ABSTRACT
Primary familial brain calcification (PFBC) is characterised by abnormal deposits of calcium phosphate within various regions of the brain that are associated with severe cognitive impairments, psychiatric conditions, and movement disorders. Recent studies in diverse populations have shown a link between mutations in myogenesis-regulating glycosidase (MYORG) and the development of this disease. MYORG is a member of glycoside hydrolase (GH) family 31 (GH31) and, like the other mammalian GH31 enzyme α-glucosidase II, this enzyme is found in the lumen of the endoplasmic reticulum (ER). Though presumed to act as an α-glucosidase due to its localization and sequence relatedness to α-glucosidase II, MYORG has never been shown to exhibit catalytic activity. Here, we show that MYORG is an α-galactosidase and present the high-resolution crystal structure of MYORG in complex with substrate and inhibitor. Using these structures, we map detrimental mutations that are associated with MYORG-associated brain calcification and define how these mutations may drive disease progression through loss of enzymatic activity. Finally, we also detail the thermal stabilisation of MYORG afforded by a clinically approved small molecule ligand, opening the possibility of using pharmacological chaperones to enhance the activity of mutant forms of MYORG.
Subject(s)
Brain Diseases , Glycoside Hydrolases , Animals , Brain/metabolism , Brain Diseases/genetics , Brain Diseases/metabolism , Glycoside Hydrolases/genetics , Humans , Ligands , Mammals/metabolism , Muscle Development , Pedigree , Substrate Specificity , alpha-Galactosidase/genetics , alpha-Galactosidase/metabolism , alpha-Glucosidases/metabolismABSTRACT
We thank Dr. Weimer and her colleagues for their comments related to our recent work (Anding et al., 2023) and are grateful for the opportunity to further discuss the importance of efficient lysosomal targeting of enzyme-replacement therapies (ERT) for the treatment of Pompe disease. Patients with Pompe disease have mutations in the gene that encodes for acid α glucosidase (GAA), a lysosomal enzyme necessary for the breakdown of glycogen. The first-generation ERT, alglucosidase alfa, provides a lifesaving therapy for the severe form of the disease (infantile onset Pompe disease) and improves or stabilizes respiratory and motor function in patients with less severe disease (late onset Pompe disease). Despite these gains, significant unmet need remains, particularly in patients who display respiratory and motor decline following years of treatment. Poor tissue uptake and lysosomal targeting via inefficient binding of the cation-independent mannose-6-phosphate (M6P) receptor (CIMPR) in skeletal muscle contributed to this suboptimal treatment response, prompting the development of new ERTs with increased levels of M6P.
Subject(s)
1-Deoxynojirimycin , Enzyme Replacement Therapy , Glycogen Storage Disease Type II , Mannosephosphates , alpha-Glucosidases , Glycogen Storage Disease Type II/drug therapy , Animals , Enzyme Replacement Therapy/methods , Mannosephosphates/metabolism , Mice , alpha-Glucosidases/therapeutic use , alpha-Glucosidases/metabolism , alpha-Glucosidases/administration & dosage , 1-Deoxynojirimycin/analogs & derivatives , 1-Deoxynojirimycin/administration & dosage , 1-Deoxynojirimycin/therapeutic use , Humans , Lysosomes/drug effects , Lysosomes/metabolismABSTRACT
Dammarane triterpenoids are affordable and bioactive natural metabolites with great structural potential, which makes them attractive sources for drug development. The aim of the study was to investigate the potency of new dipterocarpol derivatives for the treatment of diabetes. Two dammaranes (dipterocarpol and its 20(24)-diene derivative) were modified by a Claisen-Schmidt aldol condensation to afford C2(E)-arylidenes in good yields. The majority of the synthesized compounds exhibited an excellent-to-moderate inhibitory effect toward α-glucosidase (from S. saccharomyces), among them eight compounds showed IC50 values less than 10â µM. 3-Oxo-dammarane-2(E)-benzylidenes (holding p-hydroxy- 3 l and p-carbonyl- 3 m substituents) demonstrated the most potent α-glucosidase inhibition with IC50 0.753 and 0.204â µM, being 232- and 857-times more active than acarbose (IC50 174.90â µM), and a high level of NO inhibition in Raw 264.7 cells with IC50 of 1.75 and 4.57â µM, respectively. An inâ vivo testing of compound 3 m (in a dose of 20â mg/kg) on a model of streptozotocin-induced T1DM in rats showed a pronounced hypoglycemic activity, the ability to reduce effectively the processes of lipid peroxidation in liver tissue and decrease the excretion of glucose and pyruvic acid in the urine. Compound 3 m reduced the death of diabetic rats and preserved their motor activity.
