Artigos

URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11800

Navegar

Resultados da Pesquisa

Agora exibindo 1 - 7 de 7
  • Imagem de Miniatura
    Item
    Bis(4-fluorophenylsulfonyldithiocarbimato) zincate(ii) salts: new antifungals for the control of botrytis blight
    (Química Nova, 2015-07) Oliveira, Alexandre A.; Oliveira, Marcelo R. L.; Rubinger, Mayura M. M.; Piló, Elisa L.; Menezes, Daniele C.; Zambolim, Laércio
    Botrytis blight or gray mold is a highly destructive disease caused by Botrytis spp., that infects flowers, trees vegetables, fruit, especially grapevines and strawberry. Three new compounds with general formula (A)2[Zn(4-FC6H4SO2N=CS2)2], where A = PPh3CH3 (2a), PPh3C2H5 (2b), PPh3C4H9 (2c), and the previously published compounds where A = PPh4 (2d) and NBu4 (2e), were synthesized by the reaction of 4-fluorophenylsulfonyldithiocarbimate potassium dihydrate and zinc(II) acetate dihydrate with the appropriate counter cations (A) halides. The new compounds were characterized by infrared, 1H and 13C NMR spectroscopies. All these salts inhibited the growth of Botrytis cinerea, with compounds 2c and 2d showing greater antifungal activity than zinc dimethyldithiocarbamate, the active principle of the fungicide Ziram. The bis(dithiocarbimate)zincate(II) salts are also active against the bacteria Escherichia coli and Staphylococcus aureus.
  • Imagem de Miniatura
    Item
    Síntese e caracterização de novos organometálicos de estanho (iv) com ligantes ditiocarbimatos e sua ação acceleradora na vulcanização de borracha nitrílica
    (Química Nova, 2016-08) Bottega, Fernanda C.; Oliveira, Marcelo R. L.; Sérvulo, Vanessa Pio; Visconte, Leila L. Y.; Ardisson, José D.; Rubinger, Mayura M. M.
    This paper describes the synthesis of four new organotin compounds of general formula: (Ph4P)[Sn(Cy)3(RSO2N=CS2)] [Ph4P = tetraphenylphosphonium cation, Cy = cyclohexyl, R = C6H5 (1), 4-ClC6H4 (2), 4-BrC6H4 (3) and 4-IC6H4 (4)]. They were obtained by the reaction between four different potassium N-R-sulfonyldithiocarbimate salts and tricyclohexyltin chloride in methanol, and were isolated as tetraphenylphosphonium salts. The elemental analyses of C, H, N and the data of high-resolution mass spectrometry were consistent with the proposed formulae. The 119Sn NMR spectra and 119Sn Mössbauer spectroscopic data were consistent with the presence of tetracoordinated tin(IV) species in solution and in the solid state. The electrolytic molar conductance and the integration curves in the 1H NMR spectra are in accord with the 1:1 proportion between the tetraphenylphosphonium cations and the complex anions. The activity of the new compounds in the vulcanization of nitrile rubber was evaluated and the results were compared to those achieved with the commercial accelerators: N-tert-butyl-2-benzothiazolesulfenamide (TBBS), tetramethylthiuram disulfide (TMTD) and zinc diethyldithiocarbamate (ZEDC).
  • Imagem de Miniatura
    Item
    Sais de tetrafenilfosfônio e tris( 1,10- fenantrolina) ferro( ii) de complexos aniônicos de dibutilestanho( iv) com ditiocarbimatos: síntese, caracterização e atividade antifúngica
    (Química Nova, 2016-06) Bottega, Fernanda C.; Oliveira, Marcelo R. L.; Rubinger, Mayura M. M.; Bellato, Carlos R.; Ardisson, José D.; Zambolim, Laercio
    Six new salts of organometallic complexes of tin(IV) with the general formulae: (Ph4P)2[Sn(Bu)2(RSO2N=CS2)2] and [Fe(phen)3][Sn(Bu)2(RSO2N=CS2)2] [Ph4P = tetraphenylphosphonium, R = CH3 (1), C2H5 (2) and C4H9 (3); Fe(phen)3 = tris(1,10-phenanthroline)iron(II), R = CH3 (4), C2H5 (5) and C4H9 (6)] were synthetized from potassium dithiocarbimates (RSO2N=CS2K2.H2O) in reaction with dichlorobis-n-butyltin(IV) and tetraphenylphosphonium chloride (1-3) in N,N-dimethylformamide or tris(1,10-phenanthroline)iron(II) (4-6) in methanol. The new compounds were characterized by elemental analysis of Fe and Sn, and by vibrational, Mössbauer and nuclear magnetic resonance of 1H, 13C and 119Sn spectroscopies. High-resolution mass spectra in the negative and positive modes were also obtained. The elemental analyses and the exact masses obtained for the cations and the complex anions were consistent with the proposed formulae. The Mössbauer spectroscopic data were consistent with the presence of tin(IV) with coordination numbers between 4 and 5 (compounds 1-6), and of hexacoordinated iron(II) (compounds 4-6). The 1H and 13C NMR spectra presented all the expected signals for the cations and anions, and the signals observed in the 119Sn NMR spectra indicated an equilibrium between tetra- and pentacoordination around the tin atoms in solution. The in vitro activity of the new compounds was evaluated against Botrytis cinerea and Colletotrichum acutatum.
  • Imagem de Miniatura
    Item
    Tetraphenylphosphonium allyldithiocarbimates derived from Morita- Baylis-Hillman adducts: Synthesis, characterization, crystal structure and antifungal activity
