黄芩愈伤组织中多酚氧化酶活性与黄芩苷合成的关系研究

目的 研究黄芩愈伤组织中多酚氧化酶活性变化规律及其与黄芩苷次生合成之间的关系.方法 采用紫外分光光度法测定多酚氧化酶活性,采用高效液相色谱法测定黄芩苷的量.研究不同添加物(抗坏血酸、氯化钠、苯甲酸、聚乙烯吡咯烷酮、硫酸铜)对多酚氧化酶和黄芩苷量的影响.结果 在黄芩愈伤组织生长周期的前20 d,黄芩苷基本没有合成,多酚氧化酶的活性低水平表达;20～35 d,黄芩苷大量合成,多酚氧化酶的活性有所降低,但降低趋势较小;35～50 d,多酚氧化酶活性高水平表达,黄芩苷次生合成受到抑制.结论 多酚氧化酶的高水平表达不利于黄芩苷的次生合成,抗坏血酸、氯化钠、苯甲酸等均可抑制多酚氧化酶的活性,促进黄芩苷次生合成,其中以添加0.02%的抗坏血酸效果最为明显,可使黄芩苷的量提高17.6%(82.3 mg/g),而聚乙烯吡咯烷酮、硫酸铜对多酚氧化酶的活性有着明显的促进作用,抑制了黄芩苷的积累.

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

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 sDectrophotometry 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 Deriod,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 activitv and greatly inhibit the baicalin accumulation.