Patrick Moyna

Can ionic liquids dissolve wood? Processing and analysis of lignocellulosic materials with 1-n-butyl-3-methylimidazolium chloride

The bulk of the cellulose currently employed by industry is isolated from wood through Kraft pulping, a process which traditionally involves a barrage of environmentally detrimental chemicals and is undeniably ‘non-green.’ In this report we present a simple and novel alternative approach for the processing of lignocellulosic materials that relies on their solubility in solvent systems based on the ionic liquid (IL) 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl). Dissolution profiles for woods of different hardness are presented, making emphasis on the direct analysis of the cellulosic material and lignin content in the resulting liquors by means of conventional 13C NMR techniques. We also show that cellulose can be readily reconstituted from the IL-based wood liquors in fair yields by the addition of a variety of precipitating solvents. Spectroscopic and thermogravimetric studies indicate that the polysaccharide obtained in this manner is virtually free of lignin and hemicellulose and has characteristics that are comparable to those of pure cellulose samples subjected to similar processing conditions.

Extraction of essential oils from lime (Citrus latifolia Tanaka) by hydrodistillation and supercritical carbon dioxide

Neste trabalho o oleo essencial de lima acida foi extraido por hidrodestilacao e CO2 supercritico. No caso da hidrodestilacao, os parâmetros avaliados foram o tempo de processo e caracteristicas do material vegetal. Em extracao supercritica, os parâmetros avaliados foram temperatura, pressao e fluxo do CO2, tempo de processo e caracteristicas do material. Considerando o conteudo de citral, os melhores resultados para hidrodestilacao foram obtidos em um tempo de processo de 3 horas utilizando-se cascas inteiras. Os melhores resultados para extracao supercritica foram obtidos a 60oC, 90 bar, a um fluxo de CO2 de 1 mL/ min para 30 minutos de processo utilizando-se cascas moidas. Os melhores resultados em termos de rendimento de oleo essencial foram obtidos por hidrodestilacao (5,45% p/p) e extracao supercritica (7,93% p/p), para cascas moidas.

Physico-chemical evaluation of Rosmarinus officinalis L. essential oils

Dezenove amostras de Rosmarinus officinalis foram extraidas por destilacao por arraste a vapor em uma planta piloto e os oleos essenciais foram avaliados quanto a composicao quimica e caracteristicas fisico-quimicas. Os rendimentos de oleo essencial variaram de 0,37% (media de 1999) a 0,49% (media de 1998). Vinte componentes foram identificados nos oleos essenciais. Os componentes majoritarios foram a-pineno (40,55 a 45,10%), 1,8-cineol (17,40 a 19,35%), canfeno (4,73 a 6,06%) e verbenona (2,32 a 3,86%). A media por safra dos parâmetros fisico-quimicos avaliados resultaram em 0,8887g/cm3 para densidade especifica, 1,4689 para indice de refracao e +11,82o para rotacao optica, sendo que as variacoes encontradas para os parâmetros quimicos e fisico-quimicos dos oleos essenciais nao variaram significativamente em funcao do ano de producao.

Efeito fungicida dos óleos essenciais de Schinus molle L. e Schinus terebinthifolius Raddi, Anacardiaceae, do Rio Grande do Sul

Uma das alternativas para reduzir o uso de agrotoxicos pode ser a utilizacao de oleos essenciais para o controle de doencas e pragas que afetam a producao agricola. O objetivo do presente estudo foi verificar o efeito fungicida dos oleos essenciais de Schinus molle L. e Schinus terebinthifolius Raddi, especies nativas amplamente distribuidas na regiao. Os oleos foram extraidos por hidrodestilacao e analisados por cromatografia gasosa. Os fungos fitopatogenos Alternaria spp., Botrytis spp., Colletotrichum spp. e Fusarium spp., foram isolados a partir de gerberas e rosas com sintomas de doenca e os ensaios de atividade antifungica foram realizados atraves da tecnica de difusao em disco e os dados analisados pelo teste de Tukey e Duncan a 5%. Em geral o oleo essencial de S. molle foi efetivo para os quatro fungos testados, nas quatro diluicoes utilizadas e para todos os tempos avaliados e o oleo essencial de S. terebinthifolius apresenta efeito fungicida mais pronunciado contra Botrytis spp., a partir de testes in vitro.

