Chemical Composition and Antioxidant Activity of Essential Oils from Populations of Baccharis dracunculifolia DC. in Southern Brazil

HIGHLIGHTS Essential oils from populations of B. dracunculifolia were investigated. β-pinene and (E)-nerolidol were the main compounds in B. dracunculifolia populations. The difference in the chemical profile of the essential oils is quantitative only. There is a negative correlation between the antioxidant activity and spathulenol.

Abstract Baccharis dracunculifolia DC. is a Brazilian native plant, presenting wide chemical diversity and numerous pharmaceutical and industrial applications. This research assessed the yield, antioxidant activity and the chemical similarity of essential oils from 10 populations of B. dracunculifolia in the state of Paraná, southern Brazil. The extraction of the volatile compounds was carried out by hydrodistillation, the chemical composition was determined by GC/FID and GC/MS and the antioxidant activity by the DPPH method. The essential oil yield of wild B. dracunculifolia populations ranged from 0.14 to 0.87%. The oils were predominantly composed of oxygenated sesquiterpenes (34.16 - 51.01%), monoterpene hydrocarbons (18.02 - 46.17%) and sesquiterpenes hydrocarbons (9.60 - 17.70%). The major compounds found in all populations were β-pinene (7.65 - 29.8%) and (E)-nerolidol (9.11 - 21.68%). Essential oil solutions (20%) from different populations presented antioxidant capacity ranging from 27.78 to 91.67%. A negative correlation was found between the antioxidant activity and spathulenol (r = -0.696). Multivariate analyses separated the populations into three groups: (1) low concentrations of α-pinene (2.02 - 2.06%), (2) high concentrations of α-pinene (4.17 - 4.61%) and β-pinene (22.54 - 29.80%), and (3) intermediate concentrations of α-pinene (2.38 - 3.31%), β-pinene (12.77 - 19.03%) and spathulenol (6.02 - 9.06%).

Propagação vegetativa via estaquia de azaléia-arbórea (Rhododendron Tomsonii HOOK.f.) / Vegetative propagation by cuttings of azaléia tree(Rhododendron thomsonii HOOK. f.) / Vegetative propagation by cuttings of azalélia tree (Rhododendron thomsonii HOOK.f. )

Rhododendron thomsonii (Ericaceae) é uma espécie lenhosa, ornamental originária da China cujas sementes são utilizadas exclusivamente para produção de híbridos, sendo a propagação vegetativa uma ferramenta viável para a produção de mudas em larga escala. Com a finalidade de avaliar o enraizamento desta espécie para estacas colhidas na primavera (setembro/2004), foram selecionadas plantas-matrizes adultas situadas no município de Curitiba-PR. As estacas semilenhosas foram obtidas com comprimento aproximado de 12cm, cortadas em bisel na parte inferior e em corte reto na parte superior, com duas folhas reduzidas à metade. O tratamento fitossanitário foi realizado utilizando-se imersão das estacas em hipoclorito de sódio 0,5 (10 minutos) seguida de lavagem em água corrente (5 minutos). Posteriormente as bases das estacas foram imersas em soluções alcoólicas (50) com diferentes concentrações de ácido indol butírico (IBA), (),1000,2000 e 4000mgL-1), e em talco (0,1000,2000 e 4000mgKg-1), totalizando 8 tratamentos com 4 repetições de 9 estacas por parcela. O delineamento experimental utilizado foi o arranjo fatorial (4 X 2) entre as dosagens utilizadas e as formas de aplicação. As estacas foram plantadas em tubetes contendo vermiculita de granulometria média e mantidas em casa-de-vegetação climatizada por 70 dias. As avaliações compreenderam porcentagens de estacas enraizadas, com calos (sem raiz e com calos), vivas (sem raízes e sem calos) e mortas. Não houve enraizamento para estacas coletadas nesta época do ano. A análise de variância revelou que os fatores dosagens e formas de aplicação não apresentaram interação. Na comparação de médias para porcentagens de estacas vivas e mortas, os tratamentos não apresentaram diferenças estatisticamente significativas.

Rhododendron thomsonii (Ericaceae) is a chinese ornamental hardwood species. The seeds are usedjust for hybrids production, therefore, vegetative propagation is an appropriate way for large scale plantproduction. The rooting potential was evaluated in cuttings collected in spring/2004 from stock plants localized in Curitiba, Paraná. The stem cuttings were produced with 12 cm long, right cut upper and bevelbellow, with two half leaves and treated with sodium hypochlorite for ten minutes and current water forfive minutes. The cuttings basis were dipped in IBA treatments (0, 1000, 2000, 4000mgL-1) in alcoholicsolutions and talc (0, 1000, 2000, 4000 mgKg-1), totalling eight treatments with four replications of ninecuttings. Mean separation were made using a pair wise design (4X2) in a association between dosageand application ways. The cuttings were planted in vermiculite medium and maintained in greenhousefor 70 days. The evaluation included percentage of rooting, callus cuttings (without root with callus),alive and dead cuttings. No rooting was verified in cuttings collected in this season. The varianceanalysis showed no interactions between dosage and application ways