Glucosylation of α-butyl- and α-octyl-d-glucopyranosides by dextransucrase and alternansucrase from Leuconostoc mesenteroides Original Research Article

For the first time, glucosylation of α-butyl- and α-octylglucopyranoside was achieved using dextransucrase (DS) of various specificities, and alternansucrase (AS) from Leuconostoc mesenteroides. All the glucansucrases (GS) tested used α-butylglucopyranoside as acceptor; in particular, DS produced α-d-glucopyranosyl-(1→6)-O-butyl-α-d-glucopyranoside and α-d-glucopyranosyl-(1→6)-α-d-glucopyranosyl-(1→6)-O-butyl-α-d-glucopyranoside. In contrast, α-octylglucopyranoside was glucosylated only by AS which was shown to be the most efficient catalyst. The conversion rates, obtained with this enzyme at sucrose to acceptor molar ratio of 2:1 reached 81 and 61% for α-butylglucopyranoside and α-octylglucopyranoside, respectively. Analyses obtained from liquid chromatography coupled with mass spectrometry revealed that different series of α-alkylpolyglucopyranosides regioisomers of increasing polymerization degree can be formed depending on the specificity of the catalyst.