scholarly journals NonToxic Silver/Poly-1-Vinyl-1,2,4-Triazole Nanocomposite Materials with Antibacterial Activity

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1477 ◽  
Author(s):  
Irina A. Shurygina ◽  
Galina F. Prozorova ◽  
Irina S. Trukhan ◽  
Svetlana A. Korzhova ◽  
Tatiana V. Fadeeva ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Antimicrobial Properties ◽  
Fibroblast Cell ◽  
Nanocomposite Materials ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Fibroblast Cell Culture

Novel silver/poly-1-vinyl-1,2,4-triazole nanocomposite materials—possessing antimicrobial activity against Gram-positive and Gram-negative bacteria—have been synthesized and characterized in the solid state and aqueous solution by complex of modern physical-chemical and biologic methods. TEM-monitoring has revealed the main stages of microbial cell (E. coli) destruction by novel nanocomposite. The concept of direct polarized destruction of microbes by nanosilver proposed by the authors allows the relationship between physicochemical and antimicrobial properties of novel nanocomposites. At the same time, it was shown that the nanocomposite was nontoxic to the fibroblast cell culture. Thus, the synthesized nanocomposite combining antibacterial activity against Gram-positive and Gram-negative bacteria as well as the absence of toxic effects on mammalian cells is a promising material for the development of catheters, coatings for medical devices.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

scholarly journals Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

2019 ◽  
Vol 18 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
Rehan Khan ◽  
Melis Özkan ◽  
Aisan Khaligh ◽  
Dönüs Tuncel
Keyword(s):  
Antibacterial Activity ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Water Dispersible ◽  
Gram Positive Bacteria ◽  
High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

scholarly journals Synthesis and Antibacterial Activity of Chalcones and Pyrimidine-2-ones

2005 ◽  
Vol 2 (2) ◽  
pp. 109-112
Author(s):  
A. K. Parekh ◽  
K. K. Desai
Keyword(s):  
Antibacterial Activity ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Aromatic Aldehydes ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
H Nmr

Some new chalcones have been prepared by Claisen-schmidt condensation of ketone and different aromatic aldehydes. These chalcones on condensation with urea in presence of acid gave Pyrimidine-2-ones. The synthesized compounds have been characterized by elemental analysis, IR and1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B. subtillis & S. aureus and Gram negative bacteria E. coli & S. typhi.

scholarly journals Antibacterial Activityof Aqueous And Ethanolic Leaf Extracts Of Vernonia Amygdalina On Selected Species Of Gram Positive And Gram Negative Bacteria

2013 ◽  
Vol 2 (1) ◽  
pp. 147-152 ◽  
Author(s):  
AM Bukar ◽  
MA Isa ◽  
HS Bello ◽  
AS Abdullahi
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Drug ◽  
Gram Negative Bacteria ◽  
Phytochemical Screening ◽  
Vernonia Amygdalina ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Pseudomonas Species

The phytochemical screening and antibacterial activity of ethanolic and Methanolic leaves extract of Vernonia amygdalina against five clinical isolates (Staphylococcus aureus, E. coli, Pseudomonas species, Salmonella species and Proteus species) was determined using standard method of analysis. The results of the antibacterial activity of ethanol, methanol and aqueous extract of leaves of V. amygdalina have diameters ranging between 0.4 to 10mm. The plant extracts from the plants had profound activities against gram-positive than gram negative bacteria. From the above studies, it has clearly indicated that V. amygdalina extract may represent new sources of antibacterial drug, if the phytoactive components are purified and proper dosage are determined for administration. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 147-152 DOI: http://dx.doi.org/10.3126/ije.v2i1.9217

Study on the Antimicrobial Properties of ZnO Suspension against Gram-Positive and Gram-Negative Bacteria Strains

2011 ◽  
Vol 393-395 ◽  
pp. 1488-1491 ◽  
Author(s):  
Ling Ling Zhang ◽  
Bo Chen ◽  
Lan Lan Xie ◽  
Zi Fu Li
Keyword(s):  
Antimicrobial Properties ◽  
Growth Curves ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Ph Values ◽  
Killing Action ◽  
Number Of Bacteria

