Enhancement of the selective enzymatic biotransformation of rutin to isoquercitrin using an ionic liquid as a co-solvent

- Ionic liquid-containing buffer system was first applied in conversion of rutin.
- Both [Bmim][BF4] and [Emim][BF4] improve selective synthesis of isoquercitrin.
- [Bmim][BF4]-glycine-sodium hydroxide buffer (pH 9.0) (10:90, v/v) is the best.
- The highest rutin conversion and isoquercitrin yield were 93.40% and 91.41%.