The Extraction And Identification Of Epidermis Rust Material Of Pyrus Bretschneideri Rehd During Storage

Korla fragrant pear is a high-quality fruit by Xinjiang unique climatic conditions, mainly produced in southern regions of Xinjiang Uygur Autonomous Region, particularly in the middle suburbs Peacock River of Korla in the Yi Autonomous Prefecture of the most famous, in addition, in the Aksu, Kashgar, Khotan and the Ili Valley of the northern area, is also cultivated. Korla fragrant pear with the features of thin Roucui and refreshing juicy, rated enclosed share of pear, sold abroad. As Korla fragrant pear skin is easy to produce rust during storage, caused by the decline in the quality of appearance, to the sale of Korla fragrant pear is a big influence. In view of this, the thesis uses epidermal rust material of Korla fragrant pear as the study object, its analysis and identification provide the theoretical basis for the formation mechanism of Korla fragrant pear epidermis rust material. The main results as follows:1,The extraction study of Korla fragrant pear epidermis rust material shows that:Ethanol as solvent, 262nm for the determination wavelength of rust extract, Response Surface Optimization of pear rust material extraction process, Identified the various factors on the extraction rate was significantly affected by the order of A (ethanol concentration)>C (extraction time)> B (liquid ratio)> D (extraction temperature); The optimum extraction conditions are:A (ethanol concentration)=75%, B (liquid ratio)=18:1, C (extraction time)=4.5h, D (extraction temperature)=48℃, the rate under this Extraction condition (expressed in absorbance) is 0.228.2,The separation and purification of Korla fragrant pear epidermis rust material shows that:Pear rust material ethanol extract is concentrated, after concentrated solution mixing with water, then extracted with petroleum ether and chloroform, has been part of petroleum ether and chloroform.The part of Petroleum ether by petroleum ether-acetone (4:1) elution and petroleum ether-acetone (5:1) repeated elution obtained eluate 1, eluate 2; The part of chloroform by petroleum ether:ethyl acetate gradient elution, then by repeated chloroform elution obtained eluate 3, eluate 4, eluate 5.The purity of five eluate were tested by thin layer chromatography and liquid chromatography,Elution test results show that the five have reached a high purity.3,The identification and analysis of Korla fragrant pear epidermis rust material shows that:Five eluate knowledge by chemical qualitative analysis, UV-visible spectral scanning qualitative analysis, silica gel thin layer chromatography qualitative analysis, liquid chromatography and mass spectrometry qualitative analysis, Identification results for the eluate 1 belonging to the anthraquinone rhein, elution 2 belonging to the anthraquinones aloe-emodin, eluate 3 belonging to the anthraquinones chrysophanol, elution 4 belonging to the anthraquinones emodin, eluate 5 contains two substances by LC-MS analysis, molecular weight of 610,624 and both substances contain carbonyl and unsaturated conjugated system. Because the content of eluate 5 is less in Korla fragrant pear epidermis rust material and limited experimental conditions, So without further analysis identification for eluate 5.