New Oxadiazole Derivatives: Synthesis and Appraisal of Their Potential as Antimicrobial Agents

2018 ◽  
Vol 15 (1) ◽  
pp. 21-30
Author(s):  
Deboleena Dhara ◽  
Dhanya Sunil ◽  
Pooja R. Kamath ◽  
K. Ananda ◽  
S. Shrilakshmi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Spectral Techniques ◽  
Docking Simulations ◽  
E Coli ◽  
Oxadiazole Derivatives ◽  
Bacteria And Fungi ◽  
Almost All

Introduction: The escalating threat due to dwindling effect of antibiotics and challenge of tackling rising drug-resistant infections has gathered high focus in current medicinal research. Methods: In an attempt to find new molecules that can defeat microbial resistance, two new series of 2-[2-substituted ethenyl]-5-(substituted methoxy)-1,3,4-oxadiazole derivatives were synthesized. Various aromatic hydrazides were allowed to undergo cyclization to substituted oxadiazole-2- amines in the presence of cyanogen bromide and further condensed with different heterocyclic aldehydes to give new oxadiazole derivatives. The synthesized molecules were fully characterized by various spectral techniques and tested for antimicrobial activity. Results: Almost all the newly synthesized compounds especially (5g-5l) displayed remarkable growth inhibition against three bacterial strains: M. smegmatis, S. aureus, E. coli and fungi C. albicans. The antimicrobial activity was further confirmed by MIC assay against the same microorganisms. Oxadiazole 5g displayed promising activity with a MIC value of 0.025 mM for two bacteria and fungi, whereas MIC of this compound for E. coli was 0.1 mM. Other active compounds (5h-5l) also exhibited good MIC ranging between 0.313 to 5.0 mM against the selected microorganisms. Docking simulations were generated to explore the potential binding approaches of ligand 5g at the D-alanine:d-alanine ligase (Ddl) protein of E. coli and S. aureus. Conclusion: Molecule 5g was active even at a lower concentration and could probably act as a prospective lead molecule for targeting the drug resistant microorganisms.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

scholarly journals Synthesis and Biological Evaluation of Novel Aminochalcones as Potential Anticancer and Antimicrobial Agents

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4129 ◽  
Author(s):  
Joanna Kozłowska ◽  
Bartłomiej Potaniec ◽  
Dagmara Baczyńska ◽  
Barbara Żarowska ◽  
Mirosław Anioł
Keyword(s):  
Antimicrobial Activity ◽  
Cell Lines ◽  
Antimicrobial Agents ◽  
Human Colon ◽  
Biological Properties ◽  
Biological Evaluation ◽  
Human Colon Cancer ◽  
E Coli ◽  
Almost All ◽  
Ht 29

A series of 18 aminochalcone derivatives were obtained in yields of 21.5–88.6% by applying the classical Claisen-Schmidt reaction. Compounds 4–9, 14 and 16–18 with 4-ethyl, 4-carboxy-, 4-benzyloxy- and 4-benzyloxy-3-methoxy groups were novel, not previously described in the scientific literature. To determine the biological properties of the synthesized compounds, anticancer and antimicrobial activity assays were performed. Antiproliferative potential was evaluated on four different human colon cancer cell lines—HT-29, LS180, LoVo and LoVo/DX —using the SRB assay and compared with green monkey kidney fibroblasts COS7. Anticancer activity was described as the IC50 value. The best results were observed for 2′-aminochalcone (1), 3′-aminochalcone (2) and 4′-aminochalcone (3) (IC50 = 1.43–1.98 µg·mL−1) against the HT-29 cell line and for amino-nitrochalcones 10–12 (IC50 = 2.77–3.42 µg·mL−1) against the LoVo and LoVo/DX cell lines. Moreover, the antimicrobial activity of all derivatives was evaluated on two strains of bacteria: Escherichia coli ATCC10536 and Staphylococcus aureus DSM799, the yeast strain Candida albicans DSM1386 and three strains of fungi: Alternaria alternata CBS1526, Fusarium linii KB-F1 and Aspergillus niger DSM1957. In the case of E. coli ATCC10536 almost all derivatives hindered the bacterial growth (∆OD = 0). Furthermore, the best results were observed in the presence of 4′-aminochalcone (3), that completely limited the growth of all tested strains at the concentration range of 0.25–0.5 mg·mL−1. The strongest bacteriostatic activity was exhibited by novel 3′-amino-4-benzyloxychalcone (14), that prevented the growth of E. coli ATCC10536 with MIC = 0.0625 mg·mL−1.

