Quinoline-Proline,Triazole Hybrids: Design,Synthesis, Antituberculosis,Molecular Docking,and ADMET Studies

A series of novel quinoline-proline hybrids ( 11a-g ) and quinoline-proline-1,2,3-triazole hybrids ( 12-14 ) were synthesized by click chemistry based on molecular hybridization concept and were characterized by NMR, mass spectrometry, and elemental analysis. All the titled target compounds were tested for antitubercular activity by MABA and LORA methods by in vitro. Interestingly, two compounds (2R,4S)-1-((2-cyclopropyl-4-(4-fluorophenyl)-quinolin-3-yl)-methyl)-4-(4-nitrobenzamido)-N-phenylpyrrolidine-2-carboxamide ( 11b ) and (2R,4S)-1-((2-cyclopropyl-4-(4-fluorophenyl)-quinolin-3-yl)-methyl)-4-(4-fluorobenzamido)-N-phenylpyrrolidine-2-carboxamide ( 11c ) exhibited significant activity against the tested Mycobacterium tuberculosis H37Rv strain. Further, the cytotoxicity ( CC ₅₀ ) profile of the titled compounds against the Vero cell was performed and discussed. A molecular docking study of the hit compounds ( 11b and 11c ) was also performed to find their putative binding interaction with the active site of the target proteins. Finally, in silico ADMET properties were also predicted for all the synthesized molecules to evaluate their drug-likeness behavior.     

Synthesis,Characterization, and Bioactivity of Novel Bicinnolines Having 1‐Piperazinyl Moieties

A number of novel bicinnolines containing piperazine moieties, 4a – o , were synthesized via polyphosphoric acid‐catalyzed intramolecular cyclization of the respective acyl amidrazone derivatives ( 3a – o ). On the other hand, the amidrazones ( 3a – o ) were prepared by reaction of N′,N″‐(biphenyl‐4,4′‐diyl)bis(2‐oxopropane hydrazonoyl chloride) ( 2 ) with the appropriate cyclic sec‐amines in the presence of trimethylamine in absolute ethanol. Structures of the newly synthesized compounds were confirmed by NMR and mass spectral data. The antitumor activity of compounds 4a – o was evaluated in vitro on human breast cancer MDA‐231 by a cell viability assay. Results revealed that compounds 4k , 4n , and 4o exhibit potential cytotoxic effects (>70%) on the cancer cells. Additionally, the antimicrobial activity of compounds 4a – o was evaluated against three clinical microbial strains: Escherichia coli (Gram‐negative bacteria), Staphylococcus aureus (Gram‐positive bacteria), and Candida albicans (fungi/yeast). Results revealed that compounds 4e and 4k exhibit good activity against all three strains included in the study and that compound 4d displays excellent activity against S. aureus strain with a minimum inhibitory concentration value of 0.187 mg/mL.     

Synthesis,antiproliferative activity, 3D-QSAR,and molecular docking studies of novel L-carvone-derived pyrimidine-urea compounds

To explore novel natural product-based nitrogen-containing heterocyclic compounds with antiproliferative activity, 20 L-carvone-derived pyrimidine-urea compounds 4a–4t were synthesized through the multi-step reaction of L-carvone, and structurally characterized by Fourier transform infrared (FT-IR), hydrogen-1 nuclear magnetic resonance (¹H-NMR), Carbon-13 nuclear magnetic resonance (¹³C-NMR), and High-resolution mass spectrometry (HRMS). Besides, the in vitro antiproliferative activity of the target compounds against HepG2, Hela, and MCF-7 cells was evaluated by methyl thiazolyl tetrazolium (MTT) assay. According to the results, the target compounds showed certain inhibitory activities against the tested cancer cell lines, and five compounds ( 4b , 4h , 4k , 4l , and 4t ) exhibited better inhibition activities against Hela cells than the positive control ( 5-FU ). Among them, compound 4b held significant antiproliferative activities against Hela and HepG2 cells, and thus deserved further study as a leading compound of new anticancer drugs. In addition, an effective and reasonable three-dimensional quantitative structure-activity relationships (3D-QSAR) model was built by the Comparative molecular field analysis (CoMFA) method to analyze the relationship between the structures of the target compounds and their antiproliferative activities (expressed as pIC₅₀) against Hela cells, and proven to have good predictive ability. Molecular docking was carried out to study the possible binding modes of compound 4b and Survivin, and it was found that compound 4b could be well embedded into the active site, along with the formation of several hydrogen bonds and hydrophobic interactions.     

