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Third-party-funded project

"Naphthylisoquinoline Alkaloids: Biological Activity, Biogenesis, and Metabolism" within the Center Grant (Sonderforschungsbereich 251) "Ecology, Physiology, and Biochemistry of Plants and Animals under Stress"

Project management at the University of Würzburg:

Participating scientists:

The naphthylisoquinoline alkaloid dioncophylline A, one of the most prominent representatives of a new class of intriguing secondary metabolites, was shown to originate from acetate units, both molecular halves, the isoquinoline part and the naphthalene portion, being formed from identical polyketide precursors. All other tetrahydroisoquinoline alkaloids previously investigated, ultimately originate from aromatic amino acids. The novel pathway to isoquinoline alkaloids (hence acetogenic) was proved by feeding experiments with 13C2-labelled precursors administered to callus cultures of Triphyophyllum peltatum (Dioncophyllaceae), followed by NMR investigations (2D INADEQUATE experiments for the identifcation of direct C-C connectivities) using the potent cryoprobe methodology. The new pathway is largely stress-sensitive: upon exposure to chemical, biotic or physical stress, T. peltatum stops producing the isoquinoline part, so that the napthalene moiety accumulates in the chemical form of naphthoquinones like plumbagin and droserone and the chiral tetralone isoshinanolone.

Key words:
    Dioncophylline A
    Polyketide Metabolism
    Naphthylisoquinoline Alkaloids
    Plant Stress
    Acetogenic Biosynthesis
    Isoquinoline Alkaloids

Projekt period: from 01.1998 to 12.2000

Funding institution:
DFG ( SFB 251, vierte Förderperiode )

Preceding project:
SFB 251, dritte Förderperiode


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