Extraction of Total Flavonoids from Bamboo Leaf Based on Propyl-alcohol Ammonium Sulfate Aqueous Two-phase System Coupling with Ultrasonic

[Objective] To investigate a propyl-alcohol ammonium sulfate aqueous two-phase system coupling with ultrasonic for extraction of total flavonoids from bamboo leaf. [Method] The propyl-alcohol ammonium sulfate aqueous two-phase system coupling with ultrasonic was used to extract and separate the total flavonoids from bamboo leaf. The effects of the ammonium sulfate and propanol content,ultrasonic time and fluid-solid ratio on the extraction yield of flavonoids were also studied. [Result] The optimum extraction conditions are as follows:propanol volume fraction 60%; (NH4)2SO4 0.35 g/ml,ultrasonic 25 min,solution to materials ratio 30:1. The extraction rates of total flavonoids was 2.03% in the optimum extraction conditions,and the purity of total flavonoids in extractives was 31.3%%,much higher than that of ultrasonic extraction. [Conclusion] The propyl-alcohol ammonium sulfate aqueous two-phase system coupling with ultrasonic used for extraction of total flavonoids from bamboo is simple and has good prospects.