Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers, and the Antioxidant and Antibacterial Capacity of the Extract

In the present work, the extraction process of total flavonoids (TFs) from X. sorbifolia flowers by ultrasound-assisted extraction was optimized under the response surface methodology (RSM) on the basis of single-factor experiments. The optimal extraction conditions were as follows: ethanol concentration of 80%, solid-liquid ratio of 1:37 (g/mL), temperature of 84 degrees C, and extraction time of 1 h. Under the optimized conditions, the extraction yield of the TFs was 3.956 +/- 0.04%. The radical scavenging capacities of TFs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were much greater than that of rutin. The results of antibacterial experiments indicated that the TFs displayed strong inhibitory activities on E. coli, S. aureus and Bacillus subtilis. Therefore, X. sorbifolia flowers can be used as a novel source of natural flavonoids, and the TFs have potential applications as natural antioxidants or antibacterial agents in the food and pharmaceutical industries.

Automated summary

In this study, the extraction conditions of total flavonoids (TFs) from X. sorbifolia flowers were optimized using ultrasound-assisted extraction, and it was found that TFs exhibited strong antioxidant and antibacterial activities. Thus, X. sorbifolia flowers can serve as a novel source of natural flavonoids, and TFs have potential applications in the food and pharmaceutical industries.