Synthesis of quinoline derivatives as diabetic II inhibitors and molecular docking studies

In searchof the potenttherapeutic agent as an α-glucosidase inhibitor, we have synthesized twenty-five analogs (1–25) of quinoline-based Schiff bases as an inhibitoragainst α-glucosidase enzyme under positive control acarbose (IC₅₀ = 38.45 ± 0.80 µM). From the activity profile it was foundthat analogs 1, 2, 3, 4, 11, 12 and 20with IC₅₀values 12.40 ± 0.40, 9.40 ± 0.30, 14.10 ± 0.40, 6.20 ± 0.30, 14.40 ± 0.40, 7.40 ± 0.20 and 13.20 ± 0.40 µMrespectively showed most potent inhibition among the series even than standard drug acarbose (IC₅₀ = 38.45 ± 0.80 µM). Here in the present study analog 4 (IC₅₀ = 6.20 ± 0.30 µM) was found with many folds better α-glucosidase inhibitory activity than the reference drug. Eight analogs like 5, 7, 8, 16, 17, 22, 24 and 25 among the whole series displayed less than 50% inhibition. The substituents effects on phenyl ring thereby superficially established through SAR study. Binding interactions of analogs and the active site of ligands proteins were confirmed through molecular docking study. Spectroscopic techniques like ¹H NMR, ¹³C NMR and ESIMS were used for characterization.     

Design,synthesis, in vitro evaluation,molecular docking and ADME properties studies of hybrid bis-coumarin with thiadiazole as a new inhibitor of Urease

Hybrid bis-coumarin derivatives 1–18 were synthesized and evaluated for their in vitro urease inhibitory potential. All compounds showed outstanding urease inhibitory potential with IC₅₀ value (The half maximal inhibitory concentration) ranging in between 0.12 SD 0.01 and 38.04 SD 0.63 µM (SD standard deviation). When compared with the standard thiourea (IC₅₀ = 21.40 ± 0.21 µM). Among these derivatives, compounds 7 (IC₅₀ = 0.29 ± 0.01), 9 (IC₅₀ = 2.4 ± 0.05), 10 (IC₅₀ = 2.25 ± 0.05) and 16 (IC₅₀ = 0.12 ± 0.01) are better inhibitors of the urease compared with thiourea (IC₅₀ = 21.40 ± 0.21 µM). To find structure–activity relationship molecular docking as well as absorption, distribution, metabolism, and excretion (ADME) studies were also performed. Various spectroscopic techniques like ¹H NMR, ¹³C NMR, and EI-MS were used for characterization of all synthesized analogs. All compounds were tested for cytotoxicity and found non-toxic.     

Synthesis,in vitro urease inhibitory activity,and molecular docking studies of thiourea and urea derivatives

The current study deals with the synthesis of urea and thiourea derivatives 1–37 which were characterized by various spectroscopic techniques including FAB-MS, ¹H-, and ¹³C NMR. The synthetic compounds were subjected to urease inhibitory activity and compounds exhibited good to moderate urease inhibitory activity having IC₅₀ values in range of 10.11–69.80 µM. Compound 1 (IC₅₀ = 10.11 ± 0.11 µM) was found to be most active and even better as compared to the standard acetohydroxamic acid (IC₅₀ = 27.0 ± 0.5 µM). A limited structure–activity relationship (SAR) was established and the compounds were also subjected to docking studies to confirm the binding interactions of ligands (compounds) with the active site of enzyme.     

Flurbiprofen derivatives as novel α-amylase inhibitors: Biology-oriented drug synthesis (BIODS), in vitro,and in silico evaluation