Subject(s)
Diabetes Mellitus, Experimental , Hypoglycemic Agents , Rats , Animals , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/chemistry , alpha-Glucosidases/metabolism , alpha-Glucosidases/therapeutic use , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/drug therapy , Molecular Docking Simulation , Structure-Activity RelationshipABSTRACT
Glycoside hydrolases (glycosidases) take part in myriad biological processes and are important therapeutic targets. Competitive and mechanism-based inhibitors are useful tools to dissect their biological role and comprise a good starting point for drug discovery. The natural product, cyclophellitol, a mechanism-based, covalent and irreversible retaining ß-glucosidase inhibitor has inspired the design of diverse α- and ß-glycosidase inhibitor and activity-based probe scaffolds. Here, we sought to deepen our understanding of the structural and functional requirements of cyclophellitol-type compounds for effective human α-glucosidase inhibition. We synthesized a comprehensive set of α-configured 1,2- and 1,5a-cyclophellitol analogues bearing a variety of electrophilic traps. The inhibitory potency of these compounds was assessed towards both lysosomal and ER retaining α-glucosidases. These studies revealed the 1,5a-cyclophellitols to be the most potent retaining α-glucosidase inhibitors, with the nature of the electrophile determining inhibitory mode of action (covalent or non-covalent). DFT calculations support the ability of the 1,5a-cyclophellitols, but not the 1,2-congeners, to adopt conformations that mimic either the Michaelis complex or transition state of α-glucosidases.
Subject(s)
Glycoside Hydrolase Inhibitors , alpha-Glucosidases , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemical synthesis , alpha-Glucosidases/metabolism , alpha-Glucosidases/chemistry , Humans , Molecular Conformation , Structure-Activity Relationship , Density Functional Theory , CyclohexanolsABSTRACT
Starfish provide important saponins with diverse bioactivities as the secondary metabolites, among which 2-O-glycosylated glycosides are commonly found. Preparation of those 1,2-trans 2-O-glycosylated glycosides usually relies on 2-O-acyl participation requiring the selective installation and cleavage of 2-O-acyl groups. A convergent synthesis using 2-O-glycosylated oligosaccharide donors would be more straightforward but also pose greater challenges. Herein, we report a convergent synthesis of a distinctive tetrasaccharide isolated from starfish Asterias rollestoni Bell. Dual 2-(diphenylphosphinoyl)acetyl (DPPA) groups at O3 and O4 on galactose moiety led to high ß-selectivities (ß/α=12/1 or ß only) in the challenging [2+2] glycosylation, giving the desired tetrasaccharides in >90 % yields from the 2-O-glycosylated disaccharide donors. These synthetic studies have also unambiguously revised the structure of these natural tetrasaccharides. This work would facilitate further studies on new inhibitors of α-glucosidase as hypoglycemic drugs.
