Studies On Fingerprints And Content Determination Of Active Components Of Scutellaria Baicalensis Georgi

Scutellaria baicalensis Georgi is one old and well-known drug in traditional Chinese medicines and widely used for treatments of bronchitis, hepatitis, tumors, and inflammatory diseases. Recently, the flavonoids of S. baicalensis have been reported possessing the inhibitory effects on human immunodeficiency virus (HIV-1) and human T-cell leukemia virus (HTLV-1).The germplasm resources of S. baicalensis were investigated in the paper. Moreover, the main active components in samples of different habitats, different varieties, different picking time and different primary processing were studied and analysed by high performance liquid chromatography (HPLC). The fingerprints of S. baicalensis were also systematically studied in order to establish its general quality control standard and offer some foundations to its good agriculture practice (GAP) and sustainable development. The main results could be concluded as follow:1. The paper established the method of extracting and determining aglycons (baicalein and wogonin) in S. baicalensis. Samples were prepared by Soxhlet extractor with chloroform. The HPLC determination conditions were: Methanol-acetonitrile-0.4 % glacial acetic acid (30:20:50);wavelength: 275 nm;flow rate: 1.0 ml · min^-1;column temperature: 40 ℃. Methodological experiments showed that the methods had high precision and good repeatability, so it can be used as the means to detect the aglycons in S. baicalensis.2. The glycosides (baicalin) and aglycons (baicalein and wogonin) in samples of different varieties and different habitats from China had been analyzed by HPLC. The results of different samples showed obvious distinction (p<0.05). The average content of baicalin was 11.19 %, the baicalein was 0.15 %, and the wogonin was 0.07 %, respectively.3. The paper compared the contents of effective components and the yields of S. baicalensis collected at different growth ages and different harvest time of the same age in Shangluo, Shaanxi. It is in October and November of the secondyear that both the contents and the yields reach their highest points, so the best harvest time should be from October to November of the second year.4. Both cooking and steaming are appropriate through systematically studying on the primary process of S. baicalensis, we can choose one of them according to practice. The processing flow could be concluded as follow, harvesting —> selecting —* watering —* steaming (20 min) or cooking (one times volume of water, 10 min) for intenerate —> slicing —?■ drying (80 "Cfor more than 24 h).5. The HPLC fingerprints of S. baicalensis were systematically studied: Samples are prepared by Soxhlet extractor with methanol and chloroform( 1 :l,v:v). Determination conditions of flavonoids were: gradient mobile system was applied with acetonitrile-0.4 % acetic acid;wavelength: 280 nm;flow rate: 1.0ml ? min"1;column temperature: 25 °C;The method had high precision, good repeatability and all of the contents were separated well, so it can be used as the means to assess the fingerprints of S. baicalensis.6. The paper mensurates and records the chromatograms of samples from eleven habitants of China, eleven habitants of Shaanxi and ten batches materials of Shangluo, Shaanxi. Eight peaks were identified as the characteristic fingerprints of S. baicalensis. Compared with reference substances we can identify that the fourths seventh and eighth peak is baicalin^ baibalein and wogonin, respectively. The fingerprints of different samples were compared with similarity evaluation software (2004A) published by committee of codex. Average similarity of samples from different places of China is 0.941, from Shaanxi is 0.954 and from Shangluo is 0.979. It is obvious that the similarity is correlated with the habitats of herb. The closer the habitat is, the higher the similarity is.7. The volatile oils and fat-soluble components in herbs and the fat-soluble components in seeds were extracted and analysed. The volatile oils were extracted by steam distillation, 45 volatile oils were identified in the herbs. The fat-soluble components were extracted by Soxhlet extractor, 39 fat-soluble components in herbs and 17 in seeds were identified, Most of them were fatty acids.