Synthesis, in vitro, and in silico study of novel pyridine based 1,3-diphenylurea derivatives as tyrosinase inhibitors.

Tyrosinase inhibitors are studied in the cosmetics and pharmaceutical sectors as tyrosinase enzyme is involved in the biosynthesis and regulation of melanin, hence these inhibitors are beneficial for the management of melanogenesis and hyperpigmentation-related disorders. In the current work, a novel series of diphenyl urea derivatives containing a halo-pyridine moiety (5a-t) was synthesized via a multi-step synthesis. In vitro, tyrosinase inhibitory assay results showed that, except for two compounds, the derivatives were excellent inhibitors of human tyrosinase. The average IC50 value of the inhibitors (15.78 µM) is lower than that of kojic acid (17.3 µM) used as the reference compound, indicating that, on average, these molecules are more potent than the reference. Derivative 5a was identified as the most potent human tyrosinase inhibitor of the series, with an IC50 value of 3.5 ± 1.2  µM, approximately 5 times more potent than kojic acid. To get further insights into the nature of binding site interactions, molecular docking and molecular dynamics simulation studies were carried out. Moreover, the evaluation of in silico ADME properties showed a highly favorable profile for the synthesized compounds. These findings suggested that the further development of this class of compounds could be useful to get potent drug-like compounds that can target hyperpigmentation-related disorders.

Exploring chromone sulfonamides and sulfonylhydrazones as highly selective ectonucleotidase inhibitors: Synthesis, biological evaluation and in silico study.

Ectonucleotidases, a well-known superfamily of plasma membrane located metalloenzymes plays a central role in mediating the process of purinergic cell signaling. Major functions performed by these enzymes include the hydrolysis of extracellular nucleosides and nucleotides which are considered as important cell-signaling molecules. Any (patho)-physiologically induced disruption in this purinergic cell signaling leads to several disorders, hence these enzymes are important drug targets for therapeutic purposes. Among the major challenges faced in the design of inhibitors of ectonucleotidases, an important one is the lack of selective inhibitors. Access to highly selective inhibitors via a facile synthetic route will not only be beneficial therapeutically, but will also lead to an increase in our understanding of intricate interplay between members of ectonucleotidase enzymes in relation to their selective activation and/or inhibition in different cells and tissues. Herein we describe synthesis of highly selective inhibitors of human intestinal alkaline phosphatase (h-IAP) and human tissue non-specific alkaline phosphatase (h-TNAP), containing chromone sulfonamide and sulfonylhydrazone scaffolds. Compound 1c exhibited highest (and most selective) h-IAP inhibition activity (h-IAP IC50 = 0.51 ± 0.20 µM; h-TNAP = 36.5%) and compound 3k showed highest activity and selective inhibition against h-TNAP (h-TNAP IC50 = 1.41 ± 0.10 µM; h-IAP = 43.1%). These compounds were also evaluated against another member of ectonucleotidase family, that is rat and human ecto-5'-nucleotidase (r-e5'NT and h-e5'NT). Some of the compounds exhibited excellent inhibitory activity against ecto-5'-nucleotidase. Compound 2 g exhibited highest inhibition against h-e5'NT (IC50 = 0.18 ± 0.02 µM). To rationalize the interactions with the binding site, molecular docking studies were carried out.

Deep eutectic solvent mediated synthesis of 3,4-dihydropyrimidin-2(1H)-ones and evaluation of biological activities targeting neurodegenerative disorders.

Substitution of hazardous and often harmful organic solvents with "green" and "sustainable" alternative reaction media is always desirous. Ionic liquids (IL) have emerged as valuable and versatile liquids that can replace most organic solvents in a variety of syntheses. However, recently new types of low melting mixtures termed as Deep Eutectic Solvents (DES) have been utilized in organic syntheses. DES are non-volatile in nature, have sufficient thermal stability, and also have the ability to be recycled and reused. Hence DES have been used as alternative reaction media to perform different organic reactions. The availability of green, inexpensive and easy to handle alternative solvents for organic synthesis is still scarce, hence our interest in DES mediated syntheses. Herein we have investigated Biginelli reaction in different DES for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Monoamine oxidases and cholinesterases are important drug targets for the treatment of various neurological disorders such as Alzheimer's disease, Parkinson's disease, depression and anxiety. The compounds synthesized herein were evaluated for their inhibitory potential against these enzymes. Some of the compounds were found to be highly potent and selective inhibitors. Compounds 1 h and 1c were the most active monoamine oxidase A (MAO A) (IC50 = 0.31 ± 0.11 µM) and monoamine oxidase B (MAO B) (IC50 = 0.34 ± 0.04 µM) inhibitors respectively. All compounds were selective AChE inhibitors and did not inhibit BChE (<29% inhibition). Compound 1 k (IC50 = 0.13 ± 0.09 µM) was the most active AChE inhibitor.

