Antioxidant activity of an isomer of gossypitrin (gossypetin-3’-O-glucoside) isolated in the petals of Talipariti elatum Sw., and determination of total phenolic content of the total flower

Abstract

Objective: Isolation and identification of the main flavonoid from petals of Talipariti elatum Sw. (Hibiscus elatus Sw), comparison of antioxidant properties, determination of total phenolic content of the flower. Method: The main flavonoid was precipitated using 1, 2 - dimethoxyethane, followed by two serial recrystallizations. Analysis of the precipitate was done with UV spectrum, MS-NMR 1H and MS-NMR 13C spectroscopy. Antioxidant activity was carried out using 1,1- diphenyl -2-picrylhydrazyl (DPPH) and I²-carotene. Results: The main flavonoid of the petals is gossypetin-3’-O-glucoside. Until now Cuban research workers argued that major flavonoid was gossypitrin (gossypetin-7-O-glucoside). DPPH test leads to an EC50 value of 0,11 mg/L, however I²-carotene bleaching test (BCB test) didn’t give positive results. Total phenolic content of ethanolic extract from dried flower is 163 ± 5 mg GAE/g. Conclusion: Talipariti elatum Sw. is a high source of natural antioxidants. Precedent publications revealed also the presence of various flavonols or flavones (quercetin, rutin). Antimicrobial, anti-hepatotoxic, anti-catarrh, anti-cough, anti-asthma properties of this specie show it great interest in health’s range.