The Isolation, Identification And Quantification Of Flavonoids In Folium Isatidis

The ethanol extract of Folium Isatidis crude drug was separated by using silica gel chromatography, polyamide column chromatography, Preparative Liquid chromatography and Sephadex LH-20 chromatography. The compounds isolated were identified by using mass spectra, NMR and physical-chemical data and they were isoscoparin (compound 1), isoscoparin3"- O- glucopyranoside (compound 2), isovitexin (compound 3), isovitexin-3"-O-glucopyranoside (compound 4), isoorientoside-3"-O- glucopyranoside (compound 5), isovitexin-6"-O-glucopyranoside (compound 6), isoorientin (compound 7) and saponarin (compound 8). Among them, compound 1, 2, 4, 6, 7 and 8 were isolated from Isatis indigotica Fort.for the first time; compound 5 was a new compound.The content of total flavonoids in Folium Isatidis was determined using ultraviolet spectrophotometry. The linear range of rutin was 11.56～57.60μg·mL^-1( r = 0. 9998); the average recovery was 100.2% with RSD of 1.4%. The sample preparation method of total flavonoids in Folium Isatidis was optimized by using orthogonal experiment design. Theoptimum conditions were as follows: 20 folds of 60% aqueous ethanol and ultrasonicextracting for 4 times, 30 min each time.The antioxidant activities of eight flavonoids isolated from Folium Isatidis and theextracts of total flavonoids were evaluated with superoxide anion radicals scavenging activityusing SOD kit. And they all showed some antioxidation activity.A CE method for the simultaneous determination of isoscoparin-3"-O-glucopyranoside,isovitexin-3"-O-glucopyranoside, isoorientoside-3"-O-glucopyranoside, isoscoparin,isovitexin and isoorientin was developed and validated. The linear ranges forisoscoparin-3"-O- glucopyranoside, isovitexin- 3"-O-glucopyranoside, isoorientoside- 3"-O-glucopyranoside, isoscoparin, isovitexin and isoorientin were 33.0～660μg·mL^-1, 10.0～200μg·mL^-1, 14.5～290μg·mL^-1,27.5～550μg·mL^-1, 33.0～660μg·mL^-1 and 12.0～240μg·mL^-1, respectively. The average recoveries were 97.7% (RSD=1.8%),97.5% (RSD=1.9%),95.3% (RSD=3.4%),91.6%(RSD=2.0%),96.3% (RSD=3.1%) and 98.3% (RSD=1.8%), respectively. The method could be used as one of the quality control methods of Folium Isatidis.