Synthesis, In-vitro evaluation and molecular docking studies of oxoindolin phenylhydrazine carboxamides as potent and selective inhibitors of ectonucleoside triphosphate diphosphohydrolase (NTPDase).

Members of the ectonucleoside triphosphate diphosphohydrolases (NTPDases) constitute the major family of enzymes responsible for the maintenance of extracellular levels of nucleotides and nucleosides by catalyzing the hydrolysis of nucleoside triphosphate (NTP) and nucleoside diphosphates (NDP) to nucleoside monophosphate (NMP). Although, NTPDase inhibitors can act as potential drug candidates for the treatment of various diseases, there is lack of potent as well as selective inhibitors of NTPDases. The current study describes the synthesis of a number of carboxamide derivatives that were tested on recombinant human (h) NTPDases. The most promising inhibitors were 2h (h-NTPDase1, IC50: 0.12 ± 0.03 µM), 2d (h-NTPDase2, IC50: 0.15 ± 0.01 µM) and 2a (h-NTPDase3, IC50: 0.30 ± 0.04 µM; h-NTPDase8, IC50: 0.16 ± 0.02 µM). Four compounds (2e, 2f, 2g and 2h) were associated with the selective inhibition of h-NTPDase1 while 2b was identified as a selective h-NTPDase3 inhibitor. Considering the importance of NTPDase3 in the regulation of insulin release, the NTPDase3 inhibitors were further investigated to elucidate their role in the insulin release. The obtained data suggested that compound 2a was actively participating in regulating the insulin release without producing any effect on NTPDase3 mRNA. Moreover, the most potent inhibitors were docked within the active site of respective enzyme and the observed interactions were in compliance with in vitro results. Hence, these compounds can be used as pharmacological tool to further investigate the role of NTPDase3 coupled to insulin release.

Synthesis of imidazole-pyrazole conjugates bearing aryl spacer and exploring their enzyme inhibition potentials.

Developing improved enzyme inhibitors is an effective therapy to counter various diseases. Aiming to build up biologically active templates, a new series of bis-diazoles conjugated with an aryl linker was designed and prepared through a convenient synthetic approach. Synthesized derivatives 6(a-m), having different substitutions at the 2nd position of the imidazole nucleus, depict the scope of present study. These compounds were characterized through spectroscopic methods and further examined for their in vitro enzyme inhibitory potentials against two selected enzymes: α-glucosidase and lipoxygenase (LOX). Overall, this series was found to be effective against α-glucosidase and moderately active against LOX enzyme. Compound 6k was the most potent α-glucosidase inhibitor with IC50 = 54.25 ± 0.67 µM as compared to reference drug acarbose (IC50 = 375.82 ± 1.76 µM). The docked conformation revealed the involvement of substituent's heteroatoms with amino acid residue Gly280 through hydrogen bonding. The most active LOX inhibitor was 6a with IC50 = 41.75 ± 0.04 µM as compared to standard baicalein (IC50 = 22.4 ± 1.3 µM). Docking model of 6a suggested the strong interaction of imidazole's nitrogen with iron atom of the active pocket of enzyme. Other features like lipophilicity, bulkiness of compounds, pi-pi interactions and/or pi-alkyl interactions also affected the inhibiting potentials of all prepared scaffolds.

Identification of NSAIDs as lipoxygenase inhibitors through highly sensitive chemiluminescence method, expression analysis in mononuclear cells and computational studies.

