Study On The Chemical Constituents And Anyioxidant Activity Of Persimmon (Diospyros Kaki) Peel

Diospyros kaki Thunb.,which was planted throughout the world belongs to Diospyros L. and Ebenaceae family. Persimmon fruits contain more phenols compounds, with hemostasis, anti-bacterial, activating blood circulation, lowering blood pressure ,antioxidant, anti-cancer and other effects. In the processing of persimmon, it will produce a lot of skin, which contains more phenols substances. However, up to date, there are few reports of separation and identification of persimmon. Therefore, this article summarizes the chemical composition of persimmon plants research status and progress of biological activity of persimmon, then preliminary study on the chemical composition of persimmon skin, and determined the polyphenols content and antioxidant activity of ethanol extract from persimmon peel.This experiments used persimmon peel from Shaanxi province as material, determined the contents of total polyphenols, reducing sugar and soluble sugar. The results showed that the content of total polyphenols, reducing sugar and soluble sugar of persimmon peel were 3.214 mg·g^-1, 229.038 mg·g^-1, 357.325 mg·g^-1,respectively.In order to explore the polyphenols of ethanol extract of persimmon peel and its antioxidant activity, the ethanol extract was suspended in water and extracted successively with ethyl acetate and n-butanol, then the polyphenols content was measured and their free radical scavenging capacity was compared. The results show that the polyphenols contents of ethyl acetate parts are highest than others, reaching 36.70 mg·g^-1; three parts have a certain degree of free radical scavenging effect, with the ethyl acetate extract is optimal, IC50 value is 243.76μg/mL. Correlation analysis shows that its antioxidant activity mainly comes from polyphenols; we conclude that persimmon polyphenols is a natural antioxidant and has relatively strong antioxidant activity.Six compounds were isolated from the ethanol extract of the persimmon peel from Shaanxi by CC, TLC, recrystallization and so on, which had been proved to be single compound by purity testing. Four of them were determined by comparing the m.p., and MS data which was found in the literature. They wereβ-sitosterol, ursolic acid, p-hydroxybenzoic acid and gallic acid, respectivly.