Identification and determination of polyphenols and tannin in the galls and in the extract of Quercus infectoria

Abstract

The aim of this study was to develop a preparation of a hydroalcoholic extract of Quercus infectoria in order to study the physicochemical parameters, and to identify and quantitatively determine the amount of Polyphenols and Tannin in the galls and in the extract. Preparation of an extract rich in Tannin from the galls of Quercus infectoria, as an astringent, can make incorporation into rectal creams easier, and improve its effect on anal fissure. A hydroalcoholic extract (1:1) of Q. infectoria galls was prepared by the method of perculation. The Polyphenols and Tannin in the galls and in the extract were determined spectrophotometrically. The maximum absorption wavelength was around 730 nm. The hydroalcoholic extract contained about 46.0 percent of the dried materials. The amount of Polyphenols and Tannin were reported in the dried materials as 42.7, and 37.2 percent respectively. The amount of Polyphenols and Tannin were in the galls as 77.5 and 68.0 percent (w/w), and in the dried extract as 93.0 and 81.0 percent (w/w) respectively. Quercus infectoria galls are rich in Tannin; Tannic acid is its main constituent. They are used externally in the treatment of infectious skin conditions. The astringent quality of the plant is due to the biological activities of its Polyphenols and Tannin. The presence of considerable amounts of Polyphenols and Tannin in the galls and in the dried extract of Q. infectoria shows its effectiveness when the extract is added into rectal creams in order to help treat the anal fissure.