ABSTRACT
Essential oils from the leaves and stems of Croton adenocalyx, C. grewioides, C. heliotropiifoliusand C. blanchetianus obtained through hydrodistillation were analyzed by GC-MS. We then investigated the lethal and sublethal effects of the Croton oils and 15 major constituents against Tetranychus urticae. ß-Caryophyllene was the major component in the leaf and stem oils from C. heliotropiifolius and C. adenocalyx. Spathulenol and (E)-anethole were the major constituents identified in the leaf and stem oils of C. blanchetianus and C. grewioides, respectively. The oil with the greatest lethal and sublethal effects was those from C. adenocalyx. Among the constituents ß-caryophyllene and spatulenol were the most toxic to the mite, where as eugenol and methyl eugenol were the most repellent. The toxicity and repellency of the Croton oils, particularly the oils from C. adenocalyx, demonstrate that these oils constitute a promising alternative to synthetic acaricides for use in the control of T. urticae.
Los aceites esenciales de las hojas y tallos de Croton adenocalyx, C. growioides, C. heliotropiifolius y C. blanchetianus obtenidos mediante hidrodestilación fueron analizados a través de GC-MS. Se investigaron los efectos letales y subletales de los aceites de Croton y 15 componentes principales contra Tetranychus urticae. El ß-cariofileno fue el componente principal en los aceites de hojas y tallos de C. heliotropiifolius y C. adenocalyx. El espatulenol y el (E)-anetol fueron los principales componentes identificados en los aceites de hojas y tallos de C. blanchetianus y C. growioides, respectivamente. El aceite con los mayores efectos letales y subletales fue el de C. adenocalyx. Entre los componentes, el ß-cariofileno y el espatulenol fueron los más tóxicos para el ácaro, mientras que el eugenol y el metil eugenol fueron los más repelentes. La toxicidad y la repelencia de los aceites de Croton, particularmente los aceites de C. adenocalyx, demuestran que estos aceites constituyen una alternativa prometedora respecto a los acaricidas sintéticos para uso en el control de T. urticae.
Subject(s)
Animals , Oils, Volatile/pharmacology , Croton/chemistry , Tetranychidae/drug effects , Acaricides/pharmacology , Terpenes/analysis , Oils, Volatile/chemistry , Chromatography, Gas/methods , Plant Leaves , Acaricides/chemistryABSTRACT
The aim of this study was to investigate the chemical composition and acaricidal effect of two Psidium species essential oils and selected compounds on Tetranychus urticae. Essential oils from the leaves of Psidium laruotteanum and Psidium myrsinites were obtained through hydrodistillation, analyzed using CG-FID and CG-MS and evaluated for toxicity to T. urticae by fumigation and residual contact. The susceptibility of T. urticae to monoterpenes and sesquiterpenes was also investigated. The major constituents of the P. laruotteanum oil were (E)-nerolidol (9.6 ± 0.4%) and γ-terpinene (9.4 ± 0.6%) and the major constituents of the P. myrsinites oil were ß-caryophyllene (21.2 ± 0.9%) and α-humulene (10.3 ± 0.5%). Based on the LC50 estimates, no significant differences were found between the two oils regarding toxicity by fumigation or residual contact. ß-Caryophyllene and (E)-nerolidol had the highest level of toxicity, independently of the method investigated. The findings indicate that both oils and selected constituents, especially ß-caryophyllene and (E)-nerolidol, are promising as natural acaricidal agents that affect T. urticae through more than one mode of action.
Los aceites esenciales de las hojas de Psidium laruotteanum y Psidium myrsinites se obtuvieron por hidrodestilación, se analizaron por CG-FID y CG-MS, y se evaluaron sus toxicidades por fumigación y contacto residual contra Tetranychus urticae. Se investigó también la susceptibilidad del T. urticae a monoterpenos y sesquiterpenos. En el aceite esencial de P. laruotteanum, (E)-nerolidol (9.6 ± 0.4%) y γ-terpinene (9.4 ± 0.6%) se identificaron como constituyentes mayoritarios, mientras que en el aceite esencial de P. myrsinites, ß-caryophyllene (21.2 ± 0.9%) y α-humulene (10.3 ± 0.5%) se encontraron como mayoritarios. Con base en las CL50 estimadas, no se observaron diferencias significativas entre las toxicidades de los aceites por fumigación, y tampoco por contacto residual. ßCaryophyllene y (E)-nerolidol presentaron las mayores toxicidades, independientemente del método investigado. Estos resultados indican, que los dos aceites, así como los constituyentes seleccionados, entre los que se destacan ß-caryophyllene y (E)-nerolidol, son promisores agentes acaricidas naturales por actuar en el T. urticae por más de un mecanismo de acción.
