Quantitative HPLC analysis of sesquiterpene lactones and determination of chemotypes in Eremanthus seidelii MacLeish & Schumacher (Asteraceae)

Abstract

Eremanthus seidelii MacLeish & Schumacher tem ocorrência restrita ao cerrado, em torno do reservatório de Furnas (MG), em habitats que vêm sendo seriamente deteriorados pela ação humana. A presente investigação fitoquímica mostrou, como metabólitos secundários majoritários das folhas de E. seidelii, as lactonas sesquiterpênicas (LS) 4β,5-diidro-2',3'-diidroxi-15-desoxigoiazensolídeo (1) e 4β,5-diidro-1',2'-epoxi-eremantolídeo-C (2); uma metodologia foi desenvolvida em CLAE para sua análise quantitativa. A análise por CLAE mostrou que não há variações sazonais significativas nas concentrações de ambas LS. Não foram encontradas diferenças qualitativas nos perfis de LS nos indivíduos amostrados. Entretanto, há diferenças no perfil quantitativo entre os indivíduos analisados, apontando para a existência de três quimiotipos quantitativos desta espécie, com diferenças possivelmente originadas na atividade enzimática das enzimas que ciclizam uma LS tipo goiazensolídeo (1) em uma LS tipo eremantolídeo (2).Eremanthus seidelii MacLeish & Schumacher has a restricted occurrence to the Brazilian "cerrado" surrounding the Furnas (MG) reservoir, in environments that have been seriously damaged by human activity. The present phytochemical investigation reveals that the sesquiterpene lactones (SL) 4β,5-dihydro-2',3'-dihydroxy-15-desoxy-goyazensolide (1) and 4β,5-dihydro-1',2'-epoxy-eremantholide-C (2) are the major secondary metabolites in E. seidelii leaves, and an HPLC method was developed for their quantitative analysis. HPLC analysis showed no significant seasonal variation in the concentrations of both SL. No qualitative differences were found in the SL patterns of all individuals sampled. However, there is a different SL quantitative pattern among the plants analyzed, pointing to the existence of three quantitative chemotypes of this species, with differences possibly originating from the activity of the enzymes that cyclize the goyazensolide type SL (1) to a eremantholide type SL (2). Keywords: HPLC, sesquiterpene lactones, chemotypes, populational variation, Eremanthus seidelii IntroductionThe genus Eremanthus Less (Asteraceae: Vernonieae) comprises 22 species that are restricted to the Brazilian "cerrado". 1,2 Previous phytochemical investigations with this genus led to the isolation of flavonoids, triterpenes, poliacetylenes and revealed sesquiterpene lactones (SL) as the main secondary metabolites. 3-9 Some of the SL isolated from the Eremanthus genus posses important biological activities, 3,[6][7][8]10 like the antiproliferative effects on some cancer cell lines 11 and the modulation of the inflammatory process in vitro, by inhibiting the NF-κβ transcriptor factor. 12 Seasonal, 13-16 circadian [17][18][19] and populational 20-24 variations in the content of almost all classes of secondary metabolites, including SL, [25][26][27][28][29] were reported. The recognition of variations in secondary metabolite production can be helpful in chemotaxonomic studies, 1397 Quantitative HPLC Analysis of Sesquiterpene Lactones V...

Spatial and Temporal Variations in Secondary Metabolites Content of the Brazilian Arnica Leaves (Lychnophora ericoides Mart., Asteraceae)

“…To date, STLs from the furanoheliangolide type have been considered as characteristic metabolite and chemotaxonomic marker of subtribe Lychnophorineae due to its isolation from plants of some genus of this subtribe. [28][29][30] However, as can be observed in these results, STLs cannot be considered as chemotaxonomic markers, at least for the species L. ericoides, due to being detected in only one population. Nevertheless, they could be considered as characteristic of a chemotype into the species L. ericoides.…”

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

“…Por outro lado, estudo recente mostrou que os metabólitos secundários de uma espécie vegetal selvagem, amostrada diretamente em seu habitat em três diferentes populações, se mantiveram em concentrações constantes durante os dois anos do estudo, demonstrando, portanto, que em alguns casos o metabolismo secundário pode não se alterar em função de fatores climáticos, temporais ou ambientais 167 .…”

Antiproliferative activity of Eremanthus crotonoides extracts and centratherin demonstrated in brain tumor cell lines

“…Regarding literature data, it can be observed that sequential partition of ethanolic extract from Eremanthus species with solvents of increasing polarity allow the achievement of a sesquiterpene enriched dichloromethane fraction (Sakamoto et al, 2005(Sakamoto et al, , 2010. Thus, chromatographic fingerprint analysis of the dichloromethane fraction (ECD) from leaves of Eremanthus crotonoides (DC.)…”

“…Studies carried out for species from this genus indicated the predominance of sesquiterpene lactones from the furanoheliangolide class (goyazensolide and eremantholide types) as their characteristic constituents (Vichnewski & Gilbert, 1972;Raffauf et al, 1975;Bohlmann et al, 1980Bohlmann et al, , 1981Bohlmann et al, , 1982Vichnewski et al, 1989;Rüngeler et al, 1998;Sacilotto et al, 2002;Sakamoto et al, 2005).…”