Chemical study and Biological Evaluation of Bauhinia acuruana Moric

Autor: Roberto Wagner da Silva Gois
Jazyk: portugalština
Rok vydání: 2015
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFCUniversidade Federal do CearáUFC.
Druh dokumentu: Doctoral Thesis
Popis: Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
FundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
O presente trabalho relata a investigaÃÃo quÃmica das raÃzes, do caule e das folhas de Bauhinia acuruana. Nesse estudo foram obtidos os extratos em hexano, em acetato de etila e em metanol das folhas e os extratos em etanol das raÃzes e do caule. O fracionamento cromatogrÃfico destes extratos permitiu o isolamento dos sesquiterpenos 1β, 6α-diidrÃxi-4(14)-eudesmeno (BA-1), aromadendrano-4β,10α-diol (BA-2); do esteroide sitosterol glicosilado (BA-4); dos bibenzis 2-hidroxi-2â,3â,5â-trimetoxibibenzila (BA-5) e 2-hidroxi-3â,5â-dimetoxibibenzila (BA-6); dos derivados oxepÃnicos pacharina (BA-7) e bauhiniastatina 1 (BA-8); dos flavonoides quercitrina (BA-3), (-)-fisetinidol (BA-9), (2R, 3S)-2-(3â,4â-diidroxifenil)-5-metoxicromano-3,7-diol (BA-10), (2R, 3S)-2-(3â,4â-diidroxifenil)-5-metoxi-6-metilcromano-3,7-diol (BA-11) e astilbina (BA-13); bem como da mistura dos esteroides sitosterol e estigmasterol (BA-12). Cabe ressaltar que os metabÃlitos secundÃrios BA-1 e BA-2 sÃo inÃditos no gÃnero, enquanto BA-5 e BA-11 sÃo inÃditos na literatura e BA-10 à inÃdito como produto natural. As estruturas dos compostos foram elucidadas atravÃs de tÃcnicas espectroscÃpicas (IV, RMN 1D e 2D), espectrometria de massas e comparaÃÃo com dados descritos na literatura. Os extratos em etanol das raÃzes e dos caules foram submetidos a testes de atividade antioxidante, apresentando atividades significativas nas concentraÃÃes de 0,1 mg/mL e 1,0 mg/mL. BA-7 foi avaliado quanto à sua atividade larvicida sobre Aedes aegypti e apresentou valor de CL50 igual a 78,9Â1,8 Âg/mL. Por outro lado, BA-5, BA-7, BA-8, BA-9, BA-10 e BA-11 foram submetidos à avaliaÃÃo de atividade citotÃxica frente a seis linhagens tumorais (HCT 116, SF 295, OVCAR, MCF-7, NCIH292 e HL60). BA-5, BA-7 e BA-8 apresentaram atividade citotÃxica significativa.
The present work reports the chemical research of the roots, stem and leaves from Bauhinia acuruana. In this study were obtained the extracts in hexane, ethyl acetate and methanol of the leaves and ethanol extracts of the roots and stems. The chromatographic fractionation of extracts allowed the isolation of sesquiterpenes 1β, 6α- dihydroxy 4-(14)-eudesmene (BA-1) and aromadendrane-4β,10α-diol (BA-2); the steroid glycosylated sitosterol (BA-4); the bibenzys 2-hydroxy-2â,3â,5â- trimethoxybybenzyl (BA-5) and 2-hydroxy-3â,5'-dimethoxybybenzyl (BA-6); the oxepin derivatives pacharin (BA-7) and bauhiniastatin 1 (BA-8); the flavonoids quercitrin (BA-3), (-)-fisetinidol (BA-9), (2R, 3S)-2-(3â,4â-dihydroxiphenyl)-5-methoxycroman-3,7-diol (BA-10), (2R,3S)-2-(3â,4â-dihydroxiphenyl)-5-methoxy-6-methylcroman-3,7-diol (BA-11) and astilbin (BA-13), as well as the steroidal mixture sitosterol and stigmasterol (BA-12). It is worth noting that the secondary metabolites BA-1 and BA-2 are unprecedented in the genus, while BA-5 and BA-11 unprecedented in the literature and BA-10 unpublished as natural product. The structures of the compounds were elucidated through spectroscopic techniques (IV, NMR 1D and 2D), mass spectrometry and comparison with data reported in literature. Ethanol extracts of the roots and of the stems were evalueted for antioxidant activity, showing significant activity at concentrations of 0.1 mg/mL and 1.0 mg/mL, respectively. BA-7 was evaluated for its larvicidal activity against Aedes aegypti and presented LC50 value of 78.9 Â 1.8 Âg/mL. In addition, BA-5, BA-7, BA-8, BA-9, BA-10 and BA-11 were submitted to evaluation of cytotoxic activity and BA-5, BA-7 and BA-8 presented significant cytotoxic activity.
Databáze: Networked Digital Library of Theses & Dissertations
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