Human Pancreatic Alpha-amylase Research Articles

Computational investigation of 2, 4-Di Tert Butyl Phenol as alpha amylase inhibitor isolated from Coccinia grandis (L.) Voigt using molecular docking, and ADMET parameters

IntroductionDiabetes Mellitus is the metabolic disorder most prevalent globally, accounting for a substantial morbidity rate. The conventional drugs available for the management of diabetes are either expensive or lack the required efficacy. The purpose of this research is to isolate and characterize an active phytoconstituent from Coccinia grandis and assess its anti-diabetic properties. Methods and materialsStems of Coccinia grandis are subjected to successive extraction and isolation. The isolated compound by column chromatography was characterized by FTIR (fourier-transform infrared), 1 H NMR (proton nuclear magnetic resonance), and Mass spectroscopy. The antidiabetic potential of the isolated compound was evaluated by in-vitro alpha-amylase inhibitory activity. Further, the compound was subjected to molecular docking studies to study its interaction with the human pancreatic alpha-amylase (Molegro Virtual Docker) as well to determine the pharmacokinetic and toxicity profile using computational techniques (OSIRIS property explorer, Swiss ADME, pkCSM, and PreADMET). ResultsThe characterization of the compound suggests the structure to be 2,4-ditertiary butyl phenol. The in-vitro alpha-amylase inhibitory study indicated a concentration-dependent inhibition and the IC50 (median lethal dose) value of the isolated compound was found to be 64.36 μg/ml. The docking study with the A chain of receptor 5EMY yielded a favorable docking score of −81.48 Kcal mol−1, suggesting that the compound binds to the receptor with high affinity through electrostatic, hydrophobic, and hydrogen bonds. Furthermore, the silico ADME analysis of the compound revealed improved metabolism, a skin permeability of −3.87 cm/s, gastrointestinal absorption of 95.48 %, and a total clearance of 0.984 log ml min−1 kg−1. In silico toxicity analysis also predicted cutaneous irritations but no carcinogenicity, mutagenicity, or hepatotoxicity. ConclusionThe data suggested that the isolated compound (2, 4-tertiary butyl phenol) has the potential to inhibit the alpha-amylase activity and possess optimal ADME properties as well as tolerable side effects.

Efficacy of the marine red alga Laurencia papillosa extract on alloxan stimulated hyperglycemic activity in male wistar albino rats

PurposeDiabetes mellitus, a main health concern worldwide, is one of the most common metabolic disorders characterized by insulin secretion dysfunction. Materials and methodsIn this work, dietary fibers of the ethanolic extract of Laurencia papillosa were detected at 0.1 and 0.2 g/kg body weight using gas chromatography-mass spectrometry (GC-MS). The extract was given orally once daily to male diabetic rats induced with alloxan for two weeks. The blood cholesterol levels, complete blood count, liver function, kidney function, and antioxidant enzymes were analyzed. The molecular docking was operated using Auto Dock Vina. ResultsTreatment with extracts of L. papillosa (0.1–0.2 g/kg) induced a decrease in pre-prandial and post-prandial glucose levels. 0.1 g/kg pre-prandial extract had the highest activity to reduction glucose level (48.670 ± 0.57 mg/dL). Moreover, the complete blood count, kidney function, and liver function differed slightly in the treated mice group compared to the non-treated diabetic group. Docking analyses demonstrated that most ethanolic compounds found within L. papillosa extract have minimum docking scores and high binding affinity against human pancreatic alpha-amylase (PDB: 4W93), insulin receptor (PDB:1IR3), and SIRT-6 (PDB: 3k35) ConclusionResults further suggested that the concentration of 0.1 g/kg of L. papillosa extract was more effective than 0.2 g/kg in reducing glucose levels. Our study induced that in vivo and in silico results indicated that L. papillosa extract has been a viable natural bioactive source and might be a great potential source for future antidiabetic medicine.

Phytochemical investigation of Mezoneuron benthamianum Baill, isolation, in vitro antioxidant, alpha-amylase inhibition, and in silico modelling studies

