Α-amylase Inhibitory Activity Research Articles

Synthesis, α-Glucosidase, α-Amylase, and Aldol Reductase Inhibitory Activity with Molecular Docking Study of Novel Imidazo[1,2-a]pyridine Derivatives.

Inhibition ofaldose reductase (AR), α-glycosidase (α-GLY), and α-amylase (α-AMY) are some of the essential targets in diabetes mellitus (DM). Here, a series of imidazo[1,2-a]pyridine-based 1,3,4-thiadiazole derivatives (8a-k) were successfully synthesized and characterized using 1H NMR, 13C NMR, and HRMS spectroscopic techniques. The inhibition effects of the synthesized derivatives against AR, α-GLY, and α-AMY were evaluated using both in vitro and in silico methods. In vitro studies revealed that the derivatives (8a-k) showed significant inhibition activity. The results showed that the novel derivatives (8a-k) demonstrated potential inhibitory activity, with K I values covering the following ranges: 23.47 ± 2.40 to 139.60 ± 13.33 nM for AR and 6.09 ± 0.37 to 119.80 ± 12.31 μM for α-GLY, with IC50 values 81.14 to 153.51 μM for α-AMY. Furthermore, many of these compounds exhibited high inhibition activity, while some of them showed higher potency than the reference compounds. Molecular docking of the target compounds was carried out in the active sites of AR (PDB ID: 4JIR) and α-GLY (PDB ID: 5NN8).

Effects of acid, alkaline and enzymatic extraction methods on functional, structural and antioxidant properties of dietary fiber fractions from quince (Cydonia oblonga Miller)

In this study, quince soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were obtained by acid extraction, enzyme extraction and alkaline extraction methods. The acid extracted DF displayed higher results compared to enzyme and alkaline extraction methods in terms of water holding capacity (15.97 g/g SDF), oil holding capacity (1.05 g/g SDF) and nitrite ion adsorption capacity (92.83 mg/g SDF). The antioxidant activity and phenolic content of acid extracted IDF were significantly higher than the other quince DFs. In addition, quince DFs exhibited in vitro hypoglycaemic activity, exhibiting high glucose adsorption capacity (237 mg/g) and α-amylase inhibition activity (82 %). Similarly, acid extracted SDF of quince showed in vitro hypolipidemic activity, with cholesterol adsorption capacity of 155 mg/g and lipase inhibition activity of 36 %. The structures and thermal properties of quince DFs were characterized by FT-IR and TGA. Quince DFs with high functional properties might be suitable agents for functional food formulations, such as meat products, low-calorie fruit bars, flour mixtures, etc.

The in vitro and in silico investigations on the α-amylase inhibitor derived from Leptadenia lanceolata (Poir.) Goyder leaf extract

An attempt has been made to assess the α-amylase inhibitory activity of a phytochemical compound extracted and purified from the leaf extract of Leptadenia lanceolata. The total yield of the crude leaf extract was 11.42% and among the different solvents involved in this study, hexane and ethyl acetate at 7:3 was effective in the separation of phytochemical compounds. Hexane and ethyl acetate at 25:75% ratios (elution S4) were found greater in inhibiting α-amylase enzyme (83%). The most abundant compound found was Phytol (3,7,11,15-tetramethyl-2-hexadecen-1-ol) and its derivatives. It resulted that the binding energy for acarbose and phytol were −8.1 kcal/mol and −5.9 kcal/mol respectively. However, the binding affinity was greater in the case of acarbose than phytol and the binding sites are different for both the ligands. Therefore, this study adds scientific evidence of the α-amylase inhibitory activity of phytol derived from the leaf extract of L. lanceolata.

