Résumé
This study was performed to prepare immobilized β-glucosidase and snailase, then optimize and compare the process conditions for conversion of icariin. Immobilized β-glucosidase and snailase were prepared using crosslink-embedding method. The best conditions of the preparation process were optimized by single factor analysis and the properties of immobilized β-glucosidase and snailase were investigated. The reaction conditions including temperature, pH, substrate ratio, substrate concentration, reaction time and reusing times of the conversion of icariin using immobilized β-glucosidase or snailase were optimized. Immobilized β-glucosidase and snailase exhibited better heat stabilities and could remain about 60% activity after storage at 4 degrees C for 4 weeks. The optimized conditions for the conversion of icariin were as follows, the temperature of 50 degrees C, pH of 5.0, enzyme and substrate ratio of 1 : 1, substrate concentration of 0.1 mg x mL(-1), reaction time of 6 h for β-glucosidase and 2 h for snailase, respectively. In 5 experiments, the average conversion ratio of immobilized β-glucosidase and snailase was 70.76% and 74.97%. The results suggest an effect of promoted stabilities, prolonged lifetimes in both β-glucosidase and snailase after immobilization. The immobilized β-glucosidase and snailase exhibited a higher conversion rate and reusability compared to the free β-glucosidase and snailase. Moreover, the conversion rate of immobilized snailase was higher than that of immobilized β-glucosidase. The process of icariin conversion using immobilized β-glucosidase and snailase was moderate and feasible, which suggests that immobilized enzymes may hold a promise for industrial usage.
Résumé
Marine actinomyces LYG-1 was isolated from marine mud flats in Lianyungang,China.Strain LYG-1 was identified using the methods of morphology,physiological and ehemotaxonomic characterization and 16S rRNA gene sequence analysis.The results showed that strain LYG-1 was a marine variable species of Streptomyces roseosporus.The fermentation broth of strain LYG-1 exhibited conspicuous antitumor activity against HepG2,MCF-7,HCT116 and MDA-MB-231 cell lines,and the IC50 values were defined by MTT method respectively.
Résumé
Objective To study chromatography fingerprints of Zanthoxylum echinocarpum by HPLC.Methods Diamonsil C18 column(250 mm?4.6 mm,5 ?m) was used with acetonitrile-water gradient elution,at flow-rate of 1.0 mL/min,detection wavelength at 278 nm.Results HPLC was used to establish fingerprint chromatograph of water extraction from ten batches of Z.echinocarpum,which had been harvested from the same area in Zhangjiajie at the same time.The result showed that 11 peaks were common.Conclusion The method could be used for the quality control of Z.echinocarpum.