Mezoneuron benthamianum (Leguminosae-caesalpinioideae family), is widely used across West Africa for the treatment of bacterial, fungal, and inflammatory diseases. This study is aimed at investigating the antioxidant and antidiabetic activities of extracts and isolated compounds from Mezoneuron benthamianum leaf and root. The pulverized leaf (1 kg) was extracted by maceration with dichloromethane and methanol to give the dichloromethane (MBLD) and methanol (MBLM) extracts, while the root (2 kg) samples were extracted using dichloromethane and methanol (1:1) to give the dichloromethane-methanol extract (MBRDM) which was further partitioned to give the hexane (MBRH), ethyl acetate (MBRE) and methanol (MBRM) extracts respectively. The leaf methanol extract (MBLM) was fractionated using column chromatography (70–230 mesh size) which led to the isolation of compound 1. The extracts and isolated compounds were subjected to in-vitro antioxidant assay with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and α-amylase inhibitory assay using porcine pancreatic α-amylase respectively. FT-IR spectroscopic analysis compound 1 showed strong peaks at 1678 and 1612 cm−1 suggesting the presence of a carbonyl and an aromatic group respectively. 1H NMR spectroscopic analysis of compound 1 showed two peaks at 3.80 (3H, s) and 7.04 ppm (2H, s) indicating methoxy and aromatic protons respectively. 13C NMR also confirmed the presence of the methoxy peak at 50.8 ppm, four aromatic peaks at 108.76, 120.19, 131.25, 145.14 ppm indicating a para-disubstituted benzene ring, and a carbonyl peak at 167.80 ppm, this led to the elucidation of compound 1 known as methyl gallate. The antioxidant activities of the extracts and compounds showed that MBLM (IC50 = 112.0 μg/ml) and MBRE (IC50 = 91.84 μg/ml) had the highest activity of the leaf and root extracts respectively while methyl gallate (IC50 = 91.84 μg/ml) had lower activity than gallic acid (IC50 = 27.4 μg/ml), ascorbic acid (IC50 = 43.94 μg/ml) and BHT (68.94 μg/ml). The α-amylase inhibitory activities showed that MBLD (IC50 = 27.4 μg/ml), MBRE (IC50 = 72.2 μg/ml), gallic acid (IC50 = 27.4 μg/ml) and methyl gallate (IC50 = 43.9 μg/ml) had higher activity than the standard drug acarbose (IC50 = 378.2 μg/ml). For the In silico study, methyl gallate was docked into the active site of the targeted diabetic proteins; human pancreatic alpha-amylase, pig pancreatic alpha-amylase, and tetrameric IIB-HSDI. The results showed that methyl gallate had good interactions with the proteins, with binding affinities of −4.8, −4.8 and −6.5 kcal/mol respectively. Furthermore, in silico pharmacokinetics and toxicology properties of methyl gallate using the AdmetSAR and SwissADME software showed that the compound has good pharmacokinetic properties and it is generally non-toixc. This research has revealed detailed chemical and biological studies on Mezoneuron benthamianum and its isolated compound as an antioxidant and antidiabetic.

In Vitro and in silico studies to explore potent antidiabetic inhibitor against human pancreatic alpha-amylase from the methanolic extract of the green microalga Chlorella vulgaris

Today’s era and lifestyle have led to a quick rise in cases of diabetes. Diabetes mellitus (DM) has risen to the top of the list of serious diseases and stems from different health disorders. Human pancreatic alpha-amylase (HPA) enzyme plays a critical role in the digestion of carbohydrates, and inhibitors of alpha-amylase have been investigated as a way to slow the absorption of carbohydrates and reduce postprandial (after meal) hyperglycemia in patients with diabetes. Recently algal derivatives have been studied for their potential as a new drug against diabetes and other diseases. The study is aimed to find active biochemical compounds from the methanolic extract of Chlorella vulgaris. The in vitro studies were carried out and the results revealed that methanolic extract from C. vulgaris showed abundant inhibition efficacy of the α-amylase (IC50 of about 2.66 µg/mL) compared to acarbose (IC50 of about 2.85 µg/mL), a standard, commercial inhibitor. All the bioactive compounds from the methanolic extract were identified from the GCMS study and considered for in silico evaluation. Out of 14 bioactive compounds from GCMS, compound C3 showed higher docking energy (-8.3 kcal/mol) compared to other compounds. Subsequently, the comparative molecular dynamic simulation of apo and ligand-bound (compound C3 and acarbose) α-amylase complexes showed overall structural stability for compound C3 at the active site of α-amylase from various MD analyses. Hence, we believe, the bioactive compounds identified from GCMS may assist in diabetic therapeutics. Moreover, the compound C3 identified in this study could be a potential antidiabetic therapeutic inhibitor. Communicated by Ramaswamy H. Sarma

Exploration of human pancreatic alpha-amylase inhibitors from Physalis peruviana for the treatment of type 2 diabetes

