New N-phenylacetamide-linked 1,2,3-triazole-tethered coumarin conjugates: Synthesis, bioevaluation, and molecular docking study.

A series of new 1,2,3-triazole-tethered coumarin conjugates linked by N-phenylacetamide was efficiently synthesized via the click chemistry approach in excellent yields. The synthesized conjugates were evaluated for their in vitro antifungal and antioxidant activities. Antifungal activity determination was carried out against fungal strains such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger and Cryptococcus neoformans. Compounds 7b, 7d, 7e, 8b and 8e displayed higher potency than the standard drug miconazole, with lower minimum inhibitory concentration values. Also, compound 7a exhibited potential radical scavenging activity as compared with the standard antioxidant butylated hydroxytoluene. In addition, a molecular docking study of the newly synthesized compounds was carried out, and the results showed a good binding mode at the active site of the fungal (C. albicans) P450 cytochrome lanosterol 14α-demethylase enzyme. Furthermore, the synthesized compounds were also tested for ADME properties, and they demonstrated potential as good candidates for oral drugs.

Design, synthesis, and pharmacological evaluation of fluorinated azoles as anti-tubercular agents.

Design, synthesis, and biological screening of 2,2-dimethyl-2,3-dihydrobenzofuran tethered 1,3,4-oxadiazole derivatives as anti-tubercular agents were described. The synthesis of the target compounds was conducted by a series of reaction schemes. All the synthesized compounds were characterized by IR, 1 H NMR, 13 C NMR, and mass spectrometry. The therapeutic potential of the synthesized compounds was confirmed by molecular docking studies. Among the synthesized compounds, 12a, 12c, 12d, 12e, 12g, and 12j were found to be more active against non-replicating than against replicating cultures of Mycobacterium tuberculosis H37Ra ex vivo and in vitro. These compounds exhibit minimum inhibitory concentration (MIC) values in the range of 2.31-23.91 µg/mL. The cytotoxicity study was conducted against the cell lines THP-1, A549 and PANC-1, and the compounds were observed to be non-toxic to host cells. Molecular docking was conducted with InhA (FabI/ENR) and suggested the antimycobacterial potential of the synthesized compounds. The investigation presented here was found to be adventitious for the development of new therapeutic agents against Mycobacterium infection.

Fungal biofilm inhibition by piperazine-sulphonamide linked Schiff bases: Design, synthesis, and biological evaluation.

We report the synthesis of some new piperazine-sulphonamide linked Schiff bases as fungal biofilm inhibitors with antibacterial and antifungal potential. The biofilm inhibition result of Candida albicans proposed that the compounds 6b (IC50 = 32.1 µM) and 6j (IC50 = 31.4 µM) showed higher inhibitory activity than the standard fluconazole (IC50 = 40 µM). Compound 6d (MIC = 26.1 µg/mL) with a chloro group at the para position was found to be the most active antibacterial agent of the series against Bacillus subtilis when compared with the standard ciprofloxacin (MIC = 50 µg/mL). Compound 6j (MIC = 39.6 µg/mL) with an OH group at the ortho position showed more potent antifungal activity as compared to that of the standard fluconazole (IC50 = 50 µM) against C. albicans. Thus, the synthesized compounds 6a-k were found to be potent biofilm inhibitors as well as active antibacterial and antifungal agents. The molecular docking study of the synthesized compounds against the secreted aspartyl protease (SAP5) enzyme of C. albicans exhibited good binding properties. The in silico ADME properties of the synthesized compounds were also analyzed and showed their potential to be developed as potential oral drug candidates.

Ultrasound Assisted Synthesis of 4-(Benzyloxy)-N-(3-chloro-2-(substitutedphenyl)-4-oxoazetidin-1-yl) Benzamide as Challenging Anti-Tubercular Scaffold.

