Abstract
Enzymatic resolution reactions were investigated using Candida rugosa lipase for the production of potically pure S-(+)-Ketoprofen. When the enzymatic hydroysis (and esterification) of recemic ketoprofen esters (and recemic ketoprofen with alcohol) was investigated comparatively, aqueous media was more specific for S-enantiomer than organic media. In the enzymatic hydrolysis of racemic ketoprofen ethyl ester in aqueous media, optimal temperature and pH for enantioselectivity were $37^{\circ}C$ and 4, respectively. The stereoselectivity of the enzyme was enhanced by adding dialcohols such as ethylene glycol and propylene glycol. The enantiomeric ratio obtained in the 40 %(v/v) ethylene glycol was 2-fold higher than that without the additive. By adding $CH_2Cl_2$, $CHCl_3$ and $CCl_4$ (5%,v/v), the enantioselectivity was reversed. A dramatic increase in the stereoselectivity was achieved using lipase purified by anion exchange chromatography. The type A lipase(the first eluted lipase fraction) showed an enantiomeric ratio of >100, whereas the type B lipase(the second eluted lipase fraction) exhibited enantimomer ratio of 9.0 in the hydrolysis of racemic ketoprofen ethyl ester.
본 연구에서는 광학적으로 순수한 S-(+)-ketoprofen을 얻기 위한 효소적 분할공정을 개발하는 것을 그 내용으로 하고 있다. 결과에 의하면 Candida rugosa 유래의 lipase는 음이온 교환수지에 의해 두 가지 형태의 효소로 분리되었으며 특히 첫 번째 peak의 lipaserk (S)-enantiomer에 대해 선택성이 매우 높은 것으로 나타났다. 온도 pH, 첨가제의 영향에 대해서 조사한 결과 높은 활성을 유지하면서 광학적으로 순수한 (S)-ketoprofen을 얻는 조건을 찾지는 못하였으나, $37^{\circ}C$의 온도에서 선택성이 높았으며 ethylen glyco과 같은 polyalcohol 종류가 첨가될 경우 선택성이 증가한다는 결과를 얻을 수 있었다.