Identification, determination, and study of antioxidative activities of hesperetin and gallic acid in hydro-alcoholic extract from flowers of Eriobotrya japonica (Lindl.)

Eriobotrya japonica belongs to the Rosaceae. Studies have shown that the flowers of this plant are rich in phenolic and flavonoid compounds. Accorrdingly, the evaluation of antioxidative effects of Eriobotrya japonica Flower Extract (EJFE) have been performed in vitro. In this study, to investigate the influences of components of EJFE on its antioxidative activity, extract was prepared using hydro-alcoholic (25:75 V/V) solvent and the antioxidative activity of the extract was evaluated based on the scavenging of various radicals (DPPH and H2O2) by spectrophotometric method and chelating of ferrous ions by ferrozine reagent. HPLC analysis of the Eriobotrya japonica Flower Extract (EJFE) revealed hesperetin and gallic acid as the major antioxidants. When the content of total flavonoid and polyphenolic compounds in the flower extract of this plant was examined, a significantly higher level of total polyphenols was found in Eriobotrya japonica flower extract. Results demonstrate that the high ability to scavenge free radicals, reducing power, and Fe+2chelating activity exerted by the EJFE were due to the high content of hesperetin and gallic acid in the flowers.