Type 2 Diabetes (T2D), a chronic metabolic disorder characterized by persistent hyperglycemia, accounts for ∼90% of all types of diabetes. Pancreatic α-amylase is a potential drug target for preventing postprandial hyperglycemia and inhibiting T2D in humans. Although many synthetic drugs have been identified against pancreatic α-amylase, however, reported several side effects, and plant-derived natural products are less explored against T2D. This study tested 34 flavonoids derived from the plant Physalis peruviana against the human pancreatic α-amylase (HPA) using in silico computational approaches such as molecular docking and molecular dynamics simulation approaches. Schrödinger, a drug discovery package with modules applicable for molecular docking, protein-ligand interaction analysis, molecular dynamics, post-dynamics simulation, and binding free energy calculation, was employed for all computational studies. Four flavonoids, namely, Chlorogenic acid, Withaperuvin F, Withaperuvin H, and Rutin, were picked based on their docking score ranging between −7.03 kcal/mol and −11.35 kcal/mol compared to the docking score −7.3 kcal/mol of reference ligand, i.e. Myricetin. The molecular dynamics analysis suggested that all flavonoids showed considerable stability within the protein’s catalytic pocket, except chlorogenic acid, which showed high deviation during the last 15 ns. However, the interactions observed in initial docking and extracted from the simulation trajectory involved > 90% identical residues, indicating the affinity and stability of the docked flavonoids with the protein. Therefore, all four compounds identified in this study are proposed as promising antidiabetic candidates and should be further considered for their in vitro and in vivo validation. Communicated by Ramaswamy H. Sarma

Alpha-glucosidase and Alpha-amylase inhibitory activity by poly herbal extract with reference to positive control acarbose

It is well known that type 2 diabetes is an endocrine disease. Among glucose-lowering medications, α glucosidase which is a membrane bound enzyme at the epithelium of the small intestine that catalyses the cleavage of glucose from disaccharide are effective for delaying for glucose absorption. i.e., inhibitors delay the absorption of ingested carbohydrates, reducing the postprandial glucose. Pancreatic α-amylase is a key enzyme in the digestive system and catalyses the initial step in hydrolysis of starch to a mixture of smaller oligosaccharides consisting of maltose, maltotriose and a number of a-(l-6) and a-(1-4) oligoglucans. These are then acted on by alpha-glucosidases and further degraded to glucose which on absorbtion enters the blood-stream. Degradation of this dietary starch proceeds rapidly and leads to elevated PPHG (post-prandial hyperglycemia). It has been shown that activity of HPA (human pancreatic alpha-amylase) in the small intestine correlates to an increase in post-prandial glucose levels, the control of which is therefore an important aspect in treatment of type 2 diabetes. Pancreatic a-amylase inhibitors offer an effective strategy to lower the levels of post-prandial hyperglycemia via control of starch breakdown. By this study the Herbal extract demonstrated potent inhibitory activity for both the enzymes.

Alpha amylase inhibitor as an Anti-diabetic potential from medicinal plants: A Review

Alpha amylases cleave the starch like molecules and led to increase in blood sugar level in diabetic patients then in order to manage it the inhibition action is carried out by their inhibitors. The α-amylase inhibitors catalyses the process of endo-hydrolysis of α (1→ 4) glycosidic linkage present in starch which ultimately led to decrease in the starch hydrolysis process. It also affects the carbohydrate absorption in the intestine. In 1945, the first alpha amylase inhibitor was reported from beans. It has already been isolated from various plant species namely, Hibiscus sabdariffa.L, Geranium pratense L and Cedrus libani A. Rich with inhibition percentage of 100, 43 and 31 respectively. The studies have already been reported on inhibitors and their interactions with human pancreatic alpha amylases are made .In-vitro and in vivo tests has already been done by various researchers which showed a significant drop in blood sugar level of a normoglycemic mice after an extract from the leaves of Bersama abbyssinica was tested for its potential effect as anti-diabetic.

Branched montbretin A mimics allow derivatisation and potent amylase inhibition.

Mimics of the complex flavonol glycoside montbretin A in which a flavonol moiety is coupled to a caffeic acid via partially peptidic linkers have proved to be potent inhibitors of human pancreatic alpha-amylase with potential as therapeutics for control of blood glucose levels. After exploring optimal linker length, a synthetic route to a version with a branched linker was devised based on the structure of the enzyme/inhibitor complex. The resultant branched inhibitors were shown to retain nanomolar potency even when decorated with polymers as a means of modifying solubility. Similar improvements, along with nanomolar affinity, could also be achieved through conjugation to cyclodextrins which have the potential to bind to starch binding sites found on the surface of human amylase. Incorporation of a conjugatable branch into this unusual pharmacophore thereby affords considerable flexibility for further modifications to improve pharmacokinetic behaviour or as a site for attachment of capture tags or fluorophores.

