scholarly journals Synthesis, Characterization and In Vitro Antibacterial Evaluation of Pyrenacantha grandiflora Conjugated Silver Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1568
Author(s):  
Arinao Murei ◽  
Karen Pillay ◽  
Patrick Govender ◽  
Ntevheleni Thovhogi ◽  
Wilson M. Gitari ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Biological Synthesis ◽  
Klebsiella Pneumonia ◽  
Drug Resistant ◽  
Biological Methods ◽  
Mic Value

In the present study, silver nanoparticles (AgNPs) were synthesized using both the chemical and biological methods and conjugated with Pyrenacantha grandiflora extracts. These were then characterized and evaluated for antimicrobial activities against multi-drug resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumonia, and Escherichia coli. Nanoparticles were analyzed with UV-visible spectrophotometer, transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDX). Silver nanoparticles, P. grandiflora extracts, and the conjugates were also analyzed with Fourier transform infrared spectroscopy (FTIR). As a result, quasi-sphere-shaped AgNPs with sizes ranging from 5 to 33 nm and spherically shaped AgNPs with sizes ranging from 3 to 25 nm were formed from chemical and biological synthesis, respectively. A well diffusion assay showed that the activity of silver nanoparticles was most improved with acetone extract against all tested bacteria with diameters in the range of 19–24 mm. The lowest MIC value of 0.0063 mg/mL against MRSA was observed when biologically synthesized AgNPs were conjugated with acetone and water extracts. Chemically synthesized silver nanoparticles showed the lowest MIC value of 0.0063 mg/mL against E. coli when conjugated with acetone and methanol extracts. This study indicates that silver nanoparticles conjugated with P. gandiflora tubers extracts exhibit strong antibacterial activities against multi-drug resistant bacterial pathogens. Therefore, biosynthesized conjugates could be utilized as antimicrobial agents for effective disease management due to the synergistic antibacterial activity that was observed.

scholarly journals Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 852
Author(s):  
Tárcio S. Santos ◽  
Tarcisio M. Silva ◽  
Juliana C. Cardoso ◽  
Ricardo L. C. de Albuquerque-Júnior ◽  
Aleksandra Zielinska ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filamentous Fungi ◽  
Entomopathogenic Fungi ◽  
Antimicrobial Agents ◽  
Insect Pests ◽  
Insect Control ◽  
Biological Synthesis ◽  
Biological Methods ◽  
Potential Use

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

scholarly journals Silica gel Supported Boric tri-Sulfuric Anhydride (SiO2-BTSA): an Efficient Catalytic System for the Synthesis of Phloroglucide analogs as Antimicrobial Agents

2019 ◽  
Author(s):  
Rahele Bargebid ◽  
Ali Khalafi-Nezhad ◽  
Kamiar Zomorodianc ◽  
Mahkameh Moradi ◽  
Soghra Khabnadideh
Keyword(s):  
Silica Gel ◽  
Antimicrobial Agents ◽  
Catalytic Amount ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
Dilution Method ◽  
Sulfuric Anhydride ◽  
Chemical Structures

An efficient procedure for the synthesis of polyhydroxyl aromatic compounds (phloroglucide analogs) is described. In this procedure a reaction was done between different 4-substituted phenols and 2,6-bis(hydroxymethy) phenols. The reactions proceed in the presence of catalytic amount of silica gel supported boric tri-sulfuric anhydride (SiO2-BTSA) in excellent yields. 16 compounds were synthesized (I1-I16). Chemical structures of all compounds were confirmed by spectroscopic methods. We optimized the chemical reactions in the presence of different acidic catalysts, different solvents and also different temperatures. Catalytic amounts of SiO2-BTSA in dichloroethane (DCE) was the best conditions. Some of the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated by broth micro dilution method as recommended by CLSI. Some of the tested compounds show good in vitro biological properties.

scholarly journals Discovery of Actinomycetes from Extreme Environments with Potential to Produce Novel Antibiotics

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Lyudmila Trenozhnikova ◽  
Azliyati Azizan
Keyword(s):  
Antimicrobial Agents ◽  
Extreme Environments ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Culture Conditions ◽  
Drug Resistant ◽  
Great Opportunity ◽  
Pure Cultures ◽  
High Concentrations ◽  
Novel Antibiotics