scholarly journals Invitro antibacterial activity of Cassia fistula Linn methanolic leaf extracts

2019 ◽  
Vol 8 (2) ◽  
pp. 270
Author(s):  
Bindhu R. Kamath ◽  
Sabeena Kizhedath
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Cassia Fistula ◽  
Leaf Extracts ◽  
E Coli

Background: Cassia fistula Linn is a plant which is widely grown in India and is used for medicinal purposes. The study was carried out with an objective to demonstrate the antimicrobial activity of leaves of Cassia fistula Linn. The aim of the study is to assess antibacterial and antifungal activity of methanolic leaf extract of Cassia fistula Linn against selected clinical isolates.Methods: The antimicrobial activity of methanolic extract of Cassia fistula was evaluated using agar well diffusion method and to zone of inhibition of extract was determined. Clinical isolates of Staphyloccocus aureus, MRSA, Pseudomonas aeruginosa, E. coli and Proteus were screened.Results: The methanolic extracts exhibited antibacterial activity against Staphylococcus aureus. The extract was not active against E. coli, Proteus, MRSA, Pseudomonas aeruginosa. The extract also failed to demonstrate antifungal activity against Candida albicans and Aspergillus niger.Conclusions: The global emergence of multidrug resistant bacterial strains is increasing, limiting the effectiveness of current drugs and treatment failure of infections. A novel approach to the prevention of antibiotic resistance of pathogenic species is the use of new compounds that are not based on existing synthetic antimicrobial agents.

SEARCH FOR ANTIMICROBIAL AGENTS: QUINOXALINE AS A PROMISING TARGET

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
E Coli ◽  
Promising Target ◽  
Quinoxaline Derivatives

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.

Synthesis and Structural Elucidation of Aminoacetylenic Derivatives of 7-Methoxy- 2-Naphthole as Antimicrobial Agents

2017 ◽  
Vol 9 (08) ◽  
Author(s):  
Abu- Safieh Rana ◽  
Muhi- Eldeen Zuhair ◽  
Alsarahni Aseel ◽  
Al-Kaissi Elham
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Naphthalene Derivatives ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Aminoacetylenic Derivatives ◽  
Derivatives Of ◽  
Mic Value

A new series of 7-methoxy-2-[4-(t-amino-1-yl)oxy]-naphthalene derivatives; 7-methoxy-2-{[4-(2-methylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ2), 7-methoxy-2-{[4-(2,6-dimethylpiperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ3), 7-methoxy-2{[4-(piperidine)but-2-yn-1-yl]oxy}-naphthalene (RZ4), 7-methoxy-2-{[4-(pyrrolidine)but-2-yn-1-yl]oxy}-naphthalene (RZ5), 7-methoxy-2-{[4-(N-methylpiperazine)but-2-yn-1-yl]oxy}-naphthalene (RZ6), 7-methoxy -2-{[4-(hexamethyleneimine)but-2-yn-1-yl]oxy}-naphthalene (RZ7) were synthesized and screened in vitro as potential antimicrobial agents. Antimicrobial activity were evaluated by measuring the minimum inhibitory and bactericidal/fungicidal concentration (MIC, MBC and MFC). RZ2, RZ5, RZ6 and RZ7 showed the highest antimicrobial activity against S. aureus with MIC value 62.5 µg/ml, compounds RZ2, RZ4, RZ5, and RZ7 have the highest antimicrobial activity against B. subtilis with MIC vale 62.5 µg/ml, RZ3, RZ6 have the same antimicrobial activity with MIC value 125µg/ml, compounds. RZ4, RZ5, RZ6 and RZ7 have the highest antimicrobial activity against E. coli with MIC value 125 µg/ml, all compounds have the same MIC value against P. aeruginosa (125 µg/ml). RZ2, RZ4, RZ5, RZ6, RZ7 showed the highest antifungal activity with MIC of 62.5 µg/ml. In conclusion, the synthesized compounds showed good antimicrobial activity and promising potency against gram positive bacteria, gram negative bacteria and fungi.