Effect of different infusion temperatures towards the phenolic content, antioxidant and α-amylase inhibitory activities of okra (Abelmoschus esculentus) infusion water

Effect of different infusion temperatures towards the phenolic content, antioxidant and α-amylase inhibitory activities of okra (Abelmoschus esculentus) infusion water

Synthesis, characterization and α-amylase inhibition activity of new family of tetrapodal ligands with pyrazole-tetrazole subunits

New family of tetrapodal compounds entitled 3-(bis((5-methyl-1-((2-isopentyl-2H-tetrazol-5-yl)methyl)-1H-pyrazol-3 yl)methyl)amino)propan-1-ol.(T1),2-(4-(bis((5-methyl-1-((2-propyl-2H-tetrazol-5-yl)methyl)-1H-pyrazol-3-yl)methyl)amino)phenyl)ethan-1-ol.(T2),N,N-bis((1-((2-isopentyl-2H-tetrazol-5-yl)methyl)-5-methyl-1H-pyrazol-3-yl)methyl)propan-1-amine.(T3).and.N,N-bis((1-((2-isopentyl-2H-tetrazol-5-yl)methyl)-5-methyl-1H-pyrazol-3-yl)methyl)propan-2 amine (T4) were synthesised as drug candidates to treat Type 2 diabetes. Their structures as the intermediates compounds were ensured by NMR and FTIR analysis as well as the spectrometric methods including high-resolution mass spectrometry and elemental analysis. The tetrapodal molecules were obtained in moderate yields in the range of 37–45 %. Their anti-diabetic activity was evaluated based on their α-amylase inhibition potency by determining their IC50 values. The obtained results showed that the tetrapodal compounds possess potent α−amylase inhibition activity 3 to 236 times higher than that of the acarbose, used as positive control. These findings were also supported by docking calculations.

Structure-Activity Relationship of Hydrazinylthiazole-5-Carbaldehydes as Potential Anti-Diabetic Agents.

Diabetes is an emerging threat to the world due to large number of deaths reported within the last decade. To overcome its spread and complications, herein, we reported synthesis and anti-diabetic potential of twelve novel 2-[(arylidenyl)methylidene]hydrazinyl-1,3-thiazole-5-carbaldehydes (3 a-l). All compounds have shown good to excellent α-amylase inhibitory activity, among them ortho substituted analogues, the compound 3 a (IC50=14.6 mM) and 3 l (IC50=17.9 mM) showed excellent inhibition potential due to the strong electron donating nature of the substituents attached at the aryl ring. The compounds 3 a-3 h (IC50=6.70-10.80 ppm) exhibited excellent anti-glycation potential as compared to standard amino-guanidine (IC50=11.92 ppm). Almost all the tested compounds are found biocompatible and very safe to the human erythrocyte cells at all tested concentrations. The molecular docking results have found that the binding energy score of all the tested compounds against human serum albumin protein (pdb: 1AO6) is between -5.1827 and -6.8661 kcal/mol which is far better than standard amino-guanidine (-4.234 kcal/mol).

Chemical composition and physiological bioactivities of Stiefia multicaulis (Vahl) Soják Vahl grown in Palestine

Background: Herbal products encompass a wide range of natural substances that show great potential as therapeutic materials. Consequently, there has been a substantial investigation into the therapeutic potential of numerous plant species in recent times. The present study sought to determine the components and assess the antioxidant, antilipase, α-amylase, and α-glycosidase enzyme inhibitory activities of Stiefia multicaulis (Vahl) Soják Vahl hexane, acetone, methanol, and aqueous fractions. Methods: Standard pharmacopeia methods were used to conduct screenings for both quantitative and qualitative phytoconstituents. The lipase, α-amylase, and α-glycosidase enzyme inhibitory activities were assessed using established reference methods. In addition, the antioxidant activity was assessed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: The screening methods of pharmacopeias revealed that S. multicaulis contains a wide range of secondary metabolites, especially tannins. However, the most potent antioxidant, antilipase, α-glucosidase, and α-amylase inhibitory activities were acetone fraction, hexane, methanol, and aqueous S. multicaulis fractions, respectively. Conclusion: The current study outcomes are the first on the α-amylase, lipase, α-glucosidase inhibitory activities of S. multicaulis four solvent fractions. Further investigations are needed to assess the in vivo potential of these plant fractions in animal models.

