High regioselective acetylation of vitamin A precursors using lipase B from Candida antarctica in organic media

• Main Authors: Sun, Jingpeng, Jing, Keju, Lu, Yinghua, 卢英华
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: ENZYMATIC-SYNTHESIS; IMMOBILIZED LIPASE; RHIZOMUCOR-MIEHEI; ISOAMYL ACETATE; RESOLUTION; SOLVENT; Antarc*; Antarctica
• Online Access: http://dspace.xmu.edu.cn/handle/2288/61365

The effect of different reaction parameters was explored on the acylation of primary hydroxyl group of 1,6-diol by lipase B from Candida antarctica catalysis in organic solvent. First, the effect of the organic solvents was investigated, and the highest conversion rate was obtained in n-hexane. Then, the effect of the acyl donor was studied. Among several reactants, including acetic acid and two different acetates, vinyl acetate gave the best yield. A maximum monoester yield of 98.5% was obtained using vinyl acetate as acyl donor in n-hexane at 50 degrees C. The substrate concentration was 25 mmol/L, while the diol to vinyl acetate molar ratio was 1:3. Substrate concentration had to be limited due to an inhibitory effect on enzyme by the diol that caused a decrease on initial reaction rate. To promote initial reaction rate, excess vinyl acetate was used. Under the optimum conditions, the conversion rate and monoacylation selectivity were 98.5 and 100%, respectively. The produced monoester was 6.1 mg/ml, and this amount can be further optimized base on the results presented here.