ABSTRACT
Some known flavonols from the outer bark polar fraction of the native species Croton polycarpus Benth. (Euphorbiaceae) were isolated and quercetin, quercitrin and rutin were identified as the most abundant constituents. From this sample, a clean TLC non polar sub- fraction (A-1) obtained by CC, afforded several isomeric compounds, which were characterized by GC-MS/EI and its results conduct to a group of eighteen sesquiterpenoids with a unique Rf value in TLC; among them, one sesquiterpene hydrocarbon with molecular weight (MW) of 200 g/mol (C15H20), two with MW 202 g/mol,(C15H22), thirteen with a MW of 204 g/mol (C15H24) and two sesquiterpenols with MW 220 g/mol (C15H24O) were determined. From its fresh leaves essential oil obtained by two methods, hydro-distillation and supercritical CO2 extraction, other terpenoids were identified, where the first one process was more efficient (1.5% DM yield) than the last one, and it was selected for a pilot study. This is the first report about chemical composition of the native species C. polycarpus, and the analysis of sesquiterpene isomerism is very important to recognize its structural diversity and similar chemical behavior.
De la fraccioÌn polar de la corteza de la especie nativa Croton polycarpus, (Euphorbiaceae) se separaron algunos flavonoles y quercetina, quercitrina y rutina se identificaron como los constituyentes maÌs abundantes. Desde una fraccioÌn apolar de esta muestra, se obtuvo por CC una fraccioÌn limpia en CCD (C-2), cuyo fraccionamiento por anaÌlisis por CGAR-EM/IE permitioÌ determinar un grupo de 18 sesquiterpenoides mayoritarios los cuales presentan un valor uÌnico de Rf; entre estos se detectoÌ un hidrocarburo de PM 200 (C15H20), dos derivados de PM 202 (C15H22), trece son hidrocarburos isoÌmeros con PM 204 g/mol (C15H24) y dos terpenoles de PM 220 uma (C15H24O). De igual forma, de las hojas frescas se extrajo el aceite esencial, por dos meÌtodos: hidrodestilacioÌn y extraccioÌn con CO2 supercriÌtico (SFE), y el primero de ellos fue el maÌs eficiente (1,5% rendimiento en peso seco) por lo cual se seleccionoÌ para el desarrollo de experimentos a escala de planta piloto. Este informe es la primera contribucioÌn al conocimiento de la composicioÌn quiÌmica y la bioactividad de las hojas y corteza de la especie arboÌrea nativa Croton polycarpus (Euphorbiaceae) y el anaÌlisis de mezclas de sesquiterpenos isoÌmericos es muy importante para reconocer la diversidad estructural y su similitud en polaridad y comportamiento quiÌmico.
Subject(s)
Sesquiterpenes/analysis , Flavonoids/analysis , Plant Leaves/chemistry , Croton/chemistry , Plant Bark/chemistry , Isomerism , Gas Chromatography-Mass SpectrometryABSTRACT
The essential oils extracted from leaves of the Southern Brazilian native species Drimys angustifolia Miers (DA) and Drimys brasiliensis Miers (DB) by Clevenger distillation were analyzed by gas chromatography/mass spectrometry (GC/MS). The oils of DA and DB consisted predominantly of monoterpenoids and sesquiterpenoids. The largest components of DA oil were bicyclogermacrene (19.6%), sabinene (9.7%)and myrcene (5.2%), while DB oil was characterized by cyclocolorenone (18.2%), followed by terpinen-4-ol (8.7%) and alpha-gurjunene (6.9%). Laboratory tests were carried out to determine the repellency of the essential oils to the drywood termite Cryptotermes brevis (Isoptera: Kalotermitidae). It was observed that the oil showed repellency at the concentrations 25, 12.5, and 6.25 μg/mL. The oils of both species exhibited a negative repellency index, which represents repellent activity, except for DA oil at the highest concentration, which was attractive. Five deaths (11% of the termitesample) were observed at 25 μg/mL DA, in the fourhour repellency test, while four deaths occurred at 12.5 μg/mL (approximately 9%). The essential oil of DB did not cause any termite deaths...
Os óleos essenciais obtidos das folhas das árvores nativas do sul do Brasil Drimys angustifolia Miers (DA)e Drimys brasiliensis Miers (DB) foram analisados por cromatografia gasosa acoplada a espectrometria de massas (CG/EM). O óleo de DA foi caracterizado pela presença de monoterpenóides e sesquiterpenóides, biciclogermacreno (19,6%), seguido por sabineno (9,7%) e mirceno (5,2%). O óleo de DB foi caracterizado por sesquiterpenóides e monoterpenóides, ciclocolorenona (18,2%), seguido por terpinen-4-ol (8,7%) e alfagurjuneno(6,9%). Os testes foram realizados a fim de se determinar o potencial repelente dos óleos essenciais contra o cupim de madeira seca Cryptotermes brevis (Isoptera: Kalotermitidae) nas doses de 25, 12,5, e 6,25 μg/mL. Ambas as espécies mostraram índice de repelência negativo, o que representa a ocorrência da atividade repelente, exceto na maior concentração de DA, na qual o óleo mostrou-se atraente. Cinco mortes foram observadas na concentração de 25 μg/mL de DA, correspondendo a 11% do total em quatro horas de análise, sendo que 9% ocorreram na concentração de 12,5 μg/mL. No caso do óleo essencial de DB não foram observadas mortes de cupins...
Subject(s)
Drimys , Insect Repellents , Isoptera , Oils, VolatileABSTRACT
The volatile compounds obtained by SFE-CO2 (supercritical fluid extraction utilizing CO2) from the barks of Aniba canelilla (H. B. K.) Mez. (Lauraceae) were analyzed by HRGC-FID (high resolution gas chromatography - flame ionization detector) and HRGC-MS (high resolution gas chromatography -mass spectrometry). Phenylpropanoids and lower amounts of sesquiterpenoids, representing ca. 97 percent of the total oil, were identified. The main compound, 2-phenylnitroethane, corresponds to 71,12 percent of the total oil.
Os constituintes químicos voláteis das cascas de Aniba canelilla (H. B. K.) Mez. (Lauraceae), obtidos por SFE-CO2 (extração com fluido supercrítico utilizando CO2), foram analisados por HRGC-FID (cromatografia gasosa de alta resolução com detector de ionização de chama) e HRGC-MS cromatografia gasosa de alta resolução acoplada à espectrometria de massas). Foram identificados fenilpropanóides e sesquiterpenos, estes últimos em pequenas quantidades, representando cerca de 97 por cento da composição total da fração volátil. O principal componente, 2-fenilnitroetano, corresponde a 71,12 por cento do extrato obtido por SFE.