Synthesis, biological and computational study of new Schiff base hydrazones bearing 3-(4-pyridine)-5-mercapto-1,2,4-triazole moiety

A series of new Schiff base hydrazones (compounds 1-16) were synthesized by condensation reaction of 4-amino-3-(4-pyridine)-5-mercapto-1,2,4-triazole with various aldehydes and/or dialdehydes. The structure of the prepared compounds was confirmed by means of 1H NMR, 13C NMR, UV-vis, IR and elemental analyses. The all prepared compounds were assayed for antibacterial (Escherichia coli and Staphylococcus aureus) and antifungal (Candida albicans) activities by disc diffusion method. The results indicate that all tested compounds did not show any antibacterial activity against E. coli, as gram negative bacteria, and antifungal activity against C. albicans. But the compounds 2, 3, 4, 6 and 8 containing 4-Cl, 4-Me, 4-MeO, 2,4-di-Cl and 2-OH substituted phenyl moiety, respectively, showed good inhibition against S. aureus as compare to standard drugs. The structure of all biologically active compounds has also been theoretically studied by ab initio Hartree-Fock (HF) methods.     

Synthesis of 5-benzylidene-3-(3-fluoro-4-yl-morpholin-4-yl-phenylimino)-thiazolidin-4-one derivatives catalyzed by [BmIm] OH and their anti-microbial activity

A series of novel 5-benzylidene-3-(3-fluoro-4-yl-morpholin-4-yl-phenylimino)thiazolidin-4-one derivatives were synthesized using[bmIm]OH as a catalyst and were tested for their antibacterial and antifungal activities.These compounds showed moderate in vitro activities against the microorganisms tested.     

Synthesis and Antimicrobial Activity of Quinazolin-4(3H)-ones Incorporating Sulfonamido-4-thiazolidinone

Some new derivatives 7‐chloro‐2‐[2‐(2,6‐dichlorophenyl)amino]benzyl‐3‐[4‐(2‐substituted phenyl‐4‐oxo‐ thiazolidin‐3‐yl)phenyl]sulfonamido‐quinazolin‐4(3H)‐ones 5a – 5l were synthesized from 2‐[2‐(2,6‐dichloro‐phenyl)amino]phenyl acetic acid via acid chloride, benzoxazinone, amino quinazolin‐4(3H)‐one and Schiff base formation. The synthesized compounds were screened for in vitro antibacterial and antifungal activities by broth micro dilution method. Some of the Schiff base as well as 4‐thiazolidinone derivatives showed promising antibacterial activity while pronounced antifungal activity was observed against C. albicans.     

Design,synthesis and biological evaluation of novel N1,N8-bis(((4-((5-aryl-1,3,4-oxadiazol-2-yl)methoxy)phenyl)amino)oxy)-1-naphthamide derivatives

A new series of 1,8-bis(4-((5-phenyl-1,3,4-oxadiazol-2-yl) methoxy)-substituted aryl) naphthalene-1,8-dicarboxamide derivatives (6a–j) were synthesized in the presence of POCl₃ and obtained good yields. All the synthesized novel compounds were characterized by IR, ¹H NMR, ¹³C NMR, HRMS spectroscopic data and elemental analysis. All the synthesized compounds evaluated for their antibacterial and antifungal activities. The antibacterial activity screened against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and used standard reference drug ciprofloxacin. The antifungal activity screened against two pathogenic fungal strains Aspergillus niger and Candida albicans used a reference standard drug Voriconazole. All these compounds (6a–j) demonstrate good antibacterial and antifungal activity. Among them, compounds 6h and 6c show highest antibacterial and antifungal activity.     

Synthesis and biological evaluation of 4-thiazolidinone derivatives as antitubercular and antimicrobial agents

New series of N-[2-{2-(substitutedphenyl)-4-oxo-5-(substitutedbenzylidene)-1,3-thiazolidine}-iminoethyl]-2-amino-5-nitrothiazole, 5(a–m) have been synthesized from 2-amino-5-nitrothiazole as a starting material by conventional as well as microwave methods. All the synthesized compounds 4(a–m) were screened for their antibacterial and antifungal activities against some selected bacteria and fungi and antitubercular activity screened against Mycobacterium tuberculosis. The structure of all the synthesized compounds were confirmed by chemical and spectral analyses such as IR, ¹H NMR, ¹³C NMR and FAB-Mass.     

