Study On Synthesis Salidroside Catalyzed By Microorganism And Enzyme

Salidroside is an important pharmacologically active compound in traditional Chinese herb Rhodiola L. It has been found to possess many medical functions such as resisting anoxia, microwave radiation and fatigue. Salidroside is a β-D-glucoside which is ordinarily obtained from plants Rhodiola L. Besides this, it can be synthesized by several methods such as chemical method and synthesis in suspension culture. However, biosynthesis salidroside by microorganism hasn't reported as yet. The natural resource of salidroside (mainly from the plant Rhodiola L.) is on the verge of exhaustion. Therefore it may be a vital alternative to synthesize salidroside by microorganism.Objective: (1) To establish the reaction system to synthesize salidroside by microorganism. (2) To explore the possibility to synthesize salidroside by β-glucosidase in biphasic system.Methods: Aspergillns oryzae and Aspergillus niger were mutagenized by UV combined with LiCl. The amount of salidroside was quantified by HPLC. The product was purified by macroporous adsorption resin chromatography and silica gel chromatography. The structure of product was analyzed by means of NMR and IR. The activities of β-glucosidase were determined by DNS reaction.Conclusion: In this work, F1 whole cells were used as catalyst to perform synthesis reaction of salidroside from D-glucose and tyrosol under experimental conditions. F1 was identified as Aspergillus oryzae which was screened from soil around the roots of Rhodiola L. The results showed that the highest yield has attained 0.7g/L under the optimal condition. The optimal concentration of tyrosol was 5g/L. The mol ratio of D-glucose to tyrosol was 1:1. The optimal synthesis time was 48h. The optimal cell concentration and pH were 150g/L and 7, respectively. Excessively high concentration of tyrosol was toxic to cell growth and the synthesis reaction was inhibited. In...