Chemical composition of essential oil from Myrcia oblongata DC and potencial antimicrobial, antioxidant and acaricidal activity against Dermanyssus gallinae (Degeer, 1778) / Composição química do óleo essencial de Myrcia oblongata DC e potencial antimicrobiano, antioxidante e acaricida contra Dermanyssus gallinae (DEGEER, 1778)

Essential oils have aroused interest in the industrial sector due to the multitude of potential applications, especially with respect their antimicrobial and antioxidant properties, among others. The objective of this study was to determine the chemical composition of the essential oil from the leaves of Myrcia oblongata DC by gas chromatography coupled to mass spectrometry (GC-MS). To evaluate the antioxidant potential of the oil by using the free radical capture method with 2,2-diphenyl-1-picryl hydrazyl (DPPH); to test the oil antimicrobial activity using the broth microdilution method; and to evaluate the repellency and fumigant potential of the oil on Dermanyssus gallinae (Degeer, 1778). The GC-MS analysis resulted in the identification of 30 oil constituents, with the bulk of the composition identified as caryophyllene oxide (22.03%) and trans-verbenol (11.94%). The oil presented moderate antioxidant activity compared to the synthetic antioxidant 2,6-di-tert-butyl-4-hydroxytoluene (BHT). Antimicrobial activity of the essential oil showed an inhibitory activity on Gram-positive bacteria, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis and for the yeast Candida albicans, and showed no activity against Gram-negative bacteria. All concentrations of the essential oil used in the fumigation test on D. gallinae resulted in mortality below 20%. For the repellency test, significant potential was observed for the concentration of 10%.

Os óleos essenciais tem despertado interesse no setor industrial por apresentarem multiplicidade de aplicações, destacando-se por suas propriedades antimicrobianas, antioxidantes dentre outras. Diante disto, o objetivo deste estudo foi determinar a composição química do óleo essencial das folhas de Myrcia oblongata DC pelo método de cromatografia gasosa acoplada à espectrometria de massas (CG-EM), avaliar o potencial antioxidante do óleo pelo método de captura do radical livre 2,2- difenil-1-picril hidrazil (DPPH), testar a atividade antimicrobiana pelo método de microdiluição em caldo, bem como avaliar a repelência e potencial fumigante deste óleo sobre Dermanyssus gallinae (Degeer, 1778). As análises de CG-EM resultaram na identificação de 30 constituintes, sendo majoritários o óxido de cariofileno (22.03%) e o trans-verbenol (11.94%). O óleo apresentou atividade antioxidante moderada quando comparada ao antioxidante sintético 2,6-di-tert-butil-4-hidroxitolueno (BHT). Em relação à atividade antimicrobiana, o óleo essencial demonstrou atividade inibitória para as bactérias Gram-positivas, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis e Staphylococcus epidermidis, e para levedura Candida albicans e não apresentou atividade para bactérias Gram negativas. Todas as concentrações do óleo essencial testadas no teste de fumigação sobre D. gallinae apresentaram mortalidade inferior a 20%. Para o teste de repelência, observou-se um potencial significativo para a concentração de 10%.

Chemical composition and antibacterial activity of essential oils from the rhizomes of cyperus papyrus L. grown in South Africa / Composición química y actividad antibacterial de los aceites esenciales de los rizomas de cyperus papurus L., crecidos en Sudafrica

Essential oils hydrodistilled from the rhizomes of Cyperus papyrus L. growing wild in two localities (KwaDlangezwa and Richard’s Bay) of uMhlathuze City, KwaZulu-Natal Province, South Africa has been studied. The major components of KwaDlangezwa oil were caryophyllene oxide (12.7 percent), cyperene (10.2 percent) and 1,8-cineole (8.4 percent). The oil of Richard’s Bay comprised mainly of caryophyllene oxide (24.4 percent), humulene epoxide II (13.2 percent), aristolene (9.1 percent) and aromadendrene epoxide II (7.3 percent). The antibacterial activity of the oils was assayed using agar-disc diffusion and broth-microdilution methods. The minimum inhibitory concentration (MIC) revealed that the oil samples inhibited the growth of Staphylococcus aureus (ATCC 3983 and ATCC 6538), with MIC of 1.25 and 0.31 mg/mL for each oil. Streptococcus faecalis (ATCC 29212; MIC of 1.25 and 0.6 mg/mL, respectively) and Escherichia coli (ATCC 4983; MIC of 1.25 mg/mL for both oils). Only the Richard Bay oil showed activity against Bacillus cereus and Bacillus pumilus with MIC of 1.25mg/mL, respectively.

Los aceites esenciales hidrodestilados de los rizomas de Cyperus papyrus L., que crecen en dos localidades (KwaDlangezwa y Bahía Richard) de la ciudad de uMhlathuze, la provincia KwaZulu-Natal, de Sudafrica han sido estudiados. Los mayores componentes del aceite de KwaDlangezwa fueron óxido de cariofileno (12,7 por ciento), cipereno (10,2 por ciento) y 1,8-cineol (8,4 por ciento). El aceite de la bahía de Richard consistió principalmente cariofileno (24,4 por ciento), epóxido II de humuleno (13,2 por ciento), aristoleno (9,1 por ciento) y epóxido II de aromandreno (7,3 por ciento). La actividad antibacterial de los aceites fueron ensayados utilizando la difusión en discos de agar y el método de microdilución en caldo. La concentración mínima inhibitoria (CMI) reveló que las muestras inhibieron el crecimiento de Staphylococcus aureus (ATCC 3983 y ATCC 6538), con una MIC de 1,25 y 0,31 mg/ml de cada aceite. Streptococcus faecalis (ATCC 29212; CMI de 1,25 y 0.6 mg/mL, respectivamente) y Escherichia coli (ATCC 4983; CMI de 1,25 mg/mL para ambos aceites). Solo el aceite de la bahía Richard mostró actividad contra Bacillus cereus y Bacillus pumilis con CMI de 1,25 mg/mL, respectivamente.