Novel derivatives of flurbiprofen 1–18 including flurbiprofen hydrazide 1, substituted aroyl hydrazides 2–9, 2-mercapto oxadiazole derivative 10, phenacyl substituted 2-mercapto oxadiazole derivatives 11–15, and benzyl substituted 2-mercapto oxadiazole derivatives 16–18 were synthesized and characterized by EI-MS, ¹H and ¹³C NMR spectroscopic techniques. All derivatives 1–18 were screened for α-amylase inhibitory activity and demonstrated a varying degree of potential ranging from IC₅₀ = 1.04 ± 0.3 to 2.41 ± 0.09 µM as compared to the standard acarbose (IC₅₀ = 0.9 ± 0.04 µM). Out of eighteen compounds, derivatives 2 (IC₅₀ = 1.69 ± 0.1 µM), 3 (IC₅₀ = 1.04 ± 0.3 µM), 9 (IC₅₀ = 1.25 ± 1.05 µM), and 13 (IC₅₀ = 1.6 ± 0.18 µM) found to be excellent inhibitors while rest of the compounds demonstrated comparable inhibition potential. A limited structure-activity relationship (SAR) was established by looking at the varying structural features of the library. In addition to that, in silico study was conducted to understand the binding interactions of the compounds (ligands) with the active site of α-amylase enzyme.     

Benzylidine indane-1,3-diones: As novel urease inhibitors; synthesis,in vitro,and in silico studies

Current study deals with the evaluation of indane-1,3-dione based compounds as new class of urease inhibitors. For that purpose, benzylidine indane-1,3-diones (1–30) were synthesized and fully characterized by different spectroscopic techniques including EI-MS, HREI-MS, ¹H, and ¹³C NMR. All synthetic molecules 1–30 were evaluated for urease inhibitory activity and showed good to moderate inhibitory potential within the range of (IC₅₀ = 11.60 ± 0.3–257.05 ± 0.7 µM) as compared to the standard acetohydroxamic acid (IC₅₀ = 27.0 ± 0.5 µM). Compound 1 (IC₅₀ = 11.60 ± 0.3 µM) was found to be most potent inhibitor amongst all derivatives. The key binding interactions of most active compounds within the enzyme pocket were evaluated through in silico studies.     

Synthesis and biological evaluation of new pyrazolone Schiff bases as monoamine oxidase and cholinesterase inhibitors

In the current work, Schiff base derivatives of antipyrine were synthesized. The chemical characterization of the compounds was confirmed using IR, ¹H NMR, ¹³C NMR and mass spectroscopies. The inhibitory potency of synthesized compounds was investigated towards acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and monoamine oxidases A and B (MAO-A and MAO-B) enzymes. Some of the compounds displayed significant inhibitory activity against AChE and MAO-B enzymes, respectively. According to AChE enzyme inhibition assay, compounds 3e and 3g were found as the most potent derivatives with IC₅₀ values of 0.285 µM and 0.057 µM, respectively. Also, compounds 3a (IC₅₀ = 0.114 µM), 3h (IC₅₀ = 0.049 µM), and 3i (IC₅₀ = 0.054 µM) were the most active derivatives against MAO-B enzyme activity. So as to understand inhibition type, enzyme kinetics studies were carried out. Furthermore, molecular docking studies were performed to define and evaluate the interaction mechanism between compounds 3g and 3h and related enzymes. ADME (Absorption, Distribution, Metabolism, and Excretion) and BBB (Blood, Brain, Barier) permeability predictions were applied to estimate pharmacokinetic profiles of synthesized compounds.     

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,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,thymidine phosphorylase,angiogenic inhibition and molecular docking study of isoquinoline derivatives

Isoquinoline analogues (KA-1 to 16) have been synthesized and evaluated for their E. coli thymidine phosphorylase inhibitory activity. Except compound 11, all other analogs showed outstanding thymidine inhibitory potential ranging in between 4.40 ± 0.20 to 69.30 ± 1.80 µM when compared with standard drug 7-Deazaxanthine (IC₅₀ = 38.68 ± 4.42 µM). Structure Activity Relationships has been established for all compounds, mainly based on substitution pattern on phenyl ring. All analogs were characterized by various spectroscopic techniques such as ¹H NMR, ¹³C NMR and EI-MS. The binding interactions of isoquinoline analogues with the active site of TP enzyme, the molecular docking studies were performed. Furthermore, the angiogenic inhibitory potentials of isoquinoline analogues (KA-1-9, 14, 12 and 16) were determined in the presence of standard drug Dexamethasone based on percentage inhibitions at various concentrations. Herein this work analogue KA-12, 14 and 16 emerged with most potent angiogenic inhibitory potentials among the synthesized analogues.     

