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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11800
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Item Composition, antifungal activity and main fungitoxic components of the essential oil of Mentha piperita L.(Journal of Food Safety, 2011-12-11) Freire, Marcelo Moreira; Jham, Gulab Newandram; Dhingra, Onkar Dev; Jardim, Carolina Marangon; Barcelos, Rosimeire Coura; Valente, Vânia Maria MoreiraTwenty-one components (93.9% of the total chromatographic peak area) were tentatively identified in the essential oil (EO) of Mentha piperita L., based on Kováts retention indices (RIs), a mass spectral database (gas chromatography-mass spectrometry, GC-MS) and visual comparison of the mass spectra of the sample peaks with those of the database. The presence of 15 compounds (corresponding to 90.7% of the total chromatographic peak area) was confirmed by authentic standards. The EO presented a good activity against the following important postharvest deteriorating fungi: Aspergillus flavus, Aspergillus glaucus, Aspergillus niger, Aspergillus ochraceous, Colletotrichum gloesporioides, Colletotrichum musae, Fusarium oxysporum and Fusarium semitectum. At a concentration of 0.2% of the EO, all the fungi were completely inhibited, except for A. glaucus and C. musae which were inhibited 90 and 98%, respectively. TLC-bioautography yielded three subfractions that prevented fungal growth, suggesting the presence of antifungals. Bioassay data of the crude EO were compared with those of the three subfractions. Based on these tests, it was concluded that several fungitoxics were responsible for the antifungal activity of M. piperita, with the principal ones being menthone, neomenthol, menthol and carvone. However, participation of other compounds cannot beruled out. This is the first study in the literature that presents data on the activity of the crude EO against eight important postharvest deteriorating fungi, characterizing the amounts and types of comounds. In addition, also for the first time, the active fractions of the crude EO were isolated, identified and the components quantified. More detailed fungal tests are being conducted to confirm the tentative preliminary antifungal data.Item Synthesis, characterization and biocidal activity of new organotin complexes of 2-(3-oxocyclohex-1-enyl)benzoic acid(European Journal of Medicinal Chemistry, 2010-03) Maia, José R. da S.; Vieira, Flaviana T.; Lima, Geraldo M. de; Speziali, Nivaldo L.; Ardisson, José D.; Rodrigues, Leonardo; Correa Junior, Ary; Romero, Oscar B.The reaction of 1,3-cyclohexadione with 2-aminobenzoic acid has produced the 2-(3-oxocyclohex-1-enyl)benzoic acid (HOBz). Subsequent reactions of the ligand with organotin chlorides led to [Me2Sn(OBz)O]2 (1), [Bu2Sn(OBz)O]2 (2), [Ph2Sn(OBz)O]2 (3), [Me3Sn(OBz)] (4), [Bu3Sn(OBz)] (5) and [Ph3Sn(OBz)] (6). All complexes have been fully characterized. In addition the structure of complexes (2) and (4) have been authenticated by X-ray crystallography. The biological activity of all derivatives has been screened against Cryptococcus neoformans and Candida albicans. In addition we have performed toxicological testes employing human kidney cell. The complexes (3), (5) and (6) displayed the best values of inhibition of the fungus growing, superior to ketoconazole. Compound (5) presented promising results in view of the antifungal and cytotoxicity assays.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.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, LaercioFour 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.