scholarly journals A PRELIMINARY OBSERVATION ON AN EXPLICIT ANTIMICROBIAL ACTION OF MANGROVE PLANTS ON PSEUDOMONAS AERUGINOSA

2019 ◽  
pp. 226-230
Author(s):  
TAMANNA SULTANA ◽  
ARUP KUMAR MITRA ◽  
SATADAL DAS
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Microtiter Plate ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Mangrove Plant ◽  
E Coli ◽  
Mangrove Plants

Objectives: Due to emerging drug-resistant microorganisms throughout the world, newer antimicrobial agents should be looked for. Plants are enriched with different bioactive chemicals. In this study, we searched antibacterial activities of some mangrove plant extracts against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Methods: In the present study, the antimicrobial activity of the leaves of Bruguiera gymnorhiza, Excoecaria agallocha, Avicennia alba, and Aegialitis rotundifolia was evaluated against a few reference pathogenic bacterial strains, namely, P. aeruginosa ATCC 27853, E. coli ATCC 25922, S. aureus ATCC 29213, and multidrug-resistant bacterial strains E. coli extended-spectrum beta-lactamases strain. Aqueous, ethanolic, methanolic, and dimethyl sulfoxide (DMSO) extracts were studied. The antimicrobial activities of the organic solvent extracts on the various test microorganisms were investigated using agar well diffusion technique followed by determination of minimum inhibitory concentration values by serial dilution in a microtiter plate. Results: Ethanol and DMSO extracts of B. gymnorhiza exhibited promising antimicrobial activity followed by extracts of A. alba and E. agallocha. Among all microorganisms studied, P. aeruginosa ATCC 27853 showed significant growth inhibition with ethanol and DMSO extracts. Conclusion: Extracts of some mangrove plants, particularly, B. gymnorhiza showed very good antimicrobial activities against common microbial agents causing human infections and in general mangrove plants appear to act better on P. aeruginosa.

scholarly journals Oxo-Titanium(IV) Complex/Polymer Composites—Synthesis, Spectroscopic Characterization and Antimicrobial Activity Test

2020 ◽  
Vol 21 (24) ◽  
pp. 9663
Author(s):  
Piotr Piszczek ◽  
Barbara Kubiak ◽  
Patrycja Golińska ◽  
Aleksandra Radtke
Keyword(s):  
Antimicrobial Activity ◽  
Room Temperature ◽  
Antimicrobial Agents ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Bacterial Strains ◽  
E Coli ◽  
Activity Test ◽  
Complex Polymer ◽  
Ir And Raman

The emergence of a large number of bacterial strains resistant to many drugs or disinfectants currently used contributed to the search of new, more effective antimicrobial agents. In the presented paper, we assessed the microbiocidal activity of tri- and tetranuclear oxo-titanium(IV) complexes (TOCs), which were dispersed in the poly(methyl methacrylate) (PMMA) matrix. The TOCs were synthesized in reaction to Ti(OR)4 (R = iPr, iBu) and HO2CR’ (R’ = 4-PhNH2 and 4-PhOH) in a 4:1 molar ratio at room temperature and in Ar atmosphere. The structure of isolated oxo-complexes was confirmed by IR and Raman spectroscopy and mass spectrometry. The antimicrobial activity of the produced composites (PMMA + TOCs) was estimated against Gram-positive (Staphylococcus aureus ATCC 6538 and S. aureus ATCC 25923) and Gram-negative (Escherichia coli ATCC 8739 and E. coli ATCC 25922) bacteria and yeasts of Candida albicans ATCC 10231. All produced composites showed biocidal activity against the bacteria. Composites containing {Ti4O2} cores and the {Ti3O} core stabilized by the 4-hydroxybenzoic ligand showed also high activity against yeasts. The results of investigations carried out suggest that produced (PMMA + TOCs) composites, due to their microbiocidal activity, could find an application in the elimination of microbial contaminations in various fields of our lives.

scholarly journals Synthesis, Identification, Computer-Aided Docking Studies, and ADMET Prediction of Novel Benzimidazo-1,2,3-triazole Based Molecules as Potential Antimicrobial Agents

