Synthesis of thiobarbituric acid derivatives: In vitro α-glucosidase inhibition and molecular docking studies

Synthesis, structure, and evaluation of in vitro α-glucosidase enzyme inhibition of a new class of diethylammonium salts of aryl substituted thiobarbituric acid is described. This protocol is straight, environmentally benign and efficient, involving Aldol-Michael addition reaction in one pot fashion. The 3D chemical structures of the synthesized compounds were assigned based on spectroscopic methods and X-ray single crystal diffraction analyses. All synthesized compounds 3a-3n were evaluated for their in vitro α-glucosidase enzyme inhibitory activity, whereas acarbose was used as the standard drug (IC₅₀ = 840 ± 1.73 µM). All tested compounds were found to possess varying degree of α-glucosidase enzyme inhibition activity with (IC₅₀ = 19.46 ± 1.84–415.8 ± 4.0 µM). Compound 3i (IC₅₀ = 19.4 ± 1.84 µM) exhibited the highest activity. To the best of knowledge this is the first report of the in vitro α-glucosidase enzyme inhibition by the diethylamonium salts of aryl substituted thiobarbituric acid. Furthermore, molecular docking studies of selected compounds were also performed to see interactions between active compounds and binding sites.     

Synthesis, α-amylase inhibitory potential and molecular docking study of indole derivatives

In search of potent α-amylase inhibitor we have synthesized eighteen indole analogs (1–18), characterized by NMR and HR-EIMS and screened for α-amylase inhibitory activity. All analogs exhibited a variable degree of α-amylase inhibition with IC₅₀ values ranging between 2.031 ± 0.11 and 2.633 ± 0.05 μM when compared with standard acarbose having IC₅₀ values 1.927 ± 0.17 μM. All compounds showed good α-amylase inhibition. Compound 14 was found to be the most potent analog among the series. Structure-activity relationship has been established for all compounds mainly based on bringing about the difference of substituents on phenyl ring. To understand the binding interaction of the most active analogs molecular docking study was performed.     

Synthesis, α-glucosidase inhibition,and molecular docking studies of novel N-substituted hydrazide derivatives of atranorin as antidiabetic agents

A series of novel N-substituted hydrazide derivatives were synthesized by reacting atranorin, a compound with a natural depside structure (1), with a range of hydrazines. The natural product and 12 new analogues (2–13) were investigated for inhibition of α-glucosidase. The N-substituted hydrazide derivatives showed more potent inhibition than the original. The experimental results were confirmed by docking analysis. This study suggests that these compounds are promising molecules for diabetes therapy. Molecular dynamics simulations were carried out with compound 2 demonstrating the best docking model using Gromac during simulation up to 20 ns to explore the stability of the complex ligand-protein. Furthermore, the activity of all synthetic compounds 2–13 against a normal cell line HEK293, used for assessing their cytotoxicity, was evaluated.     

Synthesis,in vitro α-glucosidase inhibitory activity and molecular docking studies of new thiazole derivatives

Current study based on the synthesis of new thiazole derivatives via “one pot” multicomponent reaction, evaluation of their in vitro α-glucosidase inhibitory activities, and in silico studies. All synthetic compounds were fully characterized by ¹H NMR, ¹³C NMR and EIMS. CHN analysis was also performed. These newly synthesized compounds showed activities in the range of IC₅₀ = 9.06 ± 0.10–82.50 ± 1.70 μM as compared to standard acarbose (IC₅₀ = 38.25 ± 0.12 μM). It is worth mentioning that most of the compounds such as 1 (IC₅₀ = 23.60 ± 0.39 μM), 2 (IC₅₀ = 22.70 ± 0.60 μM), 3 (IC₅₀ = 22.40 ± 0.32 μM), 4 (IC₅₀ = 26.5 ± 0.40 μM), 6 (IC₅₀ = 34.60 ± 0.60 μM), 7 (IC₅₀ = 26.20 ± 0.43 μM), 8 (IC₅₀ = 14.06 ± 0.18 μM), 9 (IC₅₀ = 17.60 ± 0.28 μM), 10 (IC₅₀ = 27.16 ± 0.41 μM), 11 (IC₅₀ = 19.16 ± 0.19 μM), 12 (IC₅₀ = 9.06 ± 0.10 μM), 13 (IC₅₀ = 12.80 ± 0.21 μM), 14 (IC₅₀ = 11.94 ± 0.18 μM), 15 (IC₅₀ = 16.90 ± 0.20 μM), 16 (IC₅₀ = 12.60 ± 0.14 μM), 17 (IC₅₀ = 16.30 ± 0.29 μM), and 18 (IC₅₀ = 32.60 ± 0.61 μM) exhibited potent inhibitory potential. Molecular docking study was performed in order to understand the molecular interactions between the molecule and enzyme. Newly identified α-glucosidase inhibitors except few were found to be completely non-toxic.     