Subject(s)
Oligosaccharides , Animals , Glycosylation , Oligosaccharides/chemistry , Oligosaccharides/chemical synthesis , Asterias/chemistry , Glycosides/chemistry , Saponins/chemistry , Saponins/chemical synthesis , alpha-Glucosidases/metabolism , alpha-Glucosidases/chemistryABSTRACT
An eco-friendly facile synthesis of a series of twenty 1-(4/6-substitutedbenzo[d]thiazol-2-yl)-3-(phenyl/substitutedphenyl)indeno[1,2-c]pyrazol-4(1H)-ones 7a-t was achieved by the reaction of 2-(benzoyl/substitutedbenzoyl)-(1H)-indene-1,3(2H)-dione 3a-t and 2-hydrazinyl-4/6-substitutedbenzo[d]thiazole 6a-t in presence of freshly dried ethanol and glacial acetic acid under reflux conditions in good yields. The newly synthesized derivatives were well characterized using different physical and spectral techniques (FTIR, 1H NMR & 13C NMR, and HRMS). All the compounds were subjected to assess their in vitro α-amylase and glucose diffusion inhibitory activity. Amongst them, the compounds 7i and 7l showed better α-amylase inhibitory activity demonstrating IC50 values of 92.99±1.94 µg/mL and 95.41±3.92 µg/mL, respectively in comparison to the standard drug acarbose (IC50 value of 103.60±2.15 µg/mL). The derivatives 7d and 7k exhibited good glucose diffusion inhibition with values of 2.25±1.16 µg/mL and 2.63±1.45 µg/mL, respectively with standard reference acarbose (2.76±0.55 µg/mL). The observed α-amylase inhibitory activity findings were corroborated through molecular docking investigations, particularly for the highly active compounds 7i (binding energy -8.0 kcal/mol) and 7l (binding energy -8.2 kcal/mol) respectively, in comparison to acarbose with a value of binding energy -6.9 kcal/mol for α-amylase.
Subject(s)
Acarbose , Glucose , Structure-Activity Relationship , Molecular Structure , Molecular Docking Simulation , alpha-Amylases/metabolism , Benzothiazoles/pharmacology , alpha-Glucosidases/metabolism , Glycoside Hydrolase Inhibitors/pharmacologyABSTRACT
α-Glucosidase is one of the therapeutic approaches for treating type 2 diabetes mellitus. Almost 95 % of diabetes patients worldwide have been diagnosed with type 2 diabetes, resulting in 1.5 million fatalities each year. Newly synthesized oxazole-based tanshinone IIA derivatives (1a-n) were designed and evaluated for their inhibitory activity against α-glucosidase enzyme. Eight compounds (1a-d, 1f-g, 1j, and 1m) demonstrated excellent inhibition with IC50 values ranging from 0.73 ± 0.11 to 9.46 ± 0.57 µM as compared to tanshinone IIA (IC50 = 11.39 ± 0.77 µM) and standard acarbose (IC50 = 100.00 ± 0.95 µM). Among this series, 1j bearing two hydroxyls group over the phenyl ring was identified as the most potent α-glucosidase inhibitor with IC50 value of 0.73 ± 0.11 µM. Molecular docking simulations were done for the most active compound to identify important binding modes responsible for inhibition activity of α-glucosidase. In addition, the kinetic study was also performed to understand the mode of inhibition.
Subject(s)
Abietanes , Glycoside Hydrolase Inhibitors , Molecular Docking Simulation , alpha-Glucosidases , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/chemical synthesis , Abietanes/chemistry , Abietanes/pharmacology , Abietanes/chemical synthesis , alpha-Glucosidases/metabolism , Structure-Activity Relationship , Molecular Structure , Humans , Dose-Response Relationship, DrugABSTRACT
In this study, new indol-fused pyrano[2,3-d]pyrimidines were designed and synthesized. These products were obtained in moderate to good yields and their structures were assigned by NMR, MS, and IR analysis. Afterwards, the biological important of the products was highlighted by evaluating in vitro for α-glucosidase inhibitory activity as well as acetylcholinesterase (AChE) inhibitory activity. Eleven products revealed substantial inhibitory activity against α-glucosidase enzyme, among which, two most potent products 11d,e were approximately 93-fold more potent than acarbose as a standard antidiabetic drug. Besides that, product 11k exhibited good AChE inhibition. The substituents on the 5-phenyl ring, attached to the pyran ring, played a critical role in inhibitory activities. The biological potencies have provided an opportunity to further investigations of indol-fused pyrano[2,3-d]pyrimidines as potential anti-diabetic agents.
