title: Indole alkaloids from Geissospermum reticulatum.
abstract: Ten indole alkaloids were isolated from Geissospermum reticulatum, seven (1-7) from the leaves and three (8-10) from the bark. Seven were aspidospermatan-type alkaloids (1-3, 5-9), including four (5-8) with a 1-oxa-3-cyclopentene group in their molecule, which we named geissospermidine subtype. Compounds 1-3, 5-8, and 10 had not been reported previously as natural products, while 4 and 9 were the known alkaloids O-demethylaspidospermine and flavopereirine. Their structures were determined by spectroscopic techniques including 1D and 2D NMR experiments (COSY, NOESY, HSQC, HMBC). Additionally, X-ray crystallographic analyses of 1, 2, and 6 were performed. Antiparasitic activities of the ethanolic and alkaloidal extracts and of the pure alkaloids were tested against Trypanosoma cruzi and Leishmania infantum. In general, the extracts exhibited selective action and were more active against Leishmania than against Trypanosoma. Alkaloid 4 was also very active against L. infantum.
authors.affiliation: Instituto de Productos Naturales y Agrobiología (IPNA) , CSIC, La Laguna, Tenerife, Spain. mreina@ipna.csic.es
authors.forename: M
authors.initials: M
authors.lastname: Reina
authors.forename: W
authors.initials: W
authors.lastname: Ruiz-Mesia
authors.forename: M
authors.initials: M
authors.lastname: López-Rodríguez
authors.forename: L
authors.initials: L
authors.lastname: Ruiz-Mesia
authors.forename: A
authors.initials: A
authors.lastname: González-Coloma
authors.forename: R
authors.initials: R
authors.lastname: Martínez-Díaz
mesh_terms: D029062:Apocynaceae / Q000737:chemistry*; D018360:Crystallography, X-Ray; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018314:Leishmania infantum / Q000187:drug effects; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D021261:Parasitic Sensitivity Tests; D010568:Peru; D018515:Plant Leaves / Q000737:chemistry; D014349:Trypanosoma cruzi / Q000187:drug effects
chemical_list: D026121:Indole Alkaloids