Gleison Antônio Casagrande

Application of Different Advanced Oxidation Processes for the Degradation of Organic Pollutants

Water is not only an economic, but also an increasingly important social commodity. Potable water is an essential resource for sustaining economic and social development in all sectors. A safe water supply and appropriate sanitation are the most essential components for a healthy and prosperous life. However, increases in human activities have led to exposure of the aqueous environment to chemical, microbial and biological pollutants as well as to micropollutants. Thus, liquid effluents containing toxic substances are generated by a variety of chemistry-related industrial processes, as well as by a number of common household or agricultural applications.

One step substitution of NO and Cl by a metal-S-C-N-ring in CpCr(NO)2Cl: synthesis and molecular structure of CpCr(NO)‘DMPYS’ (Cp=π-C5H5; DMPYS=4,6-dimethyl-pyrimidine-2-thiolato)

Abstract CpCr(NO)2Cl reacts in THF under reflux with the Na salt of 4,6-dimethyl-pyrimidin-2-thiol to give CpCr(NO)(DMPYS)·1/4 toluene (Cp=π-C5H5; DMPYS=4,6-dimethylpyrimidine-2-thiolato) and NaCl. The ligand substitution in CpCr(NO)2Cl probably occurs over displacement of NO followed by Cl− elimination. CpCr(NO)‘DMPYS’ crystallizes in the triclinic space group P 1 , formally with 25% of a toluene solvate molecule for each CpCr(NO)(DMPYS)-unity. In the new complex, the chromium atom shows a ‘tetrahedral’ coordination geometry derived from the octahedral structural principle, with a four members ring formed by the metal atom and the fragment SCN of the ligand.

H2O2-assisted photoelectrocatalytic degradation of Mitoxantrone using CuO nanostructured films: Identification of by-products and toxicity

CuO nanostructured thin films supported on silicon with 6.5 cm2 area (geometric area greater than the studies reported in the literature) were synthesized by a chemical bath deposition technique. The electrodes were characterized by MEV, XRD, XPS, contact angle, cyclic voltammetry and electrochemical impedance spectroscopy analyses. To evaluate the photoelectrochemical properties of the CuO films, photocurrent-voltage measurements were performed using linear voltammetry. The catalytic activities of CuO nanostructures were evaluated by monitoring photodegradation of Mitoxantrone (MTX) under UV-A light irradiation. The method of photoelectrocatalysis (PEC), applying a voltage of 1.5 V and assisted by adding H2O2, was undertaken. To the best of our knowledge, no studies on the degradation of anticancer agents using PEC process have been found in the literature. For comparison purposes, experiments were performed under the same conditions by assisted photocatalysis (PC) with H2O2 and direct photolysis. CuO deposits consist of a needle-like morphology. The presence of CuO in the tenorite phase was evidenced by XRD and the XPS spectra showed the presence of copper(II) oxide. The increase in current under illumination shows that CuO exhibits photoactivity. The PEC system showed a 75% level of MTX degradation, while the level achieved using PC was 50%. Under UV-A light alone only 3% removal was obtained after 180 min. Up to 10 by-products were identified by chromatography-mass spectrometry (LC-MS) with m/z values ranging between 521 and 285 and a plausible degradation route has been proposed. It is worth mentioning that 9 by-products identified in this work, were not found in the literature in other studies of degradation or products generated as metabolites. The toxicity tests of MTX before and after PEC treatment with Artemia Salina and Allium cepa showed a decrease in the acute toxicity of the medium as the antineoplastic was degraded.

A Promising Copper(II) Complex as Antifungal and Antibiofilm Drug against Yeast Infection

The high mortality rate of candidemia and the limited option for the treatment of Candida spp. infection have been driving the search for new molecules with antifungal property. In this context, coordination complexes of metal ions and ligands appear to be important. Therefore, this study aimed to synthesize two new copper(II) complexes with 2-thiouracil and 6-methyl-2-thiouracil ligands and to evaluate their mutagenic potential and antifungal activity against Candida. The complexes were synthesized and characterized by infrared vibrational spectroscopy, CHN elemental analysis, UV-Vis experiments and ESI-HRMS spectrometry studies. The antifungal activity was evaluated by broth microdilution against 21 clinical isolates of Candida species. The mutagenic potential was evaluated by the Ames test. The complexes were Cu(Bipy)Cl2(thiouracil) (Complex 1) and Cu(Bipy)Cl2(6-methylthiouracil) (Complex 2). Complex 1 showed fungicidal and fungistatic activities against all isolates. Furthermore, the Minimum Inhibitory Concentration (MIC) from 31 to 125 µg/mL and inhibition percentage of 9.9% against the biofilms of C. krusei and C. glabrata were demonstrated. At the concentrations tested, complex 1 exhibited no mutagenic potential. Complex 2 and the free ligands exhibited no antifungal activity at the concentrations evaluated. Since complex 1 presented antifungal activity against all the tested isolates and no mutagenic potential, it could be proposed as a potential new drug for anti-Candida therapy.

Ultrasound-promoted iodination of aromatic compounds in the presence of iodine and hydrogen peroxide in water.

th Brazilian Meeting on Organic Synthesis – 14 th BMOS – September 01-05, 2011-Brasilia, Brazil Ultrasound-promoted iodination of aromatic compounds in the presence of iodine and hydrogen peroxide in water. Irlon M. Ferreira, Rafael D. C. Gallo, Gleison A. Casagrande, Lucas Pizzuti* and Cristiano Raminelli* Faculdade de Ciencias Exatas e Tecnologia, Universidade Federal da Grande Dourados, Dourados, MS, Brazil *e-mail addresses: lucaspizzuti@ufgd.edu.br or raminelli@ufgd.edu.br

Iodination of aromatic and heteroaromatic compounds in the presence of iodine and hydrogen peroxide in water: A balance between atom economy and high yields.

INTRODUCTION Recently we published a work involving the efficient and selective diiodination of phenols using I2 and H2O2 30% in water. 1 Afterwards, we decided to subject aromatic and heteroaromatic compounds to the same reaction conditions, performing a balance between the amounts of the reagents and the yields obtained, aiming to the formation of interesting iodinated molecules in high yields. RESULTS AND DISCUSSION We treated phenol (1a) with 1.5 equiv. of I2 and 3 equiv. of H2O2 30% in water at 50 o C for 24 h and obtained 2,4,6-triiodophenol (2a) in a moderate yield of 65% (Table 1, entry 1). In the attempt of increasing this yield, we used 2 equiv. of I2 and 4 equiv. of H2O2 30% producing the triiodinated phenol 2a in a yield of 83% (entry 2). The aromatic compound 1b and the heteroaromatic compound 1c were subjected to the reaction with 2 equiv. of I2 and 4 equiv. of H2O2 30% resulting in the triiodinated products 2b and 2c, respectively, in good yields (entries 3 and 4). The balance between amounts of the reagents and yields obtained was extended for reactions of diiodination (entries 6 to 9) and for reactions of monoiodination (entries 10 to 15). In general, diiodinated and monoiodinated aromatic and heteroaromatic compounds were produced in considerable yields. CONCLUSION A balance between amounts of the reagents and the yields obtained was carried out for the reaction of iodination of aromatic organic compounds using I2 and H2O2 30% in water at 50 o C and interesting iodinated molecules were produced in good yields. ACKNOWLEDGEMENTS We thank CNPq and FUNDECT for support. REFERENCES