Metabolomics and chemometrics-driven valorisation of mango leaves: Unveiling putative α-amylase and α-glycosidase inhibitory metabolites

This study presents a comprehensive investigation into the metabolite composition of various mango leaf samples using Ultra Performance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS). A total of 103 chromatographic peaks representing diverse metabolite groups were annotated, revealing significant variations in chemical composition among different mango varieties. Polyphenols emerged as the most abundant class, with mangiferin being the major polyphenol detected in most varieties, including Awis, Sukari, Sinara, Sedika, and Alfonse. Trihydroxybenzoyl mangiferin was predominant in Sedika and Alfonse varieties. Flavonoids, such as flavanone glycosides and flavone glycosides, were also prominent. O-methylnaringenin pentoside was the major flavanone glycoside detected in Awis, Sukari, and Sinara varieties, while naringenin-O-hexoside was predominant in Alfonse. Phenolic acids were detected across all varieties, with protocatechuic acid and gallic acid being major components. Protocatechuic acid was identified in all varieties except Sedika and Naomi, where gallic acid dominated. Kaempferol and di-O-methylquercetin were exclusively detected in the Naomi variety. In-vitro enzyme inhibition assays against α-amylase and α-glycosidase enzymes revealed dose-dependent inhibitory effects of mango leaf extracts, with variations in potency among varieties. The most potent inhibitors of α-amylase activity were found in extracts from Sukari and Alfonse leaves, while those from Sukari and Sedika leaves showed the strongest inhibition of α-glycosidase activity. Interestingly, the extracts that exerted the highest inhibition of α-amylase activity did not necessarily inhibit α-glycosidase activity significantly. Additionally, glucose uptake promotion assays identified Awis and Sedika leaves as the most potent promoters of glucose uptake.

Design and synthesis of new coumarin-1,2,3-triazole hybrids as new antidiabetic agents: In vitro α-amylase, α-glucosidase inhibition, anti-inflammatory, and docking study

The current study focuses on the synthesis of coumarin-triazole hybrids (7i-t) starting from 4-hydroxy benzaldehyde or 4-hydroxyacetophenone (1a-b) and propargyl bromide. On the other hand, coumarin derivatives (5c-h) were prepared by Pechmann cyclization and treated with sodium azide to give the corresponding 3-azido methyl coumarins (6c-h). Finally, 1,3-dipolar cycloaddition between compounds 6c-h and terminal alkyne 2a-b produces coumarin-triazole hybrids (7i-t) utilizing click chemistry approaches that are high yielding, wide in scope and simple to perform. The structural proofs of the newly synthesized coumarin-triazole hybrids (7i-t) are proved by various spectroscopic techniques, including IR, 1H NMR, 13C NMR, and LC-MS. The synthesized new coumarin triazole hybrids (7i-t) were explored for their antihyperglycemic potential and therefore evaluated for α-glucosidase and α-amylase inhibitory activities along with anti-inflammatory. The results suggest that among the series, compound 7l showed excellent activity with an IC50 value of 0.67±0.014 mg/mL and 0.72±0.012 mg/mL for α-amylase, and α-glucosidase inhibitory potential while compound 7o showed promising anti-inflammatory activity with IC50 value of 0.54±0.003 mg/mL. To support the above findings, molecular docking studies were performed, which confirmed the interaction of the synthesized molecules 7i-t with an effective binding energy of -9.0 to -10.6 kcal/mol at the active site of the enzyme human pancreatic α-amylase (PDB ID: 1B2Y). Therefore, these scaffolds have the potential to function as lead candidates for antidiabetic and anti-inflammatory activities.

Synthesis, Characterization, and Antidiabetic Evaluation of N-((5-(3- chloro-4-nitrophenyl)-1,3,4-oxadiazol-2-yl) carbamothioyl) Benzamide Derivatives.