Introduction: Antimicrobial-resistant pathogens pose serious challenges to healthcare institutions and health of the public. Thus, there is an urgent need for the discovery of new and effective antimicrobial agents.  Microorganisms that exist in extreme environments such as those with high salinity or alkalinity, are known as extremophiles, and include various species of actinomycetes. The goal of this study is to discover novel antibiotics from extremophiles found in Kazakhstan that are effective against drug resistant pathogens.Methods: Soil from extreme environments of Kazakhstan was collected, and pure cultures of actinomycetes were isolated and cultured in modified Bennett’s broth with either high concentrations of salt or high pH to mimic extreme environments. Extracts obtained from selected actinomycetes strains were used to test for antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger.Results: A total of 5936 strains of extremophile actinomycetes were isolated; from these, 2019 strains were further isolated into pure cultures. Of these, 415 actinomycetes strains that demonstrated antagonistic antibacterial activities were selected.  These actinomycetes were further classified into groups and subgroups based on their responses to different culture conditions. Antimicrobial antagonism activity for some of the actinomycetes strains was dependent on culture conditions and development of  aerial mycelia under extreme conditions.Conclusion: We identified several interesting candidate extracts with putative antimicrobial activities against several strains of drug resistant pathogens. Our research of the actinomycetes’ ability to produce antibiotics in the near-natural conditions provides a great opportunity to assess their biodiversity and distribution in the Central Asian region and to develop new methodological approaches to the screening of new antimicrobial agents.

Copper(II) mixed-ligand complexes containing 1, 10-phenanthroline, adenine and thymine: Synthesis, characterization and antibacterial activities

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Copper Complexes ◽  
Antimicrobial Agents ◽  
Conductivity Measurement ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
E Coli ◽  
In Vivo Cytotoxicity

New copper complexes, [Cu(phen)2(Thy)]2Cl and [Cu(phen)2(Ad)]2Cl (phen = 1,10-phenantroline, Ad (Adenine, a purine nucleobase) and Thy (Thymine, a pyrimidine nucleobase)), were synthesized and characterized by atomic absorption spectroscopy (AAS), conductivity measurement, UV-visible and infrared (IR) techniques. The complexes were tested for their antimicrobial activity against two gram positive and two gram negative bacterial strains. The results of in vitro antimicrobial activities were compared with the commercially available antimicrobial agents (ciprofloxacin and chloramphenicol). This comparative study has demonstrated that [Cu(phen)2(Thy)]2Cl inhibited the growth of methicillin resistant Staphylococcus aureous (MRSA), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) better than chloramphenicol by 11.25%, 19.41% and 25.35%, respectively. It also showed better activities than ciprofloxacine on MRSA and K. pneumoniae by 2.50% and 12.13%, respectively. Similarly, [Cu(phen)2(Ad)]2Cl demonstrated better inhibitions than chloramphenicol against MRSA, E. coli and K. pneumoniae by 11.24%, 2.48% and 9.06%, respectively. Therefore, after in vivo cytotoxicity investigations, these complexes could be considered as potential antimicrobial agents.

scholarly journals Review of Biosynthesis Silver Nanoparticles by Microbiology

2020 ◽  
Vol 1 (01) ◽  
pp. 7-11
Author(s):  
Dr. Hawraa Natiq Kabroot Al-Fatlawy ◽  
Khwla Abd Al Kadhem Rahi ◽  
Diaa Sarhan Abd Al Zahra ◽  
Samara Rahem Hudud ◽  
Hussein Ali Hussein ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Pathogenic Bacteria ◽  
Endophytic Bacterium ◽  
Antibacterial Activities ◽  
Salmonella Typhi ◽  
Biological Synthesis ◽  
Klebsiella Pneumonia ◽  
Ambient Conditions ◽  
Replication Process ◽  
Synthesis Of Nanoparticles