Here we report the inhibitory effects of nine non-steroidal anti-inflammatory drugs (NSAIDs) on soybean 15-lipoxygenase (15-LOX) enzyme (EC 1.13.11.12) by three different methods; UV-absorbance, colorimetric and chemiluminescence methods. Only two drugs, Ibuprofen and Ketoprofen, exhibited enzyme inhibition by UV-absorbance method but none of the drug showed inhibition through colorimetric method. Chemiluminescence method was found highly sensitive for the identification of 15-LOX inhibitors and it was more sensitive and several fold faster than the other methods. All tested drugs showed 15-LOX-inhibition with IC50 values ranging from 3.52 ± 0.08 to 62.6 ± 2.15 µM by chemiluminescence method. Naproxen was the most active inhibitor (IC50 3.52 ± 0.08 µM) followed by Aspirin (IC50 4.62 ± 0.11 µM) and Acetaminophen (IC50 6.52 ± 0.14 µM). Ketoprofen, Diclofenac and Mefenamic acid showed moderate inhibitory profiles (IC50 24.8 ± 0.24 to 39.62 ± 0.27 µM). Piroxicam and Tenoxicam were the least active inhibitors with IC50 values of 62.6 ± 2.15 µM and 49.5 ± 1.13 µM, respectively. These findings are supported by expression analysis, molecular docking studies and density functional theory calculations. The expression analysis and flow cytometry apoptosis analysis were carried out using mononuclear cells (MNCs) which express both human 15-LOX and 5-LOX. Selected NSAIDs did not affect the cytotoxic activity of MNCs at IC50 concentrations and the cell death showed dose dependent effect. However, MNCs apoptosis increased only at the higher concentrations, demonstrating that these drugs may not induce loss of immunity in septic and other inflammatory conditions at the acceptable inhibitory concentrations. The data collectively suggests that NSAIDs not only inhibit COX enzymes as reported in the literature but soybean 15-LOX and MNCs LOXs are also inhibited at differential values. A comparison of the metabolomics studies of arachidonic acid pathway after inhibition of either COX or LOX enzymes may reconfirm these findings.

Probing phenylcarbamoylazinane-1,2,4-triazole amides derivatives as lipoxygenase inhibitors along with cytotoxic, ADME and molecular docking studies.

Hunting small molecules as anti-inflammatory agents/drugs is an expanding and successful approach to treat several inflammatory diseases such as cancer, asthma, arthritis, and psoriasis. Besides other methods, inflammatory diseases can be treated by lipoxygenase inhibitors, which have a profound influence on the development and progression of inflammation. In the present study, a series of new N-alkyl/aralky/aryl derivatives (7a-o) of 2-(4-phenyl-5-(1-phenylcarbamoyl)piperidine-4H-1,2,4-triazol-3-ylthio)acetamide was synthesized and screened for their inhibitory potential against the enzyme 15-lipoxygenase. The simple precursor ethyl piperidine-4-carboxylate (a) was successively converted into phenylcarbamoyl derivative (1), hydrazide (2), semicarbazide (3) and N-phenylated 5-(1-phenylcarbamoyl)piperidine-1,2,4-triazole (4), then in combination with electrophiles (6a-o) through further multistep synthesis, final products (7a-o) were generated. All the synthesized compounds were characterized by FTIR, 1H, 13C NMR spectroscopy, EIMS, and HREIMS spectrometry. Almost all the synthesized compounds showed excellent inhibitory potential against the tested enzyme. Compounds 7c, 7f, 7d, and 7g displayed potent inhibitory potential (IC50 9.25 ± 0.26 to 21.82 ± 0.35 µM), followed by the compounds 7n, 7h, 7e, 7a, 7b, 7l, and 7o with IC50 values in the range of 24.56 ± 0.45 to 46.91 ± 0.57 µM. Compounds 7c, 7f, 7d exhibited 71.5 to 83.5% cellular viability by MTT assay compared with standard curcumin (76.9%) when assayed at 0.125 mM concentration. In silico ADME studies supported the drug-likeness of most of the molecules. In vitro inhibition studies were substantiated by molecular docking wherein the phenyl group attached to the triazole ring was making a π-δ interaction with Leu607. This work reveals the possibility of a synthetic approach of compounds in relation to lipoxygenase inhibition as potential lead compounds in drug discovery.

Synthesis of benzimidazole based hydrazones as non-sugar based α-glucosidase inhibitors: Structure activity relation and molecular docking.