Synthesis,biological evaluation and molecular docking studies of chromone hydrazone derivatives as α-glucosidase inhibitors

A series of chromone hydrazone derivatives 4a–4p have been synthesized, characterized by ¹H NMR and ¹³C NMR and evaluated for their in vitro α-glucosidase inhibitory activity. Out of these tested compounds, six (4a, 4b, 4d, 4j, 4o and 4p) displayed potent α-glucosidase inhibitory activity with IC₅₀ values in the range of 20.1 ± 0.19 μM to 45.7 ± 0.23 μM, as compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μM). Among this series, compound 4d (IC₅₀ = 20.1 ± 0.19 μM) with 4-sulfonamide substitution at phenyl part of hydrazide was found to be the most active compound. Lineweaver-Burk plot analysis indicated that compound 4d is a non-competitive inhibitor of α-glucosidase. The binding interactions of the most active analogs were confirmed through molecular docking studies. Docking studies showed 4d are interacting with the residues Glu-276, Asp-214, Asp-349 and Arg-439 through hydrogen bonds, arene-anion and arene-cation interactions. In summary, our studies shown that these chromone hydrazone derivatives are a new class of α-glucosidase inhibitors.     

Synthesis,in vitro α-glucosidase inhibitory potential and molecular docking study of thiadiazole analogs

α-Glucosidase is a catabolic enzyme that regulates the body’s plasma glucose levels by providing energy sources to maintain healthy functioning. 2-Amino-thiadiazole (1–13) and 2-amino-thiadiazole based Schiff bases (14–22) were synthesized, characterized by ¹H NMR and HREI-MS and screened for α-glucosidase inhibitory activity. All twenty-two (22) analogs exhibit varied degree of α-glucosidase inhibitory potential with IC₅₀ values ranging between 2.30 ± 0.1 to 38.30 ± 0.7 μM, when compare with standard drug acarbose having IC₅₀ value of 39.60 ± 0.70 μM. Among the series eight derivatives 1, 2, 6, 7, 14, 17, 19 and 20 showed outstanding α-glucosidase inhibitory potential with IC₅₀ values of 3.30 ± 0.1, 5.80 ± 0.2, 2.30 ± 0.1, 2.70 ± 0.1, 2.30 ± 0.1, 5.50 ± 0.1, 4.70 ± 0.2, and 5.50 ± 0.2 μM respectively, which is many fold better than the standard drug acarbose. The remaining analogs showed good to excellent α-glucosidase inhibition. Structure activity relationship has been established for all compounds. The binding interactions of these compounds were confirmed through molecular docking.     

Synthesis of pyrimidine-2,4,6-trione derivatives: Anti-oxidant,anti-cancer, α-glucosidase, β-glucuronidase inhibition and their molecular docking studies

This paper describes a facile protocol, efficient, and environmentally benign for the synthesis a series of barbiturate acid substituted at C5 position 3a–o. The desired compounds subjected in vitro for different set of bioassays including against anti-oxidant (DPPH and super oxide scavenger assays), anti-cancer, α-glucosidase and β-glucuronidase inhibitions. Compound 3m (IC₅₀ = 22.9 ± 0.5 μM) found to be potent α-glucosidase enzyme inhibitors and showed more activity than standard acarbose (IC₅₀ = 841 ± 1.73 μM). Compound 3f (IC₅₀ = 86.9 ± 4.33 μM) found to be moderate β-Glucuronidase enzyme inhibitors and showed activity comparatively less than the standard d-saccharic acid 1,4-lactone (IC₅₀ = 45.75 ± 2.16 μM). Furthermore, in sillico investigation was carried out to investigate bonding mode of barbiturate acid derivatives.     

