Ascorbic Acid and Tannins from Emblica officinalis Gaertn.Fruits A Revisit

摘要

The fruits of Emblica officinalis Gaertn.(Euphorbiaceae),also known as amla in Ayurveda,are considered to be a rich source of ascorbic acid.However,the antioxidant activities exhibited by E.officinalis extract are superior to those of ascorbic acid itself.Low molecular hydrolyzable tannins emblicanins A and B have been suggested in the earlier literature to be the contributory antioxidant molecules in the extract.This work finds no evidence for the presence of emblicanins A and B in the extract.In addition,the high content of ascorbic acid is also questionable due to previous nonidentification of coeluting mucic acid gallates.This paper reports a new HPLC method to detect even trace amounts of ascorbic acid in E.officinalis fruit juice or extract.