Compostos organoestânicos derivados do ácido 4-fenilbutírico: síntese, elucidação estrutural e estudo da atividade antifúngica

• Ano de defesa: 2015
• Autor(a) principal: Cleidivânia Silveira Rocha
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: atividade; antifúngica; Compostos organoestânicos(IV); ácido 4-fenilbutírico; Compostos organoestânicos; Atividade antifúngica; Antimicóticos; Quimica inorganica; Fármacos
• Link de acesso: http://hdl.handle.net/1843/SFSA-AXYQBP

In this work six novel organotin compounds derivatives of 4-phenylbutyric acid were prepared and characterized and the synthesized complexes were tested as antifungal agents (against Candida spp.). The complexes were prepared from 4-phenylbutyrate sodium salt (PBANa) and the corresponding organotin chlorides (R3SnCl and R2SnCl2) under ethanol in reflux. The following products were obtained: {(C6H5)3Sn[O2CC3H6(C6H5)]}n {(CH3)3Sn[O2CC3H6(C6H5)]}n (1), (3), {(C4H9)3Sn[O2CC3H6(C6H5)]}n {(C4H9)2Sn[O2CC3H6(C6H5)]2} (2), (4), {[(CH3)2Sn(O2CC3H6(C6H5))]2O}2 (5) and [(C6H5)Sn(O)(O2CC3H6(C6H5))]6 (6). The complexes were characterized by physicochemical and spectroscopy techniques, such as melting point, elemental analysis, infrared spectroscopy, 1H, 13C and 119Sn nuclear magnetic resonance spectroscopy in solution, 119Sn Mössbauer spectroscopy andcrystallography by X-ray diffraction. Among the complexes, just the compound 6 was characterized only by X-ray diffraction, and for compound 2 it was not possible to obtain suitable crystals with the same crystallization technique. Through the analysis of obtained results by characterization techniques in solid state, it was possible toconfirm the geometries of the compounds, mainly due to crystallography diffraction Xrays. The compounds 1, 2 and 3 exhibited polymeric structures in solid state with distorted trigonal bipyramidal geometry. The compound 4 exhibited geometry distorted trans-octahedral, the compound 5 showed distannoxanic structure and the compound 6 presented hexameric drum-like structure. The antifungal in vitro activityof the complex 1-5 were evaluated against the following yeast species: Candida dubliniensis (clinical isolate 28), C. lusitaniae (CBS 6936), C. albicans (ATCC 18804), C. tropicalis (ATCC 750), C. parapsilosis (ATCC 22019), C. glabrata (ATCC 90030). The antifungal activity of the organotin precursors, the ligand 4-phenylbutyric acid and the sodium salt of the ligand were also evaluated. In order to compare the antifungal activity, usual standard clinical, such as nystatin and miconazole nitratewere also measured. The antifungal activity was expressed as the values of the inhibitory concentrations IC50 (mol.L-1). The free ligand (PBANa) and its respective acid displayed no significant antifungal activity and among the organotin precursors, the more active were Ph3SnCl and Bu3SnCl. The complexes 1 and 2 were the most active against species of Candida in comparison with other complexes, and it is noteworthythat these synthesized complexes are quite promising for the development of new antifungal agents.