A series of ten novel derivatives of 4-(benzyloxy)-N-(3-chloro-2-(substituted phenyl)-4-oxoazetidin-1-yl) benzamide 6a⁻j were synthesized in good yield from the key compound 4-(benzyloxy)-N'-(substituted benzylidene) benzo hydrazide, called Schiff 's bases 5a⁻j, by Staudinger reaction ([2 + 2] ketene-imine cycloaddition reaction) with chloro acetyl chloride in the presence of catalyst tri ethylamine and solvent dimethyl formamide (DMF), by using ultra-sonication as one of the green chemistry tools. All the synthesised compounds were evaluated for in vitro anti-tubercular activity against Mycobacterium tuberculosis (MTB) and most of them showed promising activity with an IC50 value of less than 1 µg/mL. To establish the safety, all the synthesized compounds were further tested for cytotoxicity against the human cancer cell line HeLa and all 6a⁻j compounds were found to be non-cytotoxic in nature. The molecular docking study was carried out with essential enzyme InhA (FabI/ENR) of Mycobacterium responsible for cell wall synthesis which suggests that 6a and 6e are the most active derivatives of the series. The theoretical evaluation of cell permeability based on Lipinski's rule of five has helped to rationalize the biological results and hence the synthesized azetidinone derivatives 6a⁻j were also analyzed for physicochemical evaluation that is, absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties and the results showed that all the derivatives could comply with essential features required for a potential lead in the anti-tubercular drug discovery process.

New 2-Oxoindolin Phosphonates as Novel Agents to Treat Cancer: A Green Synthesis and Molecular Modeling.

The work reports the facile synthesis of novel α-aminophosphonate derivatives coupled with indole-2,3-dione moieties, namely the diethyl(substituted phenyl/heteroaryl)(2-(2-oxoindolin-3-ylidene)hydrazinyl)methylphosphonates derivatives 4(a⁻n). One-pot three component Kabachnik-Fields reactions were used to synthesize these derivatives. The reaction was carried out at room temperature by stirring in presence of ceric ammonium nitrate (CAN) as a green catalyst. The structures of the synthesized compounds were established by spectral studies. The synthesized derivatives 4(a⁻n) were evaluated for their in vitro anticancer activity against six human cancer cell lines by the SRB assay method. The cancer cell lines used in this research work are SK-MEL-2 (melanoma), MCF-7 (breast cancer), IMR-32 (neuroblastoma) MG-63 (human osteosarcoma), HT-29 (human colon cancer) and Hep-G2 (human hepatoma). All the synthesized derivatives inhibited the cell proliferation. Importantly, all the target compounds showed no cytotoxicity towards normal tissue cells (GI50 > 250 µM). A docking study was performed to predict the mode of action. Docking results indicate that the compounds have good binding with the enzyme tyrosine kinase as well as with microtubules, which makes them dual inhibitors. The result of in-silico bioavailability studies suggests that the compounds from the present series have good oral drug-like properties and are non-toxic in nature. In vivo acute oral toxicity study results indicate that the compounds can be considered safe, and therefore could be developed in the future as good anticancer agents or as leads for the design and synthesis of novel anticancer agents.

Synthesis, antioxidant, antifungal, molecular docking and ADMET studies of some thiazolyl hydrazones.

Some thiazolyl hydrazones were synthesized by one pot reaction of thiophene-2-carbaldehyde or 2, 4-dichlorobenzaldehyde, thiosemicarbazide and various phenacyl bromides which were preliminarily screened for in vitro antioxidant and antifungal activities. Excellent DPPH and H2O2 radical scavenged antioxidant activities were observed with almost all the tested compounds. Compounds 4a, 4b, 4c, 4e, 4f and 4i showed comparable DPPH scavenged antioxidant potential (90.26-96.56%) whereas H2O2 scavenged antioxidant activity (90.98-92.08%) was noticeable in case of 4a and 4f; showing significant antioxidant potential comparable with the standard ascorbic acid (95.3%). In vitro antifungal activity of synthesized compounds against fungal species Candida albicance, Aspergillus niger and Aspergillus flavus was found to be moderate to good as compared with the standard fluconazole and MIC values were found in the range of 3.12-25µg/mL. Molecular docking studies revealed that the compounds 4a, 4b and 4c have a potential to become lead molecules in drug discovery process. In silico ADMET study was also performed for predicting pharmacokinetic and toxicity profile of the synthesized antioxidants which expressed good oral drug like behaviour and non-toxic nature.

