Detection and Partial Characterization of γ-glutamyltranspeptidase from Cordyceps sinensis Mycelia / 中国生物工程杂志

γ-glutamyltranspeptidase was detected from the cultured mycelia of Cordyceps sinensis (CSGT). Km and Vmax of CSGT was 2.54×10-4 mol/L and 0.1808 mol/L·min respectively when L-glutamic acid 5-(4-nitroanilide) (GpNA) and glycyglycine was used as its substrate. CSGT was stable from pH 8.0 to 11.0 and at or below 20℃. It was optimally active at pH 9.0～10.0 and 30℃. A series of reducing reagents could activate CSGT, and metal cations such as Zn2+, Cu2+, Hg2+ , Mn2+ inhibited strongly activity of the enzyme, but K+, Ca2+, Mg2+ and Na+ at high concentrations had no effect on its activity, indicating that its active center could contain -SH.

Molecular docking of epidermal growth factor receptor tyramine kinase domain and its inhibitor genistein / 生物工程学报

Genistein is a high specific and noncompetitive inhibitor of epidermal growth factor receptor tyramine kinase domain (EGFR-TK). In the paper, a molecular docking between genistein and EGFR-TK was studied to explore the mechanism of their interaction and antitumor mechanism of genistein by AUTODOCK 3.05 program. The results indicated that genistein located in the active cavity of EGFR-TK by high affinity (deltaG = -31.2 kJ/mol), and genistein inhibited EGFR-TK by interfering with forming of Lys721/Glu738 ion pair. The inhibition belonged to noncompetitive interaction, in which hydrophobic force and hydrogen bond played key roles.

Study on Preparation Process of Sodium Copper Porphyrin of Herba Ephedrae and Its Character / 中成药

Objective: To study the comprehensive utilization of Herba Ephedrae resources during the extraction process of ephedrin, that is the extracting of porphyrin compound.Methods: The process conditions for preparing sodium copper porphyrin were optimized by the two preparation processes and twice orthogonal tests. Results: Herba Ephedrae was powdered, steeped and boiled in alcohol, saponified, then extracted with xylene. The ephedrin was extracted from the upper layer of xylene extraction solution and sodium copper porphyrin was obtained from the lower layer by copper substituton, acidulation and alkalization. Conclusion: The optimum preparation process for producing sodium copper porphrin of Herba Ephedrae which is superior to porphyrin in the stability and colour is ascertained.

Extraction of Ephedrine and Prophyrin Copper Sodium of Ephedra / 中成药

Objective: To obtain ephedrine with porphyrin copper sodium from Herba Ephedrae. Methods: Application of ethanol to obtain ephedrine and porphyrin copper sodium from ephedra. The spoinfy reaction of porphyrin will take place, the integral ephedrine will turn into free ephedrine (dissolved in ether), when the liquor of ethanol of ethanol of ephedra are heated with NaOH. Using dimethylponyle to extract, the liquor will into two phases, one's (including sponify porphyrin) is water phase, the other's (including free ephedrine) is ether phase. Results: The yield proportion of ephedrine is 0.72%, and porphyrin copper sodium is 1.8%.Conclusion: It is practicable to extract porphyrin copper sodium with ephedrine from Herba Ephedrae.