scholarly journals Facile Synthesis of Silver Nanoparticles with High Antibacterial Activity

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2498 ◽  
Author(s):  
Anni Feng ◽  
Jiankang Cao ◽  
Junying Wei ◽  
Feng Chang ◽  
Yang Yang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Molar Ratio ◽  
Facile Synthesis ◽  
Gram Negative ◽  
Morphology Transition ◽  
Gram Positive Bacteria ◽  
High Antibacterial Activity ◽  
Reverse Microemulsion Method

We report on a reverse microemulsion method for the synthesis of silver nanocrystals and examine their antibacterial activities. As the molar ratio of water to sodium bis(2-ethylhexyl) sulfosuccinate (AOT) increases to 25, a morphology transition from a sphere-like nanocrystal to a wire-like one was observed. For both the gram-negative and gram-positive bacteria, the wire-like silver nanocrystal showed higher antibacterial activities. We conclude that the morphology of silver nanocrystals dominates their antibacterial activity.

Facile synthesis of silver nanoparticles deposited on a calcium silicate hydrate composite as an efficient bactericidal agent

RSC Advances ◽  
2016 ◽  
Vol 6 (114) ◽  
pp. 112931-112938 ◽  
Author(s):  
Wei Jiao
Keyword(s):  
Silver Nanoparticles ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Antibacterial Activities ◽  
Facile Synthesis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bactericidal Agent

Silver nanoparticles deposited calcium silicate hydrate composite was synthesized and demonstrated high antibacterial activities against Gram-negative and Gram-positive bacteria.

scholarly journals Antibacterial Activities of Xanthium Strumarium L.

2018 ◽  
Vol 29 ◽  
pp. 70-77 ◽  
Author(s):  
Anjana Devkota ◽  
Ritu Kumari Das
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Xanthium Strumarium ◽  
Distilled Water ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Antibacterial activities of Xanthium strumarium L. (Asteraceae) was carried out in laboratory. Distilled water and methanol extracts of the leaves of plant was prepared. The antibacterial activity was studied against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) at different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ ml, 250 mg/ml) of leaf extracts of X. strumurium. The phytochemical screening depicted the presence of terpenoids, saponins, flavonoids, tannins and alkaloids. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacterium was S. aureus while the most resistant bacterium was E. coli. Methanolic extract was found more effective than distilled water. These findings suggest that extracts obtained from leaves of X. strumurium possess biobactericidal potential, which can suitably be exploited for making antibacterial drugs.J. Nat. Hist. Mus. Vol. 29, 2015, Page: 70-77

scholarly journals 5-Bromo-1-(4-chlorobenzyl)-1H-indole-2-carboxamides as new potent antibacterial agents

2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Internal Standards ◽  
Gram Negative ◽  
E Coli ◽  
High Antibacterial Activity

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.

The Effects of Natural Dopant Acids on Morphologies and Antibacterial Activity of Polyaniline

2013 ◽  
Vol 650 ◽  
pp. 249-252 ◽  
Author(s):  
Jia Li Mu ◽  
Wen Jun Fan ◽  
Shao Yun Shan ◽  
Ting Wei Hu ◽  
Ya Ming Wang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Salicylic Acid ◽  
Citric Acid ◽  
Rosin Acid ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacillus Coli

Polyaniline(PANI) doped by natural acid(citric acid, salicylic acid or rosin acid)solutions was synthesized using aniline as monomer and ammonium peroxydisulfate ((NH4)2S2O8) as oxidant. The antibacterial activities of the PANI against Gram positive bacteria(Bacillus megatherium, Bacillus subtilis, Bacillus cereus and Staphylo-coccus aureus) and Gram negative bacteria(Bacillus coli) were investigated. It was shown that PANI doped by citric acid possessed the better antibacterial activity against the selected species of Gram positive bacteria and Gram negative bacteria than PANI doped by rosin acid. PANI doped by salicylic acid exhibited ascendant antibacterial activities against Gram positive bacteria, but it has little antibacterial activity against the Gram negative bacteria.

Application of Acacia modesta and Dalbergia sissoo gums as green matrix for silver nanoparticle binding

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Hira Munir ◽  
Muhammad Shahid ◽  
Fozia Anjum ◽  
Muhammad Nadeem Akhtar ◽  
Sayed M. Badawy ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Low Cost ◽  
Dalbergia Sissoo ◽  
Visible Spectroscopy ◽  
Green Matrix ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Uv Visible ◽  
Cost Efficient

AbstractA low-cost, efficient, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using gums as reducing agent was performed. The obtained nanoparticles were characterized by UV-visible spectroscopy. The antibacterial activity of the prepared nanoparticles was tested against Gram-negative and Gram-positive bacteria. The

scholarly journals Bactericidal Effect and Anti-Inflammatory Activity of Cassia garettiana Heartwood Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Sumalee Panthong ◽  
Arunporn Itharat ◽  
Suchada Naknarin ◽  
Pranporn Kuropakornpong ◽  
Buncha Ooraikul ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Chemical Constituents ◽  
Ethanolic Extract ◽  
Antibacterial Activities ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Inhibiting Effect ◽  
Anti Inflammatory ◽  
Time Kill