Design,synthesis and α-glucosidase inhibition study of novel embelin derivatives

Abstract

Embelin is a naturally occurring para-benzoquinone isolated from Embelia ribes (Burm. f.) of the Myrsinaceae family. It was first discovered to have potent inhibitory activity (IC₅₀ = 4.2?μM) against α-glucosidase in this study. Then, four series of novel embelin derivatives were designed, prepared and evaluated in α-glucosidase inhibition assays. The results show that most of the embelin derivatives synthesised are effective α-glucosidase inhibitors, with IC₅₀ values at the micromolar level, especially 10d, 12d, and 15d, the IC₅₀ values of which are 1.8, 3.3, and 3.6?μM, respectively. Structure–activity relationship (SAR) studies suggest that hydroxyl groups in the 2/5-position of para-benzoquinone are very important, and long-chain substituents in the 3-position are highly preferred. Moreover, the inhibition mechanism and kinetics studies reveal that all of 10d, 12d, 15d, and embelin are reversible and mixed-type inhibitors. Furthermore, docking experiments were carried out to study the interactions between 10d and 15d with α-glucosidase.     

Synthesis,in vitro evaluation and molecular docking studies of thiazole derivatives as new inhibitors of α-glucosidase

A series of thiazole derivatives 1–21 were prepared, characterized by EI-MS and ¹H NMR and evaluated for α-glucosidase inhibitory potential. All twenty one derivatives showed good α-glucosidase inhibitory activity with IC₅₀ value ranging between 18.23 ± 0.03 and 424.41 ± 0.94 μM when compared with the standard acarbose (IC₅₀, 38.25 ± 0.12 μM). Compound (8) (IC₅₀, 18.23 ± 0.03 μM) and compound (7) (IC₅₀ = 36.75 ± 0.05 μM) exhibited outstanding inhibitory potential much better than the standard acarbose (IC₅₀, 38.25 ± 0.12 μM). All other analogs also showed good to moderate enzyme inhibition. Molecular docking studies were carried out in order to find the binding affinity of thiazole derivatives with enzyme. Studies showed these thiazole analogs as a new class of α-glucosidase inhibitors.     

Synthesis,in-vitro α-glucosidase inhibition,antioxidant, in-vivo antidiabetic and molecular docking studies of pyrrolidine-2,5-dione and thiazolidine-2,4-dione derivatives

α-Glucosidase is considered as a therapeutic target for the treatment of type 2 diabetes mellitus (DM2). In current study, we synthesized pyrrolidine-2,5-dione (succinimide) and thiazolidine-2,4-dione derivatives and evaluated for their ability to inhibit α-Glucosidase. Pyrrolidine-2,5-dione derivatives (11a–o) showed moderate to poor α-glucosidase inhibition. Compound 11o with the IC₅₀ value of 28.3 ± 0.28 µM emerged as a good inhibitor of α-glucosidase. Thiazolidine-2,4-dione and dihydropyrimidine (TZD-DHPM) hybrids (22a–c) showed excellent inhibitory activities. The most active compound 22a displayed IC₅₀ value of 0.98 ± 0.008 µM. Other two compounds of this series also showed activity in low micromolar range. The in-vivo antidiabetic study of three compounds 11n, 11o and 22a were also determined using alloxan induced diabetes mice model. Compounds 11o and 22a showed significant hypoglycemic effect compared to the reference drug. In-vivo acute toxicity study showed the safety of these selected compounds. In-silico docking studies were carried out to rationalize the in-vitro results. The binding modes and bioassay results of TZD-DHPM hybrids showed that interactions with important residues appeared significant for high potency.     

Green synthesis,inhibition studies of yeast α-glucosidase and molecular docking of pyrazolylpyridazine amines

An efficient and environmentally benign simple fusion reaction of 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (1a) or 3-chloro-6-(3,5-dimethyl-4-nitro-1H-pyrazol-1-yl)pyridazine (2a) with different aliphatic/aromatic amines have produced a series of novel pyrazolylpyridazine amines (4a–4c & 5a–5m). All compounds exhibited moderate in vitro yeast α-glucosidase inhibition except m-chloro derivative 5g, which was found potent inhibitor of this enzyme with IC₅₀ value of 19.27 ± 0.005 µM. The molecular docking further helped in understanding the structure activity relationship of these compounds including 5g.     

