Li Cui, Zhenhai Zhang, E Sun, Xiaobin Jia, Qian Qian
Jiangsu Provincial Academy of Chinese Medicine, Jiangsu, China.
Objective: The aim of this work was to investigate the effect of β-cyclodextrin complexation on the solubility and hydrolysis rate of icariin. Material and Methods: The inclusion complex of icariin at the molar ratio of 1:1 was obtained by the dropping method and was characterized by differential scanning calorimetry. The solubility of icariin complex in water at 37C was 36 times greater than that of free icariin. Enzymatic hydrolysis conditions were tested for the bioconversion of icariin by mono-factor experimental design. Results: The enzymatic hydrolysis experiment showed that icariin can be transformed into baohuoside I. The optimum conditions determined were as follows: pH 5.0, 50C, the ratio of cellulase/substrate (0.6), the concentration of icariin 20 mg/ml, and reaction time 12 h. Under these enzymatic conditions, 98.2% transforming rate of baohuoside I from icariin in inclusion complexes was obtained. Conclusion The aqueous solubility and enzymatic hydrolysis rate of icariin were improved owing to the inclusion complexation.
Keywords: Baohuoside I, enzymolysis, icariin, inclusion complex, β?cyclodextrin-cyclodextrin.