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Araraquara, Brazil

Bormio Nunes J.H.,University of Campinas | De Paiva R.E.F.,University of Campinas | Cuin A.,Federal University of Juiz de fora | Lustri W.R.,UNIARA | Corbi P.P.,University of Campinas
Polyhedron | Year: 2015

The present work describes the synthesis and spectroscopic characterization of two silver(I) complexes with the sulfonamides sulfathiazole (AgC9H8N3O2S2, Ag-SFT) and sulfamethoxazole (AgC10H10N3O3S, Ag-SFM). Elemental analyses indicate a 1:1 metal/ligand composition for both complexes. Spectroscopic techniques such as 1H, 15N NMR and IR evidence the coordination of both ligands to silver through the nitrogen atom of the sulfonamide group, and also indicate the participation of the 5-membered N-heterocyclic ring in the coordination. The Ag-SFT crystal structure was solved by X-ray powder diffraction and indicates the formation of a dimeric structure with silver bridging between two ligand molecules. Biological studies showed the antibacterial activity of Ag-SFT and Ag-SFM complexes against Gram-positive and Gram-negative bacterial strains, with MIC values ranging from 3.45 to 6.90 mmol L-1 for the sulfathiazole complex and 1.74 to 13.9 mmol L-1 for the sulfamethoxazole complex. The complexes have shown to be more active against Gram-negative bacterial strains. © 2014 Elsevier Ltd. All rights reserved. Source


Nakahata D.H.,University of Campinas | Lustri W.R.,UNIARA | Cuin A.,Federal University of Juiz de fora | Corbi P.P.,University of Campinas
Journal of Molecular Structure | Year: 2016

A silver complex with the sulfonamide sulfameter, also known as sulfamethoxydiazine (SMTR), was prepared and characterized. Chemical analyses were consistent with the [Ag(C11H11N4O3S)] composition (AgSMTR), while conductivity measurements in DMSO indicated a non-electrolyte behavior of the complex in this solvent. High-resolution ESI(+)-QTOF mass spectrometric experiments revealed the presence of the [Ag(C11H11N4O3S)+H]+ and [Ag2(C11H11N4O3S)2+H]+ species in solution. Infrared and NMR spectroscopies indicated coordination of the ligand to the metal by the nitrogen atoms of the sulfonamide group and of the pyrimidine ring. The structure of AgSMTR was solved by powder X-ray diffraction technique using the Rietveld method. The solved structure confirms the formation of a dimer, where each silver ion is coordinated by one of the nitrogen atoms of the pyrimidine ring, the nitrogen of the sulfonamide group and by an oxygen atom from the sulfonyl group. An argentophilic interaction of 2.901(1) Å is present in this dimeric structure. The AgSMTR complex was assayed over Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains, and it was found that the compound is 8 times more active over the Gram-negative bacteria in DMSO solution, with MIC values in the micromolar range. © 2016 Elsevier B.V. Source


Costa G.S.M.,Federal University of Juiz de fora | Corbi P.P.,University of Campinas | Abbehausen C.,University of Campinas | Formiga A.L.B.,University of Campinas | And 2 more authors.
Polyhedron | Year: 2012

Two new metal complexes of penicillamine (Pen), with molecular formulas [Ag(C 5H 10O 2NS)]·H 2O and [Au(C 5H 10O 2NS)], were synthesized by the reaction of the ligand with, respectively, silver nitrate and potassium dicyanoaurate(I) salts in aqueous solutions. Analytical characterizations of the complexes were based on elemental (C, H, N and S), thermal (TG-DTA) and electrospray ionization mass spectrometry (ESI-MS) analyses. Solid-state 13C nuclear magnetic resonance (SSNMR) and infrared (IR) spectroscopic measurements indicate coordination of Pen to Ag(I) or Au(I) through the sulfur atom. Studies based on density functional theory (DFT) confirmed that Pen acts as an S-donor ligand to Au(I) or Ag(I). Thermal decompositions of the silver(I) and gold(I) complexes start at temperatures near 50 °C, leading to the formation of Ag 0 and Au 0 at 700 °C and 500 °C, respectively. Both complexes are just slightly soluble in common solvents such as water, methanol, ethanol, acetonitrile, hexane and dimethylsulfoxide. An antibiogram assay was performed by the disc diffusion method. The AgPen complex showed antibacterial activities against Escherichia coli and Pseudomonas aeruginosa bacterial strains. © 2012 Elsevier Ltd. All rights reserved. Source


Carvalho M.A.,University of Campinas | De Paiva R.E.F.,University of Campinas | Bergamini F.R.G.,University of Campinas | Gomes A.F.,University of Campinas | And 6 more authors.
Journal of Molecular Structure | Year: 2013

The synthesis, spectroscopic characterization and biological assays of a new silver(I) complex with l-tryptophan (TRP) are presented. Elemental and thermal analyses and ESI-QTOF mass spectrometric measurements of the solid compound suggest the composition AgC11H11N 2O2. Infrared and solid-state NMR analyses indicate coordination of TRP to Ag(I) ion through the nitrogen of the NH2 group and also through the oxygen of carboxylate group. Theoretical (DFT) calculations permit proposing an optimized geometry for the complex. Antibacterial assays indicated that the Ag-TRP complex is effective against Staphylococcus aureus and Enterococcus faecalis (Gram-positive), and Pseudomonas aeruginosa and Escherichia coli (Gram-negative) bacterial strains. The complex was also cytotoxic against Panc-1 (human pancreatic carcinoma) and SK-Mel 103 (human melanoma) cells. © 2012 Elsevier B.V. All rights reserved. Source


Galbiatti J.A.,UNIARA | Ariguchi B.B.,UNIFAFIBE | de Sousa C.M.,UNIFAFIBE | Caramelo A.D.,UNIFAFIBE | de Faria R.T.,Sao Paulo State University
Journal of Food, Agriculture and Environment | Year: 2015

Basil plants are cultivated in most Brazil in home gardens for spice, medicinal and ornamental uses. The present study aimed to evaluate different sources and combinations of substrates in the production of basil seedlings, through the development and production of essential oil grown in two water regimes. The experiment was conducted at the Experimental Station of Bebedouro-SP. Ten substrates were tested, resulting from the combination of commercial substrate, bovine manure, organic waste compost and organic tree pruning compost. The experimental design was randomized blocks with 20 treatments in a factorial 10 x 2 (10 substrates and 2 irrigation levels) experiment with 3 replicates. The amount of fresh matter and oil content produced in the basil leaves was evaluated. The fresh matter of the substrate 4 (60% of soil and 40% of manure) was satisfactory with 80% of evaporation. As for the substrate oil content, the substrates 4 (60% of soil and 40% of manure), 3 (60% of soil and 40% of waste compost) and 5 (60% of soil and 40% of pruning compound) were the highest oil producers, at 80% of the evapotranspiration. © 2015, World Food Ltd. and WFL Publishers. All rights reserved. Source

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