Process optimization for extraction and purification of polysaccharides from Cistanche deserticola / 中国中药杂志

In this study, taking Cistanche deserticola in Xinjiang as the experimental material, the optimal process for extracting polysaccharides from C. deserticola with water extraction was studied by using single factor and orthogonal experiment. Its effects on protein removal and polysaccharides retaining were investigated by using Sevag, enzymatic method or combination of these two methods, so as to determine the optimal method for protein removal from polysaccharides of C. deserticola; the decolorization and purification methods such as macroporous resin of AB-8 and activated Carbon were used to determine the optimal process. The results showed that the extraction rate of polysaccharides from C. deserticola was 18.40% during the optimal process of the water extraction as follows: extraction temperature 75 ℃, extraction time 165 min and solid-liquid ratio 1∶55. The protein removal rate can reach 31.40% and polysaccharide retention rate can reach 96.00% under the optimal protein removal process: temperature 50 ℃, time 2 h, and papain dosage 0.2%. The decolorization rate of activated Carbon and macroporous resin called AB-8 was 80.37% and 86.43%, and the recovery rate of polysaccharides was 77.05% and 91.93%, respectively, suggesting that macroporous resin was more suitable for decoloration. Macroporous resin named AB-8 increased the purity of the polysaccharide crude extract from 67.70% to 84.80% under the following conditions: concentration of the sample 4 g·L~(-1), concentration of the eluent 60% ethanol, and the flow rate 1 mL·min~(-1), showing significant purification effect.

Screening of differentially expressed genes in mouse hepatocarcinoma ascites cell line with high potential of lymphatic metastasis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To screen genes differentially expressed in mouse hepatocarcinoma ascites cell line with high potential of lymphatic metastasis.</p><p><b>METHODS</b>A subtracted cDNA library of mouse hepatocarcinoma cell line with high potential of lymphatic metastasis Hca-F and its synogenetic cell line Hca-P with low metastatic potential was constructed by suppression subtractive hybridization (SSH) method. The screened clones of the subtracted library were sequenced and GenBank homology search was performed.</p><p><b>RESULTS</b>Ten differentially expressed cDNA fragments of Hca-F with high potential of lymphatic spreading were obtained, two of which were newly identified ones.</p><p><b>CONCLUSION</b>SSH is a useful technique to detect genes of differential expression and an effective method to clone novel genes.</p>