Síntese e caracterização de complexos ditiocarbamatos de Sn(IV), In(III), Ga(III) e metais de transição: decomposição térmica e perfil farmacológico in vitro

• Ano de defesa: 2008
• Autor(a) principal: Daniele Cristiane Menezes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Derivados ditiocarbamatos de Sn(IV); Novos materiais; Química inorgânica
• Link de acesso: http://hdl.handle.net/1843/SFSA-7SFQXX

This work presents three complementary fields, approaching the synthesis of dithiocarbamate organotin(IV) complexes, in special, moreover Ga(III), In(III) and some transition metals. Preparation of solid tin sulphides was investigated through thermal decomposition indifferent temperatures of Sn(IV) precursors by MOD technique, metal-organic Decomposition. Besides, the in vitro pharmacologic profile, mainly antifungal, exhibited for organotin derivatives, is presented.In the Chapter 1, some perspectives in relation to the coordination inorganic chemistry are shown, approaching the obtaining of new materials starting from ideal metal-organic precursors as well as aspects of the potential biological activity exhibited by metallic complexes.In addition, the chapter presents some particularities exhibited by dithiocarbamate ligands class, focus of the present work.Concerning to the Chapter 2, the preparation of ligands is shown: pyrrolidine ([NH4{S2CN(CH2)4}]); diethyl ([Na{S2CN(C2H5)2}]); n-propylethanol ([Na{S2CN(CH2CH2CH3)CH2CH2OH}]) and tert-butylethane ([CH2CH2S2CN(CH3)3]) dithiocarbamates; used as reagents in reactions for synthesis of Sn(IV), In(III), Ga(III), Cu(II), Ni(II),Ag(I) and Co(III) complexes. The mentioned dithiocarbamate ligands were characterized by elemental analysis; infrared and nuclear magnetic resonance (1H e 13C) spectroscopies. In addition, the structures of n-propylethanol and tert-butylethane dithiocarbamates were determined by X-ray crystallography. In Chapter 3 are described the synthesis and characterization of tin(IV) compounds with pyrrolidine and diethyl dithiocarbamates ligands: [Sn{S2CN(CH2)4}2Cl2] (1), [Sn{S2CN(CH2)4}2Ph2](2), [Sn{S2CN(CH2)4}Ph3] (3), [Sn{S2CN(CH2)4}2Bu2] (4), [Sn{S2CN(CH2)4}Cy3] (5),[Sn{S2CN(C2H5)2}2Cl2] (6), [Sn{S2CN(C2H5)2}2Ph2] (7), [Sn{S2CN(C2H5)2}Ph3] (8), [Sn{S2CN(C2H5)2}3Ph](9) and [Sn{S2CN(C2H5)2}Cy3] (10), with Ph, Bu and Cy corresponding to phenyl, butyl and ciclohexyl groups, respectively. These compounds were characterized by elemental analysis; Xray electron probe microanalysis; infrared, multinuclear magnetic resonance (1H, 13C and 119Sn)and 119Sn Mössbauer spectroscopies as well as by X-ray crystallography for 2 and 4. In additional way, the preparation of complexes contends several metals with sodium npropylethanol dithiocarbamate is related in Chapter 4: [In{S2CN(CH2CH2OH)CH3CH2CH2}3] (11),[Ga{S2CN(CH2CH2OH)CH3CH2CH2}3] (12), [Cu{S2CN(CH2CH2OH)CH3CH2CH2}2] (13),[Ni{S2CN(CH2CH2OH)CH3CH2CH2}2] (14) and [Ag{S2CN(CH2CH2OH)CH3CH2CH2}] (15). The crystal structure of copper derivative was elucidated by X-ray diffraction. Moreover, all complexes were characterized by elemental analysis; atomic absorption spectrophotometry; infrared, nuclear magnetic resonance (1H and 13C) and electron paramagnetic (for compound 13) spectroscopies.Thermal decomposition experiments in N2 were carried out for both serial organotin(IV) compounds, containing pyrroline and diethyl dithiocarbamates, in order to prepare tin sulphides Síntese e caracterização de complexos ditiocarbamatos: Decomposição térmica e perfil farmacológico in different temperatures, as shown in Chapter 5. All pyrolysis products were characterized by elemental analysis; X-ray; electron probe microanalysis; 119Sn Mössbauer, ultraviolet-visible andRaman spectroscopies; multinuclear magnetic resonance (1H, 13C and 119Sn) and 119Sn Mössbauer spectroscopies; X-ray powder diffraction and scanning electron microscopy. Precursors 4, 7, 8 and 9 yielded SnS at 350ºC. Precursor 6 afforded SnS e Sn2S3 at 450 and 900ºC,respectively, and the results indicate the formation of a mixture of SnS e Sn2S3 for remaining precursors. In Chapter 6, an in vitro pharmacology study exhibited for dithiocarbamate organotin complexes is presented. The compounds have been tested against pathogen Candida species, such as Candida albicans (ATCC 18804), Candida tropicalis (ATCC 750) and resistant Candida albicans collected from HIV-positive Brazilian patients with oral candidiasis. In addition, the inhibitory activity of these compounds is shown against phytopatogenic fungi, Neurospora crassa and Colletotrichum graminicola. Results involving the antibacterial action of thesecompounds against Staphylococcus aureus also are presented. The activity of all compounds cited was investigated by agar diffusion method and minimal inhibitory concentrations, MIC (g mL-1). The effect of compounds was performed on the cellular activity of the yeast cultures.Changes in mitochondrial function have not been detected. However, all drugs reduced ergosterol and sterols biosynthesis. Preliminary studies on DNA integrity indicated that the compounds do not cause gross damaging on yeast DNA.