Centro de Ciências Exatas e Tecnológicas
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/9791
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Resultados da Pesquisa
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, LaércioBotrytis 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.Item Effect of the incorporation of lysozyme on the properties of jackfruit starch films(Journal of Polymers and the Environment, 2017-02-24) Pires, Ana Clarissa dos Santos; Bonomo, Renata Cristina Ferreira; Santos, Taline Amorim; Santos, Leandro Soares; Fontan, Rafael da Costa Ilhéu; Rodrigues, Luciano Brito; Veloso, Cristiane Martins; Gandolfi, Olga Reinert Ramos; Bonomo, PauloJackfruit starch based biodegradable films containing lysozyme were characterized for their antimicrobial activity, thickness, solubility, water vapor permeability and mechanical properties. The biodegradable films had good appearance and antimicrobial activity against Micrococcus lysodeikticus. The thickness of the biodegradable films were not affected by the variation in pH, but the addition of lysozyme increased the thickness, the thickest films being those with the highest lysozyme concentrations. The variation in pH of the filmogenic solutions affected the solubility of the biodegradable films, water solubility being greatest at pH 7.0 and with the highest lysozyme concentration. The permeability of the biodegradable films was increased by incorporating lysozyme. The lysozyme concentration and pH variation caused changes in the mechanical properties. The addition of 8% lysozyme increased the tensile strength and Young’s modulus for all the pH values studied. With respect to the release of antimicrobial activity, the diffusion of lysozyme was shown to follow Fickian transport mechanism.Item Thiobarbiturates as potential antifungal agents to control human infections caused by Candida and Cryptococcus species(Medicinal Chemistry Research, 2018-01-08) Shabeer, Muhammad; Barbosa, Luiz C. A.; Karak, Milandip; Coelho, Amanda C. S.; Takahashi, Jacqueline A.Hospitalized patients can suffer from Candida and Crytptococcus infections, aggravating underlying health conditions. Due to the development of drug-resistant microorganisms, we report here on the potential of some arylidene-thiobarbiturate to control five Candida spp. and one Cryptococcus species of medical interest. Initially, a bismuth nitrate catalyzed Knoevenagel condensation with thiobarbituric acid and aromatic aldehydes was developed. This new procedure generated seven new and thirteen known arylidene-thiobarbiturate derivatives (1–20) with excellent yields (81–95%), with a reaction time within 20 min. The antimicrobial activities of all compounds were evaluated against Candida albicans, C. tropicalis, C. parapsilosis, C. lusitaniae, C. dubliniensis, and Cryptococcus neoformans. Several compounds were as active as the commercially available drugs (IC50 < 1.95 µg mL−1) towards at least one microbial strain. The results suggest that some of the new compounds can serve as leads for new antimicrobial agents for the treatment of human fungal infections.Item Antimicrobial effect of oligomeric copper(ii) derivatives of bis(pyrimidin-2-ylthio)- and bis(4,6-dimethylpyrimidin-2 ylthio)alkanes(Revista de Engenharia Química e Química, 2016-03-02) Silva, Ricardo Soares Mota; Souza, Márcia Cristina de; Berlini, Lilian; Maia, José Roberto da Silveira; Diniz, Renata; Speziali, Nivaldo Lúcio; Dhingra, Onkar Dev; Ferraz, Vanny PerpetuaA novel series of copper(II) derivatives of bis(pyrimidin-2-ylthio)- and bis(4,6-dimethylpyrimidin-2-ylthio)alkane of general formula [Cu x Cl y (L) z ] n {x = 1, y = 2, z = 1, L = ptm (1), pte (2), dptm (4), dpte (5), dpth (6); x = 2, y = 4, z = 3, L = pth (3)} were tested for antimicrobial activity. These complexes were characterized by elemental analysis, infrared spectroscopy (IR) and gel permeation chromatography (GPC). Complex-4, 5 and 6 have the metal at the center of a square planar geometry, and in complex-1, 2 and 3 the metal is at the center of a square pyramidal geometry. The structure of complex-4, determined