LAUSR

Abstract Chemical methods for the regioselective modification of carbohydrates require several steps that involve the addition and removal of protective groups. Enzymatic methods are promising since they can give high selectivity in a single step. We developed a new method for acetylation of methyl-α- d -glucopyranoside with vinyl acetate, the reaction being catalyzed by a fermented solid containing lipases from Burkholderia contaminans LTEB11. The main product of the synthesis, methyl 6-O-acetyl-α- d -glucopyranoside (6-OAc-α-MetGlc), was identified by NMR and quantified by HPLC. The conversion of methyl-α- d -glucopyranoside to 6-OAc-α-MetGlc was evaluated at laboratory scale (4 mL) in different solvent systems. The conversion increased with increasing hydrophobicity of the solvent, with the highest conversion, 65% in 72 h, being obtained in the solvent-free system. This system was scaled up to a 1-L reaction medium. A conversion of 76% in 72 h was obtained, with a calculated yield of 1.05 g (4.43 mmol) of 6-OAc-α-MetGlc. This is the largest amount of 6-OAc-α-MetGlc (in moles) produced by enzymatic catalysis that has been reported in the literature to date. These results suggest that the fermented solid produced by B. contaminans LTEB11, which is a low-cost biocatalyst, could potentially be used for the industrial production of esters of α- d -glucose.