Synthesis and biological activity of some 3-(4-(substituted)-piperazin-1-yl)cinnolines

A new series of 6-substituted-4-methyl-3-(4-arylpiperazin-1-yl)cinnolines 8-10 were synthesized as potential antifungal agents via intramolecular cyclization of the respective 1-(2-arylhydrazono)-1-(4-arylpiperazin-1-yl)propan-2-ones 5-7, mediated by polyphosphoric acid (PPA). The amidrazones themselves were synthesized via direct interaction of the appropriate hydrazonoyl chlorides 4a-d with the corresponding N-substituted piperazine in the presence of triethylamine. The structures of the new prepared compounds were confirmed by elemental analyses, (1)H-NMR, (13)C-NMR, and ESI-HRMS spectral data. The antitumor, antibacterial, and antifungal activity of the newly synthesized compounds was evaluated.     

Synthesis, antibacterial and antifungal activity of some derivatives of 2-phenyl-chromen-4-one

Some derivatives of 2-phenyl-chromen-4-one (flavone ring) have been synthesized and tested for antibacterial and antifungal activities along with their chalcone precursors against four human pathogenic bacteria and five plant mould fungi. The structures of the synthesized compounds were elucidated by UV, IR and¹H NMR spectroscopic techniques, and elemental analysis. The antibacterial and antifungal screens of the synthesized compounds were performed in vitro by the filter paper disc diffusion method and the poisoned food technique.     

1,5-二取代吡唑基-1,4-戊二烯-3-酮类化合物的合成及生物活性研究

设计合成了13个未见文献报道的1,5-二取代吡唑基-1,4-戊二烯-3-酮类化合物, 其结构经元素分析, 1H NMR, IR确证. 初步生物活性测试结果表明, 部分化合物有一定的抗烟草花叶病毒(TMV)活性, 所有化合物抑菌活性较低.     

Dicationic liquid mediated synthesis of tetrazoloquinolinyl methoxy phenyl 4-thiazolidinones and their antibacterial and antitubercular evaluation

In a search of new potentially active antitubercular agents here we have synthesized 3-substituted phenyl-2-(4-(tetrazolo[1,5-a]quinolin-4-ylmethoxy)phenyl)thiazolidin-4-ones (8a–l) and evaluated their antibacterial, particularly antitubercular activity. These have been conveniently synthesized by performing one–pot cyclocondensation of 4-(tetrazolo[1,5-a]quinolin-4-ylmethoxy)benzaldehyde, anilines and mercaptoacetic acid in dicationic ionic liquid, (3-methyl-1-[3-(methyl-1H-imidazolium-1-yl)propyl]-1H-imidazolium dibromide [C₃(MIM)₂–2Br]) and obtained excellent yields of (8a–l). 4-Thiazolidinones (8a–l) were thoroughly characterized by their spectral analyses. These compounds have been screened for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis (BCG). The compounds 8a, 8c, and 8e exhibited notable in vitro antitubercular activity compare to the reference, Rifampicin. Molecular docking study has also been performed to know the binding mode of these analogs in to the active site of DprE1 enzyme. The synthesized compounds were also evaluated for their in vitro antibacterial activity and amongst them compound 8k has shown moderate activity against both gram-negative and gram-positive bacterial strains.     

Synthesis and biological evaluation of 2-(3-fluoro-4-nitro phenoxy)-n-phenylacetamide derivatives as novel potential affordable antitubercular agents

A novel series of 2-(3-fluoro-4-nitrophenoxy)-N-phenylacetamide compounds were designed, synthesized and in vitro assessed for their antitubercular activities by a microdilution method. All the novel derivatives exerted potent or moderate active against M. tuberculosis H??Rv, with MIC values ranging from 4 to 64 μg/mL. The most potent derivative 3m showed an identical MIC value of 4 μg/mL for both M. tuberculosis H??Rv and rifampin-resistant M. tuberculosis 261. It demonstrated no inhibitory effects against six different tumor cell lines by a MTT assay and had a good safety profile in a vero cell line, providing a good lead for subsequent optimization in search of novel affordable antitubercular agents.     

