Α-amylase Inhibitory Potential Research Articles

Benzylidenehydrazine Derivatives: Synthesis, Antidiabetic Evaluation, Antioxidation, Mode Of Inhibition, DFT And Molecular Docking Studies.

Diabetes mellitus (DM) is a metabolic condition that is a profound health concern across the globe due to its contribution to the increased mortality rate. It affects millions of people around the world and is associated with severe complications among people diagnosed with it. Herein, we report the synthesis of benzylidenehydrazine derivatives as well as their evaluation as α-glucosidase and α-amylase inhibitors including their antioxidant testing. Generally, all the synthesized derivatives were more potent inhibitors of α-amylase than of α-glucosidase. Specifically, 2,4 fluoro substituted analogue 9 (IC50 =116.19 µM) emerged as the strongest α-amylase inhibitor with ~5-fold superior activity in comparison to the standard drug, acarbose (IC50 = 600 µM). Compounds 18 (IC50= 240.59) and 19 (IC50 = 198.32 µM) displayed the strongest NO scavenging activity compared to Trolox (IC50 = 272.36 µM). In addition, the enzyme kinetic studies indicated that compound 9 acts as a non-competitive inhibitor of α-amylase. Finally, density functional theory and molecular docking studies for compound 9 were conducted to explore its structural and electronic properties as well as to determine protein-ligand interactions, respectively to decipher its observed activity.

Evaluating the antidiabetes and antioxidant activities of halogenated Schiff bases derived from 4-(diethylamino)salicylaldehyde: in vitro antidiabetes, antioxidant and computational investigation

Six Schiff bases with general name 5-(diethylamino)-2-(((halophenyl)imino)methyl)phenol (where halo = 4-fluoro (H1), 2-fluoro (H2), 2-bromo (H3), 4-bromo (H4), 4-chloro (H5) and 3-chloro-4-fluoro (H6)) were prepared by the condensation reaction between 4-(diethylamino)salicylaldehyde and suitable halogenated aromatic amines. The six halogenated Schiff bases were elucidated using different spectroscopic techniques and the structure of H3 and H6 were confirmed using single-crystal X-ray crystallography. The bond lengths of C7–N1, C7–C8 and C8–C9 obtained from structural analysis for both compounds depicted their enol-tautomeric characteristic form. The Hirshfeld analysis revealed that H‧‧‧H intermolecular contacts contributed most towards the Hirshfeld surfaces of both H3 (47.6%) and H6 (39.9%). Quantum chemical calculation studies showed that H1 and H2 have the highest and lowest energy band gap (∆E = 3.80 eV for H1 and ∆E = 3.73 eV for H2), depicting H2 and H1 as the most and least chemically reactive respectively among all the compounds. α-Amylase and α-glucosidase assay were used to evaluate the antidiabetes prowess of the synthesized compounds. All the compounds exhibited lower IC50 values than acarbose (reference drug) in α-amylase assay experiments and H5 with lowest IC50 value of 63.54 μM could be suggested to have the highest α-amylase inhibitory potential among the test samples. For α-glucosidase assay, H1–H6 displayed good antidiabetic potential. However, none of the compounds outshined acarbose with H6 having highest α-glucosidase inhibitory potential when compared to others i.e., IC50 of H6 = 60.89 μM and IC50 of acarbose = 51.42 μM. We measured the antioxidant potential of H1–H6 exploring 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and ferric reducing ability power (FRAP) assays. The DPPH as well as NO radical scavenging assay showed that all the compounds exhibited excellent antioxidant results with some of the compounds surpassing catechin (reference drug). Compound H5 with IC50 values of 30.32 mM and 31.73 mM outshined catechin with IC50 values of 31.17 mM and 140.62 mM for DPPH and NO assays respectively. All the compounds fell within the threshold of Lipinski’s Ro5 projecting them as orally bioavailable and less toxic future therapeutics.