Subject(s)
Cholinesterase Inhibitors , Glycoside Hydrolase Inhibitors , Acetylcholinesterase/metabolism , alpha-Glucosidases/metabolism , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Hypoglycemic Agents/pharmacology , Molecular Docking Simulation , Pyrans/pharmacology , Pyrans/chemistry , Pyrimidines/pharmacology , Pyrimidines/chemistry , Structure-Activity Relationship , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacologyABSTRACT
Aspergillus versicolor, an endophytic fungus associated with the herbal medicine Pedicularis sylvatica, produced four new polyketides, aspeversins A-D (1-2 and 5-6) and four known compounds, O-methylaverufin (2), aversin (3), varilactone A (7) and spirosorbicillinol A (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by calculated electronic circular dichroism (ECD) and Mo2(AcO)4-induced CD data. Compound 5 was found to exhibit α-glucosidase inhibitory activity with an IC50 value of 25.57 µM. An enzyme kinetic study indicated that 5 was a typical uncompetitive inhibitor toward α-glucosidase, which was supported by a molecular docking study. Moreover, compounds 1-3 and 5 also improved the cell viability of PC12 cells on a 1-methyl-4-phenylpyridinium (MPP+)-induced Parkinson's disease model, indicating their neuroprotective potential as antiparkinsonian agents.
Subject(s)
Aspergillus , Glycoside Hydrolase Inhibitors , Molecular Docking Simulation , Neuroprotective Agents , Polyketides , alpha-Glucosidases , Aspergillus/chemistry , Neuroprotective Agents/pharmacology , Neuroprotective Agents/chemistry , Neuroprotective Agents/isolation & purification , Polyketides/pharmacology , Polyketides/chemistry , Polyketides/isolation & purification , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/isolation & purification , PC12 Cells , Animals , Rats , alpha-Glucosidases/metabolism , Cell Survival/drug effects , Molecular StructureABSTRACT
This study presents the synthesis and bio-evaluation of new triazolylated dihydropyridine and tetrahydropyridine azasugar scaffolds (F1-14). Azasugar glycomimetics are the synthetic substances that mimic the structural and functional characteristics of natural carbohydrates showcasing promising potential as therapeutic agents for diabetes. The α-glucosidase inhibitory activity of synthesized final compounds were evaluated against the commercially available α-glucosidase enzyme. Majority of the screened compounds displayed excellent inhibition with IC50 values ranging from 2.12 to 75.11 µM, when compared to the standard drug Acarbose. Particularly, compound F5 with IC50 value of 2.12 µM was found to be the most active compound among the series. Further molecular docking studies of selected ligands were performed to investigate the binding interactions with enzyme active sites. Their specific binding patterns have been analysed with the binding sites of Saccharomyces cerevisiae α-glucosidase. These findings suggest these candidates as the potential leads for the anti-diabetic activity.
Subject(s)
Glycoside Hydrolase Inhibitors , alpha-Glucosidases , Molecular Structure , Structure-Activity Relationship , Glycoside Hydrolase Inhibitors/chemistry , Molecular Docking Simulation , alpha-Glucosidases/metabolism , Saccharomyces cerevisiaeABSTRACT
α-Glucosidase inhibitory activity of galbanic acid and its new amide derivatives 3a-n were investigated. Galbanic acid and compounds 3a-n showed excellent anti-α-glucosidase activity with IC50 values ranging from 0.3 ± 0.3 µM to 416.0 ± 0.2 µM in comparison to positive control acarbose with IC50 value of = 750.0 ± 5.6. In the kinetic study, the most potent compound 3h demonstrated a competitive mode of inhibition with Ki = 0.57 µM. The interaction of the most potent compound 3h with the α-glucosidase was further elaborated by in vitro Circular dichroism assessment and in silico molecular docking and Molecular dynamics studies. Compound 3h was also non-cytotoxic on human normal cells. In silico study on pharmacokinetics and toxicity profile of the most potent galbanic acid derivatives demonstrated that these compounds are valuable lead compounds for further study in order to achieve new anti-diabetic agents.
