Contribuição ao Conhecimento Químico de Plantas do Nordeste: Alibertia myrciifolia Spruce ex K. Schum. e Alibertia rigida K. Schum.

• Ano de defesa: 2009
• Autor(a) principal: Luciano, João Henrique Silva
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: LUCIANO, J. H. S.; LIMA, M. A. S. (2009)
• Palavras-chave em Português: Alibertia rigida; Alibertia myrciifolia
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/15848

This work reports the chemical investigation of two plants of the Rubiaceae family, belonging to the Alibertia genus: A. myrciifolia Spruce ex K. Schumman and A. rigida K. Schumman, both collected in Crato County – CE (Araripe’s Plateau). The chemical study of A. myrciifolia resulted on the isolation and characterization of nine compounds. From the hexane extract of the aerial parts was obtained β-sitosterol and stigmasterol as mixture, besides the triterpenes hydroxyhopanone and 3α,22-dihydroxyhopane. In addition, the triterpene 3β,22-dihydroxyhopane was prepared by reduction of hydroxyhopanone. From the ethanolic extract it was obtained the flavonoid 3,4-dimethoxyluteolin, the triterpene ursolic acid, the phenylpropanoid caffeic acid and the iridoids geniposidic acid, 10-O-vanilloylgeniposidic acid and 10-O-syringoyl-geniposidic acid. The hopane triterpenes are new on Alibertia genus, as well as the flavonoid and the geniposidic acid derivatives. The 10-Ovanilloyl- geniposidic acid is a new compound. Regarding the chemical analysis of the leaves from A. rigida, the flavonoids rutin, quercetin, kaempferol and the 7-methoxyapigenin (genkwanin), a catechol dimer (3,4,3’,4’- etrahydroxybiphenyl), the caffeic acid ethyl ester and the procyanidin A-2 were obtained. All compounds are new on Alibertia genus, with exception of rutin. In addition to the phytochemical study of both species, some isolated compounds were submitted to fungitoxic and antileishmanial assays. The test against pathogenic fungi showed significant inhibition on the growth of tested strains by geniposidic acid, caffeic acid ethyl ester and procyanidin A-2, while the hopane triterpenes and the 10-Ovanilloyl- geniposidic acid were inactive. In the test against Leishmania amazonensis, only caffeic acid ethyl ester showed activity. Secondary metabolites of A. myrciifolia were characterized by spectroscopic methods including IR, NMR 1H and NMR 13C, uni and bidimensional, and comparison with literature data.