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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11800
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Item Preparation, X-ray structural studies and plant growth regulatory activity of methyl 6a,7b-thiocarbonyldioxyvouacapan-17 b-oate(Journal of the Brazilian Chemical Society, 2004-03) Rubinger, Mayura M. M.; Borges, Eduardo E. L.; Castelo-Branco, Pedro de A.; Guilardi, Silvana; Souza, Elysângela M. R.; Gambardella, Maria T. do P.; Ferreira-Alves, Dalton L.; Piló-Veloso, DorilaThe 6a,7b-dihydroxyvouacapan-17b-oic acid (1) and methyl 6a,7b-dihydroxyvouacapan-17b-oate (2) are natural products isolated from the hexane extract of Pterodon polygalaeflorus Benth fruits. Here we describe the preparation and characterization by infrared and nuclear magnetic resonance spectroscopy, and by elemental analysis of the novel derivative methyl 6a,7b-thiocarbonyldioxyvouacapan-17b-oate (5), from the ester 2. The structure of compound 5 was determined by X-ray diffraction. At the concentration of 100 ppm, this compound inhibited the radicle growth of Sorgum bicolor L. (-28%) and showed no significant effect on Cucumis sativus L..Item Avaliação de bis(4-metilfenilditiocarbimato)zincato(II) de tetrabutilamônio como acelerador em composições de borracha natural(Polímeros, 2008) Mariano, Roberta M.; Visconte, Leila L. Y.; Oliveira, Marcelo R. L.; Rubinger, Mayura M. M.Neste trabalho a substância ZNIBU [bis(4-metilfenilditiocarbimato)zincato(II) de tetrabutilamônio] foi usada em formulações de borracha natural (NR) e o seu efeito como acelerador de vulcanização foi investigado. As composições, vulcanizadas com a substância em questão, foram submetidas a testes mecânicos e os resultados comparados com os de outras composições vulcanizadas com os aceleradores comerciais CBS (N-ciclohexil-2-benzotiazol-2-sulfenamida), TMTD (dissulfeto de tetrametiltiuram) e MBTS (dissulfeto de benzotiazol). Propriedades como dureza, resiliência e densidade foram avaliadas em presença ou não da carga negro de fumo.Item Synthesis, structural and spectroscopic characterization of novel zinc(II) complexes with N-methylsulfonyldithiocarbimato and N-methylsulfonyltrithiocarbimato ligands(Polyhedron, 2007-01-02) Oliveira, Marcelo R. L.; Perpetuo, Genivaldo J.; Janczak, Jan; Rubinger, Mayura M. M.Two new zinc(II)-complexes, dithiocarbimato (Ph4P)2[Zn(CH3SO2N=CS2)2] (1) and trithiocarbimato (Ph4P)2[Zn(CH3SO2N=CS3)2] (2), were obtained in the crystalline form by the reaction of potassium N-methylsulfonyldithiocarbimate (RSO2N=CS2K2) with zinc(II) acetate dihydrate and tetraphenylphosphonium chloride in dimethylformamide. Both complexes crystallize in the monoclinic system. The central Zn(II) ion has a distorted tetrahedral coordination in both compounds. In 1 the dithiocarbimato ligand coordinates via two S atoms while in 2 the trithiocarbimato ligand coordinates via S and N atoms. Both complexes were also characterized by IR, 1 H NMR and 13C NMR spectroscopies. Compound 2 is the first example of a zinc(II)-trithiocarbimato complex.Item Preparation, crystal structure and spectroscopic characterization of nickel(II) complexes with dithiocarbimate derivated of sulfonamides(Polyhedron, 2006-07-10) Oliveira, Marcelo R. L.; Franca, Eduardo de Faria; Guilardi, Silvana; Andrade, Renato Pereira de; Lindemann, Renata Hernandez; Amim Jr., Jorge; Ellena, Javier; Bellis, Vito M. de; Rubinger, Mayura M. M.This work describes the syntheses of three compounds containing [Ni(RSO2N=CS2)2]^2 anions: (Bu4N)2[Ni(CH3CH2SO2N=CS2)2] (1), (Bu4N)2[Ni(4-IC6H4SO2N=CS2)2] (2) and (Bu4N)2[Ni(2,5-Cl2C6H3SO2N=CS2)2] (3). They were obtained in the crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N=CS2K2) with nickel(II) chloride hexahydrate in methanol/water. Elemental analyses were consistent with the proposed formulae. UV–Vis and IR data are consistent with the formation of nickel–sulfur diamagnetic planar complexes. The 1H NMR and 13C NMR spectra showed the expected signals for the tetrabutylammonium cation and the dithiocarbimate moieties. Single crystal structure analyses showed that 1 crystallizes in the monoclinic space group P21/n, 2 crystallizes in the monoclinic space group P21/c and 3 crystallizes in the triclinic space group Pī. In these compounds the Ni. atom is coordinated to four S atoms in a distorted square plane geometry due to the asymmetric bidentade chelation by each ligand.Item Syntheses, crystal structure, spectroscopic characterization and antifungal activity of new N-R-sulfonyldithiocarbimate metal complexes(Journal of Inorganic Biochemistry, 2009-07) Alves, Leandro C.; Rubinger, Mayura M. M.; Lindemann, Renata H.; Perpétuo, Genivaldo Júlio; Janczak, Jan; Miranda, Liany D. L.; Zambolim, Laércio; Oliveira, Marcelo R. L.Five new compounds with the general formula of (Bu4N)2[M(RSO2NCS2)2], where Bu4N = tetrabutylammonium cation, (M = Ni, R = 4-FC6H4) (1), (M = Zn, R = 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-IC6H4), (2), (3), (4) and (5), respectively, were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2NCS2K2) with nickel(II) chloride hexahydrate or zinc(II) acetate dihydrate in metanol:water 1:1. The elemental analyses and the IR data are consistent with the formation of the expected bis(dithiocarbimato)metal(II) complexes. The 1H and 13C NMR spectra showed the signals for the tetrabutylammonium cation and the dithiocarbimate moieties. The compounds 1, 2 and 5 were also characterized by X-ray diffraction techniques. The nickel(II) is coordinated by two N-4-fluorophenylsulphonyldithiocarbimato(2-) ligands forming a planar coordination. The zinc(II) exhibits distorted tetrahedral configuration in compounds 2 and 5 due to the chelation effect of two sulfur atoms of the N-R-sulfonyldithiocarbimate ligands. The antifungal activities of the compounds were tested in vitro against Colletotrichum gloeosporioides, an important fungus that causes the plant disease known as anthracnose in fruit trees. All the complexes were active.Item Synthesis and antifungal activity of aromatic bis-g-lactones analogous to avenaciolide(Chemistry & Biodiversity, 2007-02-13) Castelo-Branco, Pedro A.; Rubinger, Mayura M. M.; Alves, Leandro de C.; Barros, Pauline M. de; Pereira, Sinval G.; Melo, Vanessa J. de; Pilo-Veloso, Dorila; Zambolim, LaércioAvenaciolide is a bis-γ-lactone isolated from Aspergillus avenaceus and possesses antifungal activity. Here, we describe the total syntheses and characterization by elemental analyses, and IR and NMR spectroscopy of three new bis-γ-lactones analogous to avenaciolide, where the octyl group of the natural product was replaced by aromatic groups. The effects of the avenaciolide, the novel compounds, and their synthetic precursors on the mycelia development and conidia germination of Colletotrichum gloeosporioides were evaluated in vitro. The new compounds were as active as avenaciolide in the tested conditions, while the synthetic precursors were inactive. The preparation and characterization of 15 new synthetic intermediates are also described.