Nos poucos estudos publicados comparando óleos essenciais de espécimes femininos e masculinos de espécies Baccharis, fortes diferenças entre as composições de ambas as amostras foram sempre encontradas. Os experimentos realizados nesta pesquisa utilizam estratégias para minimizar a interferência de fatores genéticos e ecológicos. Os óleos essenciais das folhas de espécimes femininos e masculinos de cinco espécies Baccharis foram pesquisados com uso de um cromatógrafo gasoso acoplado a um espectrômetro de massas e a um detector de ionização de chama (CG-EM-DIC): B. caprariaefolia e B. dracunculifolia, já pesquisadas anteriormente com objetivos similares; e B. coridifolia, B. semiserrata var. elaegnoides e B. pentaptera, as duas últimas ainda não mencionadas na literatura química. Os resultados foram acompanhados por análise hierárquica de grupos, verificando-se a formação de grupos indicativos da grande similaridade entre óleos essenciais dos espécimes masculinos e femininos de todas as cinco espécies. O estudo reafirma o valor das observações de campo na pesquisa de produtos naturais, e aponta fatores genéticos e ecológicos como principais responsáveis por diferenças no metabolismo secundário das plantas estudadas.In the few studies published on essential oils from female and male specimens of Baccharis species, strong differences between the compositions of both samples were always found. The experiments conducted in this study make use of strategies to minimize the interference from genetic and environmental factors. Essential oils from leaves of female and male specimens of five Baccharis species were investigated by gas chromatography-mass spectrometry plus flame ionization detector (GC-MS-FID): B. caprariaefolia and B. dracunculifolia, which have been previously studied with similar aims; and B. coridifolia, B. semiserrata var. elaegnoides and B. pentaptera, the latter two not yet mentioned in the literature. The results were followed by hierarchical cluster analysis, verifying the formation of groups indicative of the great similarity of essential oils from male and female specimens of all five species. The study reinforces the value of field observation in natural product research and points genetic and ecological factors as main responsible for differences in the secondary metabolites of the studied plants.Keywords: Baccharis species, male and female specimens, essential oils J. Braz. Chem. Soc. 1042 Chemical Composition Similarity between Essential Oils Isolated from Male and Female Baccharis Species IntroductionReview articles show that the research regarding the chemical compounds produced by about 120 species from the Baccharis L. (Asteraceae) genus resulted mainly in the isolation of diterpenes and flavonoids.1,2 On the other hand, the available data show that about 52 species from the Baccharis genus have been characterized on the basis of the chemical composition of their essential oils. The seasonal variability of the chemical composition of essential oils from some Baccharis species cultivate...

Recebido em 25/10/12; aceito em 5/5/13; publicado na web em 17/7/13 GC/MS/FID analyses of volatile compounds from cladodes and inflorescences from male and female specimens of Baccharis trimera (Less.) DC. collected in the states of Paraná and Santa Catarina, Brazil, showed that carquejyl acetate was the primary volatile component (38% to 73%), while carquejol and ledol were identified in lower concentrations. Data were subjected to hierarchical cluster analysis and principal component analysis, which confirmed that the chemical compositions of all samples were similar. The results presented here highlight the occurrence of the same chemotype of B. trimera in three southern states of Brazil.

This study aimed to characterize and compare essential oils and ethyl acetate fractions obtained in basic and acidic conditions from both male and female Baccharis species (Baccharis myriocephala and Baccharis trimera) from two different Brazilian regions. Samples were characterized according to their chemical compositions and antiradical activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Principal component analysis (PCA) provided a clear separation regarding the chemical composition of essential oils from the samples obtained from different regions by using gas chromatography–mass spectrometry with flame-ionization detection (GC-MS-FID). PCA also revealed that gender and region of plant collections did not influence the chemical composition and antiradical activity of ethyl acetate fractions, which was corroborated with hierarchical cluster analysis (HCA) data. High performance liquid chromatography with diode-array detector (HPLC-DAD) identified significant quantities of flavonoids and phenolic acids in the fractions obtained in basic and acidic fractions, respectively. The obtained results clearly demonstrated that the geographical region of plant collection influenced the chemical composition of essential oils from the studied Baccharis species. Moreover, the obtained fractions were constituted by several antiradical compounds, which reinforced the usage of these species in folk medicine.

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