| Autor: |
Yamamoto H; Medicinal Plants Garden, School of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan., Hori M, Kuwajima H, Inoue K |
| Jazyk: |
angličtina |
| Zdroj: |
Planta [Planta] 2003 Jan; Vol. 216 (3), pp. 432-6. Date of Electronic Publication: 2002 Sep 18. |
| DOI: |
10.1007/s00425-002-0896-0 |
| Abstrakt: |
A microsomal fraction prepared from Abeliophyllum distichumNakai (Oleaceae) cell suspension cultures oxidized salidroside, a glucoside of 4-hydroxyphenylethyl alcohol, to cornoside possessing a unique benzoquinol ring. The enzyme named salidroside mono-oxygenase required NADPH as the only cofactor, and molecular oxygen. The reaction was strongly inhibited by CO as well as several cytochrome P450 inhibitors, such as cytochrome c and miconazole, indicating the involvement of a cytochrome P450 enzyme. Salidroside mono-oxygenase accepted salidroside as the only substrate, but did not oxidize 4-hydroxyphenylethyl alcohol, the salidroside aglucone, and 4-hydroxybenzoic acid. The optimum pH of the reaction was 7.5, and apparent K(m) values for salidroside and NADPH were 44 micro M and 33 micro M, respectively. The benzoquinol ring formation mechanism is discussed in comparison to the mechanism for ipso substitution of 4-hydroxybenzoate by active oxygen species followed by elimination leading to hydroquinone. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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