Fangrong Lou’s research while affiliated with Ludong University and other places

Inocutis tamaricis, a medicinal fungus, is rich in flavonoids, triterpenes, polyphenols, and other active ingredients. In this study, wild basidiomata of I. tamaricis were used for optimized extraction of fungal flavonoids by ultrasound-assisted deep eutectic solvent (DES) extraction method. The efficiency of the extraction method was optimized based on the one-factor analysis and response surface methodology. Also, the activity analysis of I. tamaricis flavonoids was performed, including 1,1-diphenyl-2-pic-rylhydrazyl (DPPH⁻) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) clearance ability, reducing ability, and α-glucosidase inhibitory activity. The optimization results indicated that DES with l-proline and 1,2-propanediol produced the best extraction outcome and the conditions were as follows: moisture content, 20%; ultrasonic power, 300 W; extraction time, 40 min; solid–liquid ratio, 60 mg/mL. Under these extraction conditions, the maximum yield of flavonoids was 26.54 mg/g, which was 77% higher than the traditional ethanol extraction method (15.02 mg/g). The in vitro results indicated that flavonoids extracted from I. tamaricis are potent antioxidants and possess hypoglycemic potential; the DPPH and ABTS free radicals clearance rates and the α-glucosidase inhibition rate were more than 80%. Additionally, the flavonoids reducing ability was 1.449, which was not significantly different from that of the standard product (P < 0.05). In conclusion, the DES extraction method is an effective technique for the extraction of flavonoids from I. tamaricis. These flavonoids with significant antioxidant and hypoglycemic potential can be developed into natural antioxidants and hypoglycemic drugs. This study serves as a basis for the future discovery and application of active ingredients from I. tamaricis.