Highly efficient and regioselective acylation of arbutin catalyzed by lipase from Candida sp.

Arbutin, as a simple polyphenol, can be extracted from almost all the natural plants and has various important bioactivities. Regioselective acylation of arbutin can improve its cell membrane penetration and enhance its biological activity. The regioselective acylation of arbutin catalyzed by lipase from Candida sp. (CSL, expressed from Canadia sp. 99–125) has been successfully conducted in non-aqueous media. Under the optimum conditions (arbutin, 0.73 mmol; vinyl acetate, 29.71 mmol; organic solvent, 20 ml tetrahydrofuran; initial water activity, 0.63; temperature, 40 °C; enzyme dosage, 100 mg enzyme powder in this reaction system), the highest enzyme activity (3.71 ± 0.13 μmol/h/mg) could be obtained. The conversion could reach 91.42 ± 2.43% after 24 h and the regioselectivity of the CSL-catalyzed acylation was highly specific at the C-6′ position in the glucose moiety of arbutin (>99%). CSL has been proven to be an excellent candidate as a catalyst for highly regioselective acylation of arbutin. [ABSTRACT FROM AUTHOR]