title: Alkaloidal components in the poisonous plant, Ipomoea carnea (Convolvulaceae).
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 B(1) (3), B(2) (4), B(3) (5), and C(1) (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 approximately 10 times higher than those in the leaves and flowers. Alkaloids 3, 4, and 6 showed a potent inhibitory activity toward rat lysosomal beta-glucosidase, with IC(50) values of 2.1, 0.75, and 0.84 microM, respectively, and alkaloid 5 was a moderate inhibitor of alpha- and beta-mannosidases. Although alkaloid 1 is known as a powerful inhibitor of lysosomal alpha-mannosidase (IC(50) = 0.02 microM), alkaloid 2, which has been thought to be an intermediate in the biosynthesis of 1, was also a potent inhibitor of alpha-mannosidase with an IC(50) value of 4.6 microM.
authors.affiliation: Animal Health Center, Biological Institute of São Paulo, São Paulo, Brazil.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Haraguchi
authors.forename: Silvana L
authors.initials: SL
authors.lastname: Gorniak
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ikeda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Minami
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
authors.forename: Alison A
authors.initials: AA
authors.lastname: Watson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Nash
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Molyneux
authors.forename: Naoki
authors.initials: N
authors.lastname: Asano
mesh_terms: D000470:Alkaloids / Q000032:analysis* / Q000633:toxicity; D000818:Animals; D004791:Enzyme Inhibitors / Q000633:toxicity; D035264:Flowers / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006900:Hydroxylation; D027741:Ipomoea / Q000737:chemistry*; D008247:Lysosomes / Q000201:enzymology; D008297:Male; D008361:Mannosidases / Q000037:antagonists & inhibitors; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D012639:Seeds / Q000737:chemistry; D043323:alpha-Mannosidase; D001617:beta-Glucosidase / Q000037:antagonists & inhibitors; D044902:beta-Mannosidase
chemical_list: D000470:Alkaloids; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D008361:Mannosidases; D001617:beta-Glucosidase; D043323:alpha-Mannosidase; D044902:beta-Mannosidase