Subject(s)
Animals , Oils, Volatile/pharmacology , Plant Leaves/chemistry , Tetranychidae/drug effects , Psidium/chemistry , Acaricides/pharmacology , Terpenes/analysis , Brazil , Oils, Volatile/chemistry , Pest Control , Fumigation , Acaricides/chemistry , Flame Ionization , Gas Chromatography-Mass SpectrometryABSTRACT
Essential oils from leaves of Ocotea limae and Ocotea gardneri species were analyzed by GC-FID and GC-MS. The analysis revealed the presence of 48 components accounting for 98.1 ± 1.3% e 98.0 ± 0.5% of the essential oils from the O. limae and O. gardneri, respectively. The oils were characterized by high percentage of sesquiterpenes. The mains compounds identified in the essential oils were spathulenol (13.3 ± 0.5%), ß-caryophyllene (12.4 ± 0.5%), bicyclogermacrene (11.3 ± 0.4%) and germacrene D (10.9 ± 0.3%) from the O. limae and germacrene D (26.9 ± 0.9%) e bicyclogermacrene (21.7 ± 0.7%) from the O. glomerata.
Los aceites esenciales de hojas de Ocotea limae y Ocotea gardneri fueron analizados por GC-FID y GC-MS. El anaÌlisis reveloÌ la presencia de 48 componentes que representan 98,1 ± 1,3% y 98,0 ± 0,5% de los aceites esenciales de O. limae y O. gardneri, respectivamente. Los aceites se caracterizaron por un alto porcentaje de sesquiterpenos. Los principales compuestos identificados en los aceites esenciales fueron espatulenol (13,3 ± 0,5%), ß-cariofileno (12,4 ± 0,5%), biciclogermacreno (11,3 ± 0,4%) y germacreno D (10,9 ± 0,3%) de O. limae y germacreno D (26,9 ± 0,9%) y bicyclogermacreno (21,7 ± 0,7%) de la O. glomerata.
Subject(s)
Sesquiterpenes/analysis , Oils, Volatile/chemistry , Plant Leaves/chemistry , Ocotea , Terpenes/analysis , Brazil , Chromatography, Gas/methodsABSTRACT
ABSTRACT Essential oils from the leaves of two species of the genus Ocotea that occur in the Atlantic Forest in the state of Pernambuco, Brazil, were analyzed using gas chromatography-mass spectrometry. The acaricidal activity of these oils as well as 11 selected components and blends were evaluated in fumigation and residual contact tests against the two-spotted spider mite (Tetranychus urticae). Sixty-seven constituents were identified, totaling 97.3 ± 0.3% and 97.8 ± 0.5% of the oils from O. duckei and O. glomerata, respectively. Sesquiterpene was the dominant class. The compounds β-caryophyllene (18.6 ± 0.1%) and aromadendrene (17.3 ± 0.6%) were the main constituents of the oils from O. duckei and O. glomerata, respectively. Acaricidal action varied depending on the method employed, species and chemical nature of the selected constituents. The mites were susceptible to the oils and chemical constituents using the fumigation method. The O. duckei oil was respectively 2.5-fold and 1.5-fold more toxic than the O. glomerata oil using the fumigation and residual contact methods. Among the selected constituents, β-caryophyllene was the most toxic, independently of the method employed. The individual toxicity of the selected compounds and their blends as well as the role of these constituents in the overall toxicity of the essential oils are also discussed.
Subject(s)
Animals , Terpenes/toxicity , Oils, Volatile/toxicity , Ocotea/chemistry , Tetranychidae/drug effects , Acaricides/toxicity , Terpenes/isolation & purification , Brazil , Acaricides/isolation & purification , Gas Chromatography-Mass SpectrometryABSTRACT
The composition of the essential oil from the leaves of Piper marginatum (Piperaceae) shows circadian variation and a higher yield during high solar incidence. The essential oils samples were investigated by GC-FID and GC-MS, which allowed identification of 29 compounds. Principal component analysis (PCA) and cluster analysis (CA) showed a significant quantitative variability in the chemical composition of the studied samples as well as a correlation between the oil profiles and the collection time. Two main groups were observed, with predominance of phenylpropanoids or sesquiterpenes. The predominant chemical compounds were phenylpropanoids, having as main representative (Z)-asarone and (E)-asarone.
La composición del aceite esencial de hojas de Piper marginatum (Piperaceae) muestra una variación circadiana y un mayor rendimiento durante la mayor incidencia solar. Las muestras de aceites esenciales se investigaron por GC-FID y GC-MS, lo que permitió la identificación de 29 compuestos. El análisis de componentes principales y el análisis de conglomerados mostraron una variación cuantitativa significativa en la composición química de las muestras estudiadas, así como una correlación entre los perfiles del aceite esencial y el tiempo de recolección. Se observaron dos grupos principales, con predominio de fenilpropanoides o sesquiterpenos. Los compuestos predominantes fueron los fenilpropanoides, (Z)-asarona y (E)-asarona.