Planta Med 1998; 64(8): 705-710
DOI: 10.1055/s-2006-957562
Papers
Biochemistry, Physiology, in vitro Cultures
© Georg Thieme Verlag Stuttgart · New York

Effects of Digitoxigenin, Digoxigenin, and Various Cardiac Glycosides on Cardenolide Accumulation in Shoot Cultures of Digitalis lanata

Christoph Theurer1 , Wolfgang Kreis2 , Ernst Reinhard1
  • 1Pharmazeutisches Institut, Eberhard-Karls-Universität, Tübingen, Germany
  • 2Lehrstuhl für Pharmazeutische Biologie, Friedrich-Alexander-Universität Erlangen-Nümberg, Erlangen, Germany
Further Information

Publication History

1998

1998

Publication Date:
04 January 2007 (online)

Abstract

Various cardenolide genins and cardenolide glycosides were administered to light-grown and dark-grown Digitalis lanata shoot cultures to investigate conversion reactions related to the formation and rearrangement of the sugar side chain of Digitalis glycosides. Digitoxigenin was converted to digitoxigen-3-one, 3-epidigitoxigenin, and digoxigenin. In addition, various cardiac glycosides were formed, including mono-glycosides with glucose, glucomethylose, fucose, and digitalose, as well as the corresponding diglycosides, all containing a terminal glucose. Digitoxosylated cardenolides were not formed, although the light-grown shoot cultures were capable of producing these compounds. Exogenous cardenolide fuco-sides were not converted into cardenolide digitoxosides. Administration of evatromonoside (digitoxigenin monodigitoxoside) did not force the formation of cardenolide di- or tridigitoxosides. Our results support the hypothesis that cardenolide fucosides and digitoxosides are formed via different biosynthetic routes and that cardenolide genins can be fucosylated but not digitoxosylated, indicating that digitoxosylation may only occur at an earlier stage in the cardenolide pathway.