MOLECULAR DOCKING STUDY OF COMPOUND ISOLATED FROM COCCINIA GRANDIS (L.) VOIGT

Compound (9Z, 12Z)-octadeca-9, 12-dienoic acid (CGHY 02) was isolated from Coccinia grandis (L.) Voigt n-butanol extract by column chromatography. A molecular docking study against human pancreatic alpha-amylase enzyme (PDB: 3OLE) yielded a good docking score of -112.37 Kcal mol-1, indicating a high affinity of the compound to the receptor via hydrogen bonds, electrostatic interactions and hydrophobic interactions. The hydrogen bond was observed between the hydroxyl group of the compound and glutamine 8, whereas the carbonyl group and C5-C9 chain of the compound revealed steric interactions with glutamine 8 and aspartate 402, respectively. In vitro alpha-amylase inhibition of (CGHY 02) demonstrated remarkable inhibition (68.47 %) at low concentration (100 µL mL-1) compared to standard acarbose. Moreover, in silico ADME analysis of the compound exhibited 92.282 % gastrointestinal absorption, skin permeability, activity as a substrate for CYP2D6 and CYP3A4 enzymes resulting in better metabolism and 1.936 (logn ml min-1 kg-1) of total clearance of the compound. In silico toxicity predicted carcinogenicity, mutagenicity via PreADMET online server and hepatotoxicity and skin irritations via pkCSM online platforms. Antidiabetic potential of (CGHY 02) is attributed through inhibition of human pancreatic alpha amylase enzyme.

Evaluation of the Antifungal, Antioxidant, and Anti-Diabetic Potential of the Essential Oil of Curcuma longa Leaves from the North-Western Himalayas by In Vitro and In Silico Analysis.

Essential oils (EOs) have gained immense popularity due to considerable interest in the health, food, and pharmaceutical industries. The present study aimed to evaluate the antimicrobial and antioxidant activity and the anti-diabetic potential of Curcuma longa leaf (CLO) essential oil. Further, major phytocompounds of CLO were analyzed for their in-silico interactions with antifungal, antioxidant, and anti-diabetic proteins. CLO was found to have a strong antifungal activity against the tested Candida species with zone of inhibition (ZOI)-11.5 ± 0.71 mm to 13 ± 1.41 mm and minimum inhibitory concentration (MIC) was 0.63%. CLO also showed antioxidant activity, with IC50 values of 5.85 ± 1.61 µg/mL using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and 32.92 ± 0.64 µM using ferric reducing antioxidant power (FRAP) assay. CLO also showed anti-diabetic activity with an IC50 of 43.06 ± 1.24 µg/mL as compared to metformin (half maximal inhibitory concentration, IC50-16.503 ± 0.66 µg/mL). Gas chromatography-mass spectrometry (GC-MS) analysis of CLO showed the presence of (-)-zingiberene (17.84%); 3,7-cyclodecadien-1-one, 3,7-dimethyl-10-(1-methylethylidene)-(15.31%); cyclohexene, 4-methyl-3-(1-methylethylidene) (12.47%); and (+)-4-Carene (11.89%) as major phytocompounds. Molecular docking of these compounds with antifungal proteins (cytochrome P450 14 alpha-sterol demethylase, PDB ID: 1EA1, and N-myristoyl transferase, PDB ID: 1IYL), antioxidant (human peroxiredoxin 5, PDB ID: 1HD2), and anti-diabetic proteins (human pancreatic alpha-amylase, PDB ID: 1HNY) showed strong binding of 3,7-cyclodecadien-1-one with all the selected protein targets. Furthermore, molecular dynamics (MD) simulations for a 100 ns time scale revealed that most of the key contacts of target proteins were retained throughout the simulation trajectories. Binding free energy calculations using molecular mechanics generalized born surface area (MM/GBSA), and drug-likeness and toxicity analysis also proved the potential for 3,7-cyclodecadien-1-one, 3,7-dimethyl-10-(1-methylethylidene) to replace toxic synthetic drugs and act as natural antioxidants.

