The invention provides a method for extracting and purifying total flavonoids of
Physalis pubescens fruits through
antioxidant activity tracking and ultrasonic assistance. A certain amount of dried
Physalis pubescens fruit
powder is mixed with an
ethanol solution with the concentration of 60%-95% in a certain
solid-to-
liquid ratio, extracted for a period of time under ultrasonic assistance at certain power, and an extraction solution is subjected to vacuum concentration; a concentrated solution is subjected to
freeze drying treatment,
powder is formed, and rough flavonoids of the
Physalis pubescens fruits are obtained. The rough flavonoids are purified with AB-8 macroporous adsorption resin, firstly eluted with water for
impurity removal and then eluted with an
ethanol solution with the concentration of 20%-100%, filtrate is collected, and refined flavonoids of
Physalis pubescens are obtained after vacuum concentration and
drying. With the adoption of the method, purification is performed 1-3 times, and the purity is increased from 92.7% to 40.02%-65.3%. The flavonoids, prepared with the method, of
Physalis pubescens have reducing power and the capability of
scavenging negative
oxygen ions, hydroxyl radicals and
DPPH (diphenyl-picryl hydrazyl) free radicals, and the reducing power and the capability of
scavenging negative
oxygen ions, hydroxyl radicals and
DPPH free radicals are both higher than those of the rough flavonoids and higher than Vc after purification, and the flavonoids of
Physalis pubescens can be used for research and development of medicines, healthcare products, food and
cosmetics. Extraction and purification of flavonoids are rapid, efficient and convenient, the
oxidation resistance of the total flavonoids is reserved to the greatest extent, a basis is provided for industrial production of the flavonoids of Physalis pubescens fruits, and the method has certain practical significance.