by X-ray diffraction analysis, shows this compound as an oligomer with one-dimensional chain in zigzag conformation. The high average molecular weight (Mw) of these copper(II) complexes confirms their oligomeric character. Although the free ligands were inactive against the microorganisms tested, the copper(II) derivatives showed good antifungal and antibacterial inhibition against C. albicans, C. tropicalis, S. aureus and E. coli, more effective than Nystatin and Norfloxacin.Item Assessing the chemical composition and antimicrobial activity of essential oils from Brazilian plants—Eremanthus erythropappus (Asteraceae), Plectrantuns barbatus, and P. amboinicus (Lamiaceae)(Molecules, 2015-05-11) Santos, Nara O. dos; Mariane, Bruna; Lago, João Henrique G.; Sartorelli, Patricia; Rosa, Welton; Soares, Marisi G.; Silva, Adalberto M. da; Lorenzi, Harri; Vallim, Marcelo A.; Pascon, Renata C.The chemical composition and antimicrobial activity of essential oils obtained from three Brazilian plant species—leaves and branches of Eremanthus erythropappus (Asteraceae), leaves of Plectranthus barbatus, and leaves of P. amboinicus (Lamiaceae)—were determined. Analysis by GC/MS and determination of Kovats indexes both indicated δ-elemene (leaves—42.61% and branches—23.41%) as well as (−)-α-bisabolol (leaves—24.80% and stem bark—66.16%) as major constituents of E. erythropappus essential oils. The main components of leaves of P. barbatus were identified as (Z)-caryophyllene (17.98%), germacrene D (17.35%), and viridiflorol (14.13%); whereas those of leaves of P. amboinicus were characterized as p-cymene (12.01%), γ-terpinene (14.74%), carvacrol (37.70%), and (Z)-caryophyllene (14.07%). The antimicrobial activity against yeasts and bacteria was assessed in broth microdilution assays to determine the minimum inhibitory concentration (MIC) necessary to inhibit microbial growth. In addition, the crude oil of branches of E. erythropappus was subjected to chromatographic separation procedures to afford purified (−)-α-bisabolol. This compound displayed biological activity against pathogenic yeasts, thus suggesting that the antimicrobial effect observed with crude oils of E. erythropappus leaves and branches may be related to the occurrence of (−)-α-bisabolol as their main component. Our results showed that crude oils of Brazilian plants, specifically E. erythropappus, P. barbatus, and P. amboinicus and its components, could be used as a tool for the developing novel and more efficacious antimicrobial agents.Item Chemical variability and biological activities of Eucalyptus spp. essential oils(Molecules, 2016-09-07) Barbosa, Luiz Claudio Almeida; Filomeno, Claudinei Andrade; Teixeira, Robson RicardoMany plant species produce mixtures of odorous and volatile compounds known as essential oils (EOs). These mixtures play important roles in Nature and have been utilized by mankind for different purposes, such as pharmaceuticals, agrochemicals, aromatherapy, and food flavorants. There are more than 3000 EOs reported in the literature, with approximately 300 in commercial use, including the EOs from Eucalyptus species. Most EOs from Eucalyptus species are rich in monoterpenes and many have found applications in pharmaceuticals, agrochemicals, food flavorants, and perfumes. Such applications are related to their diverse biological and organoleptic properties. In this study, we review the latest information concerning the chemical composition and biological activities of EOs from different species of Eucalyptus. Among the 900 species and subspecies of the Eucalyptus genus, we examined 68 species. The studies associated with these species were conducted in 27 countries. We have focused on the antimicrobial, acaricidal, insecticidal and herbicidal activities, hoping that such information will contribute to the development of research in this field. It is also intended that the information described in this study can be useful in the rationalization of the use of Eucalyptus EOs as components for pharmaceutical and agrochemical applications as well as food preservatives and flavorants. View Full-Text