Quercetin

COA of Sophora Japonica Quercetin

Preparation

1. Natural extraction and separation

Since the content of quercetin in plants is only a few thousandths to a few thousandths, and the extraction and separation is difficult and the cost is high, it is not practical to extract quercetin directly from plants. However, when analyzing, identifying flavonoids or preparing analytically pure samples, quercetin extraction and separation techniques are used.

2. Acid hydrolysis method

The rutin (rutin) of quercetin is widely distributed in nature and has a high content. For example, the content in sophora japonica is as high as 20%. Rutin is first extracted from Sophora japonica, and then acid hydrolyzed to generate quercetin. This method is feasible in production.

The extraction methods of rutin mainly include alkali extraction and acid precipitation, organic solvent extraction and dipping, among which alkali extraction and acid precipitation is the most practical. Select 0.05% NaOH solution to boil for 20min, filter while hot, extract 4 times with the same method to obtain an alkaline aqueous solution of rutin, add acid to make it precipitate, add acid after filtration to make it hydrolyzed to obtain water-insoluble quercetin, filter , washed with water, and dried to obtain quercetin solid.

3. Enzymatic conversion method

Enzymatic hydrolysis of rutin is used to prepare a large amount of quercetin monomers with less content in plants. The operation is simple and safe, the whole process is economical and applicable, the yield is large, suitable for industrial production, and the product purity is more than 90%, which can meet the needs of food and clinical applications . Therefore, enzymatic transformation is undoubtedly a very promising preparation method.