Subject(s)
Amides , Glycoside Hydrolase Inhibitors , Molecular Docking Simulation , alpha-Glucosidases , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/chemical synthesis , alpha-Glucosidases/metabolism , Humans , Structure-Activity Relationship , Molecular Structure , Amides/chemistry , Amides/pharmacology , Amides/chemical synthesis , Dose-Response Relationship, Drug , Saccharomyces cerevisiae/enzymologyABSTRACT
In order to find effective α-glucosidase inhibitors, a series of thiazolidine-2,4-dione derivatives (C1 â¼ 36) were synthesized and evaluated for α-glucosidase inhibitory activity. Compared to positive control acarbose (IC50 = 654.35 ± 65.81 µM), all compounds (C1 â¼ 36) showed stronger α-glucosidase inhibitory activity with IC50 values of 0.52 ± 0.06 â¼ 9.31 ± 0.96 µM. Among them, C23 with the best anti-α-glucosidase activity was a reversible mixed-type inhibitor. Fluorescence quenching suggested the binding process of C23 with α-glucosidase in a static process. Fluorescence quenching, CD spectra, and 3D fluorescence spectra results also implied that the binding of C23 with α-glucosidase caused the conformational change of α-glucosidase to inhibit the activity. Molecular docking displayed the binding interaction of C23 with α-glucosidase. Compound C23 (8 â¼ 64 µM) showed no cytotoxicity against LO2 and 293 cells. Moreover, oral administration of C23 (50 mg/kg) could reduce blood glucose and improve glucose tolerance in mice.
Subject(s)
Glycoside Hydrolase Inhibitors , Hypoglycemic Agents , Thiazolidinediones , Mice , Animals , Glycoside Hydrolase Inhibitors/chemistry , Hypoglycemic Agents/chemistry , Molecular Structure , Structure-Activity Relationship , alpha-Glucosidases/metabolism , Molecular Docking Simulation , ThiazolidinesABSTRACT
Inhibition of α-glucosidase and α-amylase is an important target for treatment of type 2 diabetes. In this work, a novel series of pyrano[2,3-b]chromene derivatives 5a-m was designed based on potent α-glucosidase and α-amylase inhibitors and synthesized by simple chemical reactions. These compounds were evaluated against the latter enzymes. Most of the title compounds exhibited high inhibitory activity against α-glucosidase and α-amylase in comparison to standard inhibitor (acarbose). Representatively, the most potent compound, 4-methoxy derivative 5d, was 30.4 fold more potent than acarbose against α-glucosidase and 6.1 fold more potent than this drug against α-amylase. In silico molecular modeling demonstrated that compound 5d attached to the active sites of α-glucosidase and α-amylase with a favorable binding energies and established interactions with important amino acids. Dynamics of compound 5d also showed that this compound formed a stable complex with the α-glucosidase active site. In silicodrug-likeness as well as ADMET prediction of this compound was also performed and satisfactory results were obtained.