Antileishmanial potential of fused 5-(pyrazin-2-yl)-4H-1,2,4-triazole-3-thiols: Synthesis, biological evaluations and computational studies.

A series of newer 1,2,4-triazole-3-thiol derivatives 5(a-m) and 6(a-i) containing a triazole fused with pyrazine moiety of pharmacological significance have been synthesized. All the synthesized compounds were screened for their in vitro antileishmanial and antioxidant activities. Compounds 5f (IC50=79.0µM) and 6f (IC50=79.0µM) were shown significant antileishmanial activity when compared with standard sodium stibogluconate (IC50=490.0µM). Compounds 5b (IC50=13.96µM) and 6b (IC50=13.96µM) showed significant antioxidant activity. After performing molecular docking study and analyzing overall binding modes it was found that the synthesized compounds had potential to inhibit L. donovani pteridine reductase 1 enzyme. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.

Ionic Liquid-Catalyzed Green Protocol for Multi-Component Synthesis of Dihydropyrano[2,3-c]pyrazoles as Potential Anticancer Scaffolds.

A series of 6-amino-4-substituted-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles 5a-j were synthesized via one-pot, four-component condensation reactions of aryl aldehydes 1a-j, propanedinitrile (2), hydrazine hydrate (3) and ethyl acetoacetate (4) under solvent-free conditions. We report herein the use of the Brønsted acid ionic liquid (BAIL) triethylammonium hydrogen sulphate [Et3NH][HSO4] as catalyst for this multi-component synthesis. Compared with the available reaction methodology, this new method has consistent advantages, including excellent yields, a short reaction time, mild reaction conditions and catalyst reusability. Selected synthesized derivatives were evaluated for in vitro anticancer activity against four human cancer cell lines viz. melanoma cancer cell line (SK-MEL-2), breast cancer cell line(MDA-MB-231), leukemia cancer cell line (K-562) and cervical cancer cell line (HeLa). Compounds 5b, 5d, 5g, 5h and 5j exhibited promising anticancer activity against all selected human cancer cell lines, except HeLa. Molecular docking studies also confirmed 5b and 5d as good lead molecules. An in silico ADMET study of the synthesized anticancer agents indicated good oral drug-like behavior and non-toxic nature.

Insilico structure based drug design approach to find potential hits in ventilator-associated pneumonia caused by Pseudomonas aeruginosa.

Tetraacyldisaccharide 4'-kinase (LpxK) is the prime enzyme responsible for the biosynthesis of lipid A. LpxK is a key antibacterial drug target, but it is less exploitation in Pseudomonas aeruginosa and other bacterial species limits its therapeutic use. Pseudomonas aeruginosa is responsible for severe infections like pneumonia and urinary tract infections. The precautionary measures of Pseudomonas aeruginosa infections are decisive as it results in extensive drug resistance, systemic bacteremia, and ventilator-associated pneumonia. The current rational approach highlights exploiting the use of computer-aided drug design approaches to counter Pseudomonas aeruginosa specific LpxK. The various approaches used were exploring the metabolic pathway database (Metacyc), drug target validation using DEG, protein modeling, ligand docking, e-pharmacophore assisted virtual screening, physicochemical and Toxicity profile prediction studies, and molecular simulations in spotting out novel potential hits compounds. The virtual hits which have highly ranked in the study were STOCK4S-16119, STOCK1S -60869, STOCK6S -43621, STOCK6S -3328, and STOCKS-39892 which can act as a scaffold for the establishment of new hits against LpxK and can result in control of Pseudomonas aeruginosa infectivity.

Pyridine and Benzoisothiazole Decorated Vanillin Chalcones: Synthesis, Antimicrobial, Antioxidant, Molecular Docking Study and ADMET Properties.

