Self-organizing maps in chemotaxonomic studies of Asteraceae: a classification oftribes using flavonoid data

Abstract

Flavonóides são considerados bons marcadores químicos da família Asteraceae. Nesse artigo 4700 ocorrências de flavonóides (cerca de 800 substâncias) foram utilizadas em um sistema especialista desenvolvido para estudos taxonômicos. Através do uso de Mapas Auto-Organizáveis foram estabelecidas relações filogenéticas entre as subfamílias e as tribos de Asteraceae, as quais foram classificadas com base no número de ocorrências e nos padrões de oxidação de flavonóides. Os resultados obtidos permitiram a diferenciação das duas subfamílias de Asteraceae a correlação de tribos na subfamília Cichiroideae de acordo com a árvore topológica proposta por Karis o agrupamento de tribos de acordo com a árvore baseada em dados de CpDNA proposta por Jansen e separar as subtribos de Asteroideae bem como as tribos de acordo com o grau de metoxilação x glicosilação de flavonóides. A partir desses resultados pode-se afirmar que o método descrito com dados químicos pode ser utilizado como uma ferramenta complementar na classificação de plantas. Flavonoids have shown good chemical markers for Asteraceae. In this paper, 4,700 occurrences of flavonoids (about 800 compounds) were considered in an expert system developed for taxonomic purposes. Through the use of Self-Organizing Maps (SOM) phylogenetic relationships among the subfamilies and tribes of Asteraceae were established. These taxa were classified on the basis of their occurrences and oxidation patterns of the flavonoids. The obtained results show the separation between the two subfamilies of Asteraceae the correlation among the tribes of the Cichiroideae subfamily according to the topological tree proposed by Karis the clustering of the tribes according to the tree proposed by Jansen based on CpDNA and the separation of the tribes classified in the Asteroideae subfamily as well as the tribes based on the methoxylation x glycosylation level in flavonoids. From these results one can affirm that the method applied with chemical data can be used as a complementary tool in plant classification.

TOCSY, hydrogen decoupling and computational calculations to an unequivocal structural elucidation of a new sesquiterpene derivative and identification of other constituents from Praxelis sanctopaulensis

“…Eupatorieae tribe was restructured by King and Robinson, and some species of the Eupatorium genus were transferred to other genera based only on anatomical characteristics 2 . As appointed earlier, Praxelis genus belong to the same subtribe as Chromolaena (Praxelinae), 13 and since only two species of Praxelis were phytochemically investigated in this work we will compare the flavonoids identified from P. sanctopaulensis with those found in Chromolaena genus.…”

“…Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker Avance III HD spectrometer operating at 500 MHz for proton ( 1 H) and 125 MHz for carbon-13 ( 13 C), using deuterated chloroform (CDCl 3 ) as solvent and tetramethylsilane (TMS) for reference. Conventional 1 H, 13 C, ( 1 H-1 H)-COSY, ( 1 H-13 C)-HSQC and ( 1 H-13 C)-HMBC spectra were used for elucidation. In addition, 1 H-homo decoupled spectra, with selective irradiation in δ H 1.08, and total correlation spectroscopy ( 1 H-TOCSY), with selective excitation of the same signal using D9 = 80 milliseconds, were acquired.…”

“…A voucher specimen was deposited at the herbarium at Universidade Estadual de Ponta Grossa (HUPG 22274). (500 MHz, CDCl 3 ) and 13 C-NMR (125 MHz, CDCl 3 ) data see Table 1.…”

“…[3][4][5][6][7][8][9] Analysis of P. clematidea and P. pauciflora essential oil showed the presence of mono and sesquiterpenes. 9,10 Flavonoids have been isolated in great scale from Asteraceae, [11][12][13] four species of Eupatorium senso latu that occurs in Campos Gerais has been studied by our research group, [14][15][16][17] and in all of these species flavonoids have been found, especially in species belonging to the Chromolaena genus. 12,17 Chromolaena and Praxelis belong to the same subtribe, Praxelinae, and phylogenetic analysis of DNA sequence data showed a close relationship between these genera.…”

Análise metabolômica aplicada à quimiotaxonomia de espécies do gênero <i>Vernonia sensu lato</i> (Vernonieae)

“…A partir dos estudos metabolômicos, é possível comparar diferentes amostras para a determinação de seus componentes, permitindo uma caracterização detalhada sobre as diferenças e semelhanças na composição fitoquímica (KEURENTJES et al, 2006;SCHAUER;ZAMIR;FERNIE, 2005). Assim, ao invés das clássicas e trabalhosas triagens fitoquímicas, os resultados obtidos a partir de técnicas atuais de abordagens metabolômicas, associados a análises multivariadas, podem ser aplicados na quimiotaxonomia para auxiliar nas classificações taxonômicas (ALVARENGA et al, 2001;ALVES, 2009;DA COSTA;TERFLOTH;GASTEIGER, 2005;EMERENCIANO et al, 2007;FERREIRA et al, 2005;GOBBO-NETO;LOPES, 2008;PADILLA-GONZÁLES, 2014 Após a escolha da metodologia analítica mais adequada aos propósitos das análises metabolômicas, as amostras foram injetadas (2μL) em sequência utilizando injetor automático. No início e durante as análises (a cada 50 amostras) foram injetadas solução "branco" de metanol:água (7:3) e amostra "pool", constituída por todas as amostras vegetais, com o intuito de verificar a reprodutibilidade do método.…”