Synthesis and biological activities of cyclanone O-(2-(3-aryl-4- amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives

Twelve cyclanone O-(2-(3-aryl-4-amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives were synthesized and their structures were confirmed by spectroscopy (IR, ¹H NMR, ¹³C NMR, ¹⁹F NMR) and elemental analysis. Their antifungal and antibacterial activities were evaluated against six fungi (Gibberella zeae, Fusarium oxysporum, Clematis mandshurica, Phytophthora infestans, Paralepetopsis sasakii, Sclerotinia sclerotiorum) and two bacteria (Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas citri subsp. Citri (Xcc)). The results indicated that most of the title compounds exhibited good antibacterial activities. Among them, compounds 6d, 6g, 6h, and 6j showed better antibacterial activities against Xoo and Xcc than that of the commercial agent thiodiazole-copper.     

Synthesis and antimicrobial activity of N-(substituted)-N'-(2,3-dihydro-2-oxido-5-benzoyl-1H-1,3,2-benzodiazaphosphol-2-yl) ureas

N-(substituted)-N'-(2,3-dihydro-5-benzoyl-2-oxido-1H-1,3,2-benzodiazaphosphol-2-yl) ureas were synthesized by reacting 3,4-diaminobenzophenone (4) with different chlorides of carbamidophosphoric acids (3) in the presence of triethylamine at 40-45 degrees C. Their 1H-, 13C- and 31P-NMR spectral data are discussed. The title compounds were screened for antifungal and antibacterial activity against the fungi Aspergillus niger and Fusarium solani and bacteria Escherichia coli and Staphylococcus aureus. These compounds showed higher antibacterial activity when compared with antifungal activity.     

Synthesis of Functionalized H‐[1]Benzopyrano[2,3‐b]pyridines by the Friedländer Approach: Antimycobacterial and Antimicrobial Profile

A series of functionalized H‐[1]benzopyrano[2,3‐b]pyridine derivatives were synthesized by the Friedländer reaction of 2‐amino‐4‐oxo‐4H‐chromene‐3‐carbonitriles 1 with malononitrile, ethyl cyanoacetate, or acetophenone (Scheme). The synthesized compounds 2 – 4 were screened for their in vitro activity against antitubercular, antibacterial, and antifungal species (Fig., Table). Among the synthesized compounds, 3c and 4f were the most active with 99% inhibition against Mycobacterium tuberculosis H₃₇Rv, while compounds 2f, 3f , and 4d exhibited 69%, 63%, and 61% inhibition, respectively. The 4‐amino‐7,9‐dibromo‐1,5‐dihydro‐2,5‐dioxo‐2H‐chromeno[2,3‐b]pyridine‐3‐carbonitrile ( 3b ) showed the most potent antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. Several chromeno[2,3‐b]pyridine derivatives showed equal or more potency against Staphylococcus aureus and Candida albicans.     

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 and antibacterial activity of brominated 2''(4'')-nitro-3-hydroxy diphenyl ethers

Eight new brominated 2'(4')-nitro-3-hydroxy diphenyl ethers have been designed and synthesized.The structures of new compounds were confirmed by 1H NMR.IR and HRMS.The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria.These new compounds cannot be transformed into dioxins when they were manufactured and used.     

Synthesis,Characterization, Antibacterial,and Antifungal Activity of Novel 2‐(2‐hydroxy‐5‐((aryl)‐diazenyl)phenyl)‐3‐(4‐hydroxyphenyl)‐thiazolidin‐4‐one

A series of novel thiazolidinones, that is, 2‐(2‐hydroxy‐5‐((aryl)‐diazenyl)phenyl)‐3‐(4‐hydroxyphenyl)‐thiazolidin‐4‐one, have been synthesized by reaction of various Schiff bases 2‐(4‐hydroxyphenylimino)methyl)‐4‐(aryl)diazenyl)phenol with ethanolic thioglycolic acid. Schiff bases were obtained by the reactions of 4‐amino phenol with 2‐hydroxy‐5‐((aryl)diazenyl)benzaldehyde. The structures of the newly synthesized compounds were confirmed by IR, ¹H NMR, mass spectra, and C, H, N elemental analysis. The thiazolidinone derivatives were evaluated for their antibacterial and antifungal activity.     