A series of novel N-((5-(3-chloro-4-nitrophenyl)-1,3,4-oxadiazol-2-yl) carbamothioyl) benzamide derivatives (2a-2h) were synthesized and characterized for their potential antidiabetic properties. The synthesis involved multi-step reactions starting from 3-chloro-4-nitrobenzoic acid, and the final compounds were purified by recrystallization. The structures were confirmed using melting points, TLC, FTIR, 1 H-NMR, 13C-NMR, and LC-MS. In-silico pharmacokinetic analysis using SwissADME indicated favorable drug-likeness properties for the synthesized compounds, particularly those with electron-withdrawing substituents. In-vitro assays demonstrated significant α-amylase and α-glucosidase inhibitory activities, with compounds 2a, 2g, and 2h showing the highest potency (IC50 values: 23.19-28.61 µM for α-amylase and 23.25-28.25 µM for α-glucosidase), comparable to the standard drug acarbose. The presence of electron-withdrawing groups enhanced the inhibitory effects, while electron-donating groups reduced efficacy. These findings suggest that the synthesized compounds, particularly 2a, 2g, and 2h, hold promise as effective antidiabetic agents.

Design, Synthesis, Anticholinesterase and Antidiabetic Inhibitory Activities, and Molecular Docking of Novel Fluorinated Sulfonyl Hydrazones.

In this study, it was aimed to synthesize (E)-N'-(2-hydroxybenzylidene)-substituted benzenesulfonohydrazide (1-7) from the 2-hydroxybenzaldehyde reaction of different substituted fluorinated sulfonyl hydrazides. The structures of the synthesized molecules were characterized by elemental analysis, FTIR, 1H NMR, 13C NMR, 19F NMR, and 2D NMR (HMBC, correlation spectroscopy, and HQSC). The anticholinesterase (AChE and BChE) and antidiabetic (α-glucosidase, α-amylase) inhibition activities of the synthesized compounds were evaluated. According to biological activity test results, (E)-N'-(2-hydroxybenzylidene)-4-(trifluoromethoxy)benzenesulfonohydrazide (compound 7 among hydrazone derivatives 1-7) demonstrated better BChE inhibitor activity than galantamine in anticholinesterase inhibition; and in the α-glucosidase and α-amylase assay, it exhibited more antidiabetic inhibition activity than the reference standard.

In-vitro antidiabetic activity of ethanolic extract from Khla (Schumannianthus dichotomus Roxb.) rhizome.

Schumannianthus dichotomus Roxb. in Thai, namely “Khla,” is notably distributed in South and South-East Asia regions. In Thai traditional medicine, rhizome has a bland taste, and after decoction, it is used to reduce body heat and fever and treatment of skin diseases. Recently, the methanolic extract of rhizome had reported the hepatoprotective and hypoglycemic activities in mice. Aims of this study were conducted to determine the nutritional value of rhizome and to evaluate α-glucosidase, and α-amylase inhibitory activities of ethanol extract from the rhizome (KE). The rhizome had a high content of dietary fiber and iron, while it was low in calories, fat, and carbohydrates. Thus, it can become an ingredient of a healthy diet. The total phenolic content of KE contained 229.8 ± 6.23 mg of gallic acid equivalent (GAE)/g. There was strongly inhibited α-glucosidase (IC50 = 0.11 ± 0.03 mg/mL) and comparable with the antidiabetic drug acarbose (IC50 = 0.10 ± 0.03 mg/mL). Therefore, KE was slightly inhibited by α-amylase (IC50 = 0.42 ± 0.05 mg/mL), when compared with acarbose (IC50 = 0.016 ± 0.001 mg/mL). Thus, the phytochemicals of different extracts are necessary to be identified. Therefore, the advance techniques were the limitation of our study.