Novel 1,3,4‐Oxadiazole Derivatives of Dihydropyrimidinones: Synthesis,Anti‐Inflammatory,Anthelmintic, and Antibacterial Activity Evaluation

The present study depicts synthesis of a series of some novel 5‐(5‐(aryl)‐1,3,4‐oxadiazol‐2‐yl)‐3,4‐dihydro‐6‐methyl‐4‐styrylpyrimidin‐2(1H)‐one derivatives. All the newly synthesized compounds were characterized by FTIR, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. The compounds were evaluated for their in vivo anti‐inflammatory activity by the carrageenan‐induced rat paw edema method. The compounds were also screened for their anthelmintic activity on Indian earthworms and antibacterial activity against some gram positive and gram negative strains of bacteria. This pharmacological activity evaluation revealed that, among all the compounds screened, compounds 4b and 4c were found to have promising anti‐inflammatory activity. Interestingly, compounds 4b , 4c , and 4i exhibited appreciable anthelmintic property, while compounds 4c , 4g , and 4h showed leading antibacterial activity against the selected pathogenic strains of bacteria.     

Synthesis of isoniazid-1,2,3-triazole conjugates: Antitubercular,antimicrobial evaluation and molecular docking study

In the present study, a series of new isoniazid-1,2,3-triazole conjugates ( 5a-k ) was synthesized via click chemistry approach. The newly synthesized compounds were assessed for their in vitro antitubercular and antimicrobial activities. The compound 5g has displayed potent antitubercular activity against Mycobacterium tuberculosis H37Rv (Mtb) with MIC value 1.56 μg/mL. The active compounds were screened for their cytotoxicity profile by MTT assay against RAW 264.7 cell line. The four compounds have shown good in vitro antimicrobial activities against both antibacterial and antifungal pathogens. A molecular docking study was accomplished to identify the probable mode of action of synthesized derivatives. These compounds have shown excellent binding affinity toward Enoyl-acp reductase (INHA) and DNA gyrase.     

Synthesis,characterization, and investigations of antimicrobial activity of benzopyrans,benzofurans and spiro[4.5]decanes

In this study, the radical cyclization reactions of cyclic 1,3-dicarbonyl compounds (1a–c) and α,β-unsaturated alcohols (2a–d) through Mn(OAc)₃ were performed. A series of biologically interesting dihydropyrans (3–5) and dihydrofurans (6–18) were synthesized as a result of these reactions. Spiro compounds (19–20) were obtained from the reactions of 1,3-dicarbonyl compounds and (E)-2,4-diphenyl-but-3-en-2-ol (2e). The unique structure of compound 19 was also confirmed by X-ray crystallography. In addition, the antibacterial activities of synthesized compounds were screened against some bacteria. Their zone diameters showed better results than some known antibiotics.     

Design,Synthesis, and Biological Evaluations of Several Fasudil Analogues

In our previous work, (S)‐6H‐1‐(5‐isoquinolinesulfonyl)‐2‐hydroxymethyl‐1‐pyrrolidine and (S)‐6H‐1‐(5‐isoquinolinesulfonyl)‐2‐chloromethyl‐1‐pyrrolidine displayed potent inhibitory activity. Therefore, with these two substances as lead compounds, we designed and synthesized their enantiomers to reveal the inhibitory effects of chirality on Rho kinase. It is found that their enantiomers exhibited much better Rho kinase inhibitory activity and strongly promoted synapse formation. Experimental autoimmune encephalomyelitis is a murine autoimmune disease used to study multiple sclerosis. With added antigens, the changes from C57BL/6 mice's limbs and tail was observed and scored by clinical evaluation. The synthetic compounds may simultaneously reduce symptoms of experimental autoimmune encephalomyelitis and inhibit inflammatory infiltration of the central nervous system. Thus, these compounds may be potential candidates for inhibition of Rho kinase and should be considered for further experimental study in relation to multiple sclerosis.     

One-pot three-component azide-alkyne cycloaddition: Synthesis of new pyrazole, 1,2,3-triazole,and oxadiazole tethered and their anti-inflammatory,quantitative structure-activity relationship,and docking studies

A simple and efficient one-pot three-component azide-alkyne cycloaddition of 5-chloro-1-phenyl-pyrazole-4-carbaldehyde with 2-(prop-2-yn-1-ylthio)-5-(substituted phenoxy)methyl-1,3,4-oxadiazole and sodium azide is reported. The newly synthesized compounds were characterized by spectral and analytical data. They were screened for in vitro anti-inflammatory activity by bovine serum albumin denaturation assay. All the tested compounds showed moderate anti-inflammatory activity, whereas three compounds ( 4d , 4i , and 4k ) showed excellent activity comparable with that of the standard drug diclofenac sodium. The quantitative structure-activity relationship (QSAR) study was carried out for anti-inflammatory activities of the synthesized compounds and developed a QSAR model. Inspired by their in vitro anti-inflammatory activities, they were docked to the active site of COX-2 to know the anti-inflammatory potency in silico.     

