The dynamic changes of secondary metabolites and tyrosinase activity of Malus pumila flowers were investigated during blooming for full use of M. pumila flowers. Phlorizin, astragalin and afzelin were selected as the indicators to determine the optimum extraction conditions of M. pumila flowers by HPLC analysis and three-factor and three-level orthogonal design experiments. When the smashing mesh number was 40 mesh, the ultrasonic time was 30 min, the solid–liquid ratio was 1:120, and the centrifugal speed was 10,000 r/min, the total content of the three compounds was the highest. The total content of phlorizin, astragalin and afzelin increased firstly and then decreased, and the highest was on the third day (176.74 mg/g). At the same time, the tyrosinase activity of M. pumila flowers showed that it had an activation effect on tyrosinase during early blooming period, however it exhibited inhibitory effect during late blooming period.

中文翻译：

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海棠花次生代谢产物和酪氨酸酶活性的动态变化

为了充分利用普米桑花，研究了海棠花次生代谢产物的动态变化和酪氨酸酶活性。通过高效液相色谱分析和三因素，三水平正交设计实验，选择了芦荟素，黄芪素和黄酮作为指示剂，确定了普um花的最佳提取条件。当粉碎筛目数为40目时，超声时间为30分钟，固液比为1：120，离心速度为10,000 r / min，这三种化合物的总含量最高。phlorizin，astragalin和afzelin的总含量先上升然后下降，最高的是第三天（176.74 mg / g）。同时，M的酪氨酸酶活性。