Synthesis of new arylhydrazide bearing Schiff bases/thiazolidinone: α-Amylase,urease activities and their molecular docking studies

Alpha-amylase and urease enzyme over expression endorses various complications like rheumatoid arthritis, urinary tract infection, colon cancer, metabolic disorder, cardiovascular risk, and chronic kidney disease. To overcome these complications, we have synthesized new arylhydrazide bearing Schiff bases/thiazolidinone analogues as α-amylase and urease inhibitors. The analogues 1a-r were evaluated for α-amylase inhibitory potential. All analogues were found active and show IC₅₀ value ranging between 0.8 ± 0.05 and 12.50 ± 0.5 μM as compare to standard acarbose (IC₅₀ = 1.70 ± 0.10 μM). Among the synthesized analogs, compound 1j, 1r, 1k, 1e, 1b and 1f having IC₅₀ values 0.8 ± 0.05, 0.9 ± 0.05, 1.00 ± 0.05, 1.10 ± 0.10, 1.20 ± 0.10 and 1.30 ± 0.10 μM respectively showed an excellent inhibitory potential. Analogs 2a-o were evaluated against urease activity. All analogues were found active and show IC₅₀ value ranging between 4.10 ± 0.02 and 38.20 ± 1.10 μM as compare to standard thiourea (IC₅₀ = 21.40 ± 0.21 μM). Among the synthesized analogs, compound 2k, 2a, 2h, 2j, 2f, 2e, 2g, 2b and 2l having IC₅₀ values 4.10 ± 0.02, 4.60 ± 0.02, 4.70 ± 0.03, 5.40 ± 0.02, 6.70 ± 0.05, 8.30 ± 0.3, 11.20 ± 0.04, 16.90 ± 0.8 and 19.80 ± 0.60 μM respectively showed an excellent inhibitory potential. All compounds were characterized through ¹H, ¹³C NMR and HR-EIMS analysis. Structure activity relationship of the synthesized analogs were recognized and confirmed through molecular docking studies.     

New indole based hybrid oxadiazole scaffolds with N-substituted acetamides: As potent anti-diabetic agents

Current study is based on the sequential conversion of indolyl butanoic acid (1) into ethyl indolyl butanoate (2), indolyl butanohydrazide (3), and 1,3,4-oxadiazole-2-thiol analogs (4) by adopting chemical transformations. In a parallel series of reactions, 2-bromo-N-phenyl/arylacetamides (7a-l) were synthesized by reacting different amines derivatives (5a-l) with 2-bromoacetyl bromide (6) to serve as electrophile. Then, the synthesized electrophiles (7a-l) were treated with nucleophilic 1,3,4-oxadiazole-2-thiol analog (4) to afford a range of N-substituted derivatives (8a-l). The structural confirmation of all the synthetic compounds was carried out by IR, ¹H-, ¹³C NMR, EI-MS, and CHN analysis data. All synthesized molecules (8a-l) were tested for their antidiabetic potential via inhibition of the α-glucosidase enzyme followed by their in silico study. Their cytotoxicity profile was also ascertained via hemolytic activity and all of them possessed very low cytotoxicity. Compounds 8h and 8l were found most active having IC₅₀ values 9.46 ± 0.03 µM and 9.37 ± 0.03 µM, respectively. However, all other molecules also exhibited good to moderate inhibition potential with IC₅₀ values between 12.68 ± 0.04–37.82 ± 0.07, compared to standard acarbose (IC₅₀ = 37.38 ± 0.12 µM), hence can be used as lead molecules for further research in order to get better antidiabetic agents.     

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.     

