Plant Cell Reports

, Volume 5, Issue 6, pp 442–445

UDP-glucose:digitoxin 16′-O-glucosyltransferase from suspension-cultured Digitalis lanata cells

  • Wolfgang Kreis
  • Ursula May
  • Ernst Reinhard
Article

Abstract

Suspension cultures from several cell lines of Digitalis lanata, as well as cultures from 6 other plant species were checked for their ability to form purpurea-glycoside A from digitoxin. An in-vitro assay for the UDP-glucose:digitoxin 16′-O-glucosyltransferase (DGT, EC 2.4.1.-) has been established based on an HPLC method. The enzyme is located in the soluble fraction. Its pH optimum is at 7.4. No enzyme activity was found in either purified vacuole preparations or lysed vacuoles. Ascorbate (10 mM) increased the transferase activity about 4-fold. Of the sugar nucleotides tested, only UDP-glucose served as a glucosyl donor. Digitoxin, digoxin, α -acetyldigitoxin, and α-acetyldigoxin are substrates for the glucosyltransferase. The role of the DGT during the biotransformation of cardenolides in Digitalis lanata cell suspension cultures is discussed.

Abbreviation

DGT

UDP-glucose:digitoxin 16′-C-glucosyltransferase

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Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Wolfgang Kreis
    • 1
  • Ursula May
    • 1
  • Ernst Reinhard
    • 1
  1. 1.Pharmazeutisches Institut (Pharmazeutische Biologie) der Universität TübingenTübingenFRG

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