Design, synthesis, biological evaluation, kinetic studies and molecular modeling of imidazo-isoxazole derivatives targeting both α-amylase and α-glucosidase inhibitors

Herein, a novel set of imidazo-isoxazole derivatives containing thiourea and urea scaffolds were synthesized, characterized (1H NMR, 13C NMR, and elemental analysis). These compounds were biologically evaluated for their α-amylase and α-glucosidase inhibitory activity, identifying 5f as the most active (IC50 26.67 ± 1.25 μM and 39.12 ± 1.83 μM against α-amylase α-glucosidase, respectively), better than the standard, acarbose. Enzymatic kinetic results showed that 5f and acarbose complete competitive type inhibitors. The structure-activity relationship (SAR) demonstrated that undergoing substitutions on R1 and R2 groups attached to the thiourea/urea moiety chains controlled the activity. Besides, in-silico ADMET study showed that almost title compounds exhibited satisfactory pharmacokinetic properties. In molecular docking study, the top performing compound (5f) exhibited higher binding energies (−5.501 and −6.414 kcal/mol, respectively) showing crucial interactions and that snuggly fit in their active site. To shed light on their mechanism of action, molecular dynamic (MD) simulations approach executed at 100 ns duration authenticated the high stability of 5f-1B2Y and 5f-3A4A complexes. The results of this investigation disclosed that compound 5f may serve as a potential lead, accomplished with in vivo studies, for the management of diabetes.

Multifunctional properties of peptides derived from black cricket (Gryllus assimilis) and effects of in vitro digestion simulation on their bioactivities

Insects are a rich source of proteins and are produced in systems that have lower environmental impact. As an alternative protein source, they can be consumed directly or used as an ingredient in other formulations. Recently, there has been growing interest in utilizing insect proteins as a substrate to obtain bioactive peptides as well as in investigating the maintenance of their biological properties under physiological conditions. This study aimed to evaluate the impact of simulated digestion on the bioactive properties of protein hydrolysates from black crickets (Gryllus assimilis). Following simulated digestion of the hydrolysate obtained through the application of Flavourzyme, the scavenging activities of ABTS and DPPH radicals, and ferric reducing antioxidant power (FRAP) increased by approximately 17 %, 246 %, and 173 %, respectively. For the hydrolysate obtained using the binary combination of Flavourzyme/Neutrase, the inhibitory activities of α-amylase and α-glucosidase after digestion were 47.87 % and 12.73 %, respectively, not significantly (p > 0.05) different from non-digested hydrolysates. The angiotensin-converting enzyme (ACE) inhibitory activity of the sample hydrolyzed with Flavourzyme/Alcalase proteases was 42.22 %, but this property was completely lost after in vitro digestion. Untargeted proteomic analysis allowed the identification of 22 peptides in the <3 kDa fraction of the digested black cricket protein. The LPPLP sequence was considered potentially bioactive for all activities tested in silico.

Antioxidants from Rubus idaeus leaves: LC-MS/MS chemical profiling, in vitro antiglycation, α-glucosidase and α-amylase inhibitory activities

ABSTRACT The present study evaluated a range of biological activities of Rubus idaeus leaves, often considered as by-products, in relation to hyperglycemia. The antiglycation potential of this plant has not been previously reported. In this research, the methanolic leaf extract of R. idaeus was assessed for its antioxidant, enzyme inhibitory and antiglycation activities. The bioactive compounds present in the extract were screened using LC-MS/MS. Enzyme inhibitory activities were tested on α-glucosidase and α-amylase, and the antiglycation effect was investigated using BSA-fructose model. The methanolic extract showed a high polyphenolic contents (176.26 ± 2.26 mg GAE/g) and important IC50 values for DPPH (34.79 ± 2.40 µg/mL) and ABTS radical scavenging activities (49.75 ± 2.47 µg/mL). In addition, the plant leaf extract significantly inhibited hyperglycemia-related enzymes in a dose-dependent manner and demonstrated a reduction in fluorescent AGEs, fructosamine, and dicarbonyl compounds. Therefore, R. idaeus cv Maravilla could be an effective source of therapeutics for improving the healthcare outcomes of diabetic patients.