3,4-Dimethoxybenzohydrazide derivatives as antiulcer: Molecular modeling and density functional studies

3,4-Dimethoxybenzohydrazide derivatives (1–25) have been synthesized and evaluated for their urease inhibitory potential. Among the series, compounds 2, 3, 4 and 5 with IC₅₀ values 12.61 ± 0.07, 18.24 ± 0.14, 19.22 ± 0.21, and 8.40 ± 0.05 µM, respectively, showed excellent urease inhibitory potentials when compared with standard thiourea (IC₅₀ value 21.40 ± 0.21 µM). Compounds 1, 6, 8, 18, 19 and 20 also showed good to moderate inhibition, while the remaining compounds were found to be completely inactive. The structures of compounds 6 and 25 were confirmed through X-ray crystallography while the structures of remaining compounds were confirmed through ESI-MS and ¹H NMR. Molecular docking studies were performed understand the binding interactions with enzyme active site. The synthesized compounds were evaluated for cytotoxicity and found to be nontoxic.     

1-[(4′-Chlorophenyl) carbonyl-4-(aryl) thiosemicarbazide derivatives as potent urease inhibitors: Synthesis,in vitro and in silico studies

A series of 1-[(4′-chlorophenyl)carbonyl-4-(aryl)thiosemicarbazide derivatives 1–25 was synthesized and characterized by spectroscopic techniques such as EI-MS and ¹H NMR. All compounds were screened for urease inhibitory activity in vitro and demonstrated excellent inhibitory activity in the range of IC₅₀ = 0.32 ± 0.01–25.13 ± 0.13 μM as compared to the standard thiourea (IC₅₀ = 21.25 ± 0.13 μM). Amongst the potent analogs, compounds 3 (IC₅₀ = 2.31 ± 0.01 μM), 6 (IC₅₀ = 2.14 ± 0.04 μM), 10 (IC₅₀ = 1.14 ± 0.06 μM), 20 (IC₅₀ = 2.15 ± 0.05 μM), and 25 (IC₅₀ = 0.32 ± 0.01 μM) are many folds more active than the standard. Structure-activity relationship (SAR) was rationalized by looking at the effect of diversely substituted aryl ring on inhibitory potential which predicted that regardless of the nature of substituents, their positions on aryl ring is worth important for the potent activity. Furthermore, to verify these interpretations, in silico study was performed on all compounds and a good correlation was perceived between the biological evaluation and docking study of compounds.     

Xanthenone-based hydrazones as potent α-glucosidase inhibitors: Synthesis,solid state self-assembly and in silico studies

Xanthenone based hydrazone derivatives (5a–n) have been synthesized as potential α-glucosidase inhibitors. All synthesized compounds (5a–n) are characterized by their FTIR, ¹H NMR, ¹³C NMR and HRMS, and in case of 5g also by X-ray crystallographic technique. The compounds unveiled a varying degree of α-glucosidase inhibitory activity when compared with standard acarbose (IC₅₀ = 375.38 ± 0.12 µM). Amongst the series, compound 5l (IC₅₀ = 62.25 ± 0.11 µM) bearing a trifluoromethyl phenyl group is found to be the most active compound. Molecular modelling is performed to establish the binding pattern of the more active compound 5l, which revealed the significance of substitution pattern. The pharmacological properties of molecules are also calculated by MedChem Designer which determines the ADME (absorption, distribution, metabolism, excretion) properties of molecules. The solid state self-assembly of compound 5g is discussed to show the conformation and role of iminoamide moiety in the molecular packing.     

Synthesis of alpha amylase inhibitors based on privileged indole scaffold

Twenty five derivatives of indole carbohydrazide (1–25) had been synthesized. These compounds were characterized using ¹H NMR and EI-MS, and further evaluated for their α-amylase inhibitory potential. The analogs (1–25) showed varying degree of α-amylase inhibitory potential.ranging between 9.28 and 599.0 µM when compared with standard acarbose having IC₅₀ value 8.78 ± 0.16 µM. Six analogs, 25 (IC₅₀ = 9.28 ± 0.153 µM), 22 (IC₅₀ = 9.79 ± 0.43 µM), 4 (IC₅₀ = 11.08 ± 0.357 µM), 1 (IC₅₀ = 12.65 ± 0.169 µM), 8 (IC₅₀ = 21.37 ± 0.07 µM) and 14 (IC₅₀ = 43.21 ± 0.14 µM) showed potent α-amylase inhibition as compared to the standard acarbose (IC₅₀ = 8.78 ± 0.16 µM). All other analogs displayed good to moderate inhibitory potential. Structure-activity relationship was established through the interaction of the active compounds with enzyme active site with the help of docking studies.     

