Chemical Constituents of Scutellaria Radix and Their Antioxidant Activity

Objective To study the chemical constituents of Scutellaria and their antioxidant activity.Methods Siliga gel and RP-C18 column chromatographies were used to isolate,and their structures were identified by spectral methods.Isolated compounds were tested in vitro for antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical.Results Four known flavonoids were isolated from Scutellaria radix and their structures were identified as wogonin,baicalin,5,7,2′,5′-tetrahydroxy-8,6′-dimethoxyflavone and 5,7,2′,6′-tetrahydroxyflavone.Among these,baicalein had DPPH radical scavenging effect with IC50 value of 19 μmol/L.Conclusion Baicalin was isolated as the one of major flavonoids from Scutellaria Radix with antioxidation.