Santiago del Estero, Argentina
Santiago del Estero, Argentina

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Santi E.,Quimica Inorganica | Facchin G.,Quimica Inorganica | Faccio R.,Fisica | Barroso R.P.,University of Sao Paulo | And 3 more authors.
Journal of Inorganic Biochemistry | Year: 2016

Xylitol (xylH5) is metabolized via the pentose pathway in humans, but it is unsuitable as an energy source for many microorganisms where it produces a xylitol-induced growth inhibition and disturbance in protein synthesis. For this reason, xylitol is used in the prophylaxis of several infections. In the search of better antimicrobial agents, new copper and zinc complexes with xylitol were synthesized and characterized by analytical and spectroscopic methods: Na2[Cu3(xylH-4)2]·NaCl·4.5H2O (Cu-xyl) and [Zn4(xylH-4)2(H2O)2]·NaCl·3H2O (Zn-xyl). Both copper and zinc complexes presented higher MIC against Pseudomona aeruginosa than the free xylitol while two different behaviors were found against Candida albicans depending on the complex. The growth curves showed that Cu-xyl presented lower activity than the free ligand during all the studied period. In the case of Zn-xyl the growth curves showed that the inhibition of the microorganism growth in the first stage was equivalent to that of xylitol but in the second stage (after 18 h) Zn-xyl inhibited more. Besides, the PAE (post agent effect) obtained for Zn-xyl and xyl showed that the recovery from the damage of microbial cells had a delay of 14 and 13 h respectively. This behavior could be useful in prophylaxis treatments for infectious diseases where it is important that the antimicrobial effect lasts longer. With the aim to understand the microbiological activities the analysis of the particle size, lipophilicity and Zn uptake was performed. © 2015 Elsevier Inc.

Liprandi D.A.,Quimica Inorganica | Cagnola E.A.,Quimica Inorganica | Paredes J.F.,Quimica Inorganica | Badano J.M.,CONICET | And 2 more authors.
Catalysis Letters | Year: 2012

The (Z)/(E) ratio was analyzed for the 3-hexyne semi-hydrogenation at 275, 290 and 303 K. [RhCl(NH 2(CH 2) 12CH 3) 3] pure and supported on a carbonaceous material were used as catalysts. The supported complex showed high values of conversion and selectivity, and its behaviour was much better than the Lindlar catalyst used as a reference. Graphical abstract: Conversion to (Z)-3-hexene versus 3-hexyne total conversion as a function of temperature for: (1) Lindlar catalyst, (2) homogeneous complex and (3) anchored complex on RX3.[Figure not available: see fulltext.] © 2011 Springer Science+Business Media, LLC.

Gonzalez-Baro A.C.,National University of La Plata | Pis-Diez R.,National University of La Plata | Franca C.A.,National University of La Plata | Torre M.H.,Quimica Inorganica | Parajon-Costa B.S.,National University of La Plata
Polyhedron | Year: 2010

The mononuclear Cu(II) complex, [Cu(o-Va)2(H2O)2] (o-HVa = o-vanillin, 2-hydroxy-3-methoxybenzaldehyde) has been synthesized and characterized by elemental analyses, FTIR, FT-Raman, and electronic spectroscopies and compared with the results obtained for the free ligand. The optimized geometry, the harmonic vibrational frequencies and the electronic transitions of the complex and the ligand were calculated using methods based on the density functional theory. Antimicrobial activity against Escherichia coli and Staphylococcus aureus and SOD-mimic activities of the complex were studied and compared with the analogous copper complex with vanillin, [Cu(Va)2(H2O)2]. Stability of the compounds in the essayed solution and with time was determined by means of conductimetric measurements. Their redox behavior was studied by cyclic voltammetry and was compared with that observed for the ligands. The complexes undergo two main reductions and one oxidation processes involving the metal center and the coordinated ligand, respectively. © 2009 Elsevier Ltd. All rights reserved.

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