Synthesis of vitamin E glycoside by apha-glucosidase from saccharomyces cerevisiae and cyclodextrin glycosyltransferase from Paenibacillus sp. RB01

Abstract

A novel vitamin E glycoside was synthesized by a two-step enzymatic transglycosylation system, a combination of [alpha]-glucosidase from Saccharomyces cerevisiae and cyclodextrin glycosyltransferase (CGTase) from Paenibacillus sp. RB01. 2-([alpha]-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG) was synthesized from 2-hydroxyl-2,5,7,8-tetramethylchroman-6-ol (TM) and maltose by [alpha]-glucosidase. TMG was then used as an acceptor to synthesize a novel vitamin E derivative by CGTase using [beta]-cyclodextrin ([beta]-CD) as a donor. A novel product was identified as [alpha]-D-glucopyranosyl-(14)-2-([alpha]-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG[subscript 2]) by mass spectrometry and nuclear magnetic resonance spectroscopy analysis. When 50 mM potassium phosphate buffer (pH 6.0) containing 0.5% (w/v) of TMG, 1.5% (w/v) of [beta]-CD and 100 U of CGTase was incubated at 50 [degree Celcius] for 4 hours, the percent yield of TMG[subscript 2] reached 47.2% based on the amount of TMG supplied. The solubility in water of TMG[subscript 2] was about 14 times higher than that of TMG and was more than 1 x 10[superscript 4] and 7 x 10[superscript 4] times higher than those of TM and Trolox (6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging activity of TMG[subscript 2] was found to be nearly the same as those of TMG, TM and Trolox.