Antimicrobial properties of half-sandwich Ir(iii) cyclopentadienyl complexes with pyridylbenzimidazole ligands

2020 ◽  
Vol 49 (14) ◽  
pp. 4491-4501
Author(s):  
Ahmed M. Mansour ◽  
Krzysztof Radacki

Ethyl group determined the toxicity of pyridylbenzimidazole Ir(iii) compounds and exchange of the group with sulfonate led to diminishing of the antibacterial activity. Increasing the metal content per complex, 3, gave rise to a compound with no toxicity.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Lian-Hua Fu ◽  
Qing-Long Gao ◽  
Chao Qi ◽  
Ming-Guo Ma ◽  
Jun-Feng Li

Silver-based antimicrobial nanomaterials are considered as the most promising antibacterial agents owing to their outstanding antimicrobial efficacy and their relatively low toxicity to human beings. In this work, we report on a facile and environment-friendly microwave-hydrothermal method to prepare cellulose/Ag nanocomposites using hemicellulose as the reductant. The influences of the microwave-hydrothermal heating time and temperature, as well as the hemicellulose concentration on the formation of cellulose nanocomposites, were investigated in detail. Experimental results indicated that the hemicellulose was an effective reductant for silver ions, with higher temperature and longer heating time favoring the formation of silver with higher crystallinity and mass content in the nanocomposites. Moreover, the antimicrobial properties of the as-prepared cellulose/Ag nanocomposites were explored using Gram-positive S. aureus ATCC 6538 and Gram-negative E. coli HB 101 by both disc diffusion method and agar dilution method, and the nanocomposites showed excellent antibacterial activity. These results demonstrate that the as-prepared cellulose/Ag nanocomposites, as a kind of antibacterial material, are promising for applications in a wide range of biomedical fields.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mei X. Chen ◽  
Kenneth S. Alexander ◽  
Gabriella Baki

Background. Skin infections occur commonly and often present therapeutic challenges to practitioners due to the growing concerns regarding multidrug-resistant bacterial, viral, and fungal strains. The antimicrobial properties of zinc sulfate and copper sulfate are well known and have been investigated for many years. However, the synergistic activity between these two metal ions as antimicrobial ingredients has not been evaluated in topical formulations. Objective. The aims of the present study were to (1) formulate topical creams and gels containing zinc and copper alone or in combination and (2) evaluate the in vitro antibacterial activity of these metal ions in the formulations. Method. Formulation of the gels and creams was followed by evaluating their organoleptic characteristics, physicochemical properties, and in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus. Results. Zinc sulfate and copper sulfate had a strong synergistic antibacterial activity in the creams and gels. The minimum effective concentration was found to be 3 w/w% for both active ingredients against the two tested microorganisms. Conclusions. This study evaluated and confirmed the synergistic in vitro antibacterial effect of copper sulfate and zinc sulfate in a cream and two gels.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 980 ◽  
Author(s):  
Dorra Dridi ◽  
Aicha Bouaziz ◽  
Sondes Gargoubi ◽  
Abir Zouari ◽  
Fatma B’chir ◽  
...  

We report an analysis of chemical components of essential oils from barks of Ceylon cinnamon and cloves of Syzygium aromaticum and an investigation of their antibacterial activity. The components of oils were determined by using Gas Chromatography/Mass Spectrometry (GC-MS) analysis, and the antimicrobial activity was assessed by the disk diffusion test. The synergic effect of essential oils mixture (cinnamon oil and clove oil) was evaluated. Antimicrobial properties were conferred to cellulosic fibers through microencapsulation using citric acid as a green binding agent. Essential oil mixture was encapsulated by coacervation using chitosan as a wall material and sodium hydroxide as a hardening agent. The diameter of the produced microcapsules varies between 12 and 48 μm. Attachment of the produced microcapsules onto cotton fabrics surface was confirmed by Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FTIR) spectroscopy, optical microscopy and Scanning Electron Microscopy (SEM) analysis. The results show that microcapsules were successfully attached on cotton fabric surfaces, imparting antibacterial activity without significantly affecting their properties. The finished cotton fabrics exhibited good mechanical properties and wettability.


Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 951 ◽  
Author(s):  
Michał Abendrot ◽  
Lilianna Chęcińska ◽  
Joachim Kusz ◽  
Katarzyna Lisowska ◽  
Katarzyna Zawadzka ◽  
...  

