Aquatic plants are special plant resources, mainly distributed in the water environment, and their growth environment and physiological metabolism process are different from those of terrestrial plants. Flavonoids are important secondary metabolites in aquatic plants, which have wide medicinal value and application prospect. However, aquatic plants often contain high contents of fatty acids and lipids, which will interfere with the extraction, separation and purification of flavonoids, thus affecting the subsequent analysis and application.

Therefore, in order to obtain high-quality flavonoids extracts from aquatic plants, degreasing steps are needed. Defatting can be carried out by solvent extraction, extraction, column chromatography and other methods to remove fatty acids and lipids, and relatively pure flavonoids extract can be obtained.