In search for α-glucosidase inhibitors used in the treatment of diabetes mellitus, a series of unique benzimidazole based hydrazones derivatives were synthesized (5a-5p), which were then investigated for their in vitro α-glucosidase inhibitory potential. The compounds of interest were characterized by modern spectroscopic approaches including CHN, 1 HNM R, 13 CN MR and FTIR. The structure of compound 5n was distinctively authenticated through single crystal X-ray study. All compounds depicted potent enzyme inhibitory potential with IC50 values in the range of 2.25 ± 0.01 to 81.16 ± 0.12 µM except 5n that showed IC50 value of 182.75 ± 0.13 µM. A limited structure-activity correlation demonstrated that substitutions of isatin, aldehydes and ketone in hydrazones moiety had remarkable contribution in the overall activity and that was further supported by molecular docking studies carried out in elucidating the mechanism of binding interaction of these compounds in the catalytic site of α-glucosidase.

Synthesis of new indazole based dual inhibitors of α-glucosidase and α-amylase enzymes, their in vitro, in silico and kinetics studies.

The current study describes the discovery of novel inhibitors of α-glucosidase and α-amylase enzymes. For that purpose, new hybrid analogs of N-hydrazinecarbothioamide substituted indazoles 4-18 were synthesized and fully characterized by EI-MS, FAB-MS, HRFAB-MS, 1H-, and 13C NMR spectroscopic techniques. Stereochemistry of the imine double bond was established by NOESY measurements. All derivatives 4-18 with their intermediates 1-3, were evaluated for in vitro α-glucosidase and α-amylase enzyme inhibition. It is worth mentioning that all synthetic compounds showed good inhibition potential in the range of 1.54 ±â€¯0.02-4.89 ±â€¯0.02 µM for α-glucosidase and for α-amylase 1.42 ±â€¯0.04-4.5 ±â€¯0.18 µM in comparison with the standard acarbose (IC50 value of 1.36 ±â€¯0.01 µM). In silico studies were carried out to rationalize the mode of binding interaction of ligands with the active site of enzymes. Moreover, enzyme inhibitory kinetic characterization was also performed to understand the mechanism of enzyme inhibition.

Probing 2-acetylbenzofuran hydrazones and their metal complexes as α-glucosidase inhibitors.

Inhibition of α-glucosidase is one of the important approaches in designing antidiabetic drugs for its role in decrease of the carbohydrates digestion to avoid post-prandial increase in blood sugar levels in diabetic patients. In the present study we designed a novel series of 2-acetylbenzofuran hydrazones (L1-L7) and their metal (II) complexes Cu (II), Co (II), Zn (II) and Mn (II) (8-29) and screened for inhibitory activity against the yeast α-glucosidase. The synthesis of hydrazones incorporated the use of I2 as a catalyst which resulted in excellent yield of 94%. The ligand L3, showed good activity (IC50 = 47.51 ± 0.86 µM) while its metal complex (10) showed potent activity (IC50 = 1.15 ± 0.001 µM) compared to reference acarbose IC50 = 378.25 ± 0.12 µM. Similarly, the Cu (II) complexes with ligands L5 and L6 showed excellent α-glucosidase inhibition (IC50 = 0.15 ± 0.003 12 and 0.21 ± 0.002 µM for 13, respectively) whereas, the metal complexes of Co (II), Mn (II), and Zn (II) showed moderate to poor inhibitory activities against α-glucosidase. The The findings are supported by the ligands and enzyme interactions through molecular docking studies. In conclusion, it is indicated that metal complexes of 2-acetylbenzofuran hydrazones have good potential for research leading to antidiabetic therapies.

4-Oxycoumarinyl linked acetohydrazide Schiff bases as potent urease inhibitors.