Nanotechnology is a multidisciplinary field that evolved within the past few decades and played a substantial role in the environment, industry, agriculture, and pharmacology. Nanoparticles are generally classified based on their dimensionality, morphology, composition, uniformity, and agglomeration. The shape, and morphology of nanoparticles play an essential role in their functionality and toxic effect on the environment and humans. In this review, we discuss the biosynthesis of nanoparticles from microbes. For the biological synthesis of nanoparticles, microbes have been exploited all over the globe. Microbes like bacteria, fungi, and yeasts are mostly preferred for nanoparticles (NPs) synthesis because of their fast growth rate, easy cultivation, and their ability to grow at ambient conditions of temperature, pH, and pressure. Applications of Nanoparticles is a field of research with tremendous prospects for the improvement of the diagnosis and treatment of human diseases. Microbial nanoparticles are found to have vigorous antibacterial activities. The nanoparticles' efficiency is probably due to their larger surface area for enhanced interaction with the micro-organisms. Nanoparticles adhere to the cell membrane and further penetrate inside by interacting with DNA, thereby interfering with the replication process or may attack the respiratory chain of pathogens. A similar bactericidal mechanism of silver nanoparticles obtained from endophytic bacterium Bacillus cereus was observed against pathogenic bacteria like Salmonella typhi, Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Pseudomonas aeruginosa.

Synthesis and Antimicrobial Activities of Novel Rutin Derivatives Carrying Quinoline Moiety

2020 ◽  
Vol 71 (6) ◽  
pp. 401-407
Author(s):  
Dan Lupascu ◽  
Lenuta Profire ◽  
Maria Apotrosoaei ◽  
Cristina Tuchilus ◽  
Ioana Mirela Vasincu ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
Research Directions ◽  
Good Antibacterial Activity ◽  
Vegetal Species

Antimicrobial resistance constitutes a topical subject and it is one of the major threats to public health. According to statistics, the incidence of multidrug-resistant microorganisms, such as bacteria, fungi and protozoa has increased in the last decades and it continues to spread. Therefore, the development of novel antimicrobial agents to combat drug-resistant infections is very important, among other research directions in this field. Quinoline ring is a very interesting structure for researchers because of its diverse biological properties (antimicrobial, anticancer, anticonvulsant, antiinflamatory and cardiovascular). On the other hand several studies showed good antibacterial activity (including anti-Pseudomonas effects) and antifungal properties of rutin or vegetal species with a high flavonoids (especially rutin) concentration. Based on the above considerations, eight novel rutin derivatives carrying 4- and 8-aminoquinoline moiety were designed, synthesized and characterized by FTIR, 1H NMR and elemental analysis. All compounds were evaluated for their in vitro antimicrobial activities against representative Gram-positive, Gram-negative and fungal pathogens. The results indicated that all rutin derivatives exhibited good antibacterial activities, similar to ciprofloxacin.

scholarly journals In Vitro Antibacterial Activity of Biological-Derived Silver Nanoparticles: Preliminary Data

2020 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Gabriele Meroni ◽  
Joel F. Soares Filipe ◽  
Piera A. Martino
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Curcuma Longa ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
E Coli ◽  
Transmission Electron ◽  
Disk Diffusion Assay ◽  
Biological Methods

Silver nanoparticles (AgNPs) are promising alternatives to antibiotics. The aims of this study were to produce AgNPs using two biological methods and determine their antibacterial activity against Pseudomonas aeruginosa and Staphylococcus pseudintermedius. AgNPs were biosynthesized from an infusion of Curcuma longa (turmeric) and the culture supernatant of E. coli. Characterization was achieved by ultraviolet-visible spectroscopy and by Transmission Electron Microscopy (TEM). The antibacterial properties of NPs from C. longa (ClAgNPs) and E. coli (EcAgNPs), alone and in combination with carbenicillin and ampicillin, were investigated through the Kirby-Bauer disk diffusion assay and the minimum inhibitory concentration (MIC). Dimensions of NPs ranged from 11.107 ± 2.705 nm (ClAgNPs) to 27.282 ± 2.68 nm (EcAgNPs). Kirby-Bauer and MIC assays showed great antibacterial abilities for both NPs alone and in combination with antibiotics. EcAgNPs alone showed the most powerful antibacterial activities, resulting in MIC values ranging from 0.438 ± 0.18 µM (P. aeruginosa) to 3.75 ± 3.65 µM (S. pseudintermedius) compared to those of ClAgNPs: 71.8 ± 0 µM (P. aeruginosa) and 143.7 ± 0 µM (S. pseudintermedius). The antibiofilm abilities were strain-dependent, but no statistical differences were found between the two NPs. These results suggest the antibacterial potential of AgNPs for the treatment of infectious diseases.

