| Autor: |
Kurosu J; Department of Applied Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan., Sato T, Yoshida K, Tsugane T, Shimura S, Kirimura K, Kino K, Usami S |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of bioscience and bioengineering [J Biosci Bioeng] 2002; Vol. 93 (3), pp. 328-30. |
| DOI: |
10.1263/jbb.93.328 |
| Abstrakt: |
Alpha-arbutin, a useful cosmetic ingredient, was selectively synthesized by alpha-anomer-selective glucosylation of hydroquinone with maltose as a glucosyl donor using lyophilized cells of Xanthomonas campestris WU-9701 as a biocatalyst. When 45 mM hydroquinone and 120 mg of lyophilized cells showing 11 nkat of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mM H3BO3NaOHKCl buffer (pH 7.5) containing 1.2 M maltose at 40 degrees C, only one form of hydroquinone glucoside was selectively obtained as a product and identified as hydroquinone 1-O-alpha-D-glucopyranoside (alpha-arbutin) by 13C-NMR, 1H-NMR and two-dimensional HMBC analysis. Although hydroquinone has two phenolic -OH groups at the para position in its structure, only one -OH group, but not both -OHs, was glucosylated and no other glucosylated products such as maltotriose were detected in the reaction mixture. The reaction at 40 degrees C for 36 h under optimum conditions yielded 42 mM alpha-arbutin, and the maximum molar conversion yield based on the amount of hydroquinone supplied reached 93%. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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