Urease enzyme is responsible to catalyze the hydrolysis of urea into carbamate and ammonia. Then carbamate hydrolyzed to ammonia and carbon dioxide. Excess release of ammonia leads to increase pH in stomach that actually encourages the survival of Helicobacter pylori. H. pylori involves in various disorders most commonly peptic ulcer, pyelonephritis, hepatic coma, kidney stone formation, urolithiasis, and encephalopathy. Apart from many pharmacological properties, coumarin and Schiff bases are known to possess urease inhibitory activity. Therefore, these two pharmacologically important scaffolds are combined into single hybrid molecules to assess their potential as urease inhibitors. For this aim, N'-benzylidene-2-((2-oxo-2H-chromen-4-yl)oxy)acetohydrazide Schiff base derivatives 3-27 were synthesized by following a three step reaction strategy. Structures of all synthetic molecules were characterized by EI-MS, 1H-, and 13C NMR spectroscopic techniques. All molecules were assessed for urease inhibitory activity and found to possess a varying degree of inhibitory potential in the range of IC50 = 12.3 ± 0.69 to 88.8 ± 0.04 µM. Amongst the active analogs, compounds 7 (IC50 = 16.2 ± 0.11 µM), 9 (IC50 = 15.2 ± 0.14 µM), 10 (IC50 = 12.3 ± 0.69 µM), 12 (IC50 = 16.3 ± 0.45 µM), and 15 (IC50 = 17.6 ± 0.28 µM) were identified as potent inhibitors compared to standard urea (IC50 = 21.5 ± 0.47 µM). It is conferred from structure-activity relationship (SAR) that variation in inhibitory activity is due to different substitutions pattern on aryl ring. Moreover, molecular docking studies were carried out to understand the interactions of ligand with the active pocket of urease enzyme.

Evaluation of sulfonate and sulfamate derivatives possessing benzofuran or benzothiophene nucleus as inhibitors of nucleotide pyrophosphatases/phosphodiesterases and anticancer agents.

Ectonucleotidases are a broad family of ectoenzymes that play a crucial role in purinergic cell signaling. Ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs) belong to this group and are important drug targets. In particular, NPP1 and NPP3 are known to be druggable targets for treatment of impaired calcification disorders (including pathological aortic calcification) and cancer, respectively. In this study, we investigated a series of sulfonate and sulfamate derivatives of benzofuran and benzothiophene as potent and selective inhibitors of NPP1 and NPP3. Compounds 1c, 1g, 1n, and 1s are the most active NPP1 inhibitors (IC50 values in the range 0.12-0.95 µM). Moreover, compounds 1e, 1f, 1j, and 1l are the most potent inhibitors of NPP3 (IC50 ranges from 0.12 to 0.95 µM). Compound 1d, 1f and 1t are highly selective inhibitors of NPP1 over NPP3, whereas compounds 1m and 1s are found to be highly selective towards NPP3 over NPP1. Structure-activity relationship (SAR) study has been discussed in detailed. With the aid of molecular docking studies, a common binding mode of these compounds and suramin (the standard inhibitor) was revealed, where the sulfonate group acts as a cation-binding moiety that comes in close contact with the zinc ion of the active site. Moreover, cytotoxic evaluation against MCF-7 and HT-29 cancer cell lines revealed that compound 1r is the most cytotoxic towards MCF-7 cell line with IC50 value of 0.19 µM. Compound 1r is more potent and selective against cancer cells than normal cells (WI-38) as compared to doxorubicin.

Sulfonylhydrazones: Design, synthesis and investigation of ectonucleotidase (ALP & e5'NT) inhibition activities.

Medicinal importance of the sulfonylhydrazones is well-evident owing to their binding ability with zinc containing metalloenzymes. In the present study, we have synthesized different series of sulfonylhydrazones by using facile synthetic methods in good to excellent yield. All the successfully prepared sulfonylhydrazones were screened for ectonucleotidase (ALP & e5'NT) inhibitory activity. Among the chromen-2-one scaffold based sulfonylhydrazones, the compounds 7 was found to be most potent inhibitor for h-TNAP (human tissue non-specific alkaline phosphatase) and h-IAP (human intestinal alkaline phosphatase) with IC50 values of 1.02 ± 0.13 and 0.32 ± 0.0 3 µM respectively, compared with levamisole (IC50 = 25.2 ± 1.90 µM for h-TNAP) and l-phenylalanine (IC50 = 100 ± 3.00 µM for h-IAP) as standards. Further, the chromen-2-one based molecule 5a showed excellent activity against h-ecto 5'-NT (human ecto-5'-nucleotidase) with IC50 value of 0.29 ± 0.004 µM compared to standard, sulfamic acid (IC50 = 42.1 ± 7.8 µM). However, among the series of phenyl ring based sulfonylhydrazones, compound 9d was found to be most potent against h-TNAP and h-IAP with IC50 values of 0.85 ± 0.08 and 0.52 ± 0.03 µM, respectively. Moreover, in silico studies were also carried to demonstrate their putative binding with the target enzymes. The potent compounds 5a, 7, and 9d against different ectonucleotidases (h-ecto 5'-NT, h-TNAP, h-IAP) could potentially serve as lead for the development of new therapeutic agents.