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7119
Author(s):  
Huda R. M. Rashdan ◽  
Aboubakr H. Abdelmonsef ◽  
Mortaga M. Abou-Krisha ◽  
Tarek A. Yousef
Keyword(s):  
Antimicrobial Activity ◽  
Binding Energy ◽  
Antimicrobial Agents ◽  
Sodium Ethoxide ◽  
Dna Gyrase ◽  
Docking Studies ◽  
Bacterial Strains ◽  
Standard Drug ◽  
E Coli

2-azido-1H-benzo[d]imidazole derivatives 1a,b were reacted with a β-ketoester such as acetylacetone in the presence of sodium ethoxide to obtain the desired molecules 2a,b. The latter acted as a key molecule for the synthesis of new carbazone derivatives 4a,b that were submitted to react with 2-oxo-N-phenyl-2-(phenylamino)acetohydrazonoyl chloride to obtain the target thiadiazole derivatives 6a,b. The structures of the newly synthesized compounds were inferred from correct spectral and microanalytical data. Moreover, the newly prepared compounds were subjected to molecular docking studies with DNA gyrase B and exhibited binding energy that extended from −9.8 to −6.4 kcal/mol, which confirmed their excellent potency. The compounds 6a,b were found to be with the minimum binding energy (−9.7 and −9.8 kcal/mol) as compared to the standard drug ciprofloxacin (−7.4 kcal/mol) against the target enzyme DNA gyrase B. In addition, the newly synthesized compounds were also examined and screened for their in vitro antimicrobial activity against pathogenic microorganisms Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. Among the newly synthesized molecules, significant antimicrobial activity against all the tested microorganisms was obtained for the compounds 6a,b. The in silico and in vitro findings showed that compounds 6a,b were the most active against bacterial strains, and could serve as potential antimicrobial agents.

scholarly journals Antimicrobial Activity of Cationic Poly(3-hexylthiophene) Nanoparticles Coupled with Dual Fluorescent and Electrochemical Sensing: Theragnostic Prospect

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1715
Author(s):  
Nada Elgiddawy ◽  
Shiwei Ren ◽  
Wadih Ghattas ◽  
Waleed M. A. El Rouby ◽  
Ahmed O. El-Gendy ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Fluorescence Spectroscopy ◽  
Bacterial Infections ◽  
Electrochemical Impedance ◽  
Spectroscopic Properties ◽  
Electrochemical Sensing ◽  
E Coli ◽  
Normal Human ◽  
Dual Detection ◽  
Bacteria And Fungi

Designing therapeutic and sensor materials to diagnose and eliminate bacterial infections remains a significant challenge for active theragnostic nanoprobes. In the present work, fluorescent/electroactive poly(3-hexylthiophene) P3HT nanoparticles (NPs) stabilized with quaternary ammonium salts using cetyltrimethylammonium bromide (CTAB), (CTAB-P3HT NPs) were prepared using a simple mini-emulsion method. The morphology, spectroscopic properties and electronic properties of CTAB-P3HT NPs were characterized by DLS, zeta potential, SEM, TEM, UV-vis spectrophotometry, fluorescence spectroscopy and electrochemical impedance spectroscopy (EIS). In an aqueous solution, CTAB-P3HT NPs were revealed to be uniformly sized, highly fluorescent and present a highly positively charged NP surface with good electroactivity. Dual detection was demonstrated as the binding of the bacteria to NPs could be observed by fluorescence quenching as well as by the changes in EIS. Binding of E. coli to CTAB-P3HT NPs was demonstrated and LODs of 5 CFU/mL and 250 CFU/mL were obtained by relying on the fluorescence spectroscopy and EIS, respectively. The antimicrobial activity of CTAB-P3HT NPs on bacteria and fungi was also studied under dark and nutritive conditions. An MIC and an MBC of 2.5 µg/mL were obtained with E. coli and with S. aureus, and of 0.312 µg/mL with C. albicans. Additionally a good biocompatibility toward normal human cells (WI38) was observed, which opens the way to their possible use as a therapeutic agent.

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
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Triazole Ring ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
Spectral Techniques ◽  
Schiff Base Derivatives ◽  
Bacteria And Fungi ◽  
Different Strains

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.

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