Phenolic derivatives and antioxidant activity of polar extracts from Bauhinia pulchella

• Autor(a) principal: Carvalho, Adonias Almeida
• Data de Publicação: 2018
• Outros Autores: Santos, Lucivania Rodrigues dos, Farias, Ruth Raquel Soares de, Chaves, Mariana Helena, Feitosa, Chistiane Mendes, Vieira Júnior, Gerardo Magela, Araújo, Mônica Regina Silva de, Ferreira, Paulo Michel Pinheiro, Pessoa, Claudia do Ó
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/36062
• topic: Antioxidantes; Antioxidants; Flavonoids; Flavonoides

A tea made with the leaves or stem bark of Bauhinia pulchella Benth (Fabaceae) is used in the treatment of diabetes. Ethanol (EEF) and aqueous (EAF) extracts were obtained from the leaves and the antioxidant and citotoxic activities were tested, as well as quantify the content of flavonoids and phenolic compounds (TPC). EEF and EAF showed similar profiles by HPLC, with the presence of three compounds. Column chromatography reverse phase (C18) and Sephadex LH-20, followed by semi preparative HPLC-C18 of EAF resulted in three flavonoids. Their structures were identified by 1 H and 13 C NMR as myricitrin ( 1 ), quercitrin ( 2 ) and afzelin ( 3 ). In assay of determination of reactive substances to thiobarbituric acid (TBARS), with DPPH, ABTS and nitric oxide (NO•) free radicals, EAF showed antioxidant potential higher than the EEF. This is the first report of the occurrence of the flavonoids 1 - 3 , in the species B. pulchella . EEF and EAF were inactive in the cytotoxicity assays. In short, the polar extracts from the leaves of B. pulchella proved to be promising sources of biomolecules phenolic, with antioxidant potential, which may, in the future, be used as chemical markers for species and validation of therapeutic use.