Introduction: Scutellaria Baicalensis Georgi (SBG), a Traditional Chinese Medicine (TCM)
used for the treatment of antiviral therapy, contains many flavonoids.
Materials and Methods: A simple, fast and accurate 1H quantitative nuclear magnetic resonance (1HqNMR)
method was established for simultaneously determination of four flavonoids (Baicalin, Baicalein,
Wogonin and Wogonoside) in SBG extract by using 3,4,5-trichloropyridine as an internal
standard (IS). All the NMR determination work was performed at 308 K on an NMR sample tube inserted
with a co-axial tube. The NMR sample tube was added with the sample (SBG extract and IS), the
co-axial insert tube was added with D2O. Quantification of four flavonoids was carried out by calculating
the relative peak area ratio of the selected proton signals from the target compounds and the IS.
Results: The validated 1H-qNMR method was successfully used to determine the four flavonoids in 9
batches of SBG from different origins and the results were in good accordance with those obtained
Conclusion: The established 1H-qNMR method could be used as a powerful tool for the quality control of
SBG from different sources and had potential in the quantification of main components from other TCMs.