In silico screening and identification of leads against multi-targets of type II diabetes in Plectranthus vettiveroides

Generally, phytochemicals have activity on multi-targets and such molecules have been used as effective drugs against the diseases caused by multi-factorial causation like diabetes mellitus (DM). Plectranthus vettiveroides (Jacob) N.P. Singh & B.D. Sharma has been used as a polychrest against various diseases including type II diabetes in tradition system of medicine. The present investigation aimed to validate anti-diabetic property of the root derived essential oil of P. vettiveroides and identification of leads with activity on six targets of DM through in silico method. A total of 78 phytochemicals determined through Gas chromatography –mass spectrometry (GC-MS) analysis of the essential oil were docked with each of the six selected targets namely 11β-hydroxysteroid dehydrogenase type 1, dipeptidyl peptidase IV, protein-tyrosine phosphatase 1B, human pancreatic alpha-amylase, human lysosomal acid-alpha-glucosidase, and phosphorylated insulin receptor tyrosine kinase. The structures of the phytochemicals were retrieved from PubChem and the targets were retrieved from Protein Data Bank (PDB). Docking was carried out in AutoDockVina and the molecules with free energy of binding ≤-6 kcal/mol were considered as hit molecule. Out of 78 phytochemicals screened, 39 have activity on all the tested targets. Based on the docking interaction, drug-likeness and absorption, distribution, metabolism, excretion and toxicity (ADMET) property the best lead molecule against each target were determined. The overall results revealed that basically majority of the hits are terpinoides and not induced any toxicity. Therefore, the oil as such can be recommended as medicament against DM, since the individual, synergistic and cumulative effect of phytochemicals may concomitantly inhibit multi-targets of DM and act as an effective drug.

In Silico Screening of Active Compounds in Garri for the Inhibition of Key Enzymes Linked to Diabetes Mellitus

Through in silico screening, this study seeks to demonstrate a connection between ethnopharmacological claims and the bioactive components found in Garri against potential targets for diabetes. The process of molecular docking involving different bonding modes of compounds in Garri with active cavities of target receptors for proteins human pancreatic alpha-amylase (HPA) and human lysosomal acid-alpha-glucosidase (GAA) was carried out in autodock vina. Density functional theory was used for quantum chemical analysis, while ADME/T properties of the top binding compounds were predicted using the Admetsar and Swissadme database. From the results, (20E)-6-hydroxycholesta-9(11),20(22)-diene-3,23-dione, 25-dedhydrotigogenin, cochlioquinone B, and psi-diosgenin, showed the best docking results (> −8.1 to −9.8 kcal/mol), when compared with the standard control drugs acarbose (−7.9 kcal/mol) and 1-deoxynojirimycin (< −5.1 kcal/mol). The results from the ADME/T prediction also revealed that the compounds had good pharmacokinetic properties. The study provided insights into the development of better inhibitors to treat diabetes from garri.

Inhibition mechanism of alpha-amylase, a diabetes target, by a steroidal pregnane and pregnane glycosides derived from Gongronema latifolium Benth.

Alpha-amylase is widely exploited as a drug target for preventing postprandial hyperglycemia in diabetes and other metabolic diseases. Inhibition of this enzyme by plant-derived pregnanes is not fully understood. Herein, we used in vitro, in silico, and in vivo studies to provide further insights into the alpha-amylase inhibitory potential of selected pregnane-rich chromatographic fractions and four steroidal pregnane phytochemicals (SPPs), viz: marsectohexol (P1), 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→14)-β-D-oleandropyranosyl]-11,12-di-O-tigloyl-17β-marsdenin (P2), 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl]-17β-marsdenin (P3), and 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-canaropyranosyl]-17β-marsdenin (P4) derived from Gongronema latifolium Benth. The results revealed that the SPPs source pregnane-rich chromatographic fractions and the SPPs (P1–P4) exhibited inhibitory potential against porcine pancreatic alpha-amylase in vitro. Compounds P1 and P2 with IC50 values 10.01 and 12.10 µM, respectively, showed greater inhibitory potential than the reference acarbose (IC50 = 13.47 µM). Molecular docking analysis suggests that the SPPs had a strong binding affinity to porcine pancreatic alpha-amylase (PPA), human pancreatic alpha-amylase (HPA), and human salivary alpha-amylase (HSA), interacting with the key active site residues through an array of hydrophobic interactions and hydrogen bonds. The strong interactions of the SPPs with Glu233 and Asp300 residues may disrupt their roles in the acid-base catalytic mechanism and proper orientation of the polymeric substrates, respectively. The interactions with human pancreatic amylase were maintained in a dynamic environment as indicated by the root mean square deviation, radius of gyration, surface accessible surface area, and number of hydrogen bonds computed from the trajectories obtained from a 100-ns molecular dynamics simulation. Key loop regions of HPA that contribute to substrate binding exhibited flexibility and interaction potential toward the compounds as indicated by the root mean square fluctuation. Furthermore, P1 significantly reduced blood glucose levels and area under the curve in albino rats which were orally challenged with starch. Therefore, Gongronema latifolium and its constituent SPPs may be exploited as inhibitors of pancreatic alpha-amylase as an oral policy for impeding postprandial blood glucose rise.

