Anomer-selective glucosylation of l-menthol by yeast alpha-glucosidase.
l-Menthol was glucosylated by the alpha-glucosidase (EC 3.2.1.20) of Saccharomyces cerevisiae using maltose as the glucosyl donor. When 50 mg of l-menthol and 1.6 M maltose in 10 mM citrate-phosphate buffer (pH 5.5) were incubated at 45 degrees C, l-menthyl alpha-D-glucopyranoside (alpha-MenG) was alpha-anomer-selectively formed as a product. The specificity of the alpha-linkage was confirmed by 13C-NMR analysis. In the reaction mixture after 2 h, alpha-MenG was mainly accumulated in a crystalline form and the concentration of dissolved alpha-MenG was constant at 1.4 mM. The molar conversion yield of alpha-MenG produced based on the supplied l-menthol was maximally 30.7% at 48 h of reaction.
Department of Applied Chemistry, School of Science and Engineering, Waseda University, Tokyo, Japan.
H
H
Nakagawa
M
M
Yoshiyama
S
S
Shimura
K
K
Kirimura
S
S
Usami
D002384:Catalysis; D006031:Glycosylation; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008320:Maltose / Q000737:chemistry; D008610:Menthol / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013237:Stereoisomerism; D000520:alpha-Glucosidases / Q000737:chemistry*
D008610:Menthol; D008320:Maltose; D000520:alpha-Glucosidases