Synthesis, C-N/N-N bond conformational analysis and evaluation of naphtho[2,3-d][1,2,3]triazole-4,9-dione tethered N-acyl hydrazones as α-amylase inhibitors: Insights from molecular modeling and ADMET analysis

In an effort to expand the repertoire of potent α-amylase inhibitors, we sought to develop novel inhibitors by combining 1,4-naphthoquinone, 1,2,3-triazole, and N-acyl hydrazone scaffolds in a single matrix. To achieve this, twelve novel naphtho[2,3-d][1,2,3]triazole-4,9‑dione tethered N-acyl hydrazones were synthesized through condensation reaction of 2-(4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d][1,2,3]triazol-1-yl)acetohydrazide with various substituted aryl aldehydes. Structural elucidation for all the compounds was performed using 1D, 2D-NMR, FTIR, and mass spectral analyses. The synthesized molecules were evaluated for their ability to inhibit α-amylase activity using acarbose as the standard drug. All the derivatives exhibited potent inhibition of α-amylase, with IC50 values ranging between 17.26 ± 0.07 to 25.62 ± 0.03 μg/mL. Notably, compound 9c possessing –meta substituted –NO2 group displayed the highest activity (IC50 = 17.26 ± 0.07 μg/mL) among the series. Structure-activity relationship (SAR) revealed the pivotal role of aryl ring substitutions in determining inhibitory efficacy. To validate these findings and to assess the binding stability of 9c within the catalytic site α-amylase dervied for A. oryzae (PDB ID:7TAA), in silico studies were performed. The compound 9c effectively occupies the enzyme's active pocket, with minimal RMSD fluctuations observed over 100 ns simulation, indicating stable protein-ligand complex. ADMET predictions suggested favorable drug-like properties, underscoring the potential of these compounds as novel α-amylase inhibitors for managing type 2 diabetes mellitus

Unraveling the Antidiabetic Effect of Alternantera brasiliana (L.) Kuntze: A Combined in Vitro and in Vivo Approach

Background of the study This study established the antidiabetic efficacy of Alternantera brasiliana in vitro and in vivo, identified the most active fraction and profiled the chemical constituents of the most active fraction. Methodology The leaf of A. brasiliana was air-dried, pulverized and extracted with methanol and evaluated for its α-amylase activity at different concentrations using in vitro method. The in vivo antidiabetic activity of the extract and glibenclamide was evaluated in glucose loaded and streptozotocin-induced diabetic rats using various doses, while the most active partitioned fraction was identified using glucose loaded method followed by identification of its chemical constituents through GC-MS analysis. Results The extract elicited good α-amylase inhibitory potential with IC50 = 0.45 mg/mL. Also, the 50 mg/kg dose demonstrated the highest percentage blood glucose level reduction and significantly ( P > 0.05) comparable to glibenclamide (5 mg/kg) from 0.5 to 4 h. The streptozotocin-induced antidiabetic assay showed that the 50 mg/kg demonstrated better activity than glibenclamide (5 mg/kg) and was significantly comparable on days 10 and 14. The aqueous methanol fraction was the most active fraction with 53% blood glucose level reduction at 4 h. The secondary metabolite profiling identified 30 chemical compounds whereby 1H-Indole-2-carboxylic acid, 6-(4-ethoxyphenyl)-3-methyl-4-oxo-4,5,6,7-tetrahydro-, isopropyl ester, Benzo[h]quinoline, 2,4-dimethyl-, thymol and 13,5-trioxane as the major constituents. Conclusion The antidiabetic activity demonstrated by the A. brasiliana extract established its antidiabetic efficacy

A promising α-glucosidase and α-amylase inhibitors based on benzimidazole-oxadiazole hybrid analogues: Evidence based in vitro and in silico studies

The present study reports the design and synthesis of new benzimidazole-oxadiazole compounds as potent inhibitors of α-glucosidase and α-amylase. The synthesized molecules were characterized through different techniques such as 1HNMR, 13CNMR, HREI-MS and evaluated for their in vitro inhibitory activities against these enzymes. Among the compounds screened, compound 8 demonstrated the highest inhibitory activity against both α-glucosidase (IC50 = 11.60 µM) and α-amylase (IC50 = 6.20 µM). Molecular docking analyses were conducted to investigate the binding modes and interactions of the active compounds within the enzyme active sites. The results demonstrate that several benzimidazole-oxadiazole hybrids exhibited potent inhibitory effects on both α-glucosidase and α-amylase, suggesting their promise as antidiabetic agents.

