Unsaturated fatty acid alpha-butylglucoside esters were prepared by enzymat
ic esterification of alpha-butylglucoside in nonaqueous media. Conditions w
ere firstly optimized using oleic acid as acyl group. Synthesis was possibl
e in several solvents but the presence of water co-product in the medium li
mited the reaction to a thermodynamic equilibrium corresponding to a maxima
l conversion yield of 62%. In pure molten substrates, the removal of water
under reduced pressure enabled yields superior to 95% to be obtained. Produ
ct profiles depended on enzyme origin : whatever the support, immobilized l
ipase B from Candida antarctica proved to be far more regioselective for th
e primary hydroxyl group of glucose than immobilized lipase from Rhizomucor
miehei. Results obtained could be easily transposed to the acylation of al
pha-butylglucoside with a commercial mixture of unsaturated fatty acids con
taining more than 60% of linoleic acid. The biocatalyst could be recycled m
ore than ten times without any significant activity loss. (C) 1999 John Wil
ey & Sons, Inc.