Synthesis of Novel 3(N,N-dialkylamino)alkyl/phenyl Substituted Thieno [2,3-d]pyrimidinones as H1-Anti-Histaminic and Antimicrobial Agents

2019 ◽  
Vol 15 (1) ◽  
pp. 63-70
Author(s):  
Shiv Dev Singh ◽  
Arvind Kumar ◽  
Firoz Babar ◽  
Neetu Sachan ◽  
Arun Kumar Sharma
Keyword(s):  
Antimicrobial Activity ◽  
Potassium Hydroxide ◽  
Antimicrobial Agents ◽  
Pyrimidine Ring ◽  
Antimicrobial Activities ◽  
Screening Methods ◽  
Chlorpheniramine Maleate ◽  
In Vivo Screening

Background: Thienopyrimidines are the bioisoster of quinazoline and unlike quinazoline exist in three isomeric forms corresponding to the three possible types annulation of thiophene to the pyrimidine ring viz thieno[2,3-d] pyrimidine, thieno[3,2-d] pyrimidine and thieno[3,4-d]pyrimidine. Heterocyclic containing the thienopyrimidinone moiety exhibits various pronounced activities such as anti-hypertensive, analgesic and anti-inflammatory, antiviral, platelet aggregation inhibitory, antiprotozoal bronchodilatory, phosphodiesterase inhibitory, antihistaminic, antipsychotic and antimicrobial activity. Objective: Synthesis of novel 3(N,N-dialkylamino)alkyl/phenyl substituted thieno[2,3-d]pyrimidinones as H1-anti-histaminic and antimicrobial agents. Methods: A series of 3-[(N,N-dialkylamino)alkyl/phenyl]-2-(1H)thioxo-5,6,7,8-tetrahydrobenzo(b) thieno(2,3-d)pyrimidine-4(3H)-ones[4a-d], their oxo analogous [5a-d] and 3-[(N,N-dialkylamino)alkyl]- 2-chlorophenyl-5,6,7,8-tetrahydrobenzo(b)thieno(2,3-d)pyrimidine- 4 (3H)-ones[6a-d]derivative were synthesized from 2-amino-4,5,6,7-tetrahydrobenzo(b)thiophene-3-carboxylic acid by nucleophilic substitution of different N,N-dialkyl alkylene/phenylene diamines on activated 3-acylchloride moiety followed by cyclocondensation with carbon disulfide and ethanolic potassium hydroxide to get [4a-d] and in second reaction by condensation with 4-chlorobenzoyl chloride to get [6a-d] by single pot novel innovative route. The oxo analogous [5a-d] were prepared by treating derivatives [4a-d] with potassium permagnate in ethanolic KOH. The synthesized compound were evaluated for H1-antihistaminic and antimicrobial activities. Results: All synthesized compounds exhibited significant H1-antihistaminic activity by in vitro and in vivo screening methods and data were verified analytically and statistically. The compound 4a, 4b, 5a and 5b showed significant H1-antihistaminiic activity than the reference standard chlorpheniramine maleate. The compound 6d, 6c, 5c and 4c exhibited significant antimicrobial activity.

scholarly journals Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2804-2837
Author(s):  
Chhangte Vanlalveni ◽  
Samuel Lallianrawna ◽  
Ayushi Biswas ◽  
Manickam Selvaraj ◽  
Bishwajit Changmai ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Plant Extracts ◽  
Antimicrobial Agents ◽  
Recent Literature ◽  
Antimicrobial Activities ◽  
New Findings ◽  
Potential Applications ◽  
Research Domain

Herein, we have reviewed new findings in the research domain of the green synthesis of silver nanoparticles using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015.

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