Analyses of Phenolic Compounds of Water Extract from Propolis by Reversed Phase High Performance Liquid Chromatography / 分析化学

A reversed phase high-performance liquid chromatography method for the simultaneous analysis of 23 kinds of phenolic components in water extract of porpolis (WEP) was developed. The separation was performed on ZORBAX Eclipse XDB C_(18) column (150 mm×4.6 mm, 5 μm) by gradient elution. The mobile phase consisted of ethanol with 0.1% formic acid at the flow rate of 1.0 mL/min. The detection wavelengths were 256 and 280 nm. The injection volume was 20 μL, and the column temperature was maintained at 35 ℃. The method showed good linear relationship, precision and repeatability. The recoveries were between 93.3% and 106.6%. Eighteen Reference compounds were detected in WEP of Hehei by this method. The content of Catechin was the highest(30.50 mg/g), the next was 3,4-dimethoxycinnamic acid (15.41 mg/g). Nine Reference compounds were detected in WEP of Yunnan. The content of catechin was also the highest (11.23 mg/g), the next was chrysin (15.41 mg/g). Similarity of WEPs between the products of Hebei and Yunnan were 0.099 (256 nm) and 0.194 (280 nm). The chemical compositions of two WEPs were remarkably different.

Isolation and identification of polysaccharide from sweet potato vines / 生物工程学报

China is the largest country of cultivating sweet potato in the world. The resources of sweet potato vines (SPV) are huge. To exploit the rich resources, SPV of XuShu 18 was selected as raw materials since it is cultivated in China widely. Polysaccharide from SPV was extracted by pilot instrument and precipitated by ethanol. The decolouring technology was studied. By primary purification, we obtained the polysaccharide from SPV (PSPV) and studied its physical and chemical characters. Using DEAE-cellulose column and NaCl solution as eluting reagent, three kinds of pure polysaccharide, named PSPV I, PSPV II and PSPVIII respectively, were obtained. Then the molecular weight distribution and sugar compositions were studied using High Performance Gel Filtration Chromatography and GC. The followings are the results. PSPV I was separated from PSPV which was extracted from SPV harvested in the middle of June. Its M.W. is 6.278 x 10(4) D and is mainly composed of Xylose, Mannose and Glucose. PSPV II and PSPVIII were separated from PSPV which was extracted from SPV harvested in the middle of October. Their M.W. are 3.801 x 10(4) D and 1.418 x 10(4) D respectively. PSPVII is mainly composed of mannose and galactan. PSPVIII is mainly composed of glucose, xylose and rhamnose. The results provide theoretical basis for the utilization of SPV.