Utilizing pistachio green hull extract to produce sugar-free muffins with antioxidant and antidiabetic potential

The current study aimed to produce sugar-free muffins containing pistachio green hull extract (PGHE) as a natural source of antioxidant and antidiabetic compounds. The effects of PGHE substitution (1, 2, and 4% w/w) on the total phenolic content, antioxidant activity (DPPH scavenging), inhibition of α-amylase and α-glucosidase activities, storage stability (peroxide value and TBA), physicochemical, and sensory properties of muffins were investigated. The antioxidant activity of samples containing 4 % PGHE, demonstrated a 22-fold increase compared to the control. Furthermore, muffins containing PGHE displayed higher oxidation stability over a 14-day storage period. PGHE could improve α-amylase and α-glucosidase inhibitory activities of muffins up to 7-fold and 2-fold, respectively. Texture analysis revealed that increasing the amount of PGHE decreased the hardness, gumminess, and chewiness of muffins. Incorporation of PGHE into samples had a significant effect on the color. The muffins containing 2 % PGHE had an overall acceptance that was not significantly different from the control.

Bioassay guided isolation and compounds identification of the anti-diabetic fractions of (rosemary) Rosmarinus officinalis leaves extract

BackgroundDiabetes mellitus is a metabolic disease characterized by prolonged elevated blood glucose levels. It is a common health problem with a high mortality and morbidity to the human race. A number of medicinal plants such as rosemary (Rosmarinus officinalis) have been used for the treatment of diabetes. Most of the anti-diabetic conventional drugs have been found to have some side effects and there is therefore need to explore new sources of anti-diabetic drugs. The aim of the current study was to investigate the possibility of getting anti-diabetic compounds from R. officinalis that can be used as leads for drug discovery.MethodologyR. officinalis leaves were macerated in 50% methanol in dichloromethane and the crude extract fractionated by column chromatography. The obtained fractions were subjected to an in-vitro alpha-amylase inhibition assay. The anti-hyperglycemic potential of the fractions was evaluated in diabetic induced Wistar rats. The most potent fractions were analyzed by gas chromatography-mass spectrophotometry (GC-MS) for identification of the compounds.ResultsA total of 21 chromatographic fractions were assembled with different alpha- amylase inhibition activity. Eleven of the fractions had more than 30% alpha-amylase inhibition activity. The ethyl acetate fraction had the highest inhibition potential (LC50 of 2.8 μg/mL). The anti-diabetic assay in rats showed that fractions (F1) and (F4) had highest blood glucose reduction of 44.5 ± 0.4 and 52.8 ± 1.3%, respectively (p < 0.05). GC-MS analysis of fractions F1 and F4 showed the presence of 21 and 23 compounds in F1 and 23, respectively.ConclusionThis study has demonstrated that R. officinalis crude extract fractions obtained from 50% methanol in dichloromethane possesses alpha-amylase inhibitory and anti-hyperglycemic activities as well as secondary metabolites with varying chemical structures. The hexane and hexane/ethyl acetate (8/2) fractions showed most potent alpha-amylase inhibition with high anti-hyperglycemic activity giving hope of a possibility of obtaining lead compounds for new anti-diabetic drugs.

Investigating the effect of different contents of mung beans on the structure and function of extruded buckwheat noodles

The effects of different contents of mung bean on microstructure, cooking property, hypoglycemic activity and in vitro starch digestion of extruded buckwheat noodles were studied. The results demonstrated that as the increase of mung bean content, the cooking loss of the noodles decreased from 19.26 % to 14.59 %, the estimated glycemic index (eGI) decreased from 85.17 to 69.66, and the content of resistant starch (RS) content increased from 39.32 % to 55.45 %; Furthermore, the α-glucosidase and α-amylase inhibitory activities were significantly enhanced; however, the overall sensory attributes did not change significantly. Afterwards, XRD and FTIR analyses revealed that the addition of mung bean promoted the formation of starch-lipid complexes and improved the short-range structural order of starch; Additionally, scanning electron microscopy (SEM) results indicated that as the content of mung bean increased, the pores within the extruded buckwheat noodle gradually became smaller, and the number of pores increased gradually, contributing a more complete network structure, which favors the formation of gels with enhanced mechanical properties. In conclusion, the comprehensive quality of extruded buckwheat noodles with the addition of mung bean was effectively improved.