Subject(s)
Diabetes Mellitus, Type 2 , Glycoside Hydrolase Inhibitors , Humans , Glycoside Hydrolase Inhibitors/chemistry , Acarbose , Diabetes Mellitus, Type 2/drug therapy , alpha-Glucosidases/metabolism , Molecular Docking Simulation , Chromones/pharmacology , Chromones/chemistry , alpha-Amylases , Structure-Activity RelationshipABSTRACT
A green catalyst WELPSA-catalyzed three-component condensation (Biginelli) process involving an aldehyde, barbituric/thiobarbituric/1,3-dimethylbarbituric acid, and urea/thiourea/guanidine hydrochloride in a single pot in presence of a green solvent for the production of DHPM have been presented. The catalyst is reusable and this methodology is scalable. By using the in vitro experiments, the antidiabetic potentiality of synthesized compounds that inhibit α-amylase along with α-glucosidase efficiencies was assessed. All the synthesized compounds except for 4a and 4e, showed the most significant inhibition for α-amylase and α-glucosidase activities. Among the synthesized DHPM compounds, 4c and 4b exhibited significant inhibition profiles compared to the standard antidiabetic drug acarbose. Furthermore, synthesized substances' energy-minimized structures, 3D structures, and DFT calculations were performed using Gaussian 09 software, hybrid models, and MM2 force approaches. Strong hydrogen bonds with amino acid residues Arg-672, Arg-600, Trp-613, Asp-404, Asp-282, and Asp-616 indicate that an α-glucosidase-inhibitory peptide may have hypoglycemic efficacy confirmed by the molecular docking study of the synthesized DHPM.
Subject(s)
Glycoside Hydrolase Inhibitors , alpha-Glucosidases , Glycoside Hydrolase Inhibitors/chemistry , Molecular Docking Simulation , alpha-Glucosidases/metabolism , alpha-Amylases/metabolism , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , CatalysisABSTRACT
Five pairs of new merosesquiterpenoid enantiomers, named dauresorcinols A-E (1-5), were isolated from the leaves of Rhododendron dauricum. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum chemical calculations, Rh2(OCOCF3)4-induced ECD, and single-crystal X-ray diffraction analysis. Dauresorcinols A (1) and B (2) possess two new merosesquiterpene skeletons bearing an unprecedented 2,6,7,10,14-pentamethyl-11-oxatetracyclo[8.8.0.02,7.012,17]octadecane and a caged 15-isohexyl-1,5,15-trimethyl-2,10-dioxatetracyclo[7.4.1.111,14.03,8]pentadecane motif, respectively. Plausible biosynthetic pathways of 1-5 are proposed involving key oxa-electrocyclization and Wagner-Meerwein rearrangement reactions. (+)/(-)-1 and 3-5 showed potent α-glucosidase inhibitory activity, 3 to 22 times stronger than acarbose, an antidiabetic drug targeting α-glucosidase. Docking results provide a basis to design and develop merosesquiterpenoids as potent α-glycosidase inhibitors.
Subject(s)
Glycoside Hydrolase Inhibitors , Rhododendron , Rhododendron/chemistry , Stereoisomerism , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/isolation & purification , Molecular Structure , Structure-Activity Relationship , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology , Sesquiterpenes/isolation & purification , alpha-Glucosidases/metabolism , Molecular Docking Simulation , Humans , Dose-Response Relationship, Drug , Plant Leaves/chemistry , Crystallography, X-Ray , Models, MolecularABSTRACT
This study investigated the inhibitory potential of a series of synthesized compounds (L1-L27) on α-glucosidase. Among them, compound L22 showed significant inhibitory effect. Through enzymatic kinetics studies, we demonstrated that L22 acts via a non-competitive inhibition mode with a Ki value of 2.61 µM, highlighting its high affinity for the enzyme. Molecular docking studies revealed the formation of hydrogen bonds between L22 and α-glucosidase and diverse interactions with neighboring amino acid residues. Furthermore, molecular dynamics simulations confirmed the stability of the L22-α-glucosidase complex. In a mouse model of type 2 diabetes, treatment with L22 significantly lowered fasting blood glucose levels, and reduced insulin resistance, suggesting its potential as a therapeutic agent for type 2 diabetes. Furthermore, L22 showed a protective effect against oxidative stress in the liver and alleviated liver and pancreatic abnormalities. These results provide valuable insights into the mechanism of action of L22 and its potential applications to treat type 2 diabetes, and improve liver health.