In silico Study with Antioxidant Activity and α-Amylase Inhibitory Potential in Ethanolic Extract of Melilotus indicus

Building upon the long history of plants as natural remedies, this study investigated the presence and content of flavonoids, a class of polyphenols, in an ethanolic extract of Melilotus indicus. The antioxidant activity of the extract was also evaluated. The Melilotus genus is renowned for its diverse biological activities, including antioxidant, anti-inflammatory, and hypoglycemic effects. As anticipated, flavonoids were the primary phenolic constituents identified in M. indicus. The extract exhibited a flavonoid content of 0.49 ± 3.818 mg/g and demonstrated comparable antioxidant activity (IC50 = 1.6 mg/mL) to vitamin C (IC50 = 0.01 mg/mL). A docking study against human salivary amylase (1C8Q), revealed promising binding scores for chlorogenic acid and kaempferol (-6.09196091 and -5.45953274 kcal/mol, respectively) compared to the acarbose drug (-8.8864727 kcal/mol). These findings suggest that M. indicus may be a valuable source of natural antioxidants with potential health benefits.

Antidiabetic and Antioxidant Activities of Indian Bay Leaf (Cinnamomum tamala (Buch.-Ham.) T. Nees & Eberm.) Essential Oils Collected from Meghalaya.

The current work investigates the chemodiversity, in vitro antioxidant, α-amylase and α-glucosidase inhibitory potential of Cinnamomum tamala (CT) leaf essential oil (EO) collected from different localities of East Khasi Hills District of Meghalaya, India. Gas chromatography-mass spectrometry (GC-MS) analysis of all the extracted leaf essential oils facilitated the identification of several compounds in a variable range along with eugenol as the major component (74.79-95.12 %). CT8 exhibited the highest antioxidant activity (IC50=11.23±0.27 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and IC50=21.54±0.37 μg/mL for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) among all EO evaluated. The results showed that the ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) values for CT8 were 83.26±1.92 μM trolox/g oil and 70.29±1.90 ascorbic acid equivalents (AAE)/g of oil. α-amylase and α-glucosidase inhibition were highest in sample CT8 with IC50 values of 3.62±0.42 μg/mL and 16.29±0.32 μg/mL respectively. Caryophyllene, cyclohexene, 1, 5, 5-trimethyl-6-(2-propenylidene), germacrene D and eugenol showed strong binding potential toward α-amylase and α-glucosidase. It concluded that the chemodiversity and antidiabetic potential of C. tamla oil from Khasi Hills have never been studied. It can be taken as a dietary supplement as an antioxidant and antidiabetic to control blood glucose.

In silico analysis reveals α-amylase inhibitory potential of Taraxerol (Coccinia indica) and Epoxywithanolide-1 (Withania coagulans): a possible way to control postprandial hyperglycemia-induced endothelial dysfunction and cardiovascular events.

