Alkaloidal Components in the Poisonous Plant, Ipomoea carnea (Convolvulaceae)

Authors Organisations
  • Mitsue Haraguchi(Author)
    Biological Institute of São Paulo
  • Silvana L. Gorniak(Author)
    University of São Paulo
  • Kyoko Ikeda(Author)
    Hokuriku University
  • Yasuhiro Minami(Author)
    Hokuriku University
  • Atsushi Kato(Author)
    University of Toyama
  • Alison Watson(Author)
    Molecular Nature Limited
  • Robert Nash(Author)
    Institute of Grassland and Environmental Research
  • Russell J. Molyneux(Author)
    USDA, ARS Research
  • Naoki Asano(Author)
    Hokuriku University
Type Article
Original languageEnglish
Pages (from-to)4995-5000
Number of pages6
JournalJournal of Agricultural and Food Chemistry
Volume51
Issue number17
DOI
Publication statusPublished - 11 Jul 2003
Links
Permanent link
View graph of relations
Citation formats

Abstract

Natural intoxication of livestock by the ingestion of Ipomoea carnea (Convolvulaceae) sometimes occurs in tropical regions of the world. Polyhydroxylated alkaloids were isolated from the leaves, flowers, and seeds of the poisonous plant and characterized. Chromatographic separation of the leaf extract resulted in the isolation of swainsonine (1), 2-epi-lentiginosine (2), calystegines B1 (3), B2 (4), B3 (5), and C1 (6), and N-methyl-trans-4-hydroxy-l-proline (7). The contents of 1 in the fresh leaves and flowers were 0.0029 and 0.0028%, respectively, whereas the contents of 1, 3, and 4 in the seeds were ∼10 times higher than those in the leaves and flowers. Alkaloids 3, 4, and 6 showed a potent inhibitory activity toward rat lysosomal β-glucosidase, with IC50 values of 2.1, 0.75, and 0.84 μM, respectively, and alkaloid 5 was a moderate inhibitor of α- and β-mannosidases. Although alkaloid 1 is known as a powerful inhibitor of lysosomal α-mannosidase (IC50 = 0.02 μM), alkaloid 2, which has been thought to be an intermediate in the biosynthesis of 1, was also a potent inhibitor of α-mannosidase with an IC50 value of 4.6 μM.

Keywords

  • Ipomoea carnea, poisonous plant, intoxication in livestock, polyhydroxylated alkaloids, glycosidase inhibition