Subject(s)
Diabetes Mellitus, Type 2 , Glycoside Hydrolase Inhibitors , Mice , Animals , Glycoside Hydrolase Inhibitors/chemistry , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Hypoglycemic Agents/chemistry , Molecular Docking Simulation , Apigenin/pharmacology , Apigenin/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , alpha-Glucosidases/metabolism , KineticsABSTRACT
Phenylpropanoids (PPs), a group of natural compounds characterized by one or more C6-C3 units, have exhibited considerable potential in addressing metabolic disease. However, the comprehensive investigation on the relationship of compound structures and involved activity, along with the action mechanisms on the drug target is absent. This study aimed to evaluate the antioxidant and inhibitory activities of 16 PPs against two digestive enzymes, including α-glucosidase and pancreatic lipase, explore the structure-activity relationships and elucidate the mechanisms underlying enzyme inhibition. The findings revealed the similarities in the rules governing antioxidant and enzyme inhibitory activities of PPs. Specifically, the introduction of hydroxyl groups generally exerted positive effects on the activities, while the further methoxylation and glycosylation were observed to be unfavorable. Among the studied PPs, esculetin exhibited the most potent antioxidant activity and dual enzymes inhibition potential, displaying IC50 values of 0.017 and 0.0428 mM for DPPH and ABTS radicals scavenging, as well as 1.36 and 6.67 mM for α-glucosidase and lipase inhibition, respectively. Quantification analysis indicated esculetin bound on both α-glucosidase and lipase successfully by a mixed-type mode. Further analyses by UV-Vis, FT-IR, fluorescence spectra, surface hydrophobicity, SEM, and molecular docking elucidated that esculetin could bind on the catalytic or non-catalytic sites of enzymes to form complex, impacting the normal spatial conformation for hydrolyzing the substrate, thus exhibiting the weakened activity. These results may shed light on the utilization value of natural PPs for the management of hyperglycemia and hyperlipemia, and afford the theoretical basis for designing drugs with stronger inhibition against the dual digestive enzymes based on esculetin.
Subject(s)
Antioxidants , Hypoglycemic Agents , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Antioxidants/pharmacology , Antioxidants/chemistry , alpha-Glucosidases/metabolism , Molecular Docking Simulation , Spectroscopy, Fourier Transform Infrared , Plant Extracts/chemistry , Lipase/metabolism , Structure-Activity RelationshipABSTRACT
Diabetes mellitus is a metabolic disease characterized by hyperglycemia, which can be counteracted by the inhibition of α-glucosidase (α-Glu) and α-amylase (α-Amy), enzymes responsible for the hydrolysis of carbohydrates. In recent decades, many natural compounds and their bioinspired analogues have been studied as α-Glu and α-Amy inhibitors. However, no studies have been devoted to the evaluation of α-Glu and α-Amy inhibition by the neolignan obovatol (1). In this work, we report the synthesis of 1 and a library of new analogues. The synthesis of these compounds was achieved by implementing methodologies based on: phenol allylation, Claisen/Cope rearrangements, methylation, Ullmann coupling, demethylation, phenol oxidation and Michael-type addition. Obovatol (1) and ten analogues were evaluated for their in vitro inhibitory activity towards α-Glu and α-Amy. Our investigation highlighted that the naturally occurring 1 and four neolignan analogues (11, 22, 26 and 27) were more effective inhibitors than the hypoglycemic drug acarbose (α-Amy: 34.6 µM; α-Glu: 248.3 µM) with IC5O value of 6.2-23.6 µM toward α-Amy and 39.8-124.6 µM toward α-Glu. Docking investigations validated the inhibition outcomes, highlighting optimal compatibility between synthesized neolignans and both the enzymes. Concurrently circular dichroism spectroscopy detected the conformational changes in α-Glu induced by its interaction with the studied neolignans. Detailed studies through fluorescence measurements and kinetics of α-Glu and α-Amy inhibition also indicated that 1, 11, 22, 26 and 27 have the greatest affinity for α-Glu and 1, 11 and 27 for α-Amy. Surface plasmon resonance imaging (SPRI) measurements confirmed that among the compounds studied, the neolignan 27 has the greater affinity for both enzymes, thus corroborating the results obtained by kinetics and fluorescence quenching. Finally, in vitro cytotoxicity of the investigated compounds was tested on human colon cancer cell line (HCT-116). All these results demonstrate that these obovatol-based neolignan analogues constitute promising candidates in the pursuit of developing novel hypoglycemic drugs.
