Distribution of metabolites in galled and non-galled leaves of Clusia lanceolata and its antioxidant activity

Essential oils of galled and non-galled leaves of Clusia lanceolata Cambess., Clusiaceae, were obtained by hydrodistillation and analyzed by GC and GC/MS. The chemical composition of both oils was similar, with a predominance of sesquiterpene caryophyllenes. The extracts from the leaves were evaluated regarding total phenols, flavonoids and proanthocyanidins. Galled leaves showed higher levels of phenolics and proanthocyanidins, since the content of flavonoids was higher in non-galled leaves. The chromatographic profiles of extracts were obtained by using HPLC/DAD and LC-ESI-MS. Electrospray ionisation (ESI) in positive and negative ion mode was used to identify four flavones C-glycosides in both extracts. The study constitutes a first report on the chemical research of C. lanceolata. The extract from galled leaves had a higher antioxidant activity.

Circadian variation of essential oil from Piper marginatum Jacq / Variaciones circadiana de aceite esencial de Piper marginatum Jacq

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.