scholarly journals Synthesis and Evaluation of Schiff Bases of 4-Amino-5-(chlorine substituted phenyl)-4H-1,2,4-triazole-3-thione as Antimicrobial Agents

2020 ◽  
Vol 41 (1) ◽  
pp. 26-35
Author(s):  
Kishor Devkota ◽  
Govinda Pathak ◽  
Bhushan Shakya

Triazole ring system has attracted a continuously growing interest of synthetic organic chemists and those dealing with the medicinal compounds due to its versatile potential to interact with biological systems. Schiff bases are also considered as one of the most biologically active compounds.  The aim of the present study was to synthesize new Schiff bases bearing triazole nucleus and to assess their antimicrobial activities. Four new Schiff base derivatives of 1,2,4-triazole-3-thione were synthesized by combining two different pharmacophores viz. triazole nucleus and Schiff base moiety and were characterized by spectral techniques (UV, FT-IR, and NMR). The Schiff bases were evaluated for antibacterial (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) and antifungal (Candida albicans) activities. The synthesized compounds exhibited good to moderate activities against different strains of bacteria and fungi tested.

2016 ◽  
Vol 9 (1) ◽  
pp. 1873-1882
Author(s):  
V. Sreenivas ◽  
G. Srikanth ◽  
Ch. Vinutha ◽  
M. Shailaja ◽  
P. Muralidhar Reddy ◽  
...  

A series of cobalt (II) complexes have been synthesized with Schiff bases derived from ortho-phthalaldehyde and various amines in aqueous methanol solution. The newly synthesized Schiff bases and their Co (II) complexes have been characterized  by elemental analysis, magnetic susceptibility, thermal, conductance measurements, mass, IR, electronic, 1H,13C-NMR spectral techniques. These ligands act as tetradentate species and coordinate to the metal center through the different potential donor atoms such as N, O and S. The probable octahedral structures have been assigned to these complexes. All the synthesized Schiff base ligands and Co(II) metal complexes have also been screened for their antimicrobial activities and metal complexes found to be more active than respective Schiff-base ligands.


2017 ◽  
Vol 1 (3) ◽  
pp. 230-234 ◽  
Author(s):  
Sefa Durmuş ◽  
Aslıhan Dalmaz ◽  
Görkem Dülger ◽  
Duygu Bircan Kadıoğlu

Abstract Thio-Schiff bases are becoming increasingly widespread in various branches such as the preparation of certain medicines, cosmetic products, and polymer production. In particular, the presence of antibacterial, antifungal, antiviral, antitumor and antimalarial properties of Schiff bases containing sulfur in the structure has made these compounds attractive in different disciplines. In this study, different derivatives of dimeric disulfide-Schiff bases have been synthesized. The antibacterial and antifungal activities of the synthesized these compounds were investigated in vitro against some human pathogens (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans, C. tropicalis, C. guilliermondii and C. glabrata). Test microorganisms were isolated from the patients appyling to Medical Faculty Hospital of Duzce University were used. Diffusion method was used to determine the antimicrobial activities of the compounds.standard antibacterial (Cefotaxime, Amoxicillin/clavulanicacid) and antifungal (Posaconazole) antibiotics were used as the control group and the results were compared. The result indicated that antimicrobial activity of Disulphide-Schiff Base Derivatives exhibited less activity against bacteria as compared to AMC30 (Amoxicillin/clavulanicacid), but highly effective against bacteria as compared to CTX30 (Cefotaxime). In addition, the compounds exhibited less activity against yeast.


2020 ◽  
Vol 1 (1) ◽  
pp. 29-36
Author(s):  
Kamal Prasad Kapri ◽  
Som Bahadur Singar ◽  
Santosh Khanal ◽  
Bhusan Shakya

In recent years, the emergence and rapid spread of multidrug-resistant microbes are increasingly becoming major concerns for public health because infections from such pathogens lead to higher mortality imposing huge healthcare costs. With the currently available drugs becoming ineffective due to the drug resistance developed by pathogens, the synthesis of more powerful antimicrobial agents with a broad spectrum of activity has become a crucial need for the treatment of microbial infections. Some new amino-substituted Schiff bases with triazole ring (4a-c) were prepared by cyclization of potassium 2-(2-hydroxybenzoyl) hydrazinecarbodithioate (2) with hydrazine hydrate followed by condensation with aromatic aldehydes. The newly synthesized compounds were characterized by spectral techniques like FTIR, 1H-NMR, and 13C-NMR. Antimicrobial screening of the synthesized compounds revealed that they possess good to moderate activities against a variety of microorganisms.


Author(s):  
Jagseer Singh ◽  
Pooja A. Chawla ◽  
Md. Jawaid Akhtar ◽  
Bhupinder Kumar

Abstract:: Schiff base or imine or azomethine is one of the most important organic compounds that has been reported to play a significant role in various biological processes. The group is a part of natural or non-natural compounds and is involved as important precursors as diversified agents and as intermediates for the synthesis of biologically active agents. The review outlines the detailed design strategy, synthesis and structure-activity relationship studies of different Schiff bases for various biological activities. We have tried to outline the key points of various researchers with respect to biological activities. The results of different studies demonstrate Schiff bases as a linker in many synthetic compounds displaying a broad range of activities. We believe that the present review will provide comprehensive knowledge about medicinal importance of Schiff bases and serve as important literature in designing the synthesis of novel molecules containing Schiff base as pharmacophore or biologically active moiety.


Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2696 ◽  
Author(s):  
Teran ◽  
Guevara ◽  
Mora ◽  
Dobronski ◽  
Barreiro-Costa ◽  
...  