Synthesis,molecular docking studies of hybrid benzimidazole as α-glucosidase inhibitor

Thiourea derivatives having benzimidazole 1–17 have been synthesized, characterized by ¹H NMR, ¹³C NMR and EI-MS and evaluated for α-glucosidase inhibition. Identification of potential α-glucosidase inhibitors were done by in vitro screening of 17 thiourea bearing benzimidazole derivatives using Baker’s yeast α-glucosidase enzyme. Compounds 1–17 exhibited a varying degree of α-glucosidase inhibitory activity with IC₅₀ values between 35.83 ± 0.66 and 297.99 ± 1.20 μM which are more better than the standard acarbose (IC₅₀ = 774.5 ± 1.94 μM). Compound 10 and 14 showed significant inhibitory effects with IC₅₀ value 50.57 ± 0.81 and 35.83 ± 0.66 μM, respectively better than the rest of the series. Structure activity relationships were established. Molecular docking studies were performed to understand the binding interaction of the compounds.     

Synthesis of 1H-1,2,3-triazole derivatives as new α-glucosidase inhibitors and their molecular docking studies

Inhibition of α-glucosidase is an effective strategy for controlling the post-prandial hyperglycemia in diabetic patients. For the identification of new inhibitors of this enzyme, a series of new (R)-1-(2-(4-bromo-2-methoxyphenoxy) propyl)-4-(4-(trifluoromethyl) phenyl)-1H-1,2,3-triazole derivatives were synthesized (8a–d and 10a–e). The structures were confirmed by NMR, mass spectrometry and, in case of compound 8a, by single crystal X-ray crystallography. The α-glucosidase inhibitory activities were investigated in vitro. Most derivatives exhibited significant inhibitory activity against α-glucosidase enzyme. Their structure-activity relationship and molecular docking studies were performed to elucidate the active pharmacophore against this enzyme. Compound 10b was the most active analogue with IC₅₀ value of 14.2 µM, while compound 6 was found to be the least active having 218.1 µM. A preliminary structure-activity relationship suggested that the presence of 1H-1,2,3-triazole ring in 1H-1,2,3-triazole derivatives is responsible for this activity and can be used as anti-diabetic drugs. The molecular docking studies of all active compounds were performed, in order to understand the mode of binding interaction and the energy of this class of compounds.     

Isatin based Schiff bases as inhibitors of α-glucosidase: Synthesis,characterization, in vitro evaluation and molecular docking studies

Isatin base Schiff bases (1–20) were synthesized, characterized by ¹H NMR and EI/MS and evaluated for α-glucosidase inhibitory potential. Out of these twenty (20) compounds only six analogs showed potent α-glucosidase inhibitory potential with IC₅₀ value ranging in between 2.2 ± 0.25 and 83.5 ± 1.0 μM when compared with the standard acarbose (IC₅₀ = 840 ± 1.73 μM). Among the series compound 2 having IC₅₀ value (18.3 ± 0.56 μM), 9 (83.5 ± 1.0 μM), 11 (3.3 ± 0.25 μM), 12 (2.2 ± 0.25 μM), 14 (11.8 ± 0.15 μM), and 20 (3.0 ± 0.15 μM) showed excellent inhibitory potential many fold better than the standard acarbose. The binding interactions of these active analogs were confirmed through molecular docking.     

Synthesis,nitric oxide release,and α-glucosidase inhibition of nitric oxide donating apigenin and chrysin derivatives

α-Glucosidase (AG) play crucial roles in the digestion of carbohydrates. Inhibitors of α-glucosidase (AGIs) are promising candidates for the development of anti-diabetic drugs. Here, five series of apigenin and chrysin nitric oxide (NO)-donating derivatives were synthesised and evaluated for their AG inhibitory activity and NO releasing capacity in vitro. Except for 9a–c, twelve compounds showed remarkable inhibitory activity against α-glucosidase, with potency being better than that of acarbose and 1-deoxynojirimycin. All organic nitrate derivatives released low concentrations of NO in the presence of l-cysteine. Structure activity relationship studies indicated that 5-OH, hydrophobic coupling chain, and carbonyl groups of the coupling chain could enhance the inhibitory activity. Apigenin and chrysin derivatives therefore represents a new class of promising compounds that can inhibit α-glucosidase activity and supply moderate NO for preventing the development of diabetic complications.     

