04 July, 2019

Enzymatic synthesis and surfactant properties of tert-butyl α-D-glucopyranosides

While testing the ability of cyclodextrin glucanotransferases (CGTases) to glucosylate a series of flavonoids in the presence of organic cosolvents, we found out that this enzyme was able to glycosylate a tertiary alcohol (tert-butyl alcohol). Two glycosylation products were characterized by mass spectrometry (MS) and nuclear magnetic resonance (NMR) as tert-butyl-α-D-glucoside (major product) and tert-butyl-α-D-maltoside (minor product). Using partially hydrolyzed starch as glucose donor, the yield of transglucosylation was approximately 44%. The synthesized tert-butyl-α-D-glucoside exhibited the typical surfactant behavior (critical micellar concentration, 4.0–4.5 mM) and its properties compared well with those of the related octyl-α-D-glucoside. To the best of our knowledge, this is the first description of an enzymatic α-glucosylation of a tertiary alcohol.

Reference; ''Production and Surfactant Properties of Tert-Butyl α-D-Glucopyranosides Catalyzed by Cyclodextrin Glucanotransferase'' H. Garcia-Arellano, J. L. Gonzalez-Alfonso, C. Ubilla, F. Comelles, M. Alcalde, M. Bernabé, J-L Parra, A. O. Ballesteros and F. J. Plou. Catalysts  (2019), https://doi.org/10.3390/catal9070575