Chemical investigations of asterÃceas of CearÃ: Baccharis trinervis, Eupatorium ballotaefolium, Eupatorium betonicaeforme, Eupatorium pauciflorum, Pectis apodocephala, Pectis oligocephala, Verbesina diversifolia, Vernonia chalybaea e Vernonia scorpioides

Este trabalho descreve a investigaÃÃo quÃmica de plantas da famÃlia Asteraceae nativas da flora cearense, pertencentes aos gÃneros Baccharis, Eupatorium, Pectis, Verbesina e Vernonia. Eupatorium ballotaefolium H.B.K. e E. betonicaeforme Baker foram selecionados para o estudo da composiÃÃo quÃmica volÃtil e nÃo-volÃtil, enquanto Baccharis trinervis (Lam.) Pers., E. pauciflorum Kunth, Pectis apodocephala Baker, P. oligocephala Baker, Verbesina diversifolia D.C., Vernonia chalybaea Mart. e V. scorpioides (Lam.) Pers, tiveram exclusivamente a composiÃÃo quÃmica dos Ãleos essenciais determinados. O potencial antimicrobiano, larvicida e nematicida de alguns Ãleos foi avaliado. O Ãleo essencial de B. trinervis apresentou moderada atividade antimicrobiana, enquanto os Ãleos essenciais de P. apodocephala, P. oligocephala e E. betonicaeforme, incluindo dois de seus principais constituintes, 2,2-dimetil-6-vinilcroman-4-ona e 2-senecioil-4-vinilfenol, apresentaram significativa atividade larvicida contra larvas do Aedes aegypti. Os Ãleos essenciais das Pectis acima mencionadas, tambÃm apresentaram propriedades nematicida contra o fito-nematÃide Meloidogyne incognita. Neste trabalho investigou-se ainda, a composiÃÃo dos Ãcidos graxos contidos nas fraÃÃes apolares dos extratos hexÃnicos da parte aÃrea de E. ballotaefolium e E. betonicaeforme. Foram identificados um total de 13 Ãcidos graxos, sendo o Ãcido hexadecanÃico (C16:0) o constituinte majoritÃrio para ambas as espÃcies. A prospecÃÃo quÃmica relativa Ãs duas espÃcies de Eupatorium resultou no isolamento e identificaÃÃo de 11 substÃncias para E. ballotaefolium e 17 substÃncias para E. betonicaeforme. Do extrato hexÃnico da parte aÃrea de E. ballotaefolium isolou-se, em mistura, os fitoesterÃides β- sitosterol e estigmasterol e os triterpenos acetato de taraxasterila e taraxasterol, enquanto do extrato etanÃlico, foram isolados e caracterizados os flavonÃides nepetina e quercetina na forma glicosilada e as formas glicosÃdicas do sitostetol e estigmasterol. Do extrato hexÃnico das raÃzes foram isolados os triterpenos epifriedelanol e dammara-20,24-dien-3β-ol e do extrato etanÃlico foi obtida a cumarina 11-hidroxi-11,12-di-hidroobliquina. Do extrato hexÃnico das flores de E. betonicaeforme foram isolados uma lactona sesquiterpÃnica, 8β- angeloiloxi-9β,10β-di-hidroxi-1-oxo-germacra-4E,11(13)dien-12,6α-olido, uma lactona de cadeia longa, 3β-hidroxieicosan-1,5β-olido, os diterpenos Ãcido grandiflÃrico e Ãcido 15α- decanoiloxi-caur-16-en-19-Ãico, o esterÃide espinasterol e o Ãcido hexacosanÃico, enquanto do extrato etanÃlico, foram isolados o triterpeno acetato de taraxasterila e os flavonÃides, nepetina, canferol e ramnocitrina. Do extrato hexÃnico das raÃzes, isolou-se em mistura, os xxiv esterÃides β-sitosterol e estigmasterol, enquanto do extrato etanÃlico isolou-se a cromona 6,6- acetil-2,2-dimetilcroman-4-ona e o flavonÃide nepetina. Do extrato hexÃnico da parte aÃrea isolou-se a mistura binÃria dos triterpenos α- e β-amirina, alÃm do acetato de taraxasterila. De acordo com o levantamento bibliogrÃfico, o diterpeno denominado Ãcido 15α-decanoiloxicaur- 16-en-19-Ãico, ainda nÃo havia sido registrado na literatura e os constituintes 8β- angeloiloxi-9β,10β-di-hidroxi-1-oxo-germacra-4E,11(13)dien-12,6α-olido, 3β- hidroxieicosan-1,5β-olido, 2,2-dimetil-6-vinil-croman-4-ona, 6-acetil -2,2-dimetil-croman-4- ona, 2-senecioil-4-vinilfenol e damara-20,24-dien-3β-ol, estÃo sendo registrados pela primeira vez no gÃnero. A lactona 8β-angeloiloxi-9β,10β-di-hidroxi-1-oxo-germacra-4E,11(13)dien- 12,6α-olido e o flavonÃide nepetina apresentaram moderado potencial citotÃxico quando testados frente a um painel de cÃlulas tumorais, apresentando IC50 nas faixas de 1,27-7,16 e 5,48-15,12 μg/mL, respectivamente. A determinaÃÃo estrutural dos metabÃlitos secundÃrios isolados