Orientador: Pedro Paulo Corbi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T10:51:51Z (GMT). No. of bitstreams: 1 Bergamini_FernandoRodriguesGoulart_M.pdf: 3949422 bytes, checksum: a370801f06af8c8a41524fa60d90e776 (MD5) Previous issue date: 2013 / Resumo: Neste trabalho, são descritas a síntese e a caracterização de três complexos inéditos de prata com os ligantes L-butionina sulfoximina (BSO), ácido 2-tiazolidina carboxílico (2-TC) e ácido 4-tiazolidina carboxílico (4-TC). O complexo de prata com BSO foi caracterizado por um conjunto de análises químicas e espectroscópicas, a saber: análise elementar, análise térmica, espectroscopia na região do infravermelho (IV), espectroscopia Raman, espectroscopia de ressonância magnética no estado sólido de C (C-RMN), estudos por DFT e ensaios biológicos. Os complexos de prata(I) com 2-TC e 4-TC, por sua vez, foram caracterizados por análise elementar, análise térmica, espectroscopia na região do infravermelho (IV), espectroscopia de ressonância magnética no estado sólido de C-RMN e N-RMN, estudos por DFT e ensaios biológicos. O complexo de prata com BSO, [Ag2(BSO)], apresenta uma composição 2:1 metal/ligante, sendo que a coordenação do ligante a um dos átomos de prata ocorre através dos grupamentos amino e carboxilato, enquanto que a coordenação ao segundo átomo de prata ocorre através do nitrogênio da sulfoximina. Os complexos de prata com 2-TC e 4-TC também apresentam proporção 2:1 metal/ligante, com um átomo de prata coordenado através do nitrogênio e o segundo átomo de prata coordenado através do carboxilato. As análises biológicas revelaram que os complexos [Ag2(BSO)], [Ag2(2-TC)] e [Ag2(4-TC)] são efetivos sobre cepas patogênicas Gram-positivas de Staphylococcus aureus, e cepas Gram-negativas de Escherichia coli e Pseudomonas aeruginosa / Abstract: This work deals with the synthesis and characterization of three new silver(I) complexes with the ligands Lbuthionine sulfoximine (BSO), thiazolidine-2 carboxylic acid (2-TC) and thiazolidine-4 carboxylic acid (4-TC). The silver complex with BSO was characterized by elemental and thermal analyses, infrared and Raman spectroscopies, C nuclear magnetic resonance in the solid-state (C-NMR), DFT studies and biological assays. The silver(I) complexes with 2-TC and 4-TC were characterized by elemental and thermal analyses, infrared spectroscopy, C and N nuclear magnetic resonance in the solid-state, DFT studies and biological assays. The silver-BSO complex, [Ag2(BSO)], presents a 2:1 metal/ligand ratio. One of the silver(I) ion was shown to be coordinated through the amine nitrogen atom and the oxygen of carboxylate, while the second ion was shown to be coordinated through the nitrogen atom of the sulfoximine group. The silver(I) complexes with 2-TC and 4-TC also presented a 2:1 metal/ligand ratio, and are coordinated by the nitrogen and the oxygen atom of the carboxylate group. The biological assays revealed that the [Ag2(BSO)], [Ag2(2-TC)] and [Ag2(4-TC)] complexes are active against Gram-positive pathogenic strains of Staphylococcus aureus and Gramnegative pathogenic strains of Escherichia coli and Pseudomonas aeruginosa / Mestrado / Quimica Inorganica / Mestre em Química

Immobilizing antimicrobial substances onto biocompatible materials is an important approach for the design of novel, functionalized medical devices. By choosing antimicrobial substances from innate immune systems, the risk for development of resistance in pathogenic microbes is lower than if conventional antibiotics are used. Combining natural antimicrobial peptides and bactericidal enzymes with strong and elastic spider silk through recombinant protein technology would enable large-scale production of materials that could serve as functionalized wound dressings. Herein, fusion proteins with the engineered spider silk sequence 4RepCT and five different antimicrobial substances were constructed using two different strategies. In the first, the fusion proteins had a His-tag as well as a solubility-enhancing domain N-terminally to the antimicrobial agent during expression. The tags were cleaved and separated from the target protein during the purification process. The other approach