Evaluation of regioselectivity of lipases based on synthesis reaction conducted with propyl alcohol, isopropyl alcohol and propylene glycol

Preliminary investigations on the regioselectiviy of various lipases were p erformed. Ten commercial lipases from different origins, including three im mobilized lipases, were tested by esterification reaction between caprylic acid and propyl or isopropyl alcohol in n-hexane. Reaction products were an alyzed with a gas chromatograph. Best yields were obtained with immobilized lipase IM60 from Rhizomucor miehei. Therefore, this enzyme was chosen as b iocatalyst for a second step of regioselectiviy study with propylene glycol which bears primary and secondary alcohol groups. It was shown, by using s everal solvents, that polarity could influence the product profile in situa tions in which multiple products of various polarities can be formed. Furth ermore, the major role of silica gel in reaction mixture was established. ( C) 2001 Elsevier Science B.V. All rights reserved.