BACKGROUND: The search for new antimicrobial drugs is a never-ending task due to microbial resistance to the existing drugs. Antioxidants are essential to prevent free radical reactions which lead to chronic diseases to humankind. OBJECTIVE: The present studies were aimed at synthesis, characterization, antimicrobial and antioxidant activities of pyridine and benzoisothiazole decorated chalcones. MATERIALS AND METHODS: FTIR spectra were recorded using KBr pellets on Shimadzu FT-IR spectrophotometer. 1H and 13C NMR spectra were recorded on Bruker 400 MHz spectrometer. Antimicrobial activity of the synthesized chalcones was found to be good against different bacterial and fungal strains. Antioxidant activity was studied in terms of 2,2-diphenyl-1-picrylhydrazyl, hydroxyI and superoxide radical scavenging activities. Molecular docking was studied using Discovery Studio Visualizer Software, version 16 whereas Autodock Vina program was used to predict the toxicity profile of the compounds using FAFDrugs2 predictor. RESULTS AND DISCUSSION: The compounds 5c, 5d & 6c showed good antioxidant activities. The insilico molecular docking study supports the experimental results and demonstrated that the chalcones 5d, 6a and 7a are the most active among the synthesized derivatives. CONCLUSION: Prediction of pharmacokinetic parameters and molecular docking studies suggest that the synthesized chalcones have good pharmacokinetic properties to act as lead molecules in the drug discovery process.

Pharmacoinformatics approaches to identify potential hits against tetraacyldisaccharide 4'-kinase (LpxK) of Pseudomonas aeruginosa.

Pseudomonas aeruginosa infection can cause pneumonia and urinary tract infection and the management of Pseudomonas aeruginosa infection is critical in multidrug resistance, hospital-acquired bacteremia and ventilator-associated pneumonia. The key enzymes of lipid A biosynthesis in Pseudomonas aeruginosa are promising drug targets. However, the enzyme tetraacyldisaccharide 4'-kinase (LpxK) has not been explored as a drug target so far. Several pharmacoinformatics tools such as comparative metabolic pathway analysis (Metacyc), data mining from a database of essential genes (DEG), homology modeling, molecular docking, pharmacophore based virtual screening, ADMET prediction and molecular dynamics simulation were used in identifying novel lead compounds against this target. The top virtual hits STOCK6S-33288, 43621, 39892, 37164 and 35740 may serve as the templates for the design and synthesis of potent LpxK inhibitors in the management of serious Pseudomonas aeruginosa infection.

Insights of tankyrases: A novel target for drug discovery.

Tankyrases are the group of enzymes belonging to a class of Poly (ADP-ribose) polymerase (PARP) recently named ADP-ribosyltransferase (ARTD). The two isoforms of tankyrase i.e. tankyrase1 (TNKS1) and tankyrase2 (TNKS2) were abundantly expressed in various biological functions in telomere regulation, Wnt/ß-catenin signaling pathway, viral replication, endogenous hormone regulation, glucose transport, cherubism disease, erectile dysfunction, and apoptosis. The structural analysis, mechanistic information, in vitro and in vivo studies led identification and development of several classes of tankyrase inhibitors under clinical phases. In the nutshell, this review will drive future research on tankyrase as it enlighten the structural and functional features of TNKS 1 and TNKS 2, different classes of inhibitors with their structure-activity relationship studies, molecular modeling studies, as well as past, current and future perspective of the different class of tankyrase inhibitors.

New N-phenylacetamide-incorporated 1,2,3-triazoles: [Et3NH][OAc]-mediated efficient synthesis and biological evaluation.

A facile, highly efficient, and greener method for the synthesis of new 1,4-disubstituted-1,2,3-triazoles was conducted using [Et3NH][OAc] as a medium by the implementation of ultrasound irradiation via click chemistry, affording excellent yields. The present synthetic method exhibited numerous advantages such as mild reaction conditions, excellent product yields, minimal chemical waste, operational simplicity, shorter reaction time, and a wide range of substrate scope. The synthesized compounds were further evaluated for in vitro antifungal activity against five fungal strains, and some of the compounds displayed equivalent or greater potency than the standard drug. A molecular docking study against the modelled three-dimensional structure of cytochrome P450 lanosterol 14α-demethylase was also performed to understand the binding affinity and binding interactions of the enzyme. Furthermore, the synthesized compounds were evaluated for DPPH radical scavenging activity and antitubercular activity against Mycobacterium tuberculosis H37Rv strain.