Design,Synthesis and Computational Studies of Novel Carbazole N‐phenylacetamide Hybrids as Potent Antibacterial,Anti‐inflammatory,and Antioxidant Agents

The present study deals with the synthesis of N‐phenylacetamide‐functionalized carbazole derivatives and their antibacterial, anti‐inflammatory, and antioxidant assays. In vitro antibacterial studies of synthesized compounds shows prominent activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. In addition, in silico molecular docking studies corroborated that the methyl substituent ( 3g ), ( 3h ), and ( 3i ) showed promising activity with lower ∆G (kcal/mol) values. This study envisages that these compounds can serve as a new leading template in the chemotherapy of various bacterial ailments.     

Design,synthesis, preliminary pharmacological evaluation,and docking studies of pyrazoline derivatives

Ten derivatives of N1 substituted/unsubstituted 5-(4-chlorophenyl)-3-(2-thienyl) pyrazoline were synthesised from chalcone-like intermediate and substituted phenyl hydrazines, hydrazine hydrate, and semi/thiosemicarbazide. The chemical structure of compounds was confirmed by means of IR, ¹H NMR, mass spectroscopy, and elemental analysis. The antidepressant and anticonvulsant activities were investigated by Porsolt’s behavioural despair test (forced swimming) and maximum electroshock seizure test, respectively. Rota-Rod test was performed to assess any probable changes in motor coordination induced by the test compounds. Four compounds (IId, IIg, IIi, and IIj) exhibited good activity profile against depression and docking studies confirmed their consensual interaction with monoamine oxidase A. In addition, compounds IIc and IIe showed protection against MES-induced seizures.     

Synthesis,characterization, and antimicrobial activity of new benzoylthiourea ligands

In this study, new benzoylthiourea derivatives, (E)-N-[(2-benzamidomethyleneamino)ethylcarbamothioyl]benzamide H₃L′, N-(1-(3-benzoylthioureido)propan-2-ylcarbamothioyl)-benzamide H₄L″, (E)-N-[4-(benzamidomethyleneamino)phenylcarbamothioyl]benzamide H₃L‴, were synthesized. Structures of the compounds were identified by spectroscopic techniques. In addition, all synthesized compounds were evaluated for in vitro antibacterial and antifungal activity. Compound H₃L‴ exhibited antibacterial activity.     

Novel imidazole derivatives as antifungal agents: Synthesis,biological evaluation,ADME prediction and molecular docking studies

Abstract

A series of 2-(substituteddithiocarbamoyl)-N-[4-((1H-imidazol-1-yl)methyl)phenyl]acetamide derivatives was designed and synthesized to combat the increasing incidence of drug-resistant fungal infections. All synthesized compounds were characterized by IR, ¹H-NMR, ¹³C-NMR, and HRMS spectra and elemental analyses. Antifungal activity tests were performed against four different fungal strains. Molecular docking studies were performed to investigate the mode of action towards the fungal lanosterol 14α-demethylase, a cytochrome P450-dependent enzyme. ADME studies were carried out and a connection between activities and physicochemical properties of the target compounds was determined. Most of the final compounds exhibited significant activity against Candida albicans and Candida krusei with MIC₅₀ value 12.5?μg/mL. The results of in vitro anti-Candida activity, a docking study and ADME prediction revealed that the newly synthesized compounds have potential anti-Candida activity and evidenced the most active derivative, 5b (2-Pyrrolidinthiocarbonylthio-N-[4-((1H-imidazol-1-yl)methyl)phenyl]acetamide), which can be further optimized as a lead compound.     

A green synthesis of quinoline-4-carboxylic derivatives using p-toluenesulfonic acid as an efficient organocatalyst under microwave irradiation and their docking,molecular dynamics,ADME-Tox and biological evaluation

P-Toluenesulfonic acid, being an efficient, nonhazardous, and fast accessible organocatalyst, was used for the preparation of quinoline-4-carboxylic acid derivatives via a one-pot three-component reaction of aromatic benzaldehyde, substituted aniline, and pyruvic acid under microwave irradiation. After completion of the reaction, the pure products were isolated by column chromatography. Here, to achieve the desired synthesis, various catalytic and solvent conditions were applied to perform a comparison study. We are using higher yield, simple work-up process, avoiding the use of hazardous organic solvents, short reaction time and higher advantages of the present protocol in the study. Biological activities of synthesized compounds were tested against various antibacterial, antifungal, antimalarial, and antituberculosis strains. Compounds 4a and 4c (MIC 50 μg/mL) and compounds 4d and 4n (MIC 62.5 μg/mL) were found active against the Escherichia coli strain, compounds 4c and 4p (MIC 25 μg/mL) were found active against the Staphylococcus aureus strain, and compounds 4c and 4d were found active against the Plasmodium falciparum strain. Molecular docking revealed that ligands and proteins fitted exactly in the binding pocket and had significant correlation with the biological activity. We have also tested molecular dynamics and ADME-Tox parameters for the synthesized compounds.     