Natural products are used as alternative drugs in traditional medicine to treat infection and inflammation and relieve pain. Heartwood of Cassia garettiana Craib has been investigated as an ingredient in Thai traditional medicine for anti-HIV protease, but there is no report on its antibacterial and anti-inflammatory activities. The objectives of this study were to investigate the anti-inflammatory and antibacterial activities, time-kill profile, and main active constituents of an ethanolic extract of C. garettiana heartwood. The study followed the generally accepted experimental design. All tests were investigated in triplicate. The heartwood of C. garettiana was extracted by maceration with 95% EtOH. The antibacterial activity of the extract and its chemical constituents were determined by their MIC values using resazurin as an indicator. Time-kill profile was determined at 0, 2, 4, 6, 8, 10, 12, and 24 hrs and expressed as log CFU/mL. The anti-inflammatory activity of the extract and its chemical components was investigated by their inhibiting effect on IL-6 and TNF-α production by ELISA. The ethanolic extract was analyzed for its chemical constituents by HPLC technique. The ethanolic extract showed both dose- and time-dependent bactericidal effects against Staphylococcus aureus, methicillin-resistance Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhi, Salmonella Typhimurium, Klebsiella pneumoniae, and Shigella dysenteriae with MIC values of 312.5, 312.5, 312.5, 1,250, 2,500, 625, 625, 2,500, and 625 μg/mL, respectively. It showed an inhibiting effect on IL-6 production at concentrations of 12.5 to 100 μg/mL. The main active chemical constituent of C. garettiana was piceatannol that showed antibacterial activity against all test bacteria except P. aeruginosa. C. garettiana showed a broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria. Piceatannol and resveratrol from the plant strongly inhibited IL-6 production. Based on these results, we concluded that the ethanolic extract of C. garettiana showed both an antibacterial activity and inhibition of IL-6. Piceatannol is the active constituent of the extract and showed anti-inflammatory and antibacterial activities against Gram-negative and Gram-positive bacteria.

scholarly journals SINTESIS NANOPARTIKEL KOBALT FERRIT (CoFe2O4) MENGGUNAKAN EKSTRAK DAUN BINAHONG (Anredera cordifolia (Ten) Steenis) DAN APLIKASINYA SEBAGAI ANTIBAKTERI

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Charissa L. Luntungan ◽  
Henry F. Aritonang ◽  
Vanda S. Kamu
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Clear Zone ◽  
Cofe2o4 Nanoparticles ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

ABSTRAKTelah dilakukan penelitian mengenai sintesis nanopartikel CoFe2O4 menggunakan ekstrak daun binahong (Anredera cordifolia (Ten) Steenis). dengan variasi perbandingan mol (Co(NO3)2.6H2O) : (Fe(NO3)3.9H2O) = 1:1 dalam 15 mL. Nanopartikel tersebut dikarakterisasi menggunakan XRD dan SEM serta diuji aktivitas antibakterinya. Uji aktivitas antibakteri mengunakan bakteri Staphylococcus aureus (gram-positif) dan Escherichia coli (gram-negatif). Hasil penelitian menunjukan bahwa ukuran nanopartikelnya adalah 37,52 nm. Kemudian aktivitas antibakteri diketahui berdasarkan luasnya zona bening yang terbentuk dengan hasil diperoleh sebesar 15 mm untuk bakteri E.coli dan 20 mm untuk bakteri S.aureus. Daun Binahong sendiri memiliki sifat sebagai antibakteri dengan hasil yang didapat adalah 8,25 mm untuk bakteri E.coli  dan 10,25 mm untuk bakteri S.aureus. Hal ini menunjukan bahwa nanopartikel CoFe2O4 1 : 1 dalam 15 mL ekstrak dapat digunakan sebagai antibakteriABSTRACTIt has been done research on the synthesis of CoFe2O4 nanoparticles using binahong (Anredera cordifolia (Ten) Steenis) leaf extract. With comparison mol variation of (Co(NO3)2.6H2O) : (Fe(NO3)3.9H2O) = 1:1 in 15 mL extract. The nanoparticles were characterized using XRD and SEM and tested for their antibacterial activities. Test antibacterial activity using Staphylococcus aureus (gram-positive) bacteria and Escherichia coli (gram-negative). The results showed that the nanoparticle size was 37.52 nm. Antibacterial activity is known by the extent of the clear zone formed with the results obtained by 15 mm for the E. coli bacteria and 20 mm for the bacteria S. aureus. The leaf Binahong itself has a trait as an antibacterial with the results obtained is 8.25 mm for the bacteria E. coli and 10.25 mm for the S.aureus bacteria. This suggests that the CoFe2O4 nanoparticles 1:1 mol in 15 mL extrack are used as antibacterial. 

scholarly journals Antibacterial activity of grapefruit peel extracts and green-synthesized silver nanoparticles

