An efficient enzymatic modification of cordycepin in ionic liquids under ultrasonic irradiation

作者：Zhang, Dan-Ni; Guo, Xiao-Yu; Yang, Qiu-Huizi; Chen, Zhi-Gang^*; Tao, Li-Jia

来源：Ultrasonics Sonochemistry, 2014, 21(5): 1682-1687.

DOI：10.1016/j.ultsonch.2014.02.023

• Cordycepin
• Ultrasonic irradiation
• Ionic liquids
• Enzymatic acylation
• Regioselectivity

A comparative study of the immobilized Candida antarctica lipase B (Novozym 435)-catalyzed acylation of cordycepin with vinyl acetate in ionic liquids (ILs) under ultrasonic irradiation and shaking was conducted. The application of ultrasonic irradiation instead of shaking during acylation resulted in an enhanced reaction rate and a higher level of substrate conversion. Among the various ILs examined, 1-butyl-3-methylimidazolium tetrafluorobrate ([C(4)MIm][BF4]) was the best medium for the reaction because it produced the highest substrate conversion. In [C(4)MIm][BF4], the optimal ultrasonic power, water activity, and reaction temperature were 120W, 0.33, and 50 degrees C, respectively. The acylation of cordycepin in [C(4)MIm][BF4] proved to be regioselective under both conditions: the C5'-OH was acylated. Novozym 435 exhibited a much higher operational stability in [C(4)MIm][BF4], and 58.0% of its original activity was maintained after ten reuse cycles under ultrasonic irradiation. Compared with the cordycepin, the rate of adenosine deaminase-catalyzed deamination was greatly reduced when the 5'-OH was substituted by acetyl group. These results demonstrated that the combined application of ultrasonic irradiation and IL as a medium was an efficient approach for the enzymatic modification of cordycepin.

• 出版日期2014-9
• 单位南京农业大学