Síntese, caracterização e avaliação da atividade antimicrobiana de complexos derivados de ligantes (N, S, O) ambidentados

• Autor(a) principal: Berlini, Lilian
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2129
• topic: Ligantes ambidentados; Fungicida; Bactericida; Ambidentate ligands; Fungicide, bactericide; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA INORGANICA

In this work the ligands mercaptopyrimidylmethane (mpm), mercaptopyrimidylethane (mpe), mercaptopyrimidylbutane (mpb) and mercaptopyrimidylhexane (mph) were synthesized. Complexes of copper(II) were obtained from these ligands. The complexes obtained from the first three ligands showed 1:1 (M: L) stoichiometry and distorted trigonal-bipyramidal geometry. The complex derivative of mph showed a 2:3 (M:L) stoichiometry. Two zinc compounds were synthesized using the mpb and mercaptopyridylhexan-N-oxide (mpoh) as ligands. These compounds showed 1:1 (M:L) stoichiometry and an octahedral geometry. Bismuth compounds were prepared from the reactions between bismuth(III) chloride and the ligands mpb, mpoh and mercaptopyridylbutan-N-oxide (mpob) in acetonitrile. The bismuth(III) is pentacoordinated in these compounds presenting a distorted trigonal-bipyramidal geometry by means of different stoichiometries. A gallium(III) derivative of sodium dehydroacetate was also synthesized in a mixture of water and ethanol, leading to a square pyramidal geometry with 1:2 (M:L) stoichiometry. The ligands and the metal compounds were characterized by infrared spectroscopy, 13C and 1H NMR, elemental analysis (CHN), melting point and X-rays. The activity of the compounds were tested against bacteria (Escherichia coli and Staphylococcus aureus), yeast (Candida albicans and C. tropicalis) and phytopathogenic fungi (Bipolaris maydis, B. sorokiniana, Colletotrichum gloeosporioides, C. musae, Alternaria alternata and Fusarium graminearum). The inhibitory activity assays showed interesting results, highlighting cases of selectivity for these microorganisms. The compounds of copper(II) were more active against bacteria than yeasts, while the zinc and gallium compounds showed higher activity against fungi. The greatest potential of fungitoxicity was obtained with zinc compounds. The bismuth compounds showed moderate activity against the microorganisms tested.