Enrichment of flavonoid-rich extract from Bidens bipinnata L. by macroporous resin using response surface methodology, UHPLC-Q-TOF MS/MS-assisted characterization and comprehensive evaluation of its bioactivities by analytical hierarchy process

The extract of Bidens bipinnata L. exhibited wide spectrum of bioactivities due to the presence of flavonoids. In this study, the purification process was developed to enrich the flavonoids-rich extract from B. bipinnata L. (BBTF). AB-8 resin was selected for the purification of total flavonoids. Response surface methodology coupled with Box-Behnken design was employed to optimize the purification condition, it was optimized as pH value 5.1, volume of ethanol 80 mL, flow rate of ethanol 1.8 BV/h and concentration of ethanol 76.0%. The total flavonoids content of BBTF was 56.48% under the optimal conditions. The identification of flavonoids in BBTF were conducted using UHPLC-ESI-Q-TOF MS. A total of 14 compounds, including 12 flavonoids were identified in BBTF. Finally, the in vitro antioxidant activities, α-glucosidase and α-amylase inhibitory activities of BBTF were comprehensive analyzed by analytical hierarchy process. The results indicated that it exhibited higher bioactivities than the crude extract. These findings suggested that the optimized process could significantly enhance the purity of flavonoids and its bioactivities. This study showed a comprehensive research of total flavonoids extract of B. bipinnata L. for the first time, which could provide a useful approach for its purification process, quality control as well as bioactivities.

Keywords: Analytical hierarchy process; Bidens bipinnata L; Bioactivities; Macroporous resins; Total flavonoids; UHPLC-Q-TOF-MS.