Studies On Separation Technology For Lyciutum Barbarum Polar Components

Lycium barbarum is one of the important traditional Chinese medicinal plant species. It has been cultivated in Northwest China and Mediterranean region. Fruits of Lycium barbarum were widely used as medicine vegetables and functional food in China. Modern pharmacological studies had shown that the extract and fractions of Lycium barbarum had a variety of pharmacological action, including enhancement of immunity, anti-tumor and elimination of free radicals. At present the study on Lycium barbarum has been mainly focused on Lycium barbarum polysaccharides and flavones compounds. In contrast, the polar compounds in Lycium barbarum were studied a little, which contained various bioactivities according to lots of reports. So, it is necessary to research polar compounds of Lycium barbarum for the comprehensive utilization of medicinal resources. In this dissertation, an integrated approach based on solid phase extraction (SPE) and HPLC coupled with diode array detector was developed. The fractions were produced from the extract of Lycium barbarum by SPE and the phytochemical components were characterized by HPLC.1. The water extract and ethanol/water (50:50) extract of Lycium barbarum was prepared and reversed-phase chromatographic mode and hydrophilic interaction chromatography mode was used for HPLC analysis. The results verificated that Lycium barbarum water extract and 50% ethanol extract containing acidic compounds and other strong polar components.2. A novel solid phase extraction method was successfully put forward to discuss acidic compounds in the water extract of Lycium barbarum employing C18, bared silica and amino modified silica as stationary phase. As a result, the extract were separated into three fractions, high polar, medium polar and acidic compounds, largely simplifying the sample complexity and realizing the selectively enrichment of acidic compounds. Developing different high performance liquid chromatography methods respectively separated the high polar, medium polar and acidic compounds in the extract. The strong polar compounds were separated by hydrophilic chromatographic stationary phases with ACN and buffer as mobile phases. The medium polar compounds were separated by reversed phase chromatographic stationary phase with ACN and water as mobile phases, and the acidic compounds were separated by adding 0.1% formic acid in the mobile phase by RPLC.3. A well-defined polymer brush of 2-hydroxy-3-[4-(hydroxymethyl)-1H-1,2,3-triazol-1-yl (HTMA) on the surface of silica gel were prepared by SI-ATRP, the SI-ATRP technique could improve the bonding dentisty of functional group. The retention mechanism of the column was investigated through adjustment ratio of water in the mobile phase, and a mixed HILIC mechanism of polar substances form Lycium barbarum (caffeic acid, p-coumaric acid, gallic acid, kaempferol, rutin) was observed at higher content of acetonitrile (85-98%, acetonitrile) in the mobile phase. From the separation ability, the stationary phase could become a valuable alternative for the separation of the compounds concerned.