scholarly journals Antibacterial Screening of Gunnera perpensa-Mediated Silver Nanoparticles

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Naazlene Patel ◽  
Kabange Kasumbwe ◽  
Viresh Mohanlall
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Bacterial Strains ◽  
Antibacterial Screening ◽  
Methods Of Synthesis ◽  
Amine Groups ◽  
Biosynthesized Agnps ◽  
Physical And Chemical ◽  
Diffusion Assay

The biosynthesis of nanoparticles has become quite popular and has been proposed as an alternative over the tedious, expensive, and toxic physical and chemical methods of synthesis due to its cost-effectiveness and ecofriendliness. This study involved the biosynthesis, characterization, and evaluation of the antibacterial activity of Gunnera perpensa-mediated AgNPs. Biosynthesized AgNPs were characterized using TEM, UV, and FTIR spectroscopy. The antimicrobial activity was evaluated in six bacterial strains, using the disc diffusion assay, and MIC was determined using the broth dilution assay. All NPs generally presented as spherical clusters, with sizes ranging from 13 to 24 nm, as determined by TEM. The absorption peaks ranging between 421 and 425 nm and the presence of the C=O bond with amine groups, as indicated by UV and FTIR spectra, confirmed the synthesis and stabilization of G. perpensa extract-mediated AgNPs. Good antimicrobial activity ranging from 7.0 to 9.0 mm was exhibited by both preparations of G. perpensa extract-mediated AgNPs against both Gram-positive and Gram-negative studied bacteria, at MIC ranging from 3.2 to 12.5 μg/ml. Overall, good antibacterial activity was achieved at lower doses with both preparations of the G. perpensa-mediated AgNPs against all tested bacterial strains, suggesting G. perpensa-mediated AgNPs as good antimicrobial agents.

scholarly journals Novel 2,4,6-Trimethylbenzenesulfonyl Hydrazones with Antibacterial Activity: Synthesis and In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2723
Author(s):  
Łukasz Popiołek ◽  
Sylwia Szeremeta ◽  
Anna Biernasiuk ◽  
Monika Wujec
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Potential Application ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Condensation Reaction ◽  
In Vitro Study ◽  
In Vitro Bioactivity ◽  
Bacterial Strains

This research describes the synthesis and in vitro antimicrobial activity study of a series of 2,4,6-trimethylbenzenesulfonyl hydrazones. Twenty-five hydrazones (2–26) were synthesized on the basis of condensation reaction. The in vitro bioactivity study confirmed the potential application of obtained derivatives as antimicrobial agents. Among the tested compounds, the highest activity was discovered for derivative 24, which possessed minimal inhibitory concentration (MIC) ranging from 7.81 to 15.62 µg/mL against Gram-positive reference bacterial strains. Synthesized benzenesulfonyl hydrazones can be applied as potential ligands for the synthesis of bioactive metal complexes.

scholarly journals Synthesis and biological evaluation of some new 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines as antimicrobial agents

2022 ◽  
Vol 11 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Iryna Myrko ◽  
Taras Chaban ◽  
Vasyl Matiychuk
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Bacterial Strains ◽  
Synthesis And Biological Evaluation

A series of some new pyrazole-substituted 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines was synthesized in this study. The structures of target substances were confirmed by using 1H and 13С NMR spectroscopy, mass spectrometry and elemental analysis. The synthesized compounds have been evaluated for antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). The antimicrobial screening studies of synthesized substances established that 2 of 12 compounds show pronounced antibacterial activity against the strain Staphylococcus aureus.

scholarly journals Antibacterial Activity of Some Nanoparticles Against Some Pathogenic Bacteria That Isolated From Urinary Tract Infections Patient

2019 ◽  
Vol 9 (04) ◽  
pp. 682-685
Author(s):  
Taha H. Alnasrawi ◽  
Zahraa A. Althabet ◽  
Ghufran S. Salih ◽  
Mohammad J. Al-Jassani
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Klebsiella Pneumonia ◽  
Bacterial Strains ◽  
High Concentration ◽  
Disk Diffusion Assay ◽  
Tract Infections ◽  
Diffusion Assay ◽  
Economical Alternative

Nanoparticles include multiple metal oxides such as yttrium, copper, nickel, zinc, iron, and silver that have antimicrobial activity. The present work evaluates the antibacterial activity of some nanoparticles (NPs)against various pathogenic bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia and Staphylococcus aureus). Antimicrobial activity of NPs was accomplished by the mean of disk diffusion assay using dilutions of (200, 100, 50, 25, and 12.5) and the MIC and MBC of each isolate is determined. NPs shows no antibacterial activity against tested bacteria. It is highly recommended using NPs as an economical alternative antibacterial agent, especially in treating ectopic infections but with high concentration since low concentration gives no result without taking the risk of developing resistant bacterial strains as with antibiotics.