Investigation of effective natural inhibitors for starch hydrolysing enzymes from Simaroubaceae plants by molecular docking analysis and comparison with in-vitro studies

The present study aims to find the effective natural enzyme inhibitors against alpha-amylase and alpha-glucosidase from the array of compounds identified in plants of the Simaroubaceae family using molecular docking and ADME/Toxicity studies. Among the 218 compounds docked against seven enzymes, buddlenol-A and citrusin-B showed the best binding energies (kcal/mol) of -7.830 and -7.383 against human salivary alpha-amylase and pancreatic alpha-amylase respectively. The other two compounds 9-hydroxycanthin-6-one and bruceolline-B had the best binding energy of -6.461 and -7.576 against N-terminal and C-terminal maltase glucoamylase respectively. Whereas the binding energy of prosopine (-6.499) and fisetinidol (-7.575) was considered as the best against N-terminal and C-terminal sucrase-isomaltase respectively. Picrasidine-X showed the best binding energy (-7.592) against yeast alpha-glucosidase. The study revealed that the seven compounds which showed the best binding energy against respective enzymes are considered as the ‘lead hit compounds’. Even though the ‘lead hit compounds’ are not obeying all the laws of ADMET, the drug-likeness properties of 9-hydroxycanthin-6-one, fisetinidol, picrasidine-X, and prosopine were considerable. Also, kaempferol-3-O-pentoside was the recent compound identified from the Simarouba glauca plant extract found to be one among the top five lead hit compounds against four enzymes. This study provides valuable insight into the direction of developing natural compounds as potential starch hydrolysing enzyme inhibitors for managing type 2 diabetes.

Synthesis, In-vitro Antioxidant, Anti-diabetic Evaluation and Docking Studies of Newly Synthesized Benzoxazole Derivatives

In the present study, a set of different benzoxazole derivatives has been synthesized from ethyl acetoacetate, ethoxymethylene malononitrile, NaNO2, and organic acids. Analytical instruments like proton NMR (1H), carbon NMR (13C), infrared spectroscopy (IR), and LC-MS mass spectrometry were used for structural characterization. Synthesized molecules were evaluated for In-vitro antioxidant property (DPPH assay, Total antioxidant &amp; reducing power method) and anti-diabetic property (alpha-amylase &amp; alpha-glucosidase assay). In silico, studies against Human pancreatic alpha-amylase (PDB ID: 3BAW) have been carried out to get the binding approach of the ligand towards the protein. The results demonstrated that compounds namely 5b, 6b, 3b and 4b had potent antioxidant and anti-diabetic activity compared with ascorbic acid and acarbose. HIGHLIGHTS Anti-oxidant (DPPH assay, Total antioxidant and Reducing power) and Anti-diabetic (alpha-amylase &amp; alpha-glucosidase assay) activities performed for synthesized molecules Sulfonamide substitutions are more potent towards biological activities In silico docking studies correlate with in vitro studies The small three-dimensional, stable structure and its ability to form hydrogen bonding the molecules show good activity towards antioxidant and anti-diabetic GRAPHICAL ABSTRACT

Molecular docking of phenolic compounds and screening of antioxidant and antidiabetic potential of Moringa oleifera ethanolic leaves extract from Qassim region, Saudi Arabia

IntroductionOxidative stress is crucial in diabetic pathophysiology, hence the prerequisite of ingesting naturally derived antioxidants as a remedial target. This study investigates the naturally occurring antioxidant and antidiabetic potential of Moringa oleifera ethanolic leaves extract. MethodsMoringa oleifera leaves were macerated (MOLE) by using 70% ethanol. Physiochemical and phytochemical examinations of MOLE was assayed using standard methods. The antioxidant activity was analyzed by DPPH (1, 1-diphenyl-2-picrylhydrazil) radical scavenging assay. In vitro antidiabetic was analyzed by pancreatic α-amylase enzyme inhibitory assay. The molecular docking was performed using AutoDock Vina v1.1.2 in PyRx 30.8. ResultsEthanolic extraction of MOLE by maceration technique, 14 % yield. Loss on drying, foreign organic matters and total ash value of OLE showed 0.27 w/w, 0.8 % and 19 %, respectively. Phytochemical test on MOLE confirmed starch, carbohydrate, flavonoid, gum, glycoside, saponin, tannin, and phenol presences. The total phenolic and flavonoid contents of MOLE are 260 mg GAE/g and 755 mg RUE/g of extract. MOLE (IC 50 55.6 ± 0.18 µg/mL) showed functional DPPH scavenging assay comparable to ascorbic acid (IC 50 46.71 ± 0.24 µg/mL). In the alpha-amylase inhibitory activity, Acarbose showed an IC 50 value of 19.45 ± 0.26 µg/mL, while MOLE portrayed an IC 50 value of 27.54 ± 0.07 µg/mL. Docking studies revealed that most phenolic compounds found within MOLE have minimum docking scores and high binding affinity against Human pancreatic alpha-amylase. ConclusionsThe invitro and docking results suggest that MOLE has been a viable natural bioactive source and might be a great potential source for future antidiabetic medicine.

