Enzymatic synthesis of amino sugar fatty acid esters

Abstract

N-Acetyl-glucosamine fatty acid esters were synthesized by a lipase-catalyzed transesterification with methyl hexanoate and N-acetyl-glucosamine (GlcNAc), which resulted in the formation of 2-(acetylamino)-2-deoxy-6-O-hexanoate-D-glucose, a novel glycolipid. Additionally N-butyryl-glucosamine (GlcNBu) was used for a similar synthesis, leading to the formation of 2-(butyrylamino)-2-deoxy-6-O-hexanoate-D-glucose. The higher hydrophobicity of GlcNBu led to an increase in the overall yield and the initial reaction rate when compared to the reaction with GlcNAc. By pre-dissolving GlcNAc and GlcNBu in dimethyl sulfoxide (DMSO), it was possible to completely dissolve both sugars in the organic solvent, thus further enhancing the initial reaction rate and yield respectively. Practical applications: Glycolipids are used in a wide range of applications, ranging from food, cosmetic, and pharmaceutical formulations, where they can be used as emulsifiers or foaming agents to classic cleaning products, utilizing their good detergent properties. Further applications may include fields like membrane protein extraction, bioremediation, or tertiary oil recovery. Novel glycolipids with tailor-made properties might be useful to improve any of the named applications and widen the diversity of available environmentally friendly surfactants, often termed "green surfactants." Glycolipids are the most prominent example therefrom. © 2014 The Authors. European Journal of Lipid Science and Technology Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.