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.

Studies on antimicrobial activity of cobalt(III) ethylenediamine complexes

2006 ◽  
Vol 52 (12) ◽  
pp. 1247-1254 ◽  
Author(s):  
Penumaka Nagababu ◽  
J Naveena Lavanya Latha ◽  
P Pallavi ◽  
S Harish ◽  
S Satyanarayana
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Mixed Ligand ◽  
Disc Diffusion ◽  
Disc Diffusion Assay ◽  
H Nmr ◽  
Time Period ◽  
Infrared Spectral ◽  
Diffusion Assay

A series of cobalt(III) mixed ligand complexes of type [Co(en)2L]+3, where L is bipyridine, 1,10-phenanthroline, imidazole, methylimidazole, ethyleimidazole, dimethylimidazole, urea, thiourea, acetamide, thioacetamide, semicarbazide, thiosemicarbazide, or pyrazole, have been isolated and characterized. The structural elucidation of these complexes has been explored by using absorption, infrared, and 1H NMR nuclear magnetic resonance spectral methods. The infrared spectral data of all these complexes exhibit a band at 1450/cm and 1560–1590/cm, which correspond to C = C and C = N, a band at 575/cm for Co-N (en), and a band at 480/cm for Co-L (ligand). All these complexes were found to be potent antimicrobial agents. The antibacterial activity was studied in detail in terms of zone inhibition, minimum bactericidal, and time period of lethal action. Among all, complexes bipyridine, 1,10-phenanthroline, dimethylimidazole, and pyrazole, possess the highest antibacterial activity. Antifungal activity was done by disc-diffusion assay and 50% inhibitory concentrations that possess high antifungal activity.Key words: cobalt(III) complexes, ethylenediamine, antimicrobial, antifungal.

Antimicrobial Activity of Highly Fluorinated Thiocarbamates and Dithiocarbamates

2019 ◽  
Vol 13 (2) ◽  
pp. 120-128
Author(s):  
Amal Thebti ◽  
Ines Chniti ◽  
Med Abderrahmane Sanhoury ◽  
Ikram Chehidi ◽  
Hadda Imene Ouzari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Fungal Species ◽  
Penicillium Expansum ◽  
Bacterial Strains ◽  
Widespread Occurrence ◽  
Antibacterial And Antifungal

Background:The widespread occurrence of resistance to current antibiotics has triggered increasing research efforts to design and develop innovative antibacterial and antifungal agents that could overcome such antimicrobial resistance.Objective:The aim of this work was the in vitro evaluation of twelve highly fluorinated Nmonosubstituted thiocarbamates and dithiocarbamates and six non-fluorinated analogs against nine bacterial strains and three fungal species.Methods:The in vitro antimicrobial activity against the tested microrganisms was evaluated using the microdilution broth method.Results:Escherichia coli ATCC 8739, Salmonella sp., Staphylococcus aureus 6539 and all the three fungi (Aspergillus niger, Aspergillus flavus and Penicillium expansum) exhibited the highest rate of susceptibility, whilst Enterococcus faecuim ATCC 19436 and particularly Escherichia coli DH5α were less susceptible. Thiocarbamate (1i) and dithiocarbamate (2i) showed both the lowest MIC values (3.9 µg/mL) and the widest spectrum of antibacterial activity. Furthermore, the N-ethyl derivatives inhibited more efficiently the growth of bacteria than N-aryl analogs.Conclusion:The fluorinated compounds showed, in general, a relatively more potent antibacterial activity than non-fluorinated counterparts. The results indicate that these thiocarbamates and dithiocarbamates could be promising candidates as potential antimicrobial agents.

Synthesis and Antimicrobial Activity of Thiohydantoins Obtained from L-Amino Acids

2019 ◽  
Vol 17 (1) ◽  
pp. 94-102 ◽  
Author(s):  
Priscila Goes Camargo de Carvalho ◽  
Jhonatan Macedo Ribeiro ◽  
Renata Perugini Biasi Garbin ◽  
Gerson Nakazato ◽  
Sueli Fumie Yamada Ogatta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Antimicrobial Agents ◽  
Ammonium Thiocyanate ◽  
Antibiofilm Activity ◽  
Bacterial Strains ◽  
Wide Range ◽  
Time Kill