A Novel Sulfonamide, 4-FS, Reduces Ethanol Drinking and Physical Withdrawal Associated With Ethanol Dependence.

Carbonic anhydrase (CA) is abundant in glial cells in the brain and CA type II isoform (CA II) activity in the hippocampus plays an important role in buffering extracellular pH transients produced by neural activity. Chronic ethanol exposure results in respiratory and metabolic acidosis, producing shifts in extracellular pH in the brain and body. These neurophysiological changes by ethanol are hypothesized to contribute to the continued drinking behavior and physical withdrawal behavior in subjects consuming ethanol chronically. We explored whether chronic ethanol self-administration (ethanol drinking, 10% v/v; ED) without or under the influence of chronic intermittent ethanol vapor (CIE-ED) experience alters the expression of CA II in the hippocampus. Postmortem hippocampal tissue analyses demonstrated that CA II levels were enhanced in the hilus region of the hippocampus in ED and CIE-ED rats. We used a novel molecule-4-fluoro-N-(4-sulfamoylphenyl) benzenesulfonamide (4-FS)-a selective CA II inhibitor, to determine whether CA II plays a role in ethanol self-administration in ED and CIE-ED rats and physical withdrawal behavior in CIE-ED rats. 4-FS (20 mg/kg, i.p.) reduced ethanol self-administration in ED rats and physical withdrawal behavior in CIE-ED rats. Postmortem hippocampal tissue analyses demonstrated that 4-FS reduced CA II expression in ED and CIE-ED rats to control levels. In parallel, 4-FS enhanced GABAA receptor expression, reduced ratio of glutamatergic GluN2A/2B receptors and enhanced the expression of Fos, a marker of neuronal activation in the ventral hippocampus in ED rats. These findings suggest that 4-FS enhanced GABAergic transmission and increased activity of neurons of inhibitory phenotypes. Taken together, these findings support the role of CA II in assisting with negative affective behaviors associated with moderate to severe alcohol use disorders (AUD) and that CA II inhibitors are a potential therapeutic target to reduce continued drinking and somatic withdrawal symptoms associated with moderate to severe AUD.

Imidazole-pyrazole hybrids: Synthesis, characterization and in-vitro bioevaluation against α-glucosidase enzyme with molecular docking studies.

Herein, substituted imidazole-pyrazole hybrids (2a-2n) were prepared via a multi component reaction employing pyrazole-4-carbaldehydes (1a-1d), ammonium acetate, benzil and arylamines as reactants. All the new compounds were characterized through their spectral and elemental analyses. Further these compounds were tested against α-glucosidase enzyme. The compounds 2k, 2l and 2n possessed good inhibition potencies, however, compounds 2f (IC50 value: 25.19 ±â€¯0.004 µM) and 2m (IC50 value: 33.62 ±â€¯0.03 µM) were the most effective compounds of the series. Furthermore, molecular docking helped to understand the binding interactions of 2f and 2m with the understudy yeast's α-glucosidase enzyme.

Acridine-based (thio)semicarbazones and hydrazones: Synthesis, in vitro urease inhibition, molecular docking and in-silico ADME evaluation.

Urease is a bacterial enzyme that is responsible for virulence of various pathogenic bacteria such as Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae, Ureaplasma urealyticum, Helicobacter pylori and Mycobacterium tuberculosis. Increased urease activity aids in survival and colonization of pathogenic bacteria causing several disorders especially gastric ulceration. Hence, urease inhibitors are used for treatment of such diseases. In search of new molecules with better urease inhibitory activity, herein we report a series of acridine derived (thio)semicarbazones (4a-4e, 6a-6l) that were found to be active against urease enzyme. Molecular docking studies were carried out to better comprehend the preferential mode of binding of these compounds against urease enzyme. Docking against urease from pathogenic bacterium S. pasteurii was also carried out with favorable results. In silico ADME evaluation was done to determine drug likeness of synthesized compounds.

