Enzymatic esterification of (−)‐menthol with lauric acid in isooctane by sorbitan monostearate‐coated lipase from Candida rugosa

Abstract Esterification of (−)‐menthol and (±)‐menthol with lauric acid in isooctane was successfully catalyzed by a commercial nonioic surfactant (sorbitan monosterate)‐coated lipase from Candida rugosa (Lipase AY “Amano” 30) at the molar ratio of 1∶1 and at 35°C using 1.5 g enzyme/g (−)‐menthol and 0.1‐g molecular sieves. After 1 h, molar conversion of (−)‐menthol reached 81%. Equilibrium was reached after ca. 4 h, giving a (−)‐menthol molar conversion of 94%. Under the same conditions, native lipase catalyzed the esterification of (−)‐menthol and lauric acid to yield a molar conversion of 93% after 72 h. Coating the lipase with sorbitan monosterate increased the esterification rates of both (−)‐menthol and (±)‐menthol with lauric acid. After 6 h, the molar conversions of (−)‐menthol and (±)‐menthol were 94, and 62%, respectively.