Synthesis, in vitro α-glucosidase inhibitory activity and docking studies of novel chromone-isatin derivatives

A novel series of chromone-isatin derivatives 6a–6p were designed, synthesized and characterized by ¹H NMR, ¹³C NMR and HRMS. These novel synthetic compounds were evaluated for inhibitory activity against yeast α-glucosidase enzyme. The results of biological test have shown that all tested compounds exhibited excellent to potent inhibitory activity in the range of IC₅₀?=?3.18?±?0.12–16.59?±?0.17?μM as compared to the standard drug acarbose (IC₅₀?=?817.38?±?6.27?μM). Compound 6j (IC₅₀?=?3.18?±?0.12?μM) with a hydroxyl group at the 7-position of chromone and a 4-bromobenzyl group at the N1-positions of isatin, was found to be the most active compound among the series. Furthermore, molecular docking study was performed to help understand binding interactions of the most active analogs with α-glucosidase enzyme. These results indicated that this class of compounds had potential for the development of anti-diabetic agents.     

Synthesis and α-glucosidase inhibition activity of dihydroxy pyrrolidines

A new series of Deacetylsarmentamide A and B derivatives, amides and sulfonamides of 3,4-dihydroxypyrrolidines as α-glucosidase inhibitors were designed and synthesized. The biological screening test against α-glucosidase showed that some of these compounds have the positive inhibitory activity against α-glucosidase. Saturated aliphatic amides were more potent than the olefinic amides. Among all the compounds, 5o/6o having polar –NH₂ group, 10f/11f having polar –OH group on phenyl ring displayed 3–4-fold more potent than the standard drugs. Acarbose, Voglibose and Miglitol were used as standard references. The promising compounds 6i, 5o, 6o, 10a, 11a, 10f and 11f have been identified. Molecular docking simulations were done for compounds to identify important binding modes responsible for inhibition activity of α-glucosidase.     

Synthesis,molecular docking and α-glucosidase inhibition of 2-((5,6-diphenyl-1,2,4-triazin-3-yl)thio)-N-arylacetamides

A novel series of 2-((5,6-diphenyl-1,2,4-triazin-3-yl)thio)-N-arylacetamides 5a–5q have been synthesized and evaluated for their α-glucosidase inhibitory activity. All newly synthesized compounds exhibited potent α-glucosidase inhibitory activity in the range of IC₅₀ = 12.46 ± 0.13–72.68 ± 0.20 μM, when compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μM). Among the series, compound 5j (12.46 ± 0.13 μM) with strong electron-withdrawing nitro group on the arylacetamide moiety was identified as the most potent inhibitor of α-glucosidase. Molecular docking study was carried out to explore the binding interactions of these compounds with α-glucosidase. Our study identifies a novel series of potent α-glucosidase inhibitors for further investigation.     

Triazinoindole analogs as potent inhibitors of α-glucosidase: Synthesis,biological evaluation and molecular docking studies

A new series of triazinoindole analogs 1–11 were synthesized, characterized by EI-MS and ¹H NMR, evaluated for α-glucosidase inhibitory potential. All eleven (11) analogs showed different range of α-glucosidase inhibitory potential with IC₅₀ value ranging between 2.46 ± 0.008 and 312.79 ± 0.06 μM when compared with the standard acarbose (IC₅₀, 38.25 ± 0.12 μM). Among the series, compounds 1, 3, 4, 5, 7, 8, and 11 showed excellent inhibitory potential with IC₅₀ values 2.46 ± 0.008, 37.78 ± 0.05, 28.91 ± 0.0, 38.12 ± 0.04, 37.43 ± 0.03, 36.89 ± 0.06 and 37.11 ± 0.05 μM respectively. All other compounds also showed good enzyme inhibition. The binding modes of these analogs were confirmed through molecular docking.     

Synthesis,biological evaluation and molecular docking study of N-arylbenzo[d]oxazol-2-amines as potential α-glucosidase inhibitors

A novel series of N-arylbenzo[d]oxazol-2-amines (4a–4m) were synthesized and evaluated for their α-glucosidase inhibitory activity. Compounds 4f–4i, 4k and 4m displayed potent inhibitory activity against α-glucosidase with IC₅₀ values in the range of 32.49 ± 0.17–120.24 ± 0.51 μM as compared to the standard drug acarbose. Among all tested compounds, compound 4g having 4-phenoxy substitution at the phenyl ring was found to be the most active inhibitor of α-glucosidase with an IC₅₀ value of 32.49 ± 0.17 μM. Analysis of the kinetics of enzyme inhibition indicated that compound 4g is a noncompetitive inhibitor of α-glucosidase with a K_i value of 31.33 μM. Binding interaction of compound 4g with α-glucosidase was explored by molecular docking simulation.