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Eucalyptus resinifera essential oils have fumigant and repellent action against...
Reyes, Etztli I. M.; Farias, Elizeu S.; Silva, Eliete M. P.; Picanço, Marcelo C.; Filomeno, Claudinei A.; Plata, Miguel A. B.; Barbosa, Luiz C. A.The coffee berry borer Hypothenemus hampei Ferrari (CBB, Coleoptera: Scolytidae) is one of the major pests of coffee causing damage in the field and in warehouses. This pest is mainly controlled with insecticides and repellents. Essential oils (EOs) have been investigated as an alternative to synthetic insecticides, however few studies on the use of EOs to control the CBB have been reported. In this study, the ...
Caracterização química do “pitch” em indústria de celulose e papel de Eucalyptus
Cruz, Mariluze P.; Barbosa, Luiz C. A.; Maltha, Célia R. A.; Gomide, José L.; Milanez, Augusto F.The chemical analysis of the acetone, chloroform, toluene and methanol extracts of a pitch sample was carried out by IR and GC-MS, leading to the identification of sixty nine compounds, including fatty acids, alcohols and hydrocarbons. Analysis of the acetone extractive of a eucalyptus wood used in Brazil for pulp production was also carried out, resulting in identification of fifty nine compounds, including ma...
Determinação da relação siringila/guaiacila da lignina em madeiras de eucalipto...
Barbosa, Luiz C. A.; Maltha, Célia R. A.; Silva, Vanessa Lopes; Colodette, Jorge LuizThe use of analytical pyrolysis combined with gas chromatography/mass spectrometry (Py-GC/MS) to determine the syringyl/guaiacyl ratio (S/G) in lignins from Eucalyptus spp woods was investigated. Sample of E. grandis and "E. urograndis" wood, with and without extractives, were subjected to pyrolysis from 300 ºC to 600 ºC. The products that results from pyrolysis were identified by mass spectrometry and the S/G ...
Síntese de novas fitotoxinas derivadas do 8- oxabiciclo[ 3. 2. 1] oct- 6- en- 3...
Barbosa, Luiz C. A.; Maltha, Célia R. A.; Demuner, Antônio J.; Ganen, Flávia R.; Silva, Antônio A. daThe [4+3] cycloaddition was utilized in order to prepare 8-oxabicyclo[3.2.1]oct-6-en-3-one (1) derivatives. The correspondent acetonide 6 was converted into several alcohols (11-16). Addition of aryllithium reagents to 6 resulted in 3-(2-fluorophenyl)-6,7-exo-isopropylidenedioxy -8-oxabicyclo[3.2.1]octan-3a-ol (11, 72%) and 3-(2,4-dimethoxyphenyl)-6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan -3a-ol (16,...
Síntese e avaliação da atividade fitotóxica de derivados da α-Santonina
Alvarenga, Elson S.; Barbosa, Luiz C. A.; Saliba, William A.; Arantes, Francisco F. P.; Demuner, Antônio J.; Silva, Antônio A.Mixtures of α-Santonin and various solvents were irradiated by either high or low pressure mercury lamps. The photochemical reactions afforded lumisantonin (11) (76% in acetonitrile), (3S,3aS,9bS)-3,6,6-trimethyl-3,3a,4,5-tetrahydronafto[1,2-b]furan-2,7(6H,9bH)dione (12) (100% in acetonitrile), 10α-acetoxy-3-oxo-1,7αH,6,11βH-guaia-4-en-6,12-olide (8) (26% in acetic acid), 10α-hydroxy-3-oxo-1,7αH,6,11βH-guaia-4-...
Síntese de 2-( 2- piridil) quinolinas promovida por micro- ondas e suas ativida...
Borel, Carmindo R.; Barbosa, Luiz C. A.; Maltha, Célia R. A.; Fernandes, Sergio A.; Santos, Larissa B.; Takahashi, Jacqueline A.In this work a series of 2-(2- pyridyl)quinolines were prepared via a Povarov reaction between anilines, 2-pyridinocarbadehyde and ethyl vinyl ether under microwaves heating conditions. The optimized conditions herein reported allowed the preparation of several pyridylquinolines in yields in the range of 30-83%, some of them not previously accessible by this multicomponent process. The reported methodology has ...
Síntese e avaliação da atividade antimicrobiana de furanonas halogenadas e de c...
Barbosa, Luiz C. A.; Maltha, Célia R. A.; Demuner, Antônio J.; Pinheiro, Patrícia F.; Varejão, Jodieh O. S.; Montanari, Ricardo M.; Andrade, Nélio J.Considering the broad spectrum of biological activity of gamma-butyrolactone derivatives, we presented the synthesis of 3,4-dihalo-5-arylidenefuran-2(5H)-ones (17-21) and analogues (24-28) of the natural product nostoclide (7,8). Furanones 17-21 were synthesized from the condensation of aromatic aldehydes with lactones 14 and 15, that were obtained from mucobromic and mucochloric acids. Lactone 15 was converted...
Hederagenin amide derivatives as potential antiproliferative agents
Barbosa, Luiz C. A.; Demuner, Antonio J.; Rodríguez-Hernández, Diego; Martins, João Paulo Ataide; Csuk, René; Fischer (nee Heller), LucieIn this study, a series of C-28 amides derivatives of hederagenin with or without the presence of an acetyl group at positions 3 and 23 in ring A, were synthetized aiming to develop potent cytotoxic agents. Their structures were confirmed by MS, IR, 1H NMR and 13C NMR spectroscopic analyses and their cytotoxic activities were screened in SRB assays using a panel of six human cancer cell lines. The majority of t...
Atividade antiinflamatória de carboidrato produzido por fermentação aquosa de g...
Moreira, Maria E. C.; Santos, Marcelo H.; Pereira, Ivan O.; Ferraz, Vany; Barbosa, Luiz C. A.; Schneedorf, José M.Kefir, a symbiont microorganism suspension, presents benefic effects to health. Some kefir grains were cultivated in brown sugar, allowing to isolate a substance named CSQ. This was evaluated on a biologic essay of mouse foot edema, presenting an inhibitory activity of 30+4 % against carrageenan after the stimulus. It was observed that a cultivation mean containing sucrose, and not the milky mean, lead to the p...
Isolation of compounds attractive to the leaf-cutting ant Atta sexdens rubropil...
Peternelli, Ethel Fernandes de O.; Barbosa, Luiz C. A.; Lucia, Terezinha M. C. DellaMabea fistulifera (Euphorbiaceae)is a pioneer plant species with seeds dispersed by the ant Atta sexdens rubropilosa. Since the ants are attracted to the seeds to use its elaiosome as a source of energy, we investigated its composition. The elaiosomes from 13,000 seeds were extracted with a methanol:chloroform mixture (2:1 v/v) and yielded 22% of a residue. This residue was fractionated by column chromatography...