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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Synthesis approaches to (−)-cytoxazone, a novel cytokine modulator, and related structures(Molecules, 2016-09) Diaz, Marisa A. N.; Miranda, Izabel L.; Lopes, Ítala K. B.; Diaz, Gaspar(−)-Cytoxazone, originally isolated from cultures of a Streptomyces species has an oxazolidin-2-one 4,5-disubstituted ring. It is known that this natural product presents a cytokine modulator effect through the signaling pathway of Th2 cells (type 2 cytokines), which are involved in the process of growth and differentiation of cells. From this, the interest in the development of research aimed at the total synthesis of this molecule and its analogs has remained high, which can be confirmed by the large number of publications on the topic, more than 30 to date. This review focuses on the various creative methods for the synthesis of (−)-cytoxazone and its congeners. The assessment of the preparation of this oxazolidinone and related structures serves as a treatise on the efforts made in the synthesis of this important class of compound from its first total synthesis in 1999.Item Antibiotic activity of plectranthus ornatus codd., a traditional medicinal plant(Anais da Academia Brasileira de Ciências, 2017-10-16) Nascimento, Fernanda R.; Albuquerque, Kamylla R.S.; Oliveira, Marcos R.; Pizziolo, Virginia R.; Brasileiro, Beatriz G.; Diaz, Gaspar; Diaz, Marisa A.N.The dichloromethane extract of Plectranthus ornatus Codd., a tradicional medicinal plant, showed antibiotic activity with minimum inhibitory concentration (MIC) values of 0.4 mg.mL-1 and 100 percent of biofilm inhibition against Staphylococcus aureus strains isolated from animals with mastitis infections. Based on these antibacterial activities, in addition to ethnopharmacological reports from healing men and farmers in Brazil, an herbal soap was produced from this active extract and was tested both in vitro and in vivo. In vivo assays conducted on these herbal soaps led to results similar to those previously conducted with the active extract. These results indicated the great potential of this plant for use as an excipient by preparing herbal antibacterial soaps as an alternative veterinary medicine aimed at controlling bovine mastitis infections on small Brazilian farms.Item Easy access to evans’ oxazolidinones. Stereoselective synthesis and antibacterial activity of a new 2-oxazolidinone derivative(Molecules, 2014-06-06) Diaz, Gaspar; Freitas, Michelle A. A. de; Ricci-Silva, Maria E.; Diaz, Marisa A. N.An interesting new approach was developed for the synthesis of Evans’ chiral auxiliaries with excellent yields. In turn, another new stereoselective and efficient strategy has also allowed for the preparation of a 2-oxazolidinone derivative in 34% overall yield from the Morita-Baylis-Hillman adduct. The antibacterial activity of this oxazolidinone was tested against Staphylococcus aureus strains isolated from animals with mastitis infections.Item Chemical constituents and an alternative medicinal veterinary herbal soap made from Senna macranthera(Hindawi, 2015-02-14) Andrade, Flávia Inoue; Purgato, Gislaine Aparecida; Maia, Thalita de Faria; Siqueira, Raoni Pais; Lima, Sâmia; Diaz, Gaspar; Diaz, Marisa Alves NogueiraUpon undergoing biomonitoring, the most active dichloromethane extract retrieved from Senna macranthera roots led to the isolation of three main compounds: emodine, physione, and chrysophanol. In this sequence, these compounds revealed a potential antibacterial activity against Staphylococcus aureus strains isolated from animals with mastitis infections with minimum inhibitory concentration (MIC) values of 20, 90, and 90 μg mL−1, respectively. Therefore, an herbal soap was also produced from this same active extract. This soap was tested in vitro using gloves contaminated by animals with bovine mastitis that had been discarded after use by milkers and showed similar results to previously tested compounds. These results indicate the potential of this plant as an alternative veterinary medicine for the production of antibacterial soaps that aimed at controlling bovine mastitis infections in small Brazilian farms.