Postprandial hyperglycemia (PPG) exacerbates endothelial dysfunction and impairs vascular function in diabetes as well in healthy people. Though synthetic drugs are available to regulate PPG, the severe gastrointestinal side effects of those medications have prompted the search for alternative treatments. Recently, some phytochemicals captured the attention because of their inhibitory effects on α-amylase to control diabetes. The aim of this study was to investigate and identify potential alpha-amylase inhibitors in C. indica and W. coagulans. This study also aims to understand one of the possible mechanisms of action of plants for their anti-diabetic activity. A total of 36 phytochemical ligands were subjected for protein-ligand docking analysis. Among the phytochemicals, Taraxerol and Epoxywithanolide-I demonstrated significant binding free energy of -10.2kcal/mol and -11.9kcal/mol respectively, which was higher than the reference acarbose with -8.6kcal/mol. These molecules were subjected for molecular dynamics simulation (MDS) analysis with alpha-amylase protein for a duration of 150ns. Among the three complexes, Taraxerol and Epoxywithanolide-I complexes demonstrates strong potential as inhibitors of the target protein. MDS results were analyzed via root mean square deviation (RMSD), fluctuation of residues, potential energy, radii of gyration and solvent access surface area analysis. Taraxerol demonstrated a significantly low potential energy of -1,924,605.25kJ/mol, and Epoxywithanolide-I demonstrated -1,964,113.3kJ/mol of potential energy. RMSD plot shows that Epoxywithanolide-I has much higher stability than the other MDS complexes. Drugability and toxicity studies show that the test ligands are demonstrating strong potential as drug like molecules. The results of the study conclude that, Taraxerol of C. indica and Epoxywithanolide-I of W. coagulans are strong inhibitors of alpha-amylase enzyme and that, this is one of the possible mechanisms of action of the plants for their reported anti-diabetic activities. Further in-vitro analysis is in demand to prove the observed results.

Lipophilic derivatives of EGCG as potent α-amylase and α-glucosidase inhibitors ameliorating oxidative stress and inflammation

Uncontrolled hyperglycemia leads to increased oxidative stress, chronic inflammation, and insulin resistance, rendering diabetes management harder to accomplish. To tackle these myriads of challenges, researchers strive to explore innovative multifaceted treatment strategies, including inhibiting carbohydrate hydrolases. Herein, we report alkyl-ether EGCG derivatives as potent α-amylase and α-glucosidase inhibitors that could simultaneously ameliorate oxidative stress and inflammation. 4″-C18 EGCG, the most promising compound, showed multifold improvement in glycaemic management compared to acarbose, with 230-fold greater inhibition (competitive) of α-glucosidase (IC50 0.81 µM) and 3-fold better inhibition of α-amylase (IC50 3.74 µM). All derivatives showed stronger antioxidant activity (IC50 6.16–15.76 µM) than vitamin C, while acarbose showed none. 4″-C18 EGCG also downregulated pro-inflammatory cytokines and showed no significant cytotoxicity up to 50 µM in primary human peripheral blood mononuclear cells (PBMC), non-cancerous cell line, 3T3-L1 and HEK 293. The in silico binding affinity analysis of 4″-C18 EGCG with α-amylase and α-glucosidase was found to exhibit a good extent of interaction as compared to acarbose. In comparison to EGCG, 4″-Cn EGCG derivatives were found to remain stable in the physiological conditions even after 24 h. Together, the reported molecules demonstrated multifaceted antidiabetic potential inhibiting carbohydrate hydrolases, reducing oxidative stress, and inflammation, which are known to aggravate diabetes.

Exploring the anti-diabetic activity of benzimidazole containing Schiff base derivatives: In vitro α-amylase, α-glucosidase inhibitions and in silico studies

The current study explores the anti-diabetic potential of some Schiff bases containing benzimidazole scaffold. These derivative were synthesized by refluxing sodium metabisulfite with ethyl 2-(2-ethoxy-6-formylphenoxy)acetate followed by the addition of ortho phenylene diamine in DMF solvent to get the benzimidazole which was further refluxed in hydrazine hydrate to obtain the hydrazide. Finally various substituted benzaldehydes were treated with the desired hydrazide using a catalytic quantity of acetic acid to obtain the hydrazone Schiff bases. These compounds were evaluated for their ability to inhibit α-amylase and α-glucosidase inhibitory potentials. Among them, six derivatives including 2g, 2h, 2q, 2p, 2i, and 2m displayed noteworthy inhibitory activities against α-amylase (IC50 = 2.15 ± 0.17 µM to 15.18 ± 3.29 µM ) and α-glucosidase (IC50 = 4.21 ± 0.78 to 16.10 ± 0.52 µM) superior than the standard acarbose, while the remaining compounds showed significant to less inhibitory activities. By clarifying the mechanisms of interaction between the chemicals and amino acid residues, the molecular docking analysis attempted to shed light on the binding modalities of these molecules. The reactivity indices of these compounds were calculated using the Density Functional Theory (TD-DFT) approach, employing the B3LYP-d energy function and lacvp**(d,p) basis set for calculations. Schiff base derivatives based on benzimidazole, especially compounds 2h and 2g, exhibited lower electrophilicity and higher bioactivity compared to their counterparts 2i and 2m.

