본 연구에서는 lipase를 이용한 라세믹-naproxen 2,2,2-trifluoroethyl thioester의 광학분할 반응을 향상시키기 위하여 반응 용매, 반응 온도, 기질 및 lipase 농도 그리고 교반속도의 변수들을 최적화 하였고, isooctane과 물의 계변을 증가시키기 위한 계면 활성제의 영향을 조사하였다. 조사된 유기용매 중 isooctane이 가장 높은 전환율 (92.19%), $V_s;(2.340{ imes}10^{-2}mM/h)$, E값 (36.12) 그리고 $V_s/(E_t)$ ($7.80{ imes}10^{-4}mmol/h{cdot}g$)를 나타내어 lipase 를 이용한 라세믹-naproxen2,2,2-trifluoroethyl thioester의 광학 분할 반응을 위한 가장 효과적인 유기용매로 판단하였다. 반응 표면 분석법을 이용한 반응조건 최적화에서는 반응 온도 $48.2^{circ}C$, 기질 농도 3.51 mM, lipase 농도 30.11 mg/ml 그리고 교반속도 180 rpm을 최적 반응 조건으로 도출하였고, 이 최적화된 반응 조건으로 광학분할 반응을 수행한 결과, $V_s$, $V_s/(E_t)$ 그리고 전환 율이 각각 19.54%, 19.12%, 4.05% 증가하였다. 계면활성제로써 첨가된 NP-10은 (S)-naproxen 2,2,2-trifluoroethyl thioester의 가장 높은 전환율 (89.43%)을 나타내었고, 반응속도의 감소를 둔화시켰으며, lipase의 광학선택성 (E=59.24)을 향상시켰다.
In this study, the reaction conditions for lipase-catalyzed resolution of racemic naproxen 2,2,2-trilfluoroethyl thioester were optimized, and the effect of surfactants was investigated. Among the organic solvents tested, the isooctane showed the highest conversion (92.19%) in a hydrolytic reaction of (S)-naproxen 2,2,2-trifluoroethyl thioester. In addition, the isooctane induced the highest initial reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=2.34{ imes}10^{-2}mM/h$), the highest enantioselectivity (E = 36.12) and the highest specific activity ($V_s/(E_t)=7.80{ imes}10^{-4}mmol/h{cdot}g$) of lipase. Furthermore, reaction conditions such as temperature, concentration of the substrate and enzyme, and agitation speed were optimized using response surface methodology (RSM), and the statistical analysis indicated that the optimal conditions were $48.2^{circ}C$, 3.51 mM, 30.11 mg/mL and 180 rpm, respectively. When the optimal reaction conditions were used, the conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester was 96.5%, which is similar to the conversion (94.6%) that was predicted by the model. After optimization of reaction conditions, the initial reaction rate, lipase specific activity and conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester increased by approximately 19.54%, 19.12% and 4.05%, respectively. The effect of surfactants such as Triton X-100 and NP-10 was also studied and NP-10 showed the highest conversion (89.43%), final reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=1.175{ imes}10^{-2}mM/h$) and enantioselectivity (E = 59.24) of lipase.
