Enzymatic synthesis of water soluble thymol glycosides were carried out using amyloglucosidase from Rhizopus mold under supercritical carbon dioxide (SCCO2) conditions of 120 bar pressure at 50 °C. Thymol 1 formed glycosides with D-galactose 2, D-mannose 3, D-fructose 4, D-ribose 5 and D-arabinose 6 in yields ranging from 20.6% to 54.2%. Spectral characterization studies revealed that the reaction occurred between the phenolic OH group of thymol and 1-O/2-O groups of D-fructose and C-1 group of D-galactose, D-mannose, D-ribose and D-arabinose resulting in monoglycosylated/arylated derivatives.
Keywords: Amyloglucosidase; C-1 glycosylation; Hydrophilicity; Supercritical carbon dioxide; Thymol.