Assessment of Nutraceuticals Potentials of Protein Isolates from Seed Coat of Four Melon Species

Recently, there has been more attention on the bioactivity of phytochemicals and other metabolites in agro-food by-products for the management of oxidative stress–related conditions. Hence, the objective of this paper is to assess the nutraceuticals potential by investigating antioxidant and α-amylase inhibitory potentials of seed coat protein isolates from four melon species namely: Citrullus colocynthis, Citrullus mucosospermus, Cucumeropsis mannii and Lagenaria siceraria using appropriate standard methods. At highest concentration, Lagenaria siceraria had the strongest free radical scavenging activity (38% inhibition). The strongest chelating effect was exhibited by C. mannii (IC50 = 0.59 ± 0.08 mg/ml), which also showed highest ferric reducing potential at all concentrations. At 0.05 mg/ml, C. colocynthis, C. mucosospermus, C. mannii, and L. siceraria seed coat protein extracts inhibited alpha-amylase activity by 43.2%, 16.76%, 2.6% and 22.3%, respectively, and inhibition of 60.9%, 28.6%, 38.3% and 29.5% were recorded for the seed protein extracts respectively, at 0.5 mg/ml. In conclusion, the various melon seed coat protein isolates showed appreciable levels of antioxidants and possessed inhibitory activity against α-amylase. Hence, the seed coats of the four melon varieties assessed in this study are promising potential sources of antioxidants for the supplementary treatment of oxidative stress–induced conditions.

A Convenient Synthesis of Short α-/β-Mixed Peptides as Potential α-Amylase Inhibitors.

Over the last decades, the increased incidence of metabolic disorders, such as type two diabetes and obesity, has motivated researchers to investigate new enzyme inhibitors. Inhibition of the α-amylase enzyme is one therapeutic approach in lowering glucose levels in the blood to manage diabetes mellitus. The objective of this study was to synthesize short α-/β-mixed peptides in the solution phase. The Boc-protected α-L-leucine was converted to β-analogue by using Arndt-Eistert synthesis with the advantage of no racemization and retention of configuration. Three novel short peptides were successfully synthesized: N(Boc)-Gly-β-Leu-OCH3(14), N(Boc)-O(Bz)α-Ser-β-Leu-OCH3(16), and N(Boc)-O(Bz)-α-Tyr-α-Gly-β-Leu-OCH3(17), characterized by FTIR and 1H NMR analysis. The synthesized peptide 16 showed highest inhibitory activity (45.22%) followed by peptide 14 (18.51%) and peptide 17 (17.05%), respectively. Intriguingly, peptide 16 showed higher inhibition on α-amylase compared with other α-/β-mixed peptides.

Ultrasound-assisted synthesis of 4-thiazolidinone Schiff bases and their antioxidant, α-glucosidase, α-amylase inhibition, mode of inhibition and computational studies

AbstractDiabetes mellitus (DM) has become a growing concern to global public health, being at the forefront of acute disorders and causes of mortality across the globe. Clinically approved drugs that are currently being used are faced with severe side effects, consequently necessitating the development of new drugs with no/fewer side effects and improved pharmacological potency. Herein, we report a rapid and efficient synthesis of thiazolidinone Schiff bases (2a-2t) from benzylidenehydrazines and thioglycolic acid under neat conditions through ultra-sonication. All the synthesized compounds were obtained in exceptional yields (89–95%) and confirmed by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, as well as High-resolution mass spectrometry (HRMS). The synthesized compounds were then evaluated for their antidiabetic activity through α-glucosidase and α-amylase inhibitory potentials and their antioxidant activity through Nitric Oxide (NO), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), and Ferric reducing antioxidant power (FRAP) assays. Among them, 2q (IC50 = 96.63 μM) and 2h (IC50 = 125.27 μM) emerged as the most potent derivatives against α-amylase relative to reference drug acarbose (IC50 = 131.63 µM), respectively. Antioxidant evaluation further revealed that the synthesized derivatives were excellent NO scavengers disclosing 2n (IC50 = 44.95 µM) as the most potent derivative. Moreover, in silico ADME calculations predicted these compounds to have excellent drug-like properties. Kinetic studies disclosed the mode of α-amylase inhibition as competitive while molecular docking studies of the most active derivatives performed into the binding active site of human pancreatic α-amylase enzyme deciphered their ligand-protein interactions that explicated their observed experimental potencies.

