Study On Flavonoids From The Stems And Leaves Of Scutellaria Baicalensis Georgi

Radix Scutellariae is the dry root of Scutellaria baicalensis Georgi[1], It was recorded in the book of Sheng Nong’s herbal classic for the first time, mainly in Hebei, Henan, Shaanxi, Shanxi, Inner Mongolia etc. its wild resources are dried up and difficult to meet people’s needs. In order to extend medicinal herbs resource, people adopt Scutellariae by artificial cultivation, in order to have full use of the resource of Scutellariae, international and domestic academics develop the stems and leaves that they are non-medicinal parts of Scutellariae. The extract mainly contains flavonoids, and the pharmacology study proved that it had effect on anti-virus, anti-bacterial, antiinflammatory, resisting arrhythmia, myocardial ischemia, reperfusion injury, protecting nerve and improving memory, protecting the liver tissue damage, hypoglycemic, and so on[2], the stems and leaves of Scutellaria baicalensis Georgi have great medicinal value, Therefore, the stems and leaves of Scutellariae need to be full used of development and utilization.As an area of Chengde city of Hebei Province with the famous-region drug, Chinese medicine group Chengde Medicine Co. Ltd. had established the planting base of Scutellaria baicalensis GAP specification. So this text studies that the chemical constituents obtained 60% of ethanol extract from scutellari-ae of stems and leaves were deeply and systematically researched, and the content of baicalin from the roots and scutellarin from the stems and leaves of scutellaria planting base at different collecting time. The first partStudy on Chemical Composition of the stems and leaves of Sctutellaria baicalensis Georgi.Objective:To separate and purify the monomer compounds from its chloroform and n-butyl alcohol extraction of 60% ethanol extract from the stems and leaves of Scutellaria baicalensis; To provide scientific basis for clarifying pharmacodynamic material basis of stems and leaves of Scutellaria baicalensis; To lay the foundation for the further development and utilization of the stems and leaves of Scutellaria baicalensis.Methods:Isolation and purification were performed to macroporous adsorption resin column(ethanol-water system), normal phase silica gel column(petroleum ether-ethyl acetate system, chloroform-methanol system), Polyamide column chromatography(methanol-water system), Sephadex LH-20 gel column chromatography(methanol-water system), a reversed-phase ODS column chromatography(methanol-water system) and semi preparative HPLC, the structures were elucidated on the basis of physical and chemical properties and spectral analysis(13C-NMR, 1H-NMR).Results:Five flavonoids were identified: 7-methoxychrysin(1), luteolin(2), genkwanin(3), 5,4’-dihydroxy-7-methoxyflavanone(4), oroxylin-A-7-O-β-D-gluclronide(5).Conclusions:Compounds 1 and 4 were isolated from Sctutellaria baicalensis Georgi for the first time.The second partDetermination of content of baicalin from Scutellaria baicalensis roots and scutellarin from stems and leaves at different collecting timeObjective:1. To study dynamic changes of the content of baicalin from the roots of Scutellaria(Longhua Country, Chengde city GAP standardized planting bases, biennial), the determination of the optimal harvest time of the roots.2. To study dynamic changes of the content of scutellarin from the stems and leaves of Scutellaria(Longhua Country, Chengde city GAP standardized planting bases, biennial), the determination of the optimal harvest time of the stems and leaves.Methods:1. Baicalin was separated on a Agilent Zorbax SB-C18(4.6 mm×250 mm, 5 μm) column and detected at 280 nm, at the flow rate of 0.8 m L·min-1 using a mixture of methanol-H2O-formic acid(53: 47: 0.1). The temperature of column was set at room temperature and injection volume was 10 μL.2. Scutellarin was separated on a Agilent Zorbax SB-C18(4.6 mm×250 mm, 5 μm) column and detected at 335 nm, at the flow rate of 0.8 m L·min-1 using a mixture of methanol-H2O-formic acid(47: 53: 0.1). The temperature of column was set at room temperature and injection volume was 10 μL.Results:1. The standard curve of baicalin was linear in the range of 3.60~120.00 μg·m L-1 with correlation coefficient 0.9997. the average recovery was 98.14%, RSD was 2.00%(n=6). The content of baicalin from the roots of Scutellaria at different harvest time respectively were 21.25%, 20.07%, 17.10%, 17.70%, 15.73%, 15.89%, 17.46%, 14.36%, 12.58%, 13.49%, 12.46%, 11.23%. The total content of baicalin from June to September decreased continuously, and the maxium value was June 10, 2012, up to 21.25%, the minimum value was September 30, low to 11.23%.2. The standard curve of scutellarin was linear in the range of 5.04~168.00 μg·m L-1 with correlation coefficient 0.9999. the average recovery were 99.37% and 99.13%, RSD were 1.88% and 1.74%(n=6). The content of scutellarin from the stems of Scutellaria at different harvest time respectively were 0.57%, 0.53%, 0.51%, 0.55%, 0.56%, 0.47%, 0.55%, 0.59%, 0.57%, 0.38%, 0.74%, 0.29%. The total content of scutellarin from June to September showed a trend of relatively stable, and the maxium value was September 20, 2012, up to 2.88%, the minimum value was September 30, low to 1.86%.Conclusion:The method was simple and the results were stable and reliable, reproducible, there were differences in the contents of baicalin and scutellarin and changed regularly.