Subject(s)
Glycoside Hydrolase Inhibitors , Lignans , alpha-Amylases , alpha-Glucosidases , alpha-Amylases/antagonists & inhibitors , alpha-Amylases/metabolism , alpha-Glucosidases/metabolism , Glycoside Hydrolase Inhibitors/chemical synthesis , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Lignans/pharmacology , Lignans/chemistry , Lignans/chemical synthesis , Structure-Activity Relationship , Humans , Molecular Structure , Dose-Response Relationship, Drug , Molecular Docking Simulation , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/chemistry , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistryABSTRACT
α-Glycosidase inhibition is one of the main approaches to treat Diabetes mellitus. Polyphenolic moieties are known to be responsible for yielding exhibit potent α-glycosidase inhibitory effects. In addition, compounds containing benzothiazole and Schiff base functionalities were previously reported to show α-glycosidase inhibition. In this paper, the synthesis of seven new phloroglucinol-containing benzothiazole Schiff base derivatives through the reaction of 6-substituted-2-aminobenzothiazole compounds with 2,4,6-trihydroxybenzaldehyde using acetic acid as a catalyst was reported. The synthesized compounds were characterized using spectroscopic methods such as FT-IR, 1H NMR, 13C NMR, and elemental analysis. The synthesized compounds were evaluated for their inhibitory effects on α-glycosidase, compounds 3f and 3g were found to show significant inhibitory properties when compared to the positive control. The IC50 values of 3f and 3g were calculated as 24.05 ± 2.28 and 18.51 ± 1.19 µM, respectively. Kinetic studies revealed that compounds 3f and 3g exhibited uncompetitive mode of inhibition against α-glycosidase. Molecular modeling predicted druglikeness for the title compounds and underpinned the importance of phloroglucinol hydroxyls for interacting with the key residues of α-glycosidase.
Subject(s)
Benzothiazoles , Enzyme Inhibitors , Polyphenols , Benzothiazoles/chemistry , Benzothiazoles/pharmacology , Benzothiazoles/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemical synthesis , Polyphenols/chemistry , Polyphenols/pharmacology , Polyphenols/chemical synthesis , Structure-Activity Relationship , Molecular Structure , Glycoside Hydrolases/antagonists & inhibitors , Glycoside Hydrolases/metabolism , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemical synthesis , Molecular Docking Simulation , Humans , Dose-Response Relationship, Drug , alpha-Glucosidases/metabolism , KineticsABSTRACT
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by high blood sugar levels. It was shown that modulating the activity of α-glucosidase, an enzyme involved in carbohydrate digestion and absorption, can improve blood sugar control and overall metabolic health in individuals with T2DM. As a result, in the current study, a series of imidazole bearing different substituted thioquinolines were designed and synthesized as α-glucosidase inhibitors. All derivatives exhibited significantly better potency (IC50 = 12.1 ± 0.2 to 102.1 ± 4.9 µM) compared to the standard drug acarbose (IC50 = 750.0 ± 5.0 µM). 8g as the most potent analog, indicating a competitive inhibition with Ki = 9.66 µM. Also, the most potent derivative was subjected to molecular docking and molecular dynamic simulation against α-glucosidase to determine its mode of action in the enzyme and study the complex's behavior over time. In vivo studies showed that 8g did not cause acute toxicity at 2000 mg/kg doses. Additionally, in a diabetic rat model, treatment with 8g significantly reduced fasting blood glucose levels and decreased blood glucose levels following sucrose loading compared to acarbose, a standard drug used for blood sugar control. The findings suggest that the synthesized compound 8g holds promise as an α-glucosidase inhibitor for improving blood sugar control and metabolic health.