Lipase-catalyzed Esterification of (S)-Naproxen Ethyl Ester in SupercriticalCarbon Dioxide

摘要

A lipase-catalyzed esterification reaction of (S)-naproxenethyl ester by CALB (Candida antarctica lipase B) enzymewas performed in supercritical carbon dioxide. Experimentswere performed in a high-pressure cell for 10 h at astirring rate of 150 rpm over a temperature range of313.15 to 333.15 K and a pressure range of 50 to 175 bar.The productivity of (S)-naproxen ethyl ester was comparedwith the result in ambient condition. The total reactiontime and conversion yields of the catalyzed reaction insupercritical carbon dioxide were compared with those atambient temperature and pressure. The experimentalresults show that the conversion and reaction rate weresignificantly improved at critical condition. The maximumconversion yield was 9.9% (216 h) at ambient conditionand 68.9% (3 h) in supercritical state. The effects ofvarying amounts of enzyme and water were also examinedand the optimum condition was found (7 g of enzyme and2% water content).