Abstract:

The effect of extraction temperature, ethanol concentration, solid/solvent ratio, extraction time and number
of extraction cycles on the yield of total flavonoids from Schisandra chinensis (Turcz.) Baill leaves (FSL) was studied
by single factor designs. Based on the results obtained, an orthogonal array design was proposed to optimize the
extraction process. The optimal extraction process was obtained by two cycles of extraction with 60% ethanol at a
solid/solvent ratio of 1:45 (g/mL) for 3.5 h at 85 ℃, resulting in an FSL yield of 9.03%. Primary purification of FSL
was performed using polyamide resin, and infrared spectroscopic studies demonstrated that the purified products
possessed spectral characteristics of flavonoids. The purified FSL had strong inhibitory effects against Staphylococcus
aureus, Escherichia coli and Bacillus subtilis as determined by agar diffusion method, and showed free radical
scavenging activity against superoxide anion and DPPH radicals.

Key words: Schisandra chinensis (Turcz.) Baill leaves, flavonoids, extraction, antibacterial effect, antioxidant activity