Abstract: The paper established a method for separation and determination of total flavonoids and three main components in Scutellaria Radix total flavone aglycone extract by ultraviolet (UV) spectrophotometry and high-performance liquid chromatography.The anlysis was performed on an Agilent 1200 Series HPLC system with Eclipse XDB-C18 (250 mm×4.6 mm,5 μm) column.The mobile phase consisted of methanol-0.2% phosphoric acid water (50:50) with the flow rate of 1 min/mL.The column remained at 35 ℃ and the detection wavelength was set at 275 nm.The linear ranges of baicalein,wogonin and oroxylin A were 3.501-70.016 μg/mL (r=0.9999), 0.832-16.640 μg/mL (r=0.9998) and 0.418-8.352 μg/mL (r=0.9999),respectively.The average recoveries (n=6) were 99.55% (RSD=1.74%),98.86% (RSD=1.74%) and 99.97% (RSD=1.70%).Total flavonoids were determined by UV spectrometry.The linear range of baicalein was 1.71-8.54 μg/mL (r=0.9991).The average recoveries (n=6) were 100.93% (RSD=2.63%).The contents of baicalein,wogonin,oroxylin A and total flavonoids were 48.22%-60.36%,12.09%-14.46%, 5.05%-8.81% and 78.11%-90.12%,respectively.

Key words: Scutellaria Radix total flavone aglycone extract, baicalein, wogonin, oroxylin A, ultraviolet, high performance liquid chromatography, content determination