Uma das alternativas para reduzir o uso de agrotóxicos pode ser a utilização de óleos essenciais para o controle de doenças e pragas que afetam a produção agrícola. O objetivo do presente estudo foi verificar o efeito fungicida dos óleos essenciais de Schinus molle L. e Schinus terebinthifolius Raddi, espécies nativas amplamente distribuídas na região. Os óleos foram extraídos por hidrodestilação e analisados por cromatografia gasosa. Os fungos fitopatógenos Alternaria spp., Botrytis spp., Colletotrichum spp. e Fusarium spp., foram isolados a partir de gérberas e rosas com sintomas de doença e os ensaios de atividade antifúngica foram realizados através da técnica de difusão em disco e os dados analisados pelo teste de Tukey e Duncan a 5%. Em geral o óleo essencial de S. molle foi efetivo para os quatro fungos testados, nas quatro diluições utilizadas e para todos os tempos avaliados e o óleo essencial de S. terebinthifolius apresenta efeito fungicida mais pronunciado contra Botrytis spp., a partir de testes in vitro.

One of the alternatives to reduce the use of pesticides may be the use of essential oils to control diseases and pests that affect agricultural production. The purpose of this study was to evaluate the fungicide effect of essential oils of Schinus molle L. and Schinus terebinthifoliusRaddi, native species widely distributed in the region. The oils were extracted by hydro distillation and analyzed by gas chromatography. The phytopathogenic fungi Alternariaspp., Botrytisspp., Colletotrichumspp. and Fusarium spp., were isolated from "gerberas" and roses with symptoms of disease and antifungal activity of the tests were carried out by the technique of spreading disk. The data was analyzed by Tukey and Duncan tests to 5%. In general, the essential oil of S. mollewas effective for the four fungi tested, for the four dilutions used and for all the times evaluated. The essential oil of S. terebinthifolius presents more pronounced fungicide effect against Botrytisspp., from in vitro tests.

Neste trabalho os óleos essenciais de S. officinalis, S. sclarea, S. lavandulifolia e Salvia sp. foram analisados quimicamente por cromatografia gasosa acoplada a espectrômetro de massas. A atividade antimicrobiana dos óleos essenciais foi testada contra 10 microrganismos utilizando o método de difusão em discos e através da determinação da Concentração Inibitória Mínima (CIM). Cânfora, α - e ß-thujone e 1,8-cineol foram os compostos majoritários identificados na maioria dos óleos essenciais, exceto para S. sclarea, em que linalol, acetato de linalil e α-terpineol foram os compostos majoritários identificados. As atividades antimicrobianas apresentaram diferenças significativas (p < 0,05) somente quando obtidas pelo método CIM. Microorganismos gram-positivos apresentaram grande sensibilidade para os óleos essenciais. A menor CIM foi observada para o Staphylococcus aureus quando exposto a 2,31 mg.mL-1 de óleo essencial de S. lavandulifolia, enquanto que a maior CIM foi observada para Shigella flexneri exposta a 9,25 mg.mL-1 do mesmo óleo essencial, provando que este óleo constitui-se em um eficiente agente bacteriostático contra microrganismos gram-positivos.

In this work, the essential oils of S. officinalis, S. sclarea, S. lavandulifolia and S. triloba were chemically analyzed by gas chromatography coupled to a mass spectrometry detector (GC/MSD), and their antimicrobial activity was tested against 10 microorganisms using the disk diffusion method and the Minimum Inhibitory Concentration (MIC) technique. The following major compounds were identified in the essential oils: α - and β-thujone, camphor and 1,8-cineole, except in S. sclarea, where linalool, linalyl acetate and α-terpineol were the major constituents. The antimicrobial activity showed significant differences (p < 0.05) only when obtained by the MIC method. Gram-positive microorganisms presented larger sensitivity for the essential oils. The lowest MIC was observed when Staphylococcus aureus was exposed to 2.31 mg.mL-1 of S. lavandulifolia essential oil, while the highest MIC value was obtained when Shigella flexneri was exposed to 9.25 mg.mL-1 of the same essential oil, thus demonstrating that this essential oil may be effective as a bacteriostatic agent against Gram-positive microorganisms.

