Correlation of polyphenol oxidase activity and baicalin synthesis in callus of Scutellaria baicalensisi / 中草药

ABSTRACT

Objective To study the correlation of polyphenol oxidase(PPO) activity and baicalin synthesis in callus of Scutellaria baicalensisi.Methods PPO Activity was determined by ultraviolet spectrophotometry and the content of baicalin was detected by HPLC.The effects of various substances(ascorbic acid,sodium chloride,benzoic acid,polyvinylpyrrolidone,and copper sulfate) on PPO activity and the content of baicalin were studied.Results There was no baicalin accumulation in the first 20 d of growth period, while PPO activity was expressed slowly during this period.From 20 d to 35 d,PPO activity increased significantly and the baicalin secondary synthesis was restrained.Conclusion The high-level expression of PPO activity do harm the baicalin secondary synthesis.These chemical substances,such as ascorbic acid, sodium chloride,and benzoic acid could inhibit the PPO activity and improve the content of baicalin;It is obvious for ascorbic acid(0.02%) to improve the content of baicalin with 17.6%(82.3 mg/g) compared with the control.However,polyvinylpyrrolidone and copper sulfate could increase the PPO activity and greatly inhibit the baicalin accumulation.