Discovery of Novel and Selective Schiff Base Inhibitors as a Key for Drug Synthesis, Molecular Docking, and Pharmacological Evaluation.

Diabetes mellitus (DM) is a chronic disorder and still a challenge throughout the world, and therefore the search for safe and effective inhibitors for α-amylase and α-glucosidase is increasing day by day. In this work, we try to carry out the synthesis, modification, and computer-aided results of and biological research on thiadiazole-based Schiff base derivatives and evaluate their in vitro α-amylase and α-glucosidase inhibitory potential (1-15). In the current series, all of the synthesized analogues were shown to have potential inhibitory effects on targeted enzymes. The IC50 values for α-amylase values ranged from 20.10 ± 0.40 to 0.80 ± 0.05 μM, compared with the standard drug acarbose having an IC50 value of 10.30 ± 0.20 μM, while for α-glucosidase, the IC50 values ranged from 20.10 ± 0.50 to 1.20 ± 0.10 μM, compared to acarbose with an IC50 value of 9.80 ± 0.20 μM. For better understanding, a SAR investigation was undertaken. In this series, nine scaffolds (1, 2, 3, 6, 9, 10, 11, 13, and 15) were more active than the reference drug and the docking parameter RMSD values for α-glucosidase and α-amylase were 1.766, 2.7746, 1.6025, 2.2112, 3.5860, 2.3360, 1.6178, 2.0254, and 2.0797 and 2.6020, 1.9509, 3.1642, 1.7547, 2.2130, 1.4221, and 1.1087, respectively. The toxicity of the selected analogues was calculated by using the OSIRIS tool, and the TPSA values were found to be lower than 140 to represent the drug-like properties; those from Molinspiration were studied as well. The following properties were studied and found to have better biological properties. The remaining analogues (4, 5, 7, 8, 12, and 14) were also identified as potential inhibitors of both enzymes, but they were less active than the reference due to the substituents attached to the aromatic parts. The structures of synthesized compounds were confirmed through different spectroscopic analyses.

The Potential of Hemp Extracts to Modify the Course of Oxidative-Stress Related Conditions.

The leaves of industrial hemp, which have long been considered as a waste product, have been proven to contain numerous compounds that possess potential biological activity. One of the most interesting groups of compounds present are polyphenolic compounds, which, due to their specific structure, have a pronounced antioxidant and antihyperglycemic potential. This study aimed to detect biological activity, including antioxidant and antihyperglycemic potential, of water and water-alcoholic extracts of five commercially available hemp teas, followed by phytochemical profiling. Hemp aqueous and ethanolic extracts demonstrate potent antioxidant properties. Ethanol extracts are better scavengers of DPPH• and OH•, while aqueous extracts neutralize NO• better. Both types of extracts exhibit antioxidant potential in the catalase test and moderate XOD inhibition. Furthermore, aqueous extracts are potent α-amylase inhibitors, while ethanolic extracts demonstrate stronger anti-α-glucosidase activity, suggesting therapeutic potential for chronic diseases like insulin resistance or diabetes. Further detailed chemical characterization and in vivo studies are needed to validate these findings.

