Optimized Ultrasonic-Assisted Extraction by Using Response Surface Methodology and Structural Analysis of Flavonoids from Alliums cepa L. var. agrogatum Don

摘要

The response surface methodology (RSM) was used to optimize ultrasonic-assisted extraction of total flavonoids from Alliums cepa L. var. agrogatum Don (ACAD). The results indicated that the highest extraction yield of flavonoids by ultrasonic-assisted extraction could obtain to be 3.36% using ethanol concentration of 70% (v/v) as solvent and liquid to solid ratio of 17:1 (mL/g) for 48 min at the temperature of 60 °C. The total flavonoids were purified by AB-8 resin column and polyamide resin column successively. In addition, the maximum absorption wavelength of ACAD flavonoids was determined by UV spectrophotometry, followed by their structural identified and analysis for flavonoids by infrared spectroscopy, high performance liquid chromatography. It could be concluded that the flavonoids of ACAD contains quercetin.