GCMS profiling and in silico screening of alpha-amylase inhibitors in traditional pigmented rice varieties (Oryza sativa Linn) of Tamil Nadu

Alpha-amylase inhibitors are oral antidiabetic drugs known for inhibiting the alpha-amylase enzyme, which carries out starch hydrolysis, enabling its assimilation in the intestine. However, these drugs can cause several adverse side effects. The present study evaluated the alpha-amylase inhibitory potential of traditional pigmented rice bran crude extracts. This was accomplished through GC-MS profiling of the metabolites contained in the extracts and exploring their alpha-amylase inhibitory potential through molecular docking. Among the six tested pigmented rice brans, the Mapillai Samba extract showed the strongest alpha-amylase inhibition (IC50 = 12.81 μg/ml), followed by Karuppu Kavuni, Elupaipoo Samba, Karuthakar, Kattuyanum, Kodavazhai, and the commercial variety White Ponni (IC50 = 20.90, 27.91, 35.71, 37.02, 45.58, and 48.18 μg/ml, respectively). The standard inhibitor, acarbose, had an IC50 value of 13.52 μg/ml. Metabolite profiling of seven rice varieties identified 127 compounds. The in-silico study screened the ability of the compounds to inhibit human pancreatic alpha-amylase (ID:1B2Y). Eight compounds, namely, tricycle [20.8.0.0 (7,16)]triacontane, 1(22),7(16)-diepoxy-; beta-D-glucopyranoside, methyl; stigmast-5-en-3-ol, (3. beta,24s)-; campesterol; stigmasta-5,20 (22)-dien-3-O; lup-20 (29)-ene-3,21,28-triol, 28-acetate; (3. beta,21. beta.)-; and (−)-vincadifformine were identified from the traditional rice varieties. Cholesterol was also identified (which was distinctive to White Ponni). These compounds had binding energies ranging from −8.26 to −9.98 kcal/mol, indicating them as ligands with stronger affinity to the active site of 1B2Y compared to acarbose (−11.08 kcal/mol). To test the alpha-amylase inhibitory activity of the high-affinity compounds, the synthetic stigmast-5-en-3-ol, (3. beta,24s)- was assayed and was found to exhibit an IC50 of 13.59 μg/ml. The findings of this study indicate that the metabolites in pigmented rice brans may function independently or synergistically to inhibit alpha-amylase.

Synthesis, structural characterization, and molecular docking studies of bioactive bismuth(III) complexes with substituted hydrazones

Eight new bismuth(III) complexes (1-8) of substituted hydrazones having general formula; [Bi(RCONHNCHC5H4N)Clx] and [Bi(RCONHNCHC9H6N)Clx], where R = C10H7O (1, and 8), C4H3S (2), C6H5O (3, and 6), C7H7(4), C5H4N (5, and 7), x = 2 or 3 have been prepared. The substituted hydrazones (I1-I8) were synthesized by reacting the stoichiometric amounts of the respective hydrazides such as p-toluic hydrazide, 4-hydroxybenzhydrazide, thiophene-2-carboxylic acid hydrazide, 3-hydroxy-2-naphthoic acid hydrazide, Isonicotic acid hydrazide and appropriate aromatic aldehydes like pridine-2-carboxaldehyde and quinoline-2-carboxyaldehyde. These hydrazones (ligands),then complexed to Bi(III) species to yield the target compounds. They were characterized by FTIR, and NMR spectroscopy to find out an explicit evidence about their structural motifs. The X-ray data for (1 & I6) further validate the chemical structures of the synthesized compounds. The molecular geometry for (1) is predominately distorted pentagonal bipyramidal where hepta-coordinated Bi(III) center is attached to the nitrogens of pyridine and of azomethine moieties along with the carbonyl oxygen, two chloro and two oxygens of the (two) DMSO molecules. The bond lengths for Bi(1)-O(1), Bi(1)-N(1) and Bi(1)-N(2) are 2.323(5), 2.539(6), 2.390(5) oA respectively indicating Bi(1)-O(1) as the strongest linkage to the metal center. The H-bonding, present in (1), contributed an extra stability to the structure. The synthesized compounds were initially screened for their possible antimicrobial, alpha-amylase, and protein kinase inhibition, some (1,2,6,8) exhibit significant activity. The experimental results are further endorsed by molecular docking studies against helicobacter pylori urease (1E9Y), epidermal growth factor receptor tyrosine kinase (1M17) and human pancreatic alpha amylase (5U3A) inhibition activity. The significant ligand-receptor interactions, observed at the binding pocket of the selected drug targets, further revealed the enzyme inhibition potential of the compounds and highlighting their possible roles as therapeutic agents in future drug discovery processes.

