Lipase-Catalyzed Solid Phase Synthesis of Sugar Fatty Acid Esters

A wide variety of unprotected sugars were acylated in high-yields with non-activated fatty acids in a regioselective manner using commercial lipase preparations. The reactions were performed in a (mainly) solid phase in the presence of an organic solvent, serving as adjuvant to maintain a small catalytic liquid phase. Optimum conditions were found using solvents with a low log P value such as acetone or dioxane, lipase from Candida antarctica (Novo SP 435) and saturated fatty acids with chain lengths from C12 to C18 as acyl donors. The esterification ofβ-D(+)-glucose with palmitic acid resulted in up to 86% conversion after 48 h and a productivity of 0.4 mmol 6-O-β-D(+)-glucose palmitate per gram lipase and hour. α-D(+)-Glucose, sorbitol, D(+)-mannose and mannitol were also successfully acylated.