Nutritional, phytochemistry, antioxidant, and antidiabetic potentials of Hippocratea velutina (Afzel.) leaves: In vitro, ex vivo and in silico studies

BackgroundHippocratea velutina is a novel folk plant that is used for lowering blood glucose and is hence a potential source of new antidiabetic medication. Therefore, this study was designed to investigate the antidiabetic and antidiabetic potential of the methanol extract of Hippocratea velutina leaves. MethodsThe nutritional, elemental, and phytochemical properties of H. velutina leaves were investigated. 1,1-diphenyl-2-picrylhydrazine (DPPH) scavenging ability, Fe2+chelation and nitric oxide scavenging abilities, FeSO4-induced pancreatic injury parameters such as catalase, GSH, ENTPase, Na/K ATPase activities, α-glucosidase and α-amylase inhibitory activities were used to assess the antioxidant and antidiabetic properties of H. velutina leaf. Furthermore, HPLC-identified constituents of H. velutina leaf methanol extract were docked against human α-glucosidase (3TOP) and human α-amylase (1B2Y). ResultsThe results revealed that H. velutina contains protein, crude fat, flavonoids, anthraquinones, magnesium, sodium, and iron. Compared with quercetin, H. velutina significantly scavenged NO• radicals and chelated Fe2+. H. velutina exhibited a greater inhibitory effect on FeSO4-induced pancreatic injury. Furthermore, H. velutina showed a dose-dependent increase in the activity of ENTPDase and the Na/K ATPase enzyme, and it also had a significantly greater inhibitory effect on α-amylase and α-glucosidase enzymes than metformin. Computational study revealed that lutein showed the highest binding free energy to 3TOP, while apigenin offered the highest binding free energy to 1B2Y. ConclusionHippocratea velutina leaf possesses significant antioxidant and antidiabetic activities.

Isolation and Characterization of Novel Pueroside B Isomers and Other Bioactive Compounds from Pueraria lobata Roots: Structure Elucidation, α-Glucosidase, and α-Amylase Inhibition Studies.

Pueraria lobata (Willd.) Ohwi is a traditional medicinal herb that has been extensively used in Chinese medicine for various therapeutic purposes. In this study, twelve chemical constituents were isolated from the roots of P. lobata, comprising three puerosides (compounds 1-3), six alkaloids (compounds 4-9), and three additional compounds (compounds 10-12). Notably, compound 1 (4R-pueroside B) was identified as a novel compound. The structures of all compounds were elucidated using a range of spectroscopic techniques, including CD spectroscopy for the first-time determination of the absolute configurations of pueroside B isomers (compounds 1 and 2). Enzyme inhibition assays revealed that, with the exception of compound 2, all isolated compounds exhibited varying degrees of α-glucosidase and α-amylase inhibitory activity. Remarkably, compound 12 demonstrated IC50 values of 23.25 μM for α-glucosidase inhibition and 27.05 μM for α-amylase inhibition, which are superior to those of the positive control, acarbose (27.05 μM and 36.68 μM, respectively). Additionally, compound 11 exhibited inhibitory activity against α-glucosidase and α-amylase comparable to the positive control, acarbose. Molecular docking studies indicated that compound 12 interacts with the active sites of the enzymes via hydrogen bonds, van der Waals forces, and hydrophobic interactions, which likely contribute to their inhibitory effects. These findings suggest that the chemical constituents of P. lobata could be potential natural sources of α-amylase and α-glucosidase inhibitors, with compound 12 being particularly promising for further investigation.