Insecticidal activity of Gallesia integrifolia (Phytolaccaceae) essential oil / Actividad insecticida del aceite esencial de Gallesia integrifolia (Phytolaccaceae)

This study evaluated the insecticidal activity of Gallesia integrifolia essential oil from fruits, leaves, and flowers against Aedes aegyptilarvae and pupae. The essential oil was obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry. Sulfur compounds represented 95 to 99% of the essential oil from fruits, leaves, and flowers. Essential oil major compounds were 2,8-dithianonane (52.6%) in fruits, 3,5-dithiahexanol-5,5-dioxide (38.9%) in leaves, and methionine ethyl ester (45.3%) in flowers. The essential oils showed high activity against larvae, and low for pupae withLC99.9of 5.87 and 1476.67µg/mL from fruits; 0.0096 and 348.33 µg/mL from leaves and 0.021and 342.84 µg/mL from flowers, respectively. The main compound with insecticide activity is probably n-ethyl-1,3-dithioisoindole, from isoindole organothiophosphate class, found in greater amount in flower and leaf essential oil. The great insecticide activity of G. integrifolia essential oil suggests that this product is a natural insecticide.

Este estudio evaluó la actividad insecticida del aceite esencial de frutos, hojas y flores de Gallesia integrifolia contra larvas y pupas de Aedes aegypti. El aceite esencial se obtuvo por hidrodestilación y se caracterizó por cromatografía de gases acoplada a espectrometría de masas. Los compuestos de azufre representaron del 95 al 99% del aceite esencial de frutas, hojas y flores. Los compuestos principales del aceite esencial fueron 2,8-ditianonano (52,6%) en frutas, 3,5-ditiahexanol-5,5-dióxido (38,9%) en hojas y éster etílico de metionina (45,3%) en flores. Los aceites esenciales mostraron alta actividad contra larvas y baja para pupas con LC99.9de 5.87 y 1476.67µg/mL de frutos; 0,0096 y 348,33 µg/mL de hojas y 0,021 y342,84 µg/mL de flores, respectivamente. El principal compuesto con actividad insecticida es probablemente el n-etil-1,3-ditioisoindol, de la clase de los organotiofosfatos de isoindol, que se encuentra en mayor cantidad en el aceite esencial de flores y hojas. La gran actividad insecticida del aceite esencial de G. integrifolia sugiere que este producto es un insecticida natural.

Actividad antioxidante y antibacteriana del aceite esencial de hoja de Myrcianthes pungens / Antioxidant and antibacterial activity of Myrcianthes pungens leaf essential oil

Myrcianthes pungens (Myrtaceae) es un árbol nativo de Brasil conocido como guabijú. En nuestro estudio, describimos la composición química del aceite esencial de las hojas secas de M. pungens, la actividad antioxidante por diferentes métodos y la actividad antibacteriana contra Staphylococcus aureus, Bacillus cereus y Pseudomonas aeruginosa. La identificación química se realizó mediante un cromatógrafo de gases acoplado a un espectrómetro de masas y la actividad antibacteriana se evaluó mediante un método de microdilución en caldo. El aceite esencial de la hoja presentó sesquiterpenos de hidrocarburos (42,6%) como su principal clase química cuyos compuestos principales fueron ß-cariofileno (11,7%) y 1,8-cineol (10,1%). La mayor protección antioxidante fue de 57.5 a 63.3% de ß-caroteno. La mayor actividad antibacteriana fue contra S. aureus (MIC de 78.12 µg/mL). Este valor fue 2,56 veces menor que el control positivo de estreptomicina. M. pungens es una fuente prometedora de moléculas naturales con potencial estudio para el desarrollo de productos farmacológicos, cosméticos y alimenticios.

Myrcianthes pungens (Myrtaceae) is a native tree to Brazil known as guabijú. In our study, we described the chemical composition of the essential oil from M. pungens dried leaves, the antioxidant activity by different methods and antibacterial activity against Staphylococcus aureus, Bacillus cereus and Pseudomonas aeruginosa. The chemical identification was done by gas chromatograph coupled to mass spectrometer and antibacterial activity was evaluated by broth microdilution method. The leaf essential oil presented hydrocarbon sesquiterpenes (42.6%) as its main chemical class whose major compounds were ß-caryophyllene (11.7%) and 1,8-cineole (10.1%). The best antioxidant protection was from 57.5 to 63.3% of ß-carotene. The highest antibacterial activity was against S. aureus (MIC of 78.12 µg/mL). This value was 2.56-fold lower than the positive streptomycin control. M. pungens is a promising source of natural molecules with potential study for the development of pharmacological, cosmetic and food products.

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.