Reverse Micelle System Lipase Catalyzed Resolution Of Racemic Menthol

There is an increased demand for optically pure enantiomers as building blocks for pharmaceutical and agrochemicals [1]. During the last decade there has been an increased interest in using enzymes for asymmetric synthesis and kinetic resolution to obtain pure enantiomers. The enzymatic resolution of enantiomers has become a common tool in organic chemistry to obtain enantiomerically pure compounds. The conventional method for enzyme catalysis is the reaction in an aqueous buffer solution. Due to some of the substrates is insoluble in organic solvent the requirements for bioconversions of hydrophobic substrates are fulfilled by using microemusions as reaction media.L-menthol and its esters are more important from industrial point of view that DL-menthol. L-menthol because of its cooling and refreshing effects is an important fragrance and flavour compound that is used largely in cosmetics, toothpaste, chewing gums, cigarettes, sweets and medicines.The esters of L-menthol can be expected to have interesting characteristic such as fragrance, which is emitted as the ester bond is hydrolyzed. The chiral menthol esters have been used in the asymmetric synthesis.In this work, we studied the parameters influencing the conversion of this reaction such as pH of buffer, water content and temperature in organic media, AOT/hexane reverse micelles systems and CTAB/hexane reverse micelles systems. Then we obtained the optimum condition for each systems and compare the stability of CCL in organic media and reverse micelles systems under their optimum condition. We studied the course of the conversion, eep and E when time goes under their optimum condition respectively. We found that at the first 3 days the conversion of AOT emulsions was smaller than that of the solvent. But after 3 days the conversion of AOT emulsions exceeded that of the solvent slowly. The conversion of the solvent stopped when it goes for about 7 days and the last conversion is 15.7%. The conversion of AOT emulsions stopped when it goes for about 17 days and the last conversion is 33%.The result hasiiiproved that stability of the CCL was high in emulsions than in solvent. This indicates that the lipase showed higher stability in reverse micelles than in organic solvent.