Vinte e sete acessos de Lippia alba Mill. coletados no Rio Grande do Sul, Brasil, foram analisados por marcadores ISSR e RAPD visando avaliar a variabilidade genética e as relações entre acessos. Seis sequencias iniciadoras de ISSR e quatro de RAPD geraram 120 fragmentos amplificados, a maior parte dos quais apresentaram algum grau de polimorfismo. A variabilidade genética geral entre acessos foi muito elevada quando comparada com outras espécies vegetais. A análise hierárquica dos dados moleculares (UPGMA) mostrou baixa relação entre acessos, e não houve formação de agrupamentos entre acessos pertencentes ao mesmo quimiotipo. Análise de funções canônicas permitiu identificar algumas variáveis relacionadas com as características químicas dos óleos essenciais. Tanto os marcadores ISSR como RAPD foram eficientes para avaliar a diversidade genética em L. alba e devem contribuir para a conservação e melhoramento desta importante espécie aromática e medicinal.

Twenty-seven accessions of Lippia alba Mill. collected in Rio Grande do Sul state, Brazil, were analysed by ISSR and RAPD markers to evaluate their genetic variability and relationships. Six ISSR primers and four RAPD primers generated 120 amplified fragments, most of which were polymorphics. The overall genetic variability among accessions was very high when compared with other plant species. The hierarchical analysis of molecular data (UPGMA) showed low relationship between accessions, and no grouping between accessions of the same chemotype. Canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. Both ISSR and RAPD markers were efficient to address the genetic diversity of L. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species.

Baccharis trimera is a native Brazilian plant which has medicinal properties. In this work a method of supercritical extraction was studied to obtain the popularly essential oil from Baccharis trimera, known as carqueja. The aim was to obtain experimental data and to compare two mathematical models used in the simulation of carqueja (Baccharis trimera) oil extraction by supercritical CO2. The two mathematical models are based on mass transfer. One of the models, proposed by Reverchon, is solved numerically and requires two adjustable parameters from the experimental data. The other model chosen is the one proposed by Sovová. This model is solved analytically and requires four adjustable parameters. Numerical results are presented and discussed for the adjusted parameters. The experimental results are obtained in a temperature range of 313.15 K to 343.15 K at 90 bar. The extraction yield of carqueja essential oil using supercritical carbon dioxide ranged between 1.72 % (w/w) at 323.15 K and 2.34 % (w/w) at 343.15 K, 90 bar with a CO2 flow rate of 3.34.10-8 m³/s for a 0.0015 kg sample of Baccharis trimera.

Supercritical CO2 extraction of essential oil from the leaves of a variety of camphor tree known as Ho-Sho was studied. Experiments were carried out within the following ranges: CO2 flow rate (1 - 4 mL/min); pressure (80 - 100 bar); temperature (40 - 60 ºC) and particle size (0.37 - 1.0 mm). The equipment used was an HP 8670 T extractor module with an extraction cell volume of 7 mL. Two mathematical models of the process were proposed. Model 1 was a modified version of the traditional shrinking core model with effective diffusivity and the external mass transfer coefficient as the fitting parameters. Model 2 used an additional kinetic parameter based on an Arrhenius-like expression. Both models took into account the cell pressurization step. The best fit between the extraction model curves and the experimental data was obtained using model 2.

Dezenove amostras de Rosmarinus officinalis foram extraídas por destilação por arraste a vapor em uma planta piloto e os óleos essenciais foram avaliados quanto a composição química e características físico-químicas. Os rendimentos de óleo essencial variaram de 0,37% (média de 1999) a 0,49% (média de 1998). Vinte componentes foram identificados nos óleos essenciais. Os componentes majoritários 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 média por safra dos parâmetros físico-químicos avaliados resultaram em 0,8887g/cm³ para densidade específica, 1,4689 para índice de refração e +11,82º para rotação óptica, sendo que as variações encontradas para os parâmetros químicos e físico-químicos dos óleos essenciais não variaram significativamente em função do ano de produção.

Nineteen samples of Rosmarinus officinalis were extracted by steam distillation in a pilot plant and evaluated in terms of chemical compositions and physico-chemical characteristics. The volatile oil yields ranged from 0.37% (1999 harvest) to 0.49% (1998 harvest). Twenty components were identified in the oils. The major components were alpha-pinene (40.55 to 45.10%), 1,8-cineole (17.40 to 19.35%), camphene (4.73 to 6.06%) and verbenone (2.32 to 3.86%). The physico-chemical parameters averaged 0.8887 g/cm³ for specific gravity, 1.4689 for refractive index, and +11.82° for optical rotation, and there were no significant variations in either the chemical or physico-chemical data in the different years.