Estudo Fitoquímico das Folhas de Psychotria hoffmannseggiana Roem. & Schult (Rubiaceae)

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Naves, Raquel Ferreira lattes
Orientador(a): Kato, Lucilia lattes
Banca de defesa: Kato, lucília, Sarragiotto, Maria Helena, Ferri, Pedro Henrique
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Goiás
Programa de Pós-Graduação: Programa de Pós-graduação em Química (IQ)
Departamento: Instituto de Química - IQ (RG)
País: Brasil
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/3612
Resumo: Psychotria hoffmannseggiana (Wild. ex Roem. & Schult.) Müll. Arg. is a subshrub of the Rubiaceae family, which belongs to the genus Psychotria L. and to the subgenus Heteropsychotria. In this genus there is several indole alkaloids, recognized by their many bioactive properties. Furthermore, these alkaloids are used as chemotaxonomic markers in the classification and delimitation of the Psychotria genus. Up to this moment, no phytochemical study has been reported for the P. hoffmannseggiana species. Therefore, in the continuous searching for secondary metabolites, the crude ethanol extract (PHF-EB) from P. hoffmannseggiana leaves has been submitted to an acid-base fractionation, and the resultant fractions were subject to column chromatography. The methyl sinapate (PH-01) and the isoscopoletin (PH-02) were identified from the acid chloroform extract (PHFA-C). In the basic chloroform extract (PHFB-C), three indole alkaloids were isolated and identified: harman (PH-03), N-methyl-1,2,3,4-tetrahydro--carboline (PH-04), N-methyltryptamine (PH-05); as well as one polyindolic alkaloid, (+)chimonantine (PH-06). Besides, a great amount of monoterpenic indole alkaloid, the strictosidinic acid (PH-07), was isolated from the basic nbutanolic extract and ethyl acetate, PHFB-n-BuOH and PHFB-AcOEt, respectively. The -ethylglucose (PH-08) was isolated from the basic nbutanolic extract (PHFB-n-BuOH). The evaluation of the antioxidant activity of the extracts PHF-EB, PHFA-C, PHFB-C, PHFB-AcOEt and n-PHFB-nBuOH showed a 50% inhibition of DPPH radical at concentrations of 176,58 ± 1 35, 105.47 ± 0.88, 77.60 ± 0.36, 191.30 ± 0.68 and 271.96 ± 0.57 g.mL1, respectively.