Synthesis,Characterization, and Investigation of Cholinesterase Inhibitory Properties of Novel Phthalocyanines

In this study, 4‐{2‐(2‐thienyl)ethoxy}phthalonitrile ( 3 ) and its tetra substituted peripherally metal‐free ( 4 ), lead (II) ( 5 ), magnesium (II) ( 6 ), and cobalt (II) ( 7 ) phthalocyanines were synthesized. The structural characterization of the obtained compounds was performed by a combination of FTIR, ¹H‐NMR, UV–vis, and MALDI‐TOF techniques. The inhibitory properties of these compounds were determined using Ingkaninan's methods against cholinesterase enzymes. Compound ( 7 ) had the highest enzyme inhibitory effect toward AChE and BuChE enzymes with IC₅₀ values of 23.71 ± 0.39 and 27.29 ± 0.22 μM, respectively. The enzyme kinetic study of compound ( 7 ) demonstrated noncompetitive AChE inhibition and uncompetitive BuChE inhibition. The K_i values of compound ( 7 ) against AChE and BuChE were found to 39.15 and 7.25 μM, respectively. In the tested compounds, ( 7 ) deserves further investigation for potential therapeutic candidates of Alzheimer's disease.     

Synthesis and X-ray study of hexahydro- and tetrahydrophospholo-[2,3-d]isoxazoles,a new class of heterocycles of potential fungicidal activity

Hexahydro-, 5b-1 and 6a,f,1 and tetrahydrophospholo[2,3-d]isoxazoles 8, 9 and 10 were synthesized by 1,3-dipolar cycloaddition of nitrones 3b-1 and benzonitrile oxide ( 4 ) to 2,3-dihydro-1-phenyl-1H-phosphole 1-oxide ( 1 ) and 2,3-dihydro-1-ethoxy-1H-phosphole 1-oxide ( 2 ). The structural assignment to the compounds was confirmed by an X-ray study of two compounds of the series 5a and 5m . The compounds show a good activity as fungicides against Plasmopara viticola on vines and against Botrytis cinerea on apples. Compounds 5a-d showed weak to moderate activity as herbicides.     

Novel Substituted Imidazo[2,1‐b][1,3,4]Thiadiazole Derivatives: Synthesis,Characterization, Molecular Docking Study,and Investigation of Their In Vitro Antifungal Activities

In this study, a new series of substituted imidazo[2,1‐b][1,3,4]thiadiazole derivatives were synthesized. To this end, first 2‐amino‐1,3,4‐thiadiazole derivatives (compounds 2a and 2b ), the starting materials, were synthesized with high yields (82% and 79%, respectively). Then imidazo[2,1‐b][1,3,4]thiadiazole derivatives ( 4 – 16 ), the target compounds, were synthesized from reactions of 2‐amino‐1,3,4‐thiadiazole derivatives ( 2a and 2b ) with 2‐bromoacetophenone derivatives ( 3a – 3i ) (in yields of 52% to 71%). All of the synthesized compounds were characterized by ¹H NMR, ¹³C NMR, Fourier transform infrared, elemental analysis, mass spectroscopy, and X‐ray diffraction analysis (compounds 4 – 12 , 14 , and 15 ) techniques. In vitro antifungal activity tests were performed for all of the synthesized compounds. Inhibition zones, percentage of inhibition, minimum fungicidal activity, minimum inhibitory concentration, and lethal dose values of the target compounds were determined against some plant pathogens. According to the results of the biological activity tests, all of the synthesized compounds showed moderate to high levels of antifungal activity. Theoretical calculations were performed to support the experimental results. The geometric parameters of selected compounds ( 5 , 6 , and 8 ) were optimized using the density functional theory B3LYP/6‐31G(d) method in the Gaussian 09W package program, and the frontier molecular orbitals (highest occupied molecular orbital–lowest unoccupied molecular orbital) were calculated theoretically. Finally, molecular docking studies were performed for antifungal activity studies of the selected compounds and to determine whether or not these compounds could be inhibitor agents for the 2RKV protein structure.     

