[Analysis of main flavonoids contents of Scutellaria baicalensis].
OBJECTIVE
To develop a HPLC-DAD method for simultaneous determination of six flavonoids in Scutellaria baicalensis, and study the effect of geographic sources, culturation, harvesting time and processing on the contents of flavonoids.


METHODS
The analysis was performed on a Thermo ODS-2 Hypersil column (4.6 mm x 250 mm, 5 microm) at 26 degrees C with a gradient program of acetonitrile-0.1% H3 PO4 aqueous solution-tetrahydrofuran as the mobile phase and a Diode Array Detector as the detector with the detection wavelength at 274 nm. The flow rate was 1.0 mL x min(-1), and the injection value was 20 microL.


RESULTS
Six flavonoids, baicalin (1), oroxylin A-7-O-glucuronide (2), wogonoside (3), baicalein (4), wogonin (5) and oroxylin A (6), were linear over the selected range with R2 > or = 0.999 3. The average recoveries were between 96.6% -103.0%, and RSD were less then 5.0% (n = 9) for flavonoids 1-6. By analyzing the data obtained, the effect of geographic sources, culturation, harvesting time and processing on the contents of flavonoids were discussed.


CONCLUSIONS
This method is simple, sensitive, reliable and reproducible. It can be used for the quality control of S. baicalensis.
Zhou
Xiqin
X
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China.
Zhang
Qingying
Q
Liang
Hong
H
Jiang
Yajie
Y
Wang
Xuan
X
Wang
Bin
B
Zhao
Yuying
Y
D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D031364:Scutellaria baicalensis / Q000737:chemistry*
D004365:Drugs, Chinese Herbal; D005419:Flavonoids