Study of Umbelliferone Hydroxylation to Esculetin Catalyzed by Polyphenol Oxidase

DOI Web Site Web Site PubMed 参考文献6件
  • Garcia-Molina Mary of the Sea
    Investigation Group of Enzimology (GENZ), Department of Biochemistry and Molecular Biology A, University of Murcia, Campus of International Excellence “Campus Mare Nostrum”
  • Munoz-Munoz Joseph Louis
    Investigation Group of Enzimology (GENZ), Department of Biochemistry and Molecular Biology A, University of Murcia, Campus of International Excellence “Campus Mare Nostrum”
  • Garcia-Molina Francis
    Investigation Group of Enzimology (GENZ), Department of Biochemistry and Molecular Biology A, University of Murcia, Campus of International Excellence “Campus Mare Nostrum”
  • Rodriguez-Lopez Joseph Neptune
    Investigation Group of Enzimology (GENZ), Department of Biochemistry and Molecular Biology A, University of Murcia, Campus of International Excellence “Campus Mare Nostrum”
  • Garcia-Canovas Francis
    Investigation Group of Enzimology (GENZ), Department of Biochemistry and Molecular Biology A, University of Murcia, Campus of International Excellence “Campus Mare Nostrum”

この論文をさがす

抄録

We characterize umbelliferone, a derivative of 2,4-dihydroxycoumaric acid, as a substrate of polyphenol oxidase. This enzyme hydroxylates umbelliferone to esculetin, its o-diphenol, and then oxidizes it to o-quinone. The findings show that umbelliferone, an intermediate in one of the coumarin biosynthesis pathways, may be transformed into its o-diphenol, esculetin, which is also an intermediate in the same pathway. The activity of the enzyme on umbelliferone was followed by measuring the consumption of oxygen, spectrophotometrically and by HPLC. Kinetic constants characterizing the hydroxylation process were: kcat=0.09±0.02 s−1 and Km=0.17±0.06 mM. The o-diphenol, esculetin, was a better substrate and when its oxidation was followed spectrophotometrically, the kinetic constants were: kcat=1.31±0.25 s−1 and Km=0.035±0.002 mM. Both compounds therefore can be considered as alternative substrates to L-tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA), since both indirectly inhibit melanogenesis.

収録刊行物

参考文献 (6)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