| Summary: | <p>Abstract</p> <p>Background</p> <p>Use of enzymes in low water media is now widely used for synthesis and kinetic resolution of organic compounds. The frequently used enzyme form is the freeze-dried powders. It has been shown earlier that removal of water molecules from enzyme by rinsing with n-propanol gives preparation (PREP) which show higher activity in low water media. The present work evaluates PREP of the lipase (from <it>Rhizomucor miehei</it>) for kinetic resolution of (<it>R,S</it>)-<it>β</it>-citronellol. The acylating agent was vinyl acetate and the reaction was carried out in solvent free media.</p> <p>Results</p> <p>The PREP, with 0.75% (v/v, reaction media) water, was indeed found to be more efficient and gave 95% conversion to the ester. Using this PREP, with no added water, 90% ee for (<it>R</it>)-(+)-<it>β</it>-citronellyl acetate at 45% conversion (E = 42) was obtained in 4 h. The control with freeze-dried enzyme, with zero water content, gave 78% ee at 30% conversion (E = 13). FT-IR analysis showed that PREP had retained the α-helical content of the enzyme. On the other hand, freeze-dried enzyme showed considerable loss in the α-helical content.</p> <p>Conclusion</p> <p>The results show that PREP may be a superior biocatalyst for enantioselective conversion by enzymes in low-water media.</p>
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