2021 ◽  
pp. 1330-1341
Author(s):  
Mbarga M. J. Arsène ◽  
I. V. Podoprigora ◽  
Anyutoulou K. L. Davares ◽  
Marouf Razan ◽  
M. S. Das ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Grapefruit Peel ◽  
Green Synthesized Silver Nanoparticles

Background and Aim: The gradual loss of efficacy of conventional antibiotics is a global issue. Plant material extracts and green-synthesized nanoparticles are among the most promising options to address this problem. Therefore, the aim of this study was to assess the antibacterial properties of aqueous and hydroalcoholic extracts of grapefruit peels as well as their inclusion in green-synthesized silver nanoparticles (AgNPs). Materials and Methods: Aqueous and hydroalcoholic extracts (80% v/v) were prepared, and the volume and mass yields were determined. The synthesis of AgNPs was done in an eco-friendly manner using AgNO3 as a precursor. The nanoparticles were characterized by ultraviolet–vis spectrometry and photon cross-correlation spectroscopy. The antibacterial activity of the extracts was tested on three Gram-positive bacteria (Staphylococcus aureus ATCC 6538, clinical Enterococcus faecalis, and S. aureus) and two Gram-negative bacteria (two clinical Escherichia coli) using various concentrations of extracts (100, 50, 25, 12, and 5 mg/mL and 5% dimethyl sulfoxide as negative control). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the microdilution method. Modulation of cefazoline and ampicillin on resistant E. coli and S. aureus strains was added to the mixture design response surface methodology with extreme vertices design, with the diameters of inhibition and the fractional inhibitory concentration index as responses and factors, respectively. The antibiotic, the ethanolic extract, and water varied from 0.1 MIC to 0.9 MIC for the first two and from 0 to 0.8 in proportion for the third. Validating the models was done by calculating the absolute average deviation, bias factor, and accuracy factor. Results: The volume yield of the EE and aqueous extract (AE) was 96.2% and 93.8% (v/v), respectively, whereas their mass yields were 7.84% and 9.41% (m/m), respectively. The synthesized AgNPs were very uniform and homogeneous, and their size was dependent on the concentration of AgNO3. The antibacterial activity of the two extracts was dose-dependent, and the largest inhibition diameter was observed for the Gram-positive bacteria (S. aureus ATCC 6538; AE, 12; EE, 16), whereas AgNPs had a greater effect on Gram-negative bacteria. The MICs (mg/mL) of the AEs varied from 3.125 (S. aureus ATCC 6538) to 12.5 (E. coli 1 and E. coli 2), whereas the MICs of the EEs varied from 1.5625 (S. aureus 1, S. aureus ATCC 6538, and E. faecalis) to 6.25 (E. coli 1). There was a significant difference between the MICs of AEs and EEs (p=0.014). The MBCs (mg/mL) of the AEs varied from 12.5 (S. aureus ATCC 6538) to 50 (S. aureus 1), whereas those of the EEs varied from 6.25 (S. aureus 1) to 25 (E. coli 1 and E. faecalis). Ethanolic grapefruit extracts demonstrated an ability to modulate cefazolin on E. coli and S. aureus but were completely indifferent to ampicillin on E. coli. Conclusion: Grapefruit peel extracts and their AgNPs exhibit antibacterial properties that can be exploited for the synthesis of new antimicrobials and their EEs may be efficiently used synergistically with other antibiotics against bacteria with intermediate susceptibility.

scholarly journals Enhancement of Antibacterial Activity of Capped Silver Nanoparticles in Combination with Antibiotics, on Model Gram-Negative and Gram-Positive Bacteria

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Aruna Jyothi Kora ◽  
Lori Rastogi
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Sodium Dodecyl ◽  
Average Particle ◽  
Gram Positive ◽  
Yellow Colour ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Xrd Patterns ◽  
Diffusion Assay

The nanoparticles used in this study were prepared from AgNO3using NaBH4in the presence of capping agents such as citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone. The formed nanoparticles were characterized with UV-Vis, TEM, and XRD. The generation of silver nanoparticles was confirmed from the appearance of yellow colour and an absorption maximum between 399 and 404 nm. The produced nanoparticles were found to be spherical in shape and polydisperse. For citrate, SDS, and PVP capped nanoparticles, the average particle sizes were38.3±13.5,19.3±6.0, and16.0±4.8 nm, respectively. The crystallinity of the nanoparticles in FCC structure is confirmed from the SAED and XRD patterns. Also, the combined antibacterial activity of these differently capped nanoparticles with selected antibiotics (streptomycin, ampicillin, and tetracycline) was evaluated on model Gram-negative and Gram-positive bacteria, employing disc diffusion assay. The activity of the tested antibiotics was enhanced in combination with all the stabilized nanoparticles, against both the Gram classes of bacteria. The combined effects of silver nanoparticles and antibiotics were more prominent with PVP capped nanoparticles as compared to citrate and SDS capped ones. The results of this study demonstrate potential therapeutic applications of silver nanoparticles in combination with antibiotics.

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