Synthesis, biological evaluation and in silico molecular modelling studies of chloro substituted bis-indole containing benzohydrazide analogues as potential anti-diabetic and anti-Alzheimer's agents

Fifteen bis-indolylmethane analogues were synthesized, characterized through NMR (1H, 13C) and high-resolution electron-impact mass spectrometry (HREI-MS), and tested against α-glucosidase, α-amylase, acetylcholinesterase, and butyrylcholinesterase inhibitory potentials. All analogues exhibited different inhibitory potentials, with IC50 values ranging between 7.5 ± 0.92 to 58.4 ± 0.07 μM (α-glucosidase), and 0.80 ± 0.05 to 15.30 ± 0.10 μM (α-amylase) as compared to the standard drug acarbose (IC50 = 38.45 ± 0.80 and 8.90 ± 0.10 μM). Out of fifteen analogues, nine showed an excellent inhibitory potency that was manyfold better than standard drugs. A slight increase or decrease in inhibition was observed due to substituents attached at imine site. In the case of α-amylase inhibition, two analogues such as 2 and 11, showed excellent inhibitory potential with IC50 values of 0.80 ± 0.05 and 0.90 ± 0.10 μM while all other analogues showed good potency. All analogues were also tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory potentials, and they showed good potentials ranging from 1.40 ± 0.20 to 16.20 ± 0.50 μM (AChE) and 3.20 ± 0.10 to 19.60 ± 0.20 μM (BuChE) as compared to the standard drug Donepezil (IC50 = 2.16 ± 0.12 μM and 4.5 ± 0.11 μM). In the case of AChE, analogue 3 is the most potent, and in the case of BuChE, analogue 9 is the most potent among the series. The structure-activity relationship was carried out, mainly associated with the nature, number, and position and the electron-donating and electron-withdrawing effects of the substituent(s) on the phenyl ring. The binding modes as well as binding free energy for α-glucosidase and α-amylase inhibitors were determined through docking studies.

Anti-diabetic activity-guided isolation of α-amylase and α-glucosidase inhibitory terpenes from Capsella bursa-pastoris Linn.

Abstract The hypoglycaemic and hypolipidemic potential of ethanol extract of C. bursa-pastoris (ECbp) in streptozotocin (STZ)-provoked diabetic rats was evaluated, and compounds with their α-amylase and α-glucosidase inhibitory potential were isolated. Acute oral toxicity was evaluated in rats. Streptozotocin (STZ) (50 mg/kg body weight) was injected intraperitoneally into rats for diabetes induction. In diabetic rats, ECbp (0.2 g/kg b.w, p.o.) was administered orally for 21 days, and its outcome on blood glucose levels and body weight was observed on a weekly basis besides lipid profile. Compound isolation from ECbp was performed using column chromatography. Oral feeding of ECbp did not produce any toxic effects or death at a dose of 2,000 mg/kg body weight. A serum glucose reduction trend was observed in rats fed with glucose pre-treated with 200 mg/kg b.w. ECbp also appreciably (p < 0.001, p < 0.01, and p < 0.05) diminished raised blood glucose with decreased blood cholesterol levels and led to increased serum high-density lipoprotein levels in comparison to diabetic control rats. Body weight levels were considerably higher (p < 0.05) in diabetic rats treated with ECbp than in diabetic control rats. Isolation of two terpene derivatives (ECbp-1 and ECbp-2) was performed using ECbp, which exhibits significant α-amylase and α-glucosidase inhibition.

Valorization of Wine Lees: Assessment of Antioxidant, Antimicrobial and Enzyme Inhibitory Activity of Wine Lees Extract and Incorporation in Chitosan Films