Benzoxazinone-thiosemicarbazones as antidiabetic leads via aldose reductase inhibition: Synthesis, biological screening and molecular docking study.

Aldose reductase is an important enzyme in the polyol pathway, where glucose is converted to fructose, and sorbitol is released. Aldose reductase activity increases in diabetes as the glucose levels increase, resulting in increased sorbitol production. Sorbitol, being less cell permeable tends to accumulate in tissues such as eye lenses, peripheral nerves and glomerulus that are not insulin sensitive. This excessive build-up of sorbitol is responsible for diabetes associated complications such as retinopathy and neuropathy. In continuation of our interest to design and discover potent inhibitors of aldo-keto reductases (AKRs; aldehyde reductase ALR1 or AKR1A, and aldose reductase ALR2 or AKR1B), herein we designed and investigated a series of new benzoxazinone-thiosemicarbazones (3a-r) as ALR2 and ALR1 inhibitors. Most compounds exhibited excellent inhibitory activities with IC50 values in lower micro-molar range. Compounds 3b and 3l were found to be most active ALR2 inhibitors with IC50 values of 0.52 ±â€¯0.04 and 0.19 ±â€¯0.03 µM, respectively, both compounds were more effective inhibitors as compared to the standard ALR2 inhibitor (sorbinil, with IC50 value of 3.14 ±â€¯0.02 µM).

Exploring antidiabetic potential of adamantyl-thiosemicarbazones via aldose reductase (ALR2) inhibition.

The role of aldose reductase (ALR2) in diabetes mellitus is well-established. Our interest in finding ALR2 inhibitors led us to explore the inhibitory potential of new thiosemicarbazones. In this study, we have synthesized adamantyl-thiosemicarbazones and screened them as aldehyde reductase (ALR1) and aldose reductase (ALR2) inhibitors. The compounds bearing phenyl 3a, 2-methylphenyl 3g and 2,6-dimethylphenyl 3m have been identified as most potent ALR2 inhibitors with IC50 values of 3.99 ±â€¯0.38, 3.55 ±â€¯0.26 and 1.37 ±â€¯0.92 µM, respectively, compared with sorbinil (IC50 = 3.14 ±â€¯0.02 µM). The compounds 3a, 3g, and 3m also inhibit ALR1 with IC50 value of 7.75 ±â€¯0.28, 7.26 ±â€¯0.39 and 7.04 ±â€¯2.23 µM, respectively. Molecular docking was also performed for putative binding of potent inhibitors with target enzyme ALR2. The most potent 2,6-dimethylphenyl bearing thiosemicarbazone 3m (IC50 = 1.37 ±â€¯0.92 µM for ALR2) and other two compound 3a and 3g could potentially lead for the development of new therapeutic agents.

Semicarbazone derivatives as urease inhibitors: Synthesis, biological evaluation, molecular docking studies and in-silico ADME evaluation.

A series of hydrazinecarboxamide derivatives were synthesized and examined against urease for their inhibitory activity. Among the series, the 1-(3-fluorobenzylidene)semicarbazide (4a) (IC50 = 0.52 ±â€¯0.45 µM), 4u (IC50 = 1.23 ±â€¯0.32 µM) and 4h (IC50 = 2.22 ±â€¯0.32 µM) were found most potent. Furthermore, the molecular docking study was also performed to demonstrate the binding mode of the active hydrazinecarboxamide with the enzyme, urease. In order to estimate drug likeness of compounds, in silico ADME evaluation was carried out. All compounds exhibited favorable ADME profiles with good predicted oral bioavailability.

Evaluation of α-glucosidase inhibiting potentials with docking calculations of synthesized arylidene-pyrazolones.

Herein, condensation of aryl(hetaryl)pyrazole-4-carbaldehydes 1(a-c) with substituted pyrazolones 2(a-d) lead to the corresponding arylidene-pyrazolones 3(a-l) which were tested against α-glucosidase enzyme. The synthesized compounds displayed moderate to good activity. Among these, a coumarin derivative 3k exhibited excellent results (IC50 2.10 ±â€¯0.004 µM) in comparison to clinical drug acarbose (IC50 37.38 ±â€¯0.12 µM). The ligand-protein interactions were identified through docking and stabilizing energy calculations.