Studies On Purification Of Punicalagin From Pomegranate Peel And Its Inhibitory Effect On Tyrosinase Activity

Punicalagin, the main ingredient of pomegranate peel (Punica granatum L.), is a kind ofhydrolysable tannins. It has great development foreground in food, cosmetics, medical treatment, healthcare attributed to its remarkable physiological activities. Two purification processes and the inhibitoryeffect on tyrosinase activity of punicalagin were studied in this paper. The main contents are as follows:First of all, the preparation and purification of punicalagin were developed. In the process ofpreparing punicalagin, a series of methods were compared, including dry column chromatography,multi-step silica gel column chromatography, HSCCC (high speed counter-current chromatography) and soon. Through the methods of dry column chromatography, HSCCC and Sephadex LH-20sequentially,punicalagin with the purity of96.21%was separated from the crude punicalagin (with the purity of40%).Secondly，the ratio of the crude punicalagin to methyl alcohol was designated as1:40forpreliminary purification by comparing the solubility of punicalagin in different solvents. The optimizedpurification conditions in HSCCC was: the mixed solution of n-butyl alcohol: water: formic acid=100:100:1(v/v) was used for the mobile phase and stationary phase, the upper solution as the mobile phase and thelower solution as the stationary phase, mainframe turned to forward set. Then punicalagin of89.18%waspurified from the crude punicalagin.At last, the inhibitory effect of punicalagin with different purities (10%,40%,60%,80%) ontyrosinase activity were studied. Results showed that punicalagin with different purities had obviousinhibitory effect on tyrosinase activity, and the higher the mass concentration was, the stronger theinhibitory effect was. The IC50of punicalagin with different purities (10%,40%,60%,80%) were0.7391,0.6572,0.5868and0.6141mg/mL, respectively.