title: Optimization of lipase-catalyzed synthesis of caffeic acid phenethyl ester in ionic liquids by response surface methodology.
abstract: Lipase-catalyzed caffeic acid phenethyl ester (CAPE) synthesis in ionic liquid, 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][Tf(2)N]), was investigated in this study. The effects of several reaction conditions, including reaction time, reaction temperature, substrate molar ratio of phenethyl alcohol to caffeic acid (CA), and weight ratio of enzyme to CA, on CAPE yield were examined. In a single parameter study, the highest CAPE yield in [Emim][Tf(2)N] was obtained at 70 °C with a substrate molar ratio of 30:1 and weight ratio of enzyme to CA of 15:1. Based on these results, response surface methodology (RSM) with a 3-level-4-factor central composite rotatable design (CCRD) was adopted to evaluate enzymatic synthesis of CAPE in [Emim][Tf(2)N]. The four major factors were reaction time (36-60 h), reaction temperature (65-75 °C), substrate molar ratio of phenethyl alcohol to CA (20:1-40:1), and weight ratio of enzyme to CA (10:1-20:1). A quadratic equation model was used to analyze the experimental data at a 95 % confidence level (p < 0.05). A maximum conversion yield of 99.8 % was obtained under the optimized reaction conditions [60 h, 73.7 °C, substrate molar ratio of phenethyl alcohol to CA (27.1:1), and weight ratio of enzyme to CA (17.8:1)] established by our statistical method, whereas the experimental conversion yield was 96.6 ± 2 %.
authors: Department of Chemical Engineering and Nano-Bio Technology, Hannam University, Daejeon, 305-811, Korea. shha@hnu.kr
authors: Sung Ho
authors: SH
authors: Ha
authors: Tran
authors: T
authors: Van Anh
authors: Yoon-Mo
authors: YM
authors: Koo
mesh_terms: D002109:Caffeic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D006358:Hot Temperature; D007093:Imidazoles / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D013449:Sulfonamides / Q000737:chemistry*
chemical_list: C500270:1-ethyl-3-methyl-imidizolium bis((trifluoromethyl)sulfonyl)amide; D002109:Caffeic Acids; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D007093:Imidazoles; D013449:Sulfonamides; C093667:Novozyme 435; D008049:Lipase; C055494:caffeic acid phenethyl ester; D010626:Phenylethyl Alcohol