Molecular docking, pharmacophore based virtual screening and molecular dynamics studies towards the identification of potential leads for the management of H. pylori.

The enzyme pantothenate synthetase panC is one of the potential new antimicrobial drug targets, but it is poorly characterized in H. pylori. H. pylori infection can cause gastric cancer and the management of H. pylori infection is crucial in various gastric ulcers and gastric cancer. The current study describes the use of innovative drug discovery and design approaches like comparative metabolic pathway analysis (Metacyc), exploration of database of essential genes (DEG), homology modelling, pharmacophore based virtual screening, ADMET studies and molecular dynamics simulations in identifying potential lead compounds for the H. pylori specific panC. The top ranked virtual hits STOCK1N-60270, STOCK1N-63040, STOCK1N-44424 and STOCK1N-63231 can act as templates for synthesis of new H. pylori inhibitors and they hold a promise in the management of gastric cancers caused by H. pylori.

Ultrasound Promoted Green Synthesis, Docking Study of Indole Spliced Thiadiazole, α-amino Phosphonates as Anticancer Agents and Antityrosinase Agents.

BACKGROUND: Regardless of recent advances in the development of clinically authorized anticancer agents the number of deaths due to cancer is increasing day by day all over the world. The aim of this research work is to synthesis novel anticancer agents. METHOD: In this work, a new series of diethyl ((1H-indole-3-yl)((5-phenyl-1,3,4-thiadiazole-2-yl)amino) methyl)phosphonate derivatives 6(a-j) were designed and synthesized in Ultrasound by green protocol using Kabachnik-Fields reaction. The structures of the synthesized compounds were confirmed by spectral analysis such as elemental analyses, IR, 1H NMR, 13C NMR, 31P NMR and mass spectra. The synthesized compounds 6(a-j) were appraised for their in vitro anticancer activity against human cancer cell lines such as SK-MEL-2 (melanoma), IMR-32 (Neuroblastoma), HT-29(Colon) and also on normal murine embryonic fibroblast NIH/3T3 by Sulforhodamine B (SRB) assay, using Adriamycin as a standard drug. RESULT: The treatment of SK-MEL-2 cancer cells with 6i showed apoptosis and morphological changes like cell shrinkage, cell wall deformation and reduced number of viable cells. The synthesized derivatives were also evaluated for their anti-tyrosinase effect. Nearly all the tested derivatives have been found to be potent tyrosinase inhibitors. CONCLUSION: Nearly all the compounds were tested, the docking study was performed and indicates that the compounds have good binding interactions with tyrosine kinase enzyme. Absorption, Distribution, Metabolism and Elimination (ADME) properties of the synthesized compounds were also analyzed which manifested their potentiality to thrive as good oral drug candidates.

Recent advances in multidimensional QSAR (4D-6D): a critical review.

The quantitative structure activity relationship (QSAR) study is the most cited and reliable computational technique used for decades to obtain information about a substituent's physicochemical property and biological activity. There is step-by-step development in the concept of QSAR from 0D to 2D. These models suffer various limitations that led to the development of 3D-QSAR. There are large numbers of literatures available on the utility of 3D-QSAR for drug design. Three-dimensional properties of molecules with non-covalent interactions are served as important tool in the selection of bioactive confirmation of compounds. With this view, 3D-QSAR has been explored with different advancements like COMFA, COMSA, COMMA, etc. Some reports are also available highlighting the limitations of 3D-QSAR. In a way, to overcome the limitations of 3D-QSAR, more advanced QSAR approaches like 4D, 5D and 6D-QSAR have been evolved. Here, in this present review we have focused more on the present and future of more predictive models of QSAR studies. The review highlights the basics of 3D to 6D-QSAR and mainly emphasizes the advantages of one dimension over the other. It covers almost all recent reports of all these multidimensional QSAR approaches which are new paradigms in drug discovery.