Benzyl alkyl sulfide was turned into chiral R-sulfoxide using chloroperoxidase (CPO)-catalyzed oxidation of (TBHP) based on CPO’s chiral recognization to organic substrate. The yield of aim products was enhanced by the introduction of polyhydroxy compound and quaternary ammonium salt. The reaction was mainly controlled by factors such as pH, oxidants, reaction time, molar ratio of oxidant/substrate, and CPO consumption. The sulfoxide yield and enantiomeric excess (ee) reached 65.5% and 96.3% when polyhydroxy compounds (glycerol, PEG400 or PEG600) were introduced into reaction system. The yield and ee of 78.2%～68.5% and 95.4%～94% were obtained when quaternary ammonium salt (TEABr, TPABr or TBABr) was introduced. UV-vis and fluorescence spectrum assay indicated that it was easier for CPO to bind with the substrate because the introduction of above additives would intensify the exposure of heme. Moreover, it was also favorable for CPO catalytic performance due to the improvement of α-helix structure of CPO. Compared to those reported methods, the preparation of chiral sulfoxide catalyzed by CPO was very efficient. CPO consumption was very small which would ensure its potential application in industry.

Key words: chloroperoxidase, chiral sulfoxide, enantio-sulfoxidation, polyhydroxy compound, quaternary ammonium salt