liquid chromatography-mass spectrometry (LC-MS). Single X-ray crystallography was confirmed the molecular structure of analogs (2d, 3e and 4e). Anticancer activity of the all derivatives was screened against human cancer cell MCF-7 and HepG2 cell lines by MTT assay. The results of anticancer activity of novel analogs 2b, 3b and 3e exhibited promising activity against MCF-7 but low toxic against the HepG2 normal cell line. By using a flow cytometry-based technique, the anticancer effectiveness of potent compounds against the MCF-7 cancer cell line was further validated. DNA binding interactions of the novel analogs 3b and 3e were carried out with calf thymus DNA (Ct-DNA) using absorption, fluorescence, circular dichroism and cyclic voltammetry. In silico molecular modelling of pyrazoline derivatives were also studied using Schrödinger-Maestro v2021-2 against tyrosine kinase receptor with PDB ID: 1M17 to explore their best hits. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical was used to measure the antioxidant capacity of active pyrazoline derivatives. Using Swiss ADMET software, the ADMET characteristics of pyrazoline derivatives were also investigated.Communicated by Ramaswamy H. Sarma.

CORAL: probing the structural requirements for α-amylase inhibition activity of 5-(3-arylallylidene)-2-(arylimino)thiazolidin-4-one derivatives based on QSAR with correlation intensity index, molecular docking, molecular dynamics, and ADMET studies

The present study aims to examine the structural requirements governing α-amylase inhibitory activity of 5-(3-arylallylidene)-2-(arylimino)thiazolidin-4-one derivatives and their precursors by employing a multifaceted approach combining in vitro and in silico studies. The in vitro assay findings revealed strong inhibitory effect of this class of compounds against α-amylase and compound 20 exhibited maximum percentage inhibition of 88.54 ± 0.69, 84.98 ± 0.40, 77.26 ± 0.75, 67.80 ± 0.54, and 62.93 ± 1.17 at 200, 100, 50, 25, and 12.5 µg mL-1, respectively. Multiple CORAL QSAR models were developed from the randomly distributed eight splits by employing two target functions (TF1, TF2 with WCII = 0.0 and = 0.3, respectively), and the quality of predictions by the produced models was validated with the help of various statistical parameters. The model M-4 (R2Val = 0.8799) and model M-11 (R2Val = 0.9064) were the leading models developed by using TF1 and TF2. We designed five new congeneric inhibitors (D-1 to D-5) by incorporating SMILES features positively correlating with the activity. Molecular docking experiments were carried out to confirm the binding of these new inhibitors with the biological receptor α-amylase (PDB ID: 7TAA). Furthermore, molecular dynamic simulations provided a thorough knowledge of the binding process by shedding insight into the dynamic behavior and stability of the ligand-receptor complex over time. The results of this study highlight the key structural characteristics needed for improved α-amylase inhibitory efficacy and provide a rational basis for the development of more effective inhibitors.Communicated by Ramaswamy H. Sarma.

Benzimidazole-Triazole Hybrids as Antimicrobial and Antiviral Agents: A Systematic Review

Bacterial infections have attracted the attention of researchers in recent decades, especially due to the special problems they have faced, such as their increasing diversity and resistance to antibiotic treatment. The emergence and development of the SARS-CoV-2 infection stimulated even more research to find new structures with antimicrobial and antiviral properties. Among the heterocyclic compounds with remarkable therapeutic properties, benzimidazoles, and triazoles stand out, possessing antimicrobial, antiviral, antitumor, anti-Alzheimer, anti-inflammatory, analgesic, antidiabetic, or anti-ulcer activities. In addition, the literature of the last decade reports benzimidazole-triazole hybrids with improved biological properties compared to the properties of simple mono-heterocyclic compounds. This review aims to provide an update on the synthesis methods of these hybrids, along with their antimicrobial and antiviral activities, as well as the structure-activity relationship reported in the literature. It was found that the presence of certain groups grafted onto the benzimidazole and/or triazole nuclei (-F, -Cl, -Br, -CF₃, -NO₂, -CN, -CHO, -OH, OCH₃, COOCH₃), as well as the presence of some heterocycles (pyridine, pyrimidine, thiazole, indole, isoxazole, thiadiazole, coumarin) increases the antimicrobial activity of benzimidazole-triazole hybrids. Also, the presence of the oxygen or sulfur atom in the bridge connecting the benzimidazole and triazole rings generally increases the antimicrobial activity of the hybrids. The literature mentions only benzimidazole-1,2,3-triazole hybrids with antiviral properties. Both for antimicrobial and antiviral hybrids, the presence of an additional triazole ring increases their biological activity, which is in agreement with the three-dimensional binding mode of compounds. This review summarizes the advances of benzimidazole triazole derivatives as potential antimicrobial and antiviral agents covering articles published from 2000 to 2023.