Enzymatic-Assisted Microwave Extraction of Total Flavonoids from Bud of Chrysanthemum indicum L. and Evaluation of Biological Activities

Abstract

Abstract An enzymatic-assisted microwave extraction method was developed to extract total flavonoids from bud of Chrysanthemum indicum L. The factors affecting total flavonoid yield were investigated and optimized by response surface design, and this extraction method was compared with water heating extraction. The antioxidant and antimicrobial activities of total flavonoids were preliminarily evaluated. The results showed that the optimized microwave extraction conditions were as follows: water–material ratio, 25:1 (mL:g); extraction time, 19 min; microwave power, 582 W. Under these conditions, the yield of total flavonoids was 11.21 ± 1.12 %, which was 53.21 % higher than water heating extraction method, and had shorter extraction time. The maximum scavenging capacity of total flavonoids (12 mg/mL) on DPPH, hydroxyl and superoxide anion free radical was 76.6 %, 78.8 % and 58.2 %, respectively. The total flavonoids showed inhibitory effect on Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Saccharomyces cerevisiae, with minimum inhibitory concentration of 8 mg/mL, 4 mg/mL, 4 mg/mL and 8 mg/mL, respectively. This study has provided the technical basis for further optimization of extraction of total flavonoids from bud of C. indicum L.