neste trabalho envolveu o uso de tÃcnicas espectromÃtricas como infravermelho (IV), espectrometria de massa (EM) e ressonÃncia magnÃtica nuclear de hidrogÃnio (RMN 1H) e carbono-13 (RMN 13C), incluindo tÃcnicas bidimensionais como COSY, HMQC, HMBC e NOESY, bem como comparaÃÃo com dados descritos na literatura.This work describes the chemical investigation of native plants of the Asteraceae family from Cearà State flora, belonging to the genera Baccharis, Eupatorium, Pectis, Verbesina and Vernonia. Eupatorium ballotaefolium H.B.K. and E. betonicaeforme Baker were selected to study their volatile and non-volatile chemical composition, while for Baccharis trinervis (Lam.) Pers., E. pauciflorum Kunth, Pectis apodocephala Baker, P. oligocephala Baker, Verbesina diversifolia D.C., Vernonia chalybaea Mart. and V. scorpioides (Lam.) Pers only the chemical composition of the essential oils, was determined. The antimicrobial, larvicidal and nematicidal potential of some of the oils were evaluated. The essential oil of B. trinervis showed moderate antimicrobial activity, while the essential oils of P. apodocephala, P. oligocephala and E. betonicaeforme, including two of their major constituents, 2,2-dimethyl-6-vinylchroman-4-one and 2-senecioyl-4-vinylphenol, showed significant larvicidal activity against the Aedes aegypti larvae. The essential oils from the above mentioned Pectis species also showed nematicidal properties against the nematode Meloidogyne incognita. The fatty acid composition of the apolar fractions from the hexane extracts of the aerial parts of E. ballotaefolium and E. betonicaeforme was also examined. A total of 13 fatty acids were identified, being hexadecanoic acid (C16:0) the major compound for both species. The chemical analysis of both Eupatorium species resulted in the isolation and characterization of 11 substances for E. ballotaefolium and 17 substances for E. betonicaeforme. From the hexane extract of the aerial parts of E. ballotaefolium was isolated a mixture of β-sitosterol and stigmasterol, the triterpenes taraxasteryl acetate and taraxasterol, while the flavonoids nepetin and quercetin-3-O-glucoside and a binary misture of sitosterol and stigmasterol glucosilated, were isolated from the ethanol extract. From the hexane extract of the roots were isolated the tritepenes epifriedelanol and dammara-20,24-dien-3β-ol and from the ethanol extract was obtained the coumarin 11-hydroxy-11,12-di-hydroobliquine. From the hexane extract of E. betonicaeforme flowers a sesquiterpene lactone, 8β- angeloyloxy-9β,10β-dihydroxy-1-oxo-germacra-4E,11(13)dien-12,6α-olide, a long chain lactone 3β-hydroxiicosan-1,5β-olide, the diterpenes grandifloric and 15α-decanoyloxy-kaur- 16-en-19-oic acids, the steroid spinasterol and hexacosanoic acid were isolated. From the ethanol extract were isolated taraxasteril acetate, nepetin, kaempferol and ramnocitrin. From the hexane extract of the roots were isolated the mixture of β-sitosterol and stigmasterol, while from the ethanol extract were isolated 6,6-acetyl-2,2-dimethylcroman-4-one and nepetin. The hexane extract of the aerial parts were obtained the binary mixture of α- and β- amyrin, and taraxasteryl acetate. To the best of our knowledge the diterpene characterized as 15α-decanoyloxy-kaur-16-en-19-oic acid is a new substance while the compounds 8β- angeloyloxy-9β,10β-dihydroxy-1-oxo-germacra-4E,11(13)dien-12,6α-olide, 3β- hydroxyeicosan-1,5β-olide, 2,2-dimethyl-6-vinyl-chroman-4-one, 6-acetyl-2,2-dimethylchroman- 4-one, 2-senecioyl-4-vinylphenol and dammara-20,24-dien-3β-ol are being reported for the first time to the genus. The lactone 8β-angeloyloxy-9β,10β-dihydroxy-1-oxogermacra- 4E,11(13)dien-12,6α-olide and the flavonoid nepetin showed moderated cytotoxic activity against a panel of five cell lines with IC50 in the range of 1,27-7,16 e 5,48-15,12 μg/mL, respectively. The structures of all secondary metabolites were established using spectrometric data such as IR, MS, 1H and 13C NMR, including bidimensional techniques (COSY, HMQC, HMBC and NOESY), and comparison with from the literature data