title: Antiamoebic and antiplasmodial activities of alkaloids isolated from Strychnos usambarensis.
abstract: Seven alkaloids isolated from Strychnos usambarensis have been assessed for in vitro activities against Entamoeba histolytica and Plasmodium falciparum and for in vivo activity against Plasmodium berghei in mice. Strychnopentamine and 3',4'-dihydrousambarensine were highly active against P. falciparum in vitro, but were inactive and non-toxic against P. berghei in vivo. Usambarensine, usambarine, and 18,19-dihydrousambarine were highly active against E. histolytica in vitro, but were less active against P. falciparum in vitro. Nb-Methylusambarensine was less active against both protozoa than was usambarensine, and akagerine possessed little antiprotozoal activity. Structure-activity relationships are discussed in the context of the reported cytotoxic and pharmacological properties of these alkaloids.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, University of London, U.K.
authors.forename: C W
authors.initials: CW
authors.lastname: Wright
authors.forename: D H
authors.initials: DH
authors.lastname: Bray
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Neill
authors.forename: D C
authors.initials: DC
authors.lastname: Warhurst
authors.forename: J D
authors.initials: JD
authors.lastname: Phillipson
authors.forename: J
authors.initials: J
authors.lastname: Quetin-Leclercq
authors.forename: L
authors.initials: L
authors.lastname: Angenot
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D004748:Entamoeba histolytica / Q000187:drug effects*; D051379:Mice; D015394:Molecular Structure; D010946:Plants, Medicinal; D010962:Plasmodium berghei / Q000187:drug effects*; D010963:Plasmodium falciparum / Q000187:drug effects*
chemical_list: D000470:Alkaloids