New triazinoindole bearing thiazole/oxazole analogues: Synthesis, α-amylase inhibitory potential and molecular docking study

New triazinoindole bearing thiazole/oxazole analogues (1–21) were synthesized and characterized through spectroscopic techniques such as HREI-MS, ¹H and ¹³C NMR. The configuration of compound 2i and 2k was confirmed through NOESY. All analogues were evaluated against α-amylase inhibitory potential. Among the synthesized analogues, compound 1h, 1i, 1j, 2a and 2f having IC₅₀ values 1.80 ± 0.20, 1.90 ± 0.30, 1.2 ± 0.30, 1.2 ± 0.01 and 1.30 ± 0.20 μM respectively, showed excellent α-amylase inhibitory potential when compared with acarbose as standard (IC₅₀ = 0.91 ± 0.20 µM). All other analogues showed good to moderate inhibitory potential. Structural activity relationship (SAR) has been established and binding interactions were confirmed through docking studies.     

Oxindole based oxadiazole hybrid analogs: Novel α-glucosidase inhibitors

Inhibition of α-glucosidase is an effective strategy for controlling post-prandial hyperglycemia in diabetic patients. Beside these α-glucosidase inhibitors has been also used as anti-obesity and anti-viral drugs. Keeping in view the greater importance of α-glucosidase inhibitors here in this study we are presenting oxindole based oxadiazoles hybrid analogs (1–20) synthesis, characterized by different spectroscopic techniques including ¹H NMR and EI-MS and their α-glucosidase inhibitory activity. All compounds were found potent inhibitors for the enzyme with IC₅₀ values ranging between 1.25 ± 0.05 and 268.36 ± 4.22 µM when compared with the standard drug acarbose having IC₅₀ value 895.09 ± 2.04 µM. Our study identifies novel series of potent α-glucosidase inhibitors and further investigation on this may led to the lead compounds. A structure activity relationship has been established for all compounds. The interactions of the active compounds and enzyme active site were established with the help of molecular docking studies.     

Synthesis,biological evaluation,and docking studies of novel 5,6-diaryl-1,2,4-triazine thiazole derivatives as a new class of α-glucosidase inhibitors

A novel 5,6-diaryl-1,2,4-triazine thiazole derivatives (7a-7q) were synthesized and characterized by ¹H NMR and ¹³C NMR and evaluated for their α-glucosidase inhibitory activity. All tested compounds displayed good α-glucosidase inhibitory activity with IC₅₀ values ranging between 2.85 ± 0.13 and 14.19 ± 0.23 μM when compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μM). Compound 7i (IC₅₀ = 2.85 ± 0.13 μM) exhibited the highest activity among this series of compounds. Molecular docking studies were carried out in order to investigate the binding mode of this class of compounds to α-glucosidase. This study showed that these 5,6-diaryl-1,2,4-triazine thiazole derivatives are a new class of α-glucosidase inhibitors.     

Synthesis, α-glucosidase inhibition and molecular docking study of coumarin based derivatives

We have synthesized seventeen Coumarin based derivatives (1–17), characterized by ¹HNMR, ¹³CNMR and EI-MS and evaluated for α-glucosidase inhibitory potential. Among the series, all derivatives exhibited outstanding α-glucosidase inhibition with IC₅₀ values ranging between 1.10 ± 0.01 and 36.46 ± 0.70 μM when compared with the standard inhibitor acarbose having IC₅₀ value 39.45 ± 0.10 μM. The most potent derivative among the series is derivative 3 having IC₅₀ value 1.10 ± 0.01 μM, which are many folds better than the standard acarbose. The structure activity relationship (SAR) was mainly based upon by bring about difference of substituent’s on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.