provided a His-tag but no additional solubility domain. The antimicrobial agents included in the work were a charge engineered enzyme and four antimicrobial peptides herein called Peptide A, Peptide B, Peptide C and Peptide D. Four out of five fusion proteins could be expressed in Escherichia coli without exhibiting noticeable toxicity to the host. However, most target proteins were found in the non-soluble fraction. For D-4RepCT, neither soluble nor non-soluble proteins were identified. An operating strategy for expression and purification of antimicrobial spider silk proteins was developed, where the construct system providing the solubility-enhancing domain N-terminally to the antimicrobial sequence, and long time expression at low temperatures is a promising approach. The fusion proteins A-4RepCT and C-4RepCT could be produced in adequate amounts, and they proved to possess the ability to assemble into stable fibers. When incubating solutions of Escherichia coli on the functionalized silk material A-4RepCT, it showed to decrease the number of living bacteria in solution, in contrary to wild-type 4RepCT on which bacteria continued to proliferate. Initial studies of the viability of bacteria adhered to the surface of the functionalized spider silk are so far inconclusive. A larger sample size, complementary experiments and methodology optimization is needed for a proper assessment of antibacterial properties. However, preliminary results for the development of antimicrobial spider silk are positive, and the approach elaborated in this work is believed to be applicable for the construction of functional spider silk with a wide range of natural antimicrobial agents for future wound healing applications.

Orientadores: Pedro Paulo Corbi, André Luiz Barboza Formiga / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-23T09:22:25Z (GMT). No. of bitstreams: 1 Sucena_SuelenFerreira_M.pdf: 3560111 bytes, checksum: 814d4167bf3e5f68f7df18e23ea1afae (MD5) Previous issue date: 2013 / Resumo: A rimantadina (C12H21N - rtd) 'e um agente antiviral, que inibe especificamente a replicacão do vírus influenza tipo A. A presença do grupo -NH2 confere a ela uma habilidade em se coordenar a diferentes íons metálicos. Neste trabalho foram sintetizado 3 novos complexos metálicos de Au(I), Ag(I) e Pd(II) com rimantadina. Os complexos foram preparados pela reacão de solucões aquosas ou alcoólicas da rimantadina com os respectivos sais de Au(I), Ag(I) e Pd(II). Os compostos foram caracterizados por um conjunto de análises químicas e espectroscópicas, bem como através de cálculos de Density Functional Theory (DFT). Os espectros no infravermelho (IV) e de ressonância magnética nuclear (RMN) da rtd livre e dos complexos indicaram a coordenação da rtd aos íons metálicos através do átomo de nitrogênio do grupo NH2. Os compostos foram analisados quanto as suas atividades biológicas antibacteriana sobre cepas de bactérias Gram-positivas e Gram-negativas. Os resultados mostraram que os complexos de Au(I) e Ag(I) são ativos sobre cepas de Staphylococcus aureus, Pseudomonas aeruginosa e Escherichia coli / Abstract: Rimantadine (C12H21N - rtd) is a antiviral agent which inhibit specifically the replication of the virus influenza A. The presence of group -NH2 confers the ability to coordinate with different metal ions. In this work 3 novel metal complexes of Au(I), Ag(I) e Pd(II) with rimantadine were synthesized. The complexes were prepared by the reaction of aqueous or alcoholic solutions of rimantadine with the respective salts of Au(I), Ag(I) e Pd(II). The compounds were characterized by a set of chemical and spectroscopic analyses, also by Density Functional Theory (DFT) studies. The infrared (IR) spectra and nuclear magnetic resonance (NMR) of the free rtd and of the compounds indicate the coordination of rtd to metallic ions through the nitrogen atom of group NH2. The compounds were analyzed concerning their antibacterial activities against Gram-positive and Gram-negative bacterial strains. The results showed that the Au(I) and Ag(I) complexes are active against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli strains / Mestrado / Quimica Inorganica / Mestra em Química