Schinus terebinthifolius essential oil and fractions in the control of Aedes aegypti / Schinus terebinthifolius óleo essencial e frações no controle do Aedes aegypti

Several technologies have been developed to controlAedes aegypti, mainly studies on isolated plant molecules. The Schinus terebinthifolius (Raddi) (Anacardiaceae), popularly known as pink pepper is a plant widely used in reforestation of degraded areas and its fruits are used as condiments. The objective of this work was to investigate the potential of essential oils (EOs) and fractions (FRs) obtained from fresh fruits and leaves of S. terebinthifolius. The EOs were obtained by hydrodistillation (2 hours), fractionated on a chromatographic column using as the stationary phase silica gel 60 (0.063-0.2mm), mobile phases: n-hexane, dichloromethane, ethyl acetate and methanol and chemically evaluated by gas chromatography coupled to mass spectrometer (GC/MS). EOs and FRs were tested against larvae of the third stage and pupae of Ae. aegypti by Immersion Test at concentrations ranging from 500.00 to 0.003 mg mL-1 (v/v). The hexane FRs obtained from fruits and leaves were the ones that showed the greatest activity on the larvae (LC99.9= 0.60 mg mL-1 and LC99.9 0.64 mg mL-1, respectively) and pupae (LC99,9 = 2.51 mg mL-1 and 2.61 mg mL-1, respectively). These results were confirmed by the anticholinesterase activity where the hexane (fruit and leaf) FRs presented the highest inhibitory potential on the acetylcholinesterase enzyme (0.156 mg mL-1 and 0.312 mg mL-1, respectively), suggesting the likely mechanism of action. The larvicidal potential can be explained by the presence of the major compounds bicyclogermacrene and germacrene D in the hexane FRs, indicating in this way that they may replace or even act in synergisms with conventional chemical larvicides. In this way the present study opens the field for new researches, aiming the development of products with the compounds bicyclogermacrene and germacrene D, as an alternative in the control of this culicide.

Diversas tecnologias têm sido desenvolvidas para o controle do Aedes aegypti, destacando pesquisas com moléculas isoladas de plantas. A Schinus terebinthifolius (Raddi) (Anacardiaceae), conhecida popularmente como pimenta rosa é uma planta muito utilizada no reflorestamento de áreas degradadas e seus frutos são utilizados como condimentos. O objetivo deste trabalho foi investigar o potencial dos óleosessenciais (OEs) e frações (FRs) obtidos dos frutos e folhas frescos de S. terebinthifolius. Os OEs foram obtidos por hidrodestilação (2 horas), fracionados em coluna cromatográfica utilizando como fase estacionária sílica gel 60 (0,063-0,2mm), fases móveis: n-hexano, diclorometano, acetato de etila e metanol e avaliados quimicamente por cromatografia gasosa acoplada à espectrometria de massas (CG/EM). Os OEs e FRs foram testados frente a larvas do terceiro estádio e pupas do Ae. aegypti pelo Teste de Imersão em concentrações que variaram de 500,00 à 0,003 mg/mL (v/v). As FRs hexano obtidas dos frutos e folhas, foram as que apresentaram maior atividade sobre as larvas (CL99,9= 0,60 mg mL-1 e CL99,9 0,64 mg mL-1, respectivamente) e pupas (CL99,9= 2,51mg mL-1 e 2,61 mg mL-1, respectivamente). Estes resultados foram confirmados pela atividade anticolinesterase onde as FRs hexano (fruto e folha), foram as que apresentaram maior potencial inibitório sobre a enzima acetilcolinesterase (0,156 mg mL-1 e 0,312 mg mL-1, respectivamente), sugerindo desta forma o provável mecanismo de ação. O potencial larvicida encontrado pode ser explicado pela presença dos compostos majoritários biciclogermacreno e germacreno D nas FRs hexano, indicando desta forma, queestes possam vir a substituir, ou até mesmo agir em sinergismos com os larvicidas químicos convencionais. Desta forma o presente estudo abre campo para novas pesquisas, visando o desenvolvimento de produtos com os compostos bicyclogermacrene e germacrene D, como alternativa no controle deste culicídeo.

Chemical variability between different organs of the medicinal plant Casearia sylvestris

The phytochemical profile of essential oils and extracts from Casearia sylvestris leaves, flowers and fruits have been investigated here. Leaf and flower extracts were prepared by sonication and analyzed by thin-layer chromatography and high-performance liquid chromatography. The phenolic content was determined by ultraviolet spectrophotometry. Leaves, flowers, and fruits essential oils were extracted by hydrodistillation. The highest extracts yields were 20.3 % (leaves) and 23.4 % (flowers) with ethanol 70 %. Essential oil extraction yields were 0.3 % (leaves) and 0.1 % (flowers and fruits). Bicyclogermacrene was the major component in all essential oil. Thin-layer chromatography suggests a chemical profile similar for leaves and flowers. The leaves and flowers phenolic content were similar (14.0 and 15.0 %, respectively). Chromatography analyses indicated the predominance of casearin clerodane diterpenes in leaves (λmax 232-235), whereas in flowers, diterpenes with a different standard diene in side-chain C13(16) and C14 (λmax 223-229). The different phytochemical profile of C. sylvestris flowers as compared to the leaves could be explored by the search for new bioactive components. This is the first report on the fruit and flower C. sylvestris essential oil composition. These data could be used as quality control of herbal medicine derived from C. sylvestris leaves.(AU)

Chemical composition of essential oils of leaves, flowers and fruits of Hortia oreadica

Abstract Hortia oreadica Groppo, Kallunki & Pirani, Rutaceae, known as “para-tudo”, “quina”, and “quina-do-campo”, is used in traditional medicine locally to treat stomach pain and fevers. The aims of this study were: analyze the chemical composition of essential oils from leaves, flowers and fruits of H. oreadica and verify the seasonal variation of the chemical components of essential oils from leaves. The essential oils were obtained by hydrodistillation using a Clevenger type apparatus and analyzed by GC/MS. The major components found in the samples of the essential oils were the amorpha-4,7(11)-diene (29.27% – flowers, 20.26% – fruits, 27.66–37.89% – leaves), bicyclogermacrene (23.28% – flowers, 20.64% – fruits, 14.71% to 31.37% – leaves). This work represents the first study of the chemical composition of essential oils from leaves, flowers and fruits and seasonal variation in the essential oils from leaves of H. oreadica.

Essential oils in aerial parts of Myrcia tomentosa: composition and variability

Species in the Myrtaceae family are used in folk medicine to treat gastrointestinal disorders, infectious diseases and hemorrhagic conditions and are known for their essential oil contents. Gas chromatography coupled with mass spectrometry (GC-MS) was used to characterize the chemical composition of essential oils of the leaves, stem bark and flowers of Myrcia tomentosa (Aubl.) DC., as well as to assess the chemical variability in the constituents of the essential oils of the leaf. Soil and foliar analyses were also performed to determine the mineral compositions. Principal component analysis (PCA) was used to examine the interrelationships between the obtained data. The most abundant component in the essential oils of the flowers was (2E,6E)-methyl farnesoate, whereas hexadecanoic acid was the most abundant essential oil component in the stem bark. The leaf essential oils showed seasonal variation in their chemical composition, with bicyclogermacrene and (2E,6E)-methyl farnesoate as the major chemical components. Forty-four constituents were identified, and only nine compounds were found in all of the samples. Sesquiterpenes were mainly produced in the flowers and leaves. The PCA showed a positive correlation between the oxygenated sesquiterpenes and the foliar nutrients Cu and P. Significant statistical correlations were verified between the climatic data, foliar nutrients and essential oil compositions.