Synthesis,crystal structure,electronic spectroscopy,electrochemistry and biological studies of carbohydrate containing ferrocene amides

A series of four new ferrocene–carbohydrate amides was prepared from pentose and hexose sugar derivatives. These include (5‐amino‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2a), (5‐amino‐3‐O‐benzyl‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2b), (methyl‐6‐amino‐6‐deoxy‐2,3‐O‐isopropylidene‐β‐d ‐ribofuranoside)‐1‐ferrocene carboxamide (2c) derived from furanose sugars and (6‐amino‐6‐deoxy‐1,2:3,4‐di‐O‐isopropylidene‐α‐d ‐galactopyranose)‐1‐ferrocene carboxamide (2d) derived from pyranose sugar. The compounds were characterized by spectroscopic means and the structure of amide derived from α‐d ‐xylofuranose (2a) was determined by X‐ray crystallography. The electronic and optical properties of the compounds were studied by means of cyclic voltammetry and absorption spectroscopy. The UV and electrochemical studies of these compounds, performed in aqueous solutions under physiological conditions (at pH 7.4), confirmed their stability. These results indicated that the compounds were suitable for conducting biological studies. The CD spectral analysis displays the effect of sugar substituents on the compounds. The cytotoxicity and antimicrobial activity of these conjugates were investigated on different cancer cell lines and microbes respectively. The degree of inhibition varied over a broad spectrum of Gram‐ positive and Gram‐negative bacteria. In addition, the compounds also exhibited antioxidant properties. Copyright © 2012 John Wiley & Sons, Ltd.     

Lycopus europaeus: phenolic fingerprint,antioxidant activity and antimicrobial effect on clinical Staphylococcus aureus strains

Lycopus europaeus L. leaves water extract (LEL) was subjected to phytochemical analysis, and evaluated for its antibacterial and antioxidant effects. Antibacterial activity testing was performed on Staphylococcus aureus clinical strains from catheter-related and skin infections by broth microdilution test. LEL showed bactericidal activity at concentrations from 2500 to 5000 μg/mL against all, including methicillin resistant and polyresistant nosocomial, strains. Antioxidant activity was examined using DPPH and ABTS (11.3 and 9.8 μg/mL, respectively) and by ferric reducing ability of the plasma method (891 μmol AAE/g dry extract). Phytochemical analysis of LEL was performed by LC-DAD-MS/MS. Ten phenolic compounds were identified; two minor compounds (glucopyranosyl rosmarinic acid and sagerinig acid) have not been described in Lycopus yet. The major compounds, considered to be responsible for biological activities detected in the study, were determined as rosmarinic acid (76 mg/g) and luteolin-7-O-glucuronide (23 mg/g). L. europaeus arises from our study as a promising source of antibacterial agent for topical usage.     

Synthesis,spectral, crystal structure,drug-likeness,in silico,and in vitro biological screening of halogen [Cl,Br] substituted N-phenylbenzo[g]indazole derivatives as antimicrobial agents

The N-phenylbenzo[g]indazole derivatives, 3-(4-chlorophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (4CLPBIC), 3-(4-bromophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (4BRPBIC), and 3-(3-bromophenyl)-3,3a,4,5-tetrahydro-N-phenylbenzo[g]indazole-2-carbothioamide (3BRPBIC), were synthesized by the one-pot green amalgamation of solvent-free granulating methodology procedure at room temperature. The synthesized crystals were characterized by single-crystal X-ray diffraction (SC-XRD), FT-IR, FT-Raman, NMR, and UV–Vis techniques. The molecular geometries from XRD experimental values of synthesized compounds 4CLPBIC, 4BRPBIC, and 3BRPBIC in the ground state are compared theoretically by applying the density functional theory (DFT), a method with the B3LYP/6-311G(d,p) basis set using Gaussian 09 software. The vibrational assignments of the synthesized compounds were studied based on potential energy distribution (PED) by the VEDA4 program. The scaled DFT/B3LYP/6-311G(d,p) results show the best agreement with the experimental values. Computational ¹H and ¹³C NMR were acquired by utilizing gauge-independent atomic orbital (GIAO) procedure, and chemical shift results are in good agreement with the experimental values. A web-based theoretical investigation was performed to understand the drug-likeness and ADMET properties of the compounds. Molecular docking studies were carried out against bacterial cholesterol inhibitor block and inhibitor of lanosterol-14α-demethylase CYP51 used in the treatment of topical and systemic mycoses in fungal to understand the inhibitory activity of synthesized compounds. The synthesized molecules were also tested for antibacterial and antifungal activities.