Leaf and fruit essential oil compositions of Pimenta guatemalensis (Myrtaceae) from Costa Rica / Aceites volátiles de hojas y frutos de Pimenta guatemalensis (Myrtaceae) de Costa Rica

Pimenta is a genus of flowering plants in the Myrtaceae family, which has about 15 species, mostly found in the Caribbean region of the Americas. Commonly used for culinary and medicinal purposes, the best known commercial species are allspice, P. dioica (P. officinalis) and bay rum, P. racemosa, but there is little information concerning P. guatemalensis. The aim of the present study was to identify the chemical composition of the leaf and fruit essential oils of P. guatemalensis. The extraction of essential oils of P. guatemalensis growing wild in Costa Rica was carried out by the hydrodistillation method at atmospheric pressure, using a modified Clevenger type apparatus. The chemical composition of the oils was analyzed by capillary gas chromatographyflame ionization detector (GC/FID) and gas chromatography-mass spectrometry (GC/MS) using the retention indices on DB-5 type capillary column. A total of 103 and 63 compounds were identified in the leaf and fruit oils, respectively, corresponding to 96.8% and 86.1% of the total amount of the oils. The leaf oil consisted mainly of eugenol (72.8%), and mono- and sesquiterpene hydrocarbons (18.2%). Among terpenes the major components were β-caryophyllene (8.2%) and terpinolene (3.0%). The fruit oil also consisted mainly of eugenol (74.7%) and minor amounts of oxygenated mono- and sesquiterpenes (7.3%), mainly caryophyllene oxide (3.3%). This is the first report of the chemical composition of the essential oils obtained from this plant species. Rev. Biol. Trop. 63 (1): 303-311. Epub 2015 March 01.

Pimenta es un género de plantas perteneciente a la familia Myrtaceae que contiene cerca de 15 especies, la mayoría ubicadas en las regiones del Caribe del Continente Americano, donde es utilizado con propósitos culinarios y medicinales. Las especies comerciales mejor conocidas son “pimienta de Jamaica” (P. dioica o P. officinalis) y “bay-rum” (P. racemosa) y existe muy poca información científica acerca de la especie P. guatemalensis. Cuando las hojas y frutos son triturados, desprenden un aroma de composición desconocida. El objetivo del presente estudio fue identificar la composición química de los aceites esenciales de las hojas y frutos de P. guatemalensis. La extracción de los aceites esenciales de P. guatemalensis, una especie arbórea silvestre en Costa Rica, se efectuó mediante el método de hidrodestilación a presión atmosférica, empleando un aparato de vidrio de tipo Clevenger. Se analizó la composición química de los aceites esenciales mediante cromatografía de gases con detector de ionización de flama (GC/FID) y cromatografía de gases acoplada a un detector de masas (GC/MS) y, utilizando índices de retención en una columna cromatográfica capilar tipo DB-5. En los aceites de hojas se identificaron 103 y en los de frutos 63 compuestos, correspondiendo a 96.8% y 86.1%, respectivamente, de los constituyentes totales. El aceite de las hojas está constituido principalmente por compuestos de naturaleza fenilpropanoide (72.9%) y de hidrocarburos monoterpénicos y sesquiterpénicos (18.2%). Los componentes mayoritarios del aceite de las hojas se identificaron como eugenol (72.8%), β-cariofileno (8.2%) y terpinoleno (3.0%). El aceite de los frutos está constituido principalmente por eugenol (74.7%), monoterpenos y sesquiterpenos oxigenados (7.3%) principalmente óxido de cariofileno (3.3%). Este es el primer informe acerca de la composición química de aceites esenciales obtenidos a partir de esta especie vegetal.

Composition of essential oil and allelopathic activity of aromatic water of Aster lanceolatus Willd: (Asteraceae) / Composição do óleo essencial e atividade alelopática de água aromática de Aster lanceolatus Willd: (Asteraceae)

The essential oil obtained from flowers of Aster lanceolatus was submitted the CG-MS and presented as result thirteen substances with largest concentration; among them, the caryophyllene oxide with the larger one. The aromatic water obtained during the extraction process of this essential oil was forwarded to allelopathic test, and demonstrated to be capable to inhibit the germination and growth of Lactuca sativa.

O óleo essencial obtido das flores de Aster lanceolatus foi submetido a CG-EM e apresentou como resultado treze substâncias, entre elas o óxido de cariofileno com a maior concentração. A água aromática obtida durante o processo de extração do óleo essencial foi encaminhada para teste alelopático, a qual demonstrou ser capaz de inibir a germinação e crescimento de Lactuca sativa.