wogonin and acteoside

Scutellaria lateriflora (American skullcap) has been used in traditional medicine to treat several medical conditions including nervous disorders and cancer. Previous studies have associated these medicinal properties to flavones present in roots and leaves of this species. In order to develop a production system and study the biosynthesis of these bioactive compounds, hairy root cultures of S. lateriflora were established and line 4 was selected for further studies based on its growth performance in a modified Murashige and Skoog's medium supplemented with 0.5mg/l indole-3-butyric acid. Scanning electron microscopy of the hairy roots showed a high profusion of hairs along the root. Several phenolic compounds, including verbascoside, and the flavones wogonin, baicalein, scutellarein and their respective glucuronides were identified by high performance liquid chromatography-tandem mass spectrometry in the root tissue, but not in the culture medium. Among these compounds, verbascoside accumulated at the highest levels. Interestingly, cultures incubated under continuous light and treated with 15mM methyl-β-cyclodextrin for 24h produced significantly higher levels of the aglycones, baicalein and wogonin, but not scutellarein, compared to cultures incubated under continuous darkness. This work demonstrates that hairy root cultures of S. lateriflora have the biosynthetic capacity to produce known Scutellaria flavones and suggest that light may have a selected regulatory effect on the synthesis or accumulation of these phenolic compounds.

Topics: Acetates; Chromatography, High Pressure Liquid; Cyclodextrins; Cyclopentanes; Flavanones; Glucosides; Indoles; Light; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oxylipins; Phenols; Plant Roots; Plants, Medicinal; Polymerase Chain Reaction; Scutellaria; Serine Endopeptidases

Micellar electrokinetic chromatography (MEKC) conditions were developed to analyze the constituents of Scutellariae Radix (SR) and Scutellaria baicalensis roots. Using the MEKC method, the major flavonoid constituents of baicalin, baicalein and wogonin of wild and cultivated S. baicalensis roots were compared. In a preliminary comparison of electropherogram, one special peak was found in a wild sample but not in a 2-year-cultivated one. The compound corresponding to the peak was isolated and identified as a phenylethanoid glycoside, acteoside, by comparing the 1H- and 13C-NMR spectral data with that of the authentic compound. This is the first time acteoside has been isolated from the Scutellaria genus. It could only be found in SR derived from wild S. baicalensis roots and 4-year-cultivated plants, but not in plant materials cultivated for 3 years. Applying the MEKC method established in this study, rapid and simultaneous determinations of acteoside together with 3 flavonoids in samples were achieved. The method can thus be used for the quality control of SR in a shorter analysis period than HPLC.

Topics: Chromatography, High Pressure Liquid; Chromatography, Micellar Electrokinetic Capillary; Flavanones; Flavonoids; Glucosides; Phenols; Plant Roots; Scutellaria; Spectrophotometry, Ultraviolet