Synthesis and biological activities of novel ethers of quinolinone linked with coumarins

Abstract  

A series of new ethers of quinolinone linked with different substituted coumarins and benzofurans were synthesized from 4-(bromomethyl)quinolinones. All newly synthesized compounds were screened for their in vitro antibacterial and antifungal activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in quinolinone showed potent antibacterial and antifungal activities. In pharmacological evaluations, some of these chloroquinolinones also showed 70–77% inhibition of inflammation after 8 h, whereas the other compounds showed 51–55% inhibition. Most of the compounds showed potent analgesic activity compared to the standard and control. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and EI-MS.     

1-(4-取代苯基)-4-苯基-5-(2-羟基苄基)氨基-1,2,3-三唑类衍生物的合成及抑菌活性

将邻羟苯基引入1,2,3-三唑结构中, 设计合成了10个1-(4-取代苯基)-4-苯基-5-取代-1,2,3-三唑类衍生物. 首先, 以对位取代的芳胺为原料, 经重氮化、叠氮化、闭环和缩合反应制得1-(4-取代苯基)-4-苯基-5-水杨醛亚胺-1,2,3-三唑类衍生物(3a~3e), 再用硼氢化钠还原制得1-(4-取代苯基)-4-苯基-5-(2-羟基苄基)氨基-1,2,3-三唑类衍生物(4a~4e). 目标化合物的结构经核磁、IR及元素分析确认. 抑菌活性测试表明, 当质量浓度为0.1 mg/L时, 除化合物3e和4e外, 所有化合物对白色念球菌的抑菌率均达95%以上, 对大肠杆菌的抑菌率达85%以上, 具有强抑菌活性, 表明该类化合物在抗菌药物开发方面有重要应用价值.     

Design and Synthesis of New Aryloxy‐linked Dimeric 1,2,3‐Triazoles via Click Chemistry Approach: Biological Evaluation and Molecular Docking Study

A quest for more potent new antitubercular agents has prompted to design and synthesize aryloxy‐linked dimeric 1,2,3‐triazoles ( 4a – j ), from azides ( 2a‐e ) and bis(prop‐2‐yn‐1‐yloxy)benzene ( 3a – b ) on 1,3‐dipolar cycloaddition reaction via copper (I)‐catalyzed click chemistry approach with good to better yields. The titled compounds ( 4a – j ) were designed using molecular hybridization approach by assembling various bioactive pharmacophoric fragments in a single molecular framework. All the synthesized compounds have been screened for their in vitro antitubercular, antifungal, and antioxidant activities against their respective strains. Among them, 4h and 4i show the highest antifungal activity, whereas compounds 4h , 4i , and 4j have revealed promising antitubercular activity against their respective strains. In addition to this, most of the synthesized compounds were found as potent antifungal and antioxidant agents. A significant network of bonded and non‐bonded interactions stabilized these molecules into the active site of fungal CYP51 that is realized from the obtained well‐placed docking poses and the associated thermodynamic interactions with the enzyme. The synthesized compounds have also been analyzed for absorption, distribution, metabolism, and excretion properties.     

Syntheses, Spectral Studies and Bioanalyses of Some Triorganotin(Ⅳ) Complexes of Cephlaxine

Five novel triorganotin(Ⅳ) complexes have been synthesized by refluxing trimethyl, triethyl, tributyl, triphenyl and tribenzyltin chloride with Cephlaxine.These compounds were characterized by spectroscopic (IR,1H, 13C, 119Sn NMR) techniques and elemental analysis.The results obtained through these techniques are in full agreement with the proposed 1:1 stoichiometry.The synthesized compounds were than tested against various microorganisms and fungi.The results of new products obtained showed that the triphenyltin(IV) complex displayed promising activity against all types of bacteria and fungi used while all other compounds showed significant antibacterial and antifungal activity.