Effect ofSolanum Glycoalkaloids on Potato Aphid,Macrosiphum euphorbiae

Macrosiphum euphorbiae, also known as the potato aphid, is a potato virus vector, associated with decreased tuber production. Feeding, toxicity, and reproductive effects of the major potato glycoalkaloids (α-chaconine and α-solanine), their common aglycone (solanidine), and a nonpotato glycoalkaloid (α-tomatine) and its aglycone (tomatidine) onM. euphorbiae were studied. As expected, neither α-chaconine nor α-solanine had a strong lethal effect on the aphid, but α-chaconine stimulated feeding at low concentrations. Both aglycones were deterrent and lethal at high concentrations and, like α-chaconine and α-tomatine, they delayed the appearance and decreased the number of nymphs.

Rosmarinus officinalis L. (Labiatae) Essential Oils from the South of Brazil and Uruguay

Abstract Rosemary oils from cultivars of Rosmarinus officinalis L. growing in different areas of Uruguay and South of Brazil (Rio Grande do Sul State) were analyzed by GC and GC/MS. The oils from Uruguay were found to be rich in αpinene (37.8–46.2%) and 1,8-cineole (13.4–13.8%). The oil from R. officinalis which was cultivated in Brazil contained αpinene (32.2%) and 1,8-cineole (14.7%), while the oil from wild plants found in Brazil contained αpinene (12.4%), myrcene (22.7%) and 1,8-cineole (15.3%).

Chemical Composition of the Essential Oils from Leaves and Fruits of Schinus molle L. and Schinus terebinthifolius Raddi from Southern Brazil

Abstract The essential oils of two Anacardiaceae species, Schinus molle L. and Schinus terebinthifolius Raddi, native from Brazil, were obtained by hydrodistillation and the oils composition studied by capillary GC and GC-MS. Twenty seven compounds were identified for S. molle and twenty nine for S. terebinthifolius. The leaves and fruits essential oils for both S. molle and S. terebinthifolius were characterised by a high percentage of sesquiterpene and monoterpene hydrocarbons. The S. terebinthifolius essential oils obtained from leaves and berries presented differences with those previously described in the literature, while the leave oil of S. molle showed similar composition to that from Uruguay. These findings have ecological and economic significance as S. molle and S. terebinthifolius are promising species in the pharmaceutical, cosmetic and chemical industries.

Use of ionic liquids in the study of fruit ripening by high-resolution 13C NMR spectroscopy: ‘green’ solvents meet green bananas

Banana pulps at any ripening stage can be completely dissolved in solvent systems based on the ionic liquid (IL) 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl), and variations in the carbohydrate composition of the fruit analyzed directly on the resulting solutions using high-resolution 13C NMR spectroscopy.

Glycoalkaloids of Solanum commersonii Dun. ex Poir

Five glycoalkaloids were identified from the aerial parts of wild Solanum commersonii Dun. ex Poir growing in Uruguay and their structures elucidated mainly by chemical and spectroscopic methods. In addition to the already known commersonine, demissine, tomatine and dehydrocommersonine, a new glycoalkaloid, identified as δ5-demissine, solanid -5-en-3-O- {β-D-Glcp-(1→2)-[β-D-Xylp-(1→3) ]β-D-Glcp-(1→4)-β-D-Galp } was found. Tomatine and dehydrocommersonine have not been reported earlier as components of this plant. The glycoalkaloid composition found in the wild plants studied differ significatively from those described earlier, and have some implications in taxonomy and its use in potato breeding.

Essential oils from leaves of Schinus molle and S. lentiscifolius of Uruguayan origin

ABSTRACT The essential oils from leaves of two Uruguayan native Anacardiaceae, Schinus molle L. and Schinus lentiscifolius(L.) March., were analyzed by GC and GC/MS. Sixteen compounds were identified in S. lentiscifolius and S. molle oils. Both oils were sesquiterpene hydrocarbon-rich with δ-cadinene (16.79%) and bicyclo-germacrene (29.20%) being the major components in the oils of S. lentiscifolius and S. molle, respectively.