Because of the excellent properties and wide applications on nanomaterials, recent years, researchers start to focus on the use of nanomaterials in wastewater treatment. This paper investigated the antimicrobial activities of ZnO against Gram-positive and Gram-negative bacteria strains – E. coli and Sarcinic pseudomycosis. Growth curves of bacteria strains were used to estimate the antimicrobial activities of ZnO suspensions. This work showed pH values of ZnO suspension did not affect the antimicrobial activities of ZnO. Besides, when treating small number of bacteria slurry, ZnO expressed the killing action. Based on this work, the possible antimicrobial mechanism is also discussed in this paper.

scholarly journals Identification of Ly2 members as antimicrobial peptides from zebrafish Danio rerio

2017 ◽  
Vol 37 (1) ◽  
Author(s):  
Xuemin Liu ◽  
Xuwen Cao ◽  
Su Wang ◽  
Guangdong Ji ◽  
Shicui Zhang ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Recombinant Proteins ◽  
Mammalian Cells ◽  
Multidrug Resistant ◽  
Scatchard Analysis ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1–3 (a novel lymphocyte antigen 6 (Ly6) gene cluster) were proteins with cationic nature and rich in cysteine content, that are characteristic of antimicrobial peptides (AMPs) and their expression were all significantly up-regulated after challenge with lipopolysaccharide (LPS). These strongly suggested that Ly2.1–3 are potential AMPs, but firm evidence are lacking. Here, we clearly showed that the recombinant proteins of Ly2.1–3 were capable of killing Gram-negative bacteria Aeromonas hydrophila and Escherichia coli, while they had little bactericidal activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. We also showed that recombinant proteins Ly2.1–3 (rLy2.1–3) were able to bind to the Gram-negative bacteria A. hydrophila, E. coli and the microbial signature molecule LPS, but not to the Gram-positive bacteria S. aureus and B. subtilis as well as the microbial signature molecule LTA. Moreover, the Scatchard analysis revealed that rLy2.1–3 could specifically bind to LPS. Finally, we found that Ly2.1–3 were not cytotoxic to mammalian cells. All these together indicate that Ly2.1–3 can function as AMPs.

scholarly journals Antibacterial Activity of Borassus flabellifer Vinegar-Graphene Quantum Dots Against Gram-Positive and Gram-Negative Bacteria

2021 ◽  
Vol 33 (11) ◽  
pp. 2662-2666
Author(s):  
Amnuay Noypha ◽  
Paweena Porrawatkul ◽  
Nongyao Teppaya ◽  
Parintip Rattanaburi ◽  
Saksit Chanthai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Antibacterial Activity ◽  
Graphene Quantum Dots ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Borassus flabellifer vinegar–graphene quantum dots (BFV-GQDs) were successfully synthesized using a pyrolysis method with Borassus flabellifer vinegar (BFV) as the precursor. All the samples were characterized using ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activities of BFV-GQDs against strains of Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were determined using the agar well diffusion method for preliminary screening, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the broth macro-dilution method. The zones of inhibition were compared with those of citric acid–graphene quantum dots (CA-GQDs). It was observed that the synthesized BFV-GQDs demonstrated excellent antibacterial activity against Staphylococcus aureus (82.3%) and good antibacterial activity against Escherichia coli (73.3%). The MIC of BFV-GQDs against E. coli was 6.25 mg/mL and S. aureus was 12.5 mg/mL, whereas the MBC of BFV-GQDs against E. coli was 12.5 mg/mL and S. aureus was 25.0 mg/mL.

C-Terminal Modifications Broaden Activity of the Proline-Rich Antimicrobial Peptide, Chex1-Arg20

2015 ◽  
Vol 68 (9) ◽  
pp. 1373 ◽  
Author(s):  
Wenyi Li ◽  
Julien Tailhades ◽  
M. Akhter Hossain ◽  
Neil M. O'Brien-Simpson ◽  
Eric C. Reynolds ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Peptide ◽  
Peptide Synthesis ◽  
Mammalian Cells ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Chemical Strategies

A series of N- and C-terminal modifications of the monomeric proline-rich antimicrobial peptide, Chex1-Arg20, was obtained via different chemical strategies using Fmoc/tBu solid-phase peptide synthesis in order to study their effects on a panel of Gram-negative bacteria. In particular, C-terminal modifications with hydrazide or alcohol functions extended their antibacterial activity from E. coli and K. pneumoniae to other Gram-negative species, A. baumannii and P. aeruginosa. Furthermore, these analogues did not show cytotoxicity towards mammalian cells. Hence, such modifications may aid in the development of more potent proline-rich antimicrobial peptides with a greater spectrum of activity against Gram-negative bacteria than the parent peptide.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

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