title: Selective alpha-glucosylation of eugenol by alpha-glucosyl transfer enzyme of Xanthomonas campestris WU-9701.
abstract: For one-step enzymatic synthesis of eugenyl alpha-glucoside as a promising pro-drug for a hair restorer and a derivative of spices, selective alpha-glucosylation of eugenol was carried out using the alpha-glucosyl transfer enzyme of Xanthomonas campestris WU-9701. When 130 micromol eugenol and crude enzyme showing 1.0 unit of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mM H3BO3-NaOH-KCl buffer (pH 8.0) containing 1.2 M maltose as a glucosyl donor at 40 degrees C, only one form of eugenyl glucoside was selectively obtained as a product and identified as eugenyl alpha-D-glucopyranoside (alpha-EG) by 13C-NMR, 1H-NMR, and two-dimensional heteronuclear multiple-bond coherence analyses. In the reaction, no other glucosylated products such as maltotriose or eugenyl maltoside were detected in the reaction mixture. The reaction at 40 degrees C for 48 h under the above conditions yielded 68 mumol alpha-EG in 2 ml suspension, and the maximum molar conversion yield based on the amount of eugenol supplied reached 52%.
authors.affiliation: Department of Applied Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sato
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Kei
authors.initials: K
authors.lastname: Takahashi
authors.forename: Jun
authors.initials: J
authors.lastname: Kurosu
authors.forename: Keishiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Takanori
authors.initials: T
authors.lastname: Tsugane
authors.forename: Susumu
authors.initials: S
authors.lastname: Shimura
authors.forename: Kuniki
authors.initials: K
authors.lastname: King
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Kirimura