Wine lees, as one of the main by-products of winery wastes, is considered a rich source of bioactive compounds such as polyphenols. Recovery of such bioactive compounds would amplify the valorization of winery by-products, as well as promote their use in cosmetics and health applications. Towards this aim, the objective of this work is the recovery of phenolic compounds from wine lees by ultrasound-assisted extraction. The effect of extraction time, and ethanol content on the extraction yield of total phenolics was investigated, while the phenolic profile of the extract was monitored by GC-MS. Under the optimized conditions, the total phenolic content was calculated at 302.6 mg gallic acid equivalents g− 1 dry extract; the dry extract was investigated for its biological activities, exhibiting excellent antioxidant and antimicrobial activity. Moreover, the extract was found to be a potent inhibitor of tyrosinase, elastase, collagenase, α-glucosidase, and α-amylase with IC50 values of 53.3, 83.5, 82.7, 19.0, and 31.3 µg mL− 1, respectively. Finally, the wine lees dry extract was incorporated into chitosan films, reinforcing the properties of the films, and providing them with excellent antioxidant activity. The results support that wine lees extract exhibits high antioxidant activity and can be used as a highly efficient inhibitor of enzymes with pharmaceutical and health interest. Moreover, the chitosan film enriched with wine lees extract is a promising material with high antioxidant potential and can lead to the development of novel food packaging films in the food industry.Graphical

Rhodanine-benzamides as potential hits for α-amylase enzyme inhibitors and radical (DPPH and ABTS) scavengers.

A series of 3-substituted and 3,5-disubstituted rhodanine-based derivatives were synthesized from 3-aminorhodanine and examined for α-amylase inhibitory, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities in vitro. These derivatives displayed significant α-amylase inhibitory potential with IC50 values of 11.01-56.04 µM in comparison to standard acarbose (IC50 = 9.08 ± 0.07 µM). Especially, compounds 7 (IC50 = 11.01 ± 0.07 µM) and 8 (IC50 = 12.01 ± 0.07 µM) showed highest α-amylase inhibitory activities among the whole series. In addition to α-amylase inhibitory activity, all compounds also demonstrated significant scavenging activities against DPPH and ABTS radicals, with IC50 values ranging from 12.24 to 57.33 and 13.29-59.09 µM, respectively, as compared to the standard ascorbic acid (IC50 = 15.08 ± 0.03 µM for DPPH; IC50 = 16.09 ± 0.17 µM for ABTS). These findings reveal that the nature and position of the substituents on the phenyl ring(s) are crucial for variation in the activities. The structure-activity relationship (SAR) revealed that the compounds bearing an electron-withdrawing group (EWG) at para substitution possessed the highest activity. In kinetic studies, only the km value was changed, with no observed changes in Vmax, indicating a competitive inhibition. Molecular docking studies revealed important interactions between compounds and the α-amylase active pocket. Further advanced research needs to perform on the identified compounds in order to obtain potential antidiabetic agents.

Exploring the synthesis, molecular structure and biological activities of novel Bis-Schiff base derivatives: A combined theoretical and experimental approach

A library of six novel bis-Schiff base derivatives (2a-f) were synthesized, characterized through modern spectroscopic techniques and screened for their α-glucosidase and α-amylase inhibitory activities (in vitro). In the series, compound 2a (IC50 = 5.64 ± 2.22 µM) and 2f (IC50 = 22.78 ± 2.37 µM) were the most potent α-amylase inhibitors while the remaining four compounds showed significant to less activity. In case of α-glucosidase inhibition, four compounds 2e (IC50 = 2.83 ± 0.18 µM), 2c (IC50 = 7.03 ± 0.15 µM), 2f (IC50 = 9.99 ± 0.20 µM), and 2d (IC50 = 14.68 ± 0.21 µM) displayed excellent inhibitory activity while two compounds showed good inhibitory activity, comparing with the standard acarbose drug. The DFT assay was used to measure the FMO of the synthesized molecules, which indicated their stability, bioactivity and charge transfer. The MEP analysis revealed the distribution of electrostatic potential on the molecular surface of 2a-f, which is helpful for understanding reactivity and interactions. The AIM study showed low hydrogen bond energy and non-covalent interactions. This implies that these molecules may have weak hydrogen bonding and non-covalent interactions, which could affect their chemical behavior. The molecular docking study has provided valuable insights into the interactions between the synthesized derivatives of 2,4-dihydroxyacetophenone with α-glucosidase and α-amylase proteins. The results not only shed light on the binding affinity and key interaction sites but also offer potential avenues for the design of novel drug candidates to control postprandial glucose level in diabetic patients.