    (Journal of Molecular Structure, 2016-02-15) Tavares, Eder C.; Rubinger, Mayura M. M.; V. Filho, Eclair; Oliveira, Marcelo R. L.; Piló-Veloso, Dorila; Ellena, Javier; Guilardi, Silvana; Souza, Rafael A. C.; Zambolim, Laércio
    Botrytis blight is a very destructive disease caused by Botrytis spp., infecting flowers, trees, vegetables and fruits. Twelve new compounds were prepared by the reaction of potassium N-aryl-sulfonyldithiocarbimates with Morita-Baylis-Hillman derivatives bearing phenyl and furyl groups. These are the first examples of allyldithiocarbimate anions and were isolated as tetraphenylphosphonium salts. The new compounds were characterized by HRMS, NMR and Infrared spectroscopy. Further, the structures of three allyldithiocarbimates were determined by single crystal X-ray diffraction. The compounds are isostructural and crystallize in the space group P21/c of the monoclinic system, and the allyldithiocarbimate anions present Z configuration. All the compounds were active against Botrytis cinerea. The best results were achieved with the tetraphenylphosphonium (Z)-3-(furan-2-yl)-2-(methoxycarbonyl)allyl-(4-chlorophenylsulfonyl)dithiocarbimate (IC50 38 μM).
  • Imagem de Miniatura
    Item
    Syntheses, characterization and antifungal activity of heteroleptic nickel(II) complexes with N-alkylsulfonyldithiocarbimates and phosphines
    (Journal of Molecular Structure, 2016-06-15) Vidigal, Antonio E. C.; Rubinger, Mayura M. M.; Oliveira, Marcelo R. L.; Guilardi, Silvana; Souza, Rafael A. C.; Ellena, Javier; Zambolim, Laercio
    Four nickel(II) complexes of general formula [Ni(RSO2NCS2) (PPh3)2] where R = CH3 (2a), CH3CH2 (2b), CH3(CH2)3 (2c) and CH3(CH2)7 (2d) and PPh3 = triphenylphosphine; and two nickel(II) complexes of general formula [Ni(RSO2NCS2)dppe] where R = CH3(CH2)3 (3c) and CH3(CH2)7 (3d) and dppe = 1,2-bis(diphenylphosphine)ethane) were prepared. These new complexes were obtained by the reaction of nickel(II) chloride hexahydrate with potassium N-alkylsulfonyldithiocarbimates and the appropriate phosphine using ethanol/water as solvent. The IR, UV–Vis and ^1 H, ^13 C and ^31 P NMR spectra, elemental analysis of Ni and the HR-ESI-MS were consistent with the formation of square planar nickel(II) complexes with mixed ligands. The structures of the compounds 2b and 2c were determined by single crystal X-ray diffraction. The compounds are isostructural and crystallize in the space group P of the triclinic system. The activities of the complexes were investigated in vitro against Botrytis cinerea, Colletotrichum acutatum and Alternaria solani, fungi species that affect various commercially important plants. All the complexes were active.
  • Imagem de Miniatura
    Item
    Synthesis and antifungal activity of halogenated aromatic bis-γ-lactones analogous to avenaciolide
    (Química Nova, 2011-11-08) Castelo-Branco, Pedro A.; Rubinger, Mayura M. M.; Alves, Leandro de C.; Liberto, Natalia A.; Nepel, Thayane C. M.; Catrinck, Mariana; Guilardi, Silvana; Silvério, Hudson A.; Zambolim, Laércio; Piló-Veloso, Dorila; F. Neto, Wilson P.
    Here we describe the total syntheses and characterization by elemental analyses, infrared and NMR spectroscopy of three new compounds analogous to avenaciolide, a bis-γ-lactone isolated from Aspergillus avenaceus that possesses antifungal activity, where the octyl group of the natural product was replaced by aromatic groups containing chlorine and fluorine atoms. The effects of the avenaciolide, the novel compounds and their synthetic precursors on mycelia development and conidia germination of Colletotrichum gloeosporioides and Fusarium solani were evaluated in vitro. The title compounds were almost as active as avenaciolide. The absolute structures of the chlorinated analogs were determined by X-ray diffraction analysis.
  • Imagem de Miniatura
    Item
    Syntheses, characterization and antifungal activity of tris(1,10-phenanthroline)iron(ii) bis(n-r-sulfonyldithiocarbimate)zincate(ii)
    (Química Nova, 2013-05-25) Bottega, Fernanda C.; Oliveira, Marcelo R. L.; Garcia, Camila V.; Menezes, Daniele C.; Rubinger, Mayura M. M.; Zambolim, Laercio
    Four new compounds with the general formula [Fe(phen)3][Zn(RSO2N=CS2)2], where phen = 1,10-phenanthroline, R = 4-FC6H4 (1), 4-ClC6H4 (2), 4-BrC6H4 (3) and 4-IC6H4 (4), respectively, were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N=CS2K2) and tris(1,10-phenanthroline)iron(II) sulfate, with zinc(II) acetate dihydrate in dimethylformamide. The elemental analyses and the IR data were consistent with the formation of the expected complexes salts. The 1H and 13C NMR spectra showed the signals for the cationic iron(II) complex and dithiocarbimate moieties. The molar conductance data were consistent with the 1:1 cation:anion complexes in 1-4. The antifungal activities of the compounds were tested in vitro against Candida albicans, Candida tropicalis and Colletotrichum gloeosporioides.