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101.
Mihaela Badea Ana-Maria Crasanda Mariana Carmen Chifiriuc Luminita Marutescu Veronica Lazar Dana Marinescu Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2013,111(3):1743-1751
New complexes [FeO(DMBG)]2 and [Fe(DMBG)2]Cl·0.5H2O (HDMBG: N,N-dimethylbiguanide) have been synthesized and characterized by microanalytical, IR and UV–Vis data. Electronic spectra of the complexes are characteristic for a tetrahedral stereochemistry, whilst the modifications in the IR spectra indicate the presence of the DMBG anion as chelate. The thermal decomposition investigated in air by thermal analysis confirmed the proposed formulas for the complexes and provided information concerning the modifications during heating and also the thermodynamic effects accompanying them. The thermal transformations are complex, according to TG and DTG curves including dehydration, hydrochloric acid elimination, oxidative degradation and condensation of –C=N– unit. The final product of decomposition was iron (III) oxide as powder XRD indicates. Complexes were screened for their antimicrobial properties against Gram-positive, Gram-negative bacterial, as well as fungal pathogenic strains. The results indicate that Fe(III) complexes exhibit an improved antibacterial activity against S. aureus and E. coli strains in comparison with free biguanide. The Fe(III) complexes also inhibit the ability of S. aureus, B. subtilis, P. aeruginosa and E. coli strains to colonize the inert substratum, accounting for their possible use as anti-biofilm agents. 相似文献
102.
Ana-Maria Ungureanu Ovidiu Oprea Bogdan Stefan Vasile Corina Andronescu Georgeta Voicu Ioana Jitaru 《Central European Journal of Chemistry》2014,12(9):909-917
We successfully synthesized tin dioxide nanoparticles with polyhedral morphology via an ethylene glycol assisted sol-gel approach. The structural characteristics of three tin dioxide samples were investigated after being thermally treated at 400°C, 600°C and 800°C. X-ray diffraction (XRD) patterns clearly show the formation of single phase tin dioxide nanoparticles, with crystallite size of 6–20 nm, in good correlation with Fourier transform infrared (FTIR) spectra. Transmission electron microscopy (TEM) analysis confirms the formation of 6nm polyhedral nanoparticles for the 400°C sample. Ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectra suggest a high concentration of oxygen vacancies. The oxygen vacancy concentration increases with temperature, due to the combined action of the formation of VO and the energetic O compensation. X-ray photoelectron spectroscopy (XPS) analysis also confirms the formation of single phase tin dioxide and the presence of oxygen vacancies in good agreement with UV-VIS and PL data. 相似文献
103.
Florea Dumitrascu Ana-Maria Udrea Mino R. Caira Diana Camelia Nuta Carmen Limban Mariana Carmen Chifiriuc Marcela Popa Coralia Bleotu Anamaria Hanganu Denisa Dumitrescu Speranta Avram 《Molecules (Basel, Switzerland)》2022,27(9)
The efficient regioselective bromination and iodination of the nonsteroidal anti-inflammatory drug (NSAID) carprofen were achieved by using bromine and iodine monochloride in glacial acetic acid. The novel halogenated carprofen derivatives were functionalized at the carboxylic group by esterification. The regioselectivity of the halogenation reaction was evidenced by NMR spectroscopy and confirmed by X-ray analysis. The compounds were screened for their in vitro antibacterial activity against planktonic cells and also for their anti-biofilm effect, using Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and Gram-negative bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853). The cytotoxic activity of the novel compounds was tested against HeLa cells. The pharmacokinetic and pharmacodynamic profiles of carprofen derivatives, as well as their toxicity, were established by in silico analyses. 相似文献
104.
Mirila Diana-Carmen Raducanu Dumitra Georgescu Ana-Maria Rosu Ana-Maria Ciubotariu Vlad Andrei Zichil Valentin Nistor Ileana-Denisa 《Molecules (Basel, Switzerland)》2022,27(18)
A facile, ecofriendly, and cost-effective method was developed to prepare a microporous material based on natural chemically modified bentonite with silver ions (BN-Ag0). This material presents a good catalytic activity against Malachite Green (MG) dye and bacteriostatic activity against a newly isolated bacterium from sewage sludge named hereafter “ISO SS” and Escherichia coli (E. coli). BN-Ag0 was characterized by the following methods: energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, temperature programmed desorption (TPD) and X-ray Diffraction (XRD). The new bacterium ISO SS, was isolated using the technique of isolating a pure culture of anaerobically stabilized sludge. A mandatory characterization of ISO SS isolated strains from anaerobic stabilized sludge was performed in the process of identifying bacterial species. The cationic clay-based nanomaterial showed appreciable antibacterial activity against ISO SS, a Gram-negative bacterium. It also showed good activity against E. coli bacteria. As a catalyst in the catalytic ozonation of MG dye, BN-Ag0 significantly improves the oxidation time of the dye, due to its good adsorption and catalytic properties. The catalytic and antibacterial activities of the natural bentonite (BN) and of BN-Ag0 were examined using performant characterization techniques. The lifetime of the BN-Ag0 catalyst was also evaluated. Results obtained are expected to provide valuable findings for the preparation of a good microporous material with multiple functionalities. 相似文献