Bioactive heteroleptic Bismuth(V) carboxylates: Synthetic Stratagem, characterization and binding pattern validation

A series of heteroleptic triorganobismuth(V) carboxylates (1–8) of general formula Ar3Bi(COOR)2; where Ar = C6H5(1–4), p-CH3C6H4(5–8) and R = C10H7(1, 5), 2-CH3C6H4(2, 6), 3, 4- (OCH2CH3)C6H3(3, 7), 2-ClC6H4(4, 8); were synthesized by a stoichiometric reaction between the precursor, Ar3BiBr2, and the respective carboxylic acidusing triethylamine as a base in dry toluene. They were characterized by FT-IR, NMR spectroscopy and X-ray diffraction technique to get unequivocal evidence for their structural motifs. The single crystal XRD data for (2 &5) revealed the existence of five coordinated bismuth centre having distorted trigonal bipyramidal molecular geometry, whereas (6) described weakly hexacoordinated bismuth including a unique anisobidentate interaction of one carboxyl group with the resultant distorted octahedral molecular geometry. The molecular docking studies demonstrate that compounds (1, 2 and 7) give significant GOLD fitness scores of 60.09, 62.65 and 56.30 against EGFR tyrosine kinase, human pancreatic alpha amylase and H. pylori urease respectively. The synthesized compounds were also preliminary screened for their antimicrobial, α-amylase inhibition and protein kinase inhibition activities to determine their biological efficacy. The antibacterial activity profile for (2) looks good with MIC value 6.25 μg/mL against E. coli whereas, (1, 2 and 5) show significant antifungal activity against A. flavus having MIC value of 6.25 μg/mL and the values are comparable to the reference drug(s). Compound (6) displays significant % alpha amylase inhibition of 34.80, whereas (2) exhibit 30 mm bald inhibition zone for protein kinase inhibition study, thus, proving their worth as moderate enzyme inhibitors. The molecular docking studies for (1–8) demonstrate strong interactions between the receptor and the molecule and a firm protein-ligand complex formation described their effective role in enzymes’ inhibition. The bioactivity data obtained from both in silico analysis and in vitro studies are quite promising ones and the synthesized compounds may find a leading role in future drug discovery programs.

Testing the ability of rhodanine and 2, 4-thiazolidinedione to interact with the human pancreatic alpha-amylase: electron-density descriptors complement molecular docking, QM, and QM/MM dynamics calculations.

A combined molecular docking, QM, and QM/MM dynamics modeling complemented with electron-density based descriptors computed at the B3LYP/6-311G++(d,p) level of theory have been carried out in order to understand the ability of the drugs rhodanine (RD) and 2,4-thiazolidinedione (TZD) in the effective treatment of type 2 diabetes mellitus. The global HOMO/LUMO descriptors provided just a very rough estimate of the chemical reactivity of both molecules, while the features of electron density studied in terms of its Laplacian and electrostatic potential allowed identifying the local electron rich/poor sites which were associated with the regions of electrophilic/nucleophilic attacks in RD and TZD. These results were thoroughly checked using the novel physically-grounded functional descriptors such as the phase-space Fisher information density and the internal kinetic electronic pressure density, which confirmed the information on bonding and lone electron pair details. The molecular docking, QM, and QM/MM dynamics analyses revealed the detailed picture of interactions of the drugs with the amino acid residues of the active site of the human pancreatic alpha-amylase protein (hPAA). The main difference in behavior of RD and TZD molecules is related to the hydrogen bond between the NH group of the ligand and Asp197. In hPAA complex with RD the proton from the NH group, which carries large positive charge (~ +0.45 e), spontaneously transfers to the carboxyl group of Asp197 and stays there, while in complex with TZD this proton frequently changes its position with the more preferable formation of covalent bond with the N atom. Upon deprotonation of the ligand, its hydrogen bonds with Arg195 and His299 become stronger. This process influences the binding with the difference of the binding constants of RD and TZD about 200 times with the higher value corresponding to the RD molecule. Thus, the cumulative results lead to the conclusion that rhodanine would have a higher binding affinity than the 2,4-thiazolidinedione molecule in the active site of human pancreatic alpha-amylase.