Our main interest is the characterization of compounds to support the development of alternatives to currently marketed drugs that are losing effectiveness due to the development of resistance. Schiff bases are promising biologically interesting compounds having a wide range of pharmaceutical properties, including anti-inflammatory, antipyretic, and antimicrobial activities, among others. In this work, we have synthesized 12 Schiff base derivatives of 4-aminoantipyrine. In vitro antimicrobial, antioxidant, and cytotoxicity properties are analyzed, as well as in silico predictive adsorption, distribution, metabolism, and excretion (ADME) and bioactivity scores. Results identify two potential Schiff bases: one effective against E. faecalis and the other with antioxidant activity. Both have reasonable ADME scores and provides a scaffold for developing more effective compounds in the future. Initial studies are usually limited to laboratory in vitro approaches, and following these initial studies, much research is needed before a drug can reach the clinic. Nevertheless, these laboratory approaches are mandatory and constitute a first filter to discriminate among potential drug candidates and chemical compounds that should be discarded.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.


2021 ◽  
Vol 9 (09) ◽  
pp. 900-909
Author(s):  
Anupama Srivastava ◽  
◽  
Shilpi Srivastava ◽  
Om. P. Pandey ◽  
Soumitra K. Sengupta ◽  
...  

Titanium(IV) complexes of type[(η5-C5H5)2TiCl(L)] have been synthesized by the reactions of bis(cyclopentadienyl)titanium(IV)dichloride with Schiff bases (LH) derived by the condensation of 5-(substituted aryl)-2-hydrazino-1,3,4-oxadiazole and indoline-2,3-dione in tetrahydrofuranin the presence oftriethylamine. All these complexes are soluble in PhNO2, DMF and DMSO.The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, UV-Vis, IR, 1H NMR, 13C NMR, XRD and SEM spectral techniques. Low molar conductance values indicate that they are non-electrolytes. The spectral data indicate5-coordinate geometry for the complexes.XRD pattern indicate that the complexes have monoclinic crystal system and particle sizes were found 49.36 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillusniger, Aspergillusflavus,ColletotrichumfalcatumandIn vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, S.typhi) and gram positive (S. aureus and B.subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The titanocene(IV) complexes have higher antimicrobial effect than the parent Schiff bases.


1970 ◽  
Vol 6 (2) ◽  
pp. 69-75 ◽  
Author(s):  
G Nagalakshmi

1,3,4-oxadiazoles are important because of its versatile biological actions. In the present study, several 2,5-disubstituted-1,3,4-oxadiazoles (3a-o) have been synthesized by the condensation of 4-hydroxybenzohydrazide (1) with various aromatic acids (2a-o) in presence of phosphorus oxychloride. The structures of the newly synthesized compounds have been established on the basis of elemental analysis, UV, IR and 1H NMR spectral data. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria and fungi viz., Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Pseudomonas aeruginosa, Shigella dysenteriae, Candida albicans, Aspergillus niger and Aspergillus flavus and the results were compared with the standard antibiotics such as chloramphenicol (50?g/ml) and Griseofulvin (50?g/ml) using agar diffusion technique. Compounds 3b, 3e, 3g, 3h, 3j, 3m and 3n exhibited strong antibacterial activity and compounds 3a, 3d, 3g, 3h and 3i showed good antifungal activity. Key words: 2,5-disubstituted-1,3,4-oxadiazoles, 4-hydroxybenzohydrazide, phosphorus oxychloride, antimicrobial evaluation, agar well diffusion method. Dhaka Univ. J. Pharm. Sci. 6(2): 69-75, 2007 (December)


2009 ◽  
Vol 6 (4) ◽  
pp. 1205-1210 ◽  
Author(s):  
J. J. Vora ◽  
S. B. Vasava ◽  
K. C. Parmar ◽  
S. K. Chauhan ◽  
S. S. Sharma

Schiff base derivatives ofN-{(1E)-[3-(mono or di-substituted aryl)-1-phenyl-1H-pyrazol-4-yl]methylene{-4-methylpyridin-2-amine were synthesized by the acid catalyzed condensation of 3-(mono- or di- substituted aryl)-1-phenyl-1H-pyrazole-4-carbaldehyde derivatives with 4-methylpyridin-2-amine. Schiff base derivatives were characterized by FT-IR,1H-NMR, Mass spectral analysis and elemental analysis. All the synthesized compounds have been screened for their antimicrobial activities by using broth dilution method.


2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Jaiprakash Biradar ◽  
Parveen Rajesab ◽  
B. Sasidhar

AbstractA novel and convenient synthesis of thiopheno-4-thiazolidinyl indole analogues is presented (IVa-IVi), with the aim of obtaining biologically active compounds. 3,5-disubstituted indol-2-carboxyhydrazides (Ia-If) were allowed to react with 3-acetyl-2,5-dichlorothiophene (II) to yield the corresponding 3,5-disubstituted indol-2-carbohydrazides (IIIa-IIIf). The pre-formed indolecarbohydrazides (IIIa-IIIf) were allowed to react with 2-mercaptoacetic acid or 2-mercaptopropanoic acid to produce thiopheno-4-thiazolidinylindoles (IVa-IVi). This reaction protocol affords a simple, eco-friendly, non-hazardous, easier preparation and high yields. The antioxidant (free radical scavenging, total antioxidant capacity and ferric-reducing antioxidant power) and antimicrobial activities of the synthesised compounds were evaluated. The structures and purity of the products were confirmed by their IR, 1H NMR, 13C NMR and mass spectral and analytical data. Most of the compounds tested showed very significant scavenging, antioxidant and antimicrobial activities. Compounds containing electron donor group (CH3) at the fifth position of indole exhibit an excellent ferric-reducing activity. The present study suggests that compounds IIIa-IIIb, IIIf, IVa-IVc, IVf-IVi, may serve as promising lead scaffolds for antioxidant and antimicrobial agents.


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