Background: Thiohydantoins are an important class of heterocyclic compounds in drug discovery since they are related to a wide range of biological properties including antimicrobial activity. Objective: The objective of this study was to synthesize a series of thiohydantoins derived from Laminoacids and to evaluated their inhibitory effect on the growth of Gram-negative and Grampositive bacteria. Methods: All title compounds were synthetized by reaction of L-amino acids with thiourea or ammonium thiocyanate. Their antimicrobial activities were evaluated against bacterial strains by broth microdilution assays. The time-kill kinetics, the antibiofilm activity and the cytotoxicity to mammalian cells were determined for the compound that exhibited the best antimicrobial profile (1b). Results: Eleven thiohydantoins were readily obtained in good yields (52-95%). In general, thiohydantoins were more effective against Gram-positive bacteria. Compound 1b (derived from Lalanine) showed the best antibacterial activity against Staphylococcus epidermis ATCC 12228 and S. aureus BEC 9393 with MIC values of 940 and 1921 µM, respectively. The time-kill kinetics demonstrated time-dependent bactericidal effect in both strains for this derivative. Besides, 1b also exhibited antibacterial activity against biofilms of S. epidermidis ATCC 12228, leading to a 40% reduction in their metabolic activity compared to the untreated control. No cytotoxicity of 1b to mammalian cells was observed at MIC values. Conclusion: The data reported herein indicate relevant antimicrobial activity of thiohydantoins derived from L-aminoacid, mainly 1b, as potential pharmacophore to guide further chemical modification aiming at the search for new and improved antimicrobial agents.

scholarly journals Isolation of a Variant of Subtilosin A with Hemolytic Activity

2009 ◽  
Vol 191 (18) ◽  
pp. 5690-5696 ◽  
Author(s):  
Tai Huang ◽  
Hao Geng ◽  
Venugopal R. Miyyapuram ◽  
Clarissa S. Sit ◽  
John C. Vederas ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Hemolytic Activity ◽  
Antimicrobial Agents ◽  
Cell Envelope ◽  
Bacterial Strains ◽  
Gram Positive Bacteria ◽  
Altered Form ◽  
Resistant Mutation

ABSTRACT Bacillus subtilis produces an anionic bacteriocin called subtilosin A that possesses antibacterial activity against certain gram-positive bacteria. In this study, we uncovered a hemolytic mutant of B. subtilis that produces an altered form of subtilosin A. The mutant bacteriocin, named subtilosin A1, has a replacement of threonine at position 6 with isoleucine. In addition to the hemolytic activity, subtilosin A1 was found to exhibit enhanced antimicrobial activity against specific bacterial strains. The B. subtilis albB mutant that does not produce a putative immunity peptide was more sensitive to both subtilosin A and subtilosin A1. A spontaneous suppressor mutation of albB that restored resistance to subtilosin A and subtilosin A1 was obtained. The sbr (subtilosin resistance) mutation conferring the resistance is not linked to the sboA-alb locus. The sbr mutation does not increase the resistance of B. subtilis to other cell envelope-targeted antimicrobial agents, indicating that the mutation specifically confers the resistance to subtilosins. The findings suggest possible bioengineering approaches for obtaining anionic bacteriocins with enhanced and/or altered bactericidal activity. Furthermore, future identification of the subtilosin-resistant mutation could provide insights into the mechanism of subtilosin A activity.

scholarly journals Synthesis, lipophilicity and antimicrobial activity evaluation of some new thiazolyl-oxadiazolines

2015 ◽  
Vol 88 (4) ◽  
pp. 521-529 ◽  
Author(s):  
Cristina Ioana Stoica ◽  
Ioana Ionuț ◽  
Adrian Pîrnău ◽  
Carmen Pop ◽  
Ancuța Rotar ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Chemical Characterization ◽  
Principal Component ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Pca Method ◽  
Physical And Chemical ◽  
Layer Chromatography

Background and aims. Synthesis of new potential antimicrobial agents and evaluation of their lipophilicity.Methods. Ten new thiazolyl-oxadiazoline derivatives were synthesized and their structures were validated by 1H-NMR and mass spectrometry. The lipophilicity of the compounds was evaluated using the principal component analysis (PCA) method. The necessary data for applying this method were obtained by reverse-phase thin-layer chromatography (RP-TLC). The antimicrobial activities were tested in vitro against four bacterial strains and one fungal strain.Results. The lipophilicity varied with the structure but could not be correlated with the antimicrobial activity, since this was modest.Conclusions. We have synthesized ten new heterocyclic compounds. After their physical and chemical characterization, we determined their lipophilicity and screened their antimicrobial activity.

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.

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