The multifunctional profile of Zn2+ has influenced its great popularity in various pharmaceutical, food, and cosmetic products. Despite the use of different inorganic and organic zinc derivatives, the search for new zinc-containing compounds with a safer skin profile still remains an open issue. The present paper describes the synthesis, structural characterization, and antibacterial activity of zinc(II) complexes with proteinogenic amino acids as potential candidates for dermatological treatments. The obtained complexes are of the general formula [Zn(AA)2], where AA represents an amino acid (L-Glu, Gly, L-His, L-Pro, L-Met, and L-Trp). Their synthesis was designed in such a way that the final bis(aminoacidate) zinc(II) complexes did not contain any counter-ions such as Cl−, NO3−, or SO42− that can cause some skin irritations. The chemical structure and composition of the compounds were identified by 1H NMR spectroscopy and elemental analysis, and four were also characterized by single-crystal X-ray diffraction. The Hirshfeld surface analysis for the Zn2+ metallic center helped to determine its coordination number and geometry for each complex. Finally, the antibacterial properties of the complexes were determined with respect to three Gram-positive strains, viz. Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, and Streptococcus pyogenes ATCC 19615, and two Gram-negative bacteria, viz. Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 27853, and were compared with the activity of zinc 2-pirrolidone 5-carboxylate (ZnPCA), commonly applied in dermatology. It was found that the Zn(II) complexes with methionine and glycine exhibited a higher antibacterial activity than the tested standard, and the antimicrobial properties of complex with Trp were satisfactory. The results of the antimicrobial activity examination allow us to postulate that the obtained zinc complexes might become new active substances for use in dermatological products.


2017 ◽  
Vol 7 (1) ◽  
pp. 28-32
Author(s):  
Sheikh Al Mamun ◽  
Farahnaaz Feroz

Citrus fruits are very popular both for raw consumption as well as juices, jam and jelly. Besides the nutritional properties, citrus fruits exhibit some antimicrobial properties by containing polymethoxylated flavones, flavonoids, steroids, saponins, alkaloids, reducing sugars, terpenoids etc. But sometimes such fruits can be contaminated with bacteria which find their ways in the consumers causing different disease conditions. The current study revealed the microbial load of Lemon, Lotkone, Orange, Malta and Amoloki and the study showed complete absence of Klebsiella spp. and Escherichia coli. The highest total viable bacterial and fungal count was 4.2×104 cfu/g and 2.0×105 cfu/g respectively. Pseudomonas spp. was the highest predominating bacteria with lower degree of contamination by Listeria spp. and Staphylococcus spp. Applying heat at 60oC for 30 minutes, 1 hour and 2 hours proved the reduction of bacteria over time. Antibacterial activity after heat treatment for all cases (after 30 minutes, 1 hour and 2 hours). Antibacterial activity was lowest after 2 hours of heat treatment for amoloki and there was no such activity at all for Amra after 2 hours. Other citrus fruits surprisingly showed no antibacterial activity after heat treatment. Stamford Journal of Microbiology, Vol.7(1) 2017: 28-32


RSC Advances ◽  
2018 ◽  
Vol 8 (70) ◽  
pp. 40454-40463 ◽  
Author(s):  
Diamela María Rocca ◽  
Julie P. Vanegas ◽  
Kelsey Fournier ◽  
M. Cecilia Becerra ◽  
Juan C. Scaiano ◽  
...  

Natural derived compounds, lignins, can be used as reducing and stabilizing agents to synthesize noble metal nanoparticles with antimicrobial properties.


2005 ◽  
Vol 109 (32) ◽  
pp. 7073-7087 ◽  
Author(s):  
Andy Y. H. Lo ◽  
Thomas E. Bitterwolf ◽  
Charles L. B. Macdonald ◽  
Robert W. Schurko

Author(s):  
Cyril O. Ehi-Eromosele ◽  
J.A.O. Olugbuyiro ◽  
A. Edobor-Osoh ◽  
A.A. Adebisi ◽  
O.A. Bamgboye ◽  
...  

Coating of magnetic nanoparticles (MNPs) is usually a requirement prior to their utilization in biomedical applications. However, coating can influence the magneto-structural properties of MNPs thereby imparting their applications. The present work highlights the combustion synthesis of Na-doped lanthanum manganites (LNMO) and the influence of silica coatings on the magneto-structural properties, colloidal stability and antimicrobial properties of LNMO MNPs with their biomedical applications in mind. The crystalline perovskite structure was the same both for the bare and silica coated LNMO samples while there was a slight increase in crystallite size after coating. The FTIR spectral analysis, reduction in agglomeration of the particles and the elemental composition of the coated nanoparticles confirmed the presence of silica. The magnetization values of 34 emu/g and 29 emu/g recorded for bare and coated LNMO samples, respectively show that LNMO MNPs retained its ferromagnetic behaviour after silica coating. The pH dependent zeta potentials of the coated sample is-22.20 mV at pH 7.4 (physiological pH) and-18 mV at pH 5.0 (cell endosomal pH). Generally, silica coating reduced the antibacterial activity of the sample except forBacillussppwhere the antibacterial activity was the same with the bare sample. These results showed that while silica coating had marginal effect on the crystalline structure, size and magnetization of LNMO MNPs, it reduced the antibacterial activity of LNMO MNPs and enhanced greatly the colloidal stability of LNMO nanoparticles. Keywords: Na-doped lanthanum manganites, Silica coating, magnetic nanoparticles, biomedical applications, antimicrobial properties, colloidal stability


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