Optimization of ultrasound-assisted extraction and quantification of rutin and quercetin in Flos Styphnolobii japonici imaturi by validated UHPLC-UV method

This study focuses on enhancing the extraction process of rutin and quercetin from Flos Styphnolobii japonici imaturi using ultrasound-assisted extraction (UAE) combined with response surface methodology (RSM). By analyzing 3D surface plots and performing regression analysis on the independent variables, the ideal extraction conditions were determined: 96% methanol concentration, a liquid-to-solid ratio of 19:1 (mL/g, v/w), and an ultrasound duration of 19 minutes. These optimized parameters were then applied to validate the quantification process. The bioactive compounds in the Flos Styphnolobii japonici imaturi extract were identified using ultra-high-performance liquid chromatography coupled with an ultraviolet absorption detector. This methodology was employed to quantify the rutin and quercetin content from samples collected across seven different locations in Vietnam. The results revealed that the concentrations of these compounds in the methanol extracts ranged from 0.325% to 35.73%. This study provides a scientific basis for optimizing the extraction process and contributes to the application of F. Styphnolobii imaturi in medicinal use.