Response surface optimization of mechanochemical-assisted extraction of flavonoids and terpene trilactones from Ginkgo leaves

Mechanochemical-assisted extraction (MCAE) method was developed for extraction of flavonoids and terpene trilactones from Ginkgo leaves. The MCAE parameters and the antioxidant activities of Ginkgo biloba extract (GBE) were investigated. Through response surface methodology design experiments, the processing conditions were optimized as follows: amount of solid reagent (NaHCO₃) 21%, milling time 7.5 min, and ratio of solvent to solid 33 mL/g. Under these conditions, the yields of flavonoids and terpene trilactones in GBE were 6.83 mg/g and 1.72 mg/g, respectively. Compared with the heat reflux extraction method, the yields of flavonoids and terpene trilactones are higher, and the extraction time was significantly shortened. What is more, the MCAE method only used water as solvent. GBE of MCAE possessed notable antioxidant activity with IC₅₀ values of 11.7 and 13.8 μg/mL, respectively.