title: Antiprotozoal compounds from Asparagus africanus.
abstract: Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol. The structure of the sapogenin was elucidated by MS and by 1D and 2D NMR methods and established by a single crystal X-ray analysis. (+)-Nyasol potently inhibits the growth of Leishmania major promastigotes, the IC50 being 12 microM, and moderately inhibits Plasmodium falciparum schizonts with the IC50 49 microM. These concentrations only moderately affect the proliferation of human lymphocytes. Muzanzagenin showed a moderate in vitro activity in all three tests, the IC50 against leishmania promastigotes was 70 microM, and against four different malaria schizont strains the IC50 values were 16, 163, 23, and 16 microM, respectively.
authors.affiliation: Phytochemistry Department, National Museums of Kenya, Nairobi.
authors.forename: H A
authors.initials: HA
authors.lastname: Oketch-Rabah
authors.forename: S F
authors.initials: SF
authors.lastname: Dossaji
authors.forename: S B
authors.initials: SB
authors.lastname: Christensen
authors.forename: K
authors.initials: K
authors.lastname: Frydenvang
authors.forename: E
authors.initials: E
authors.lastname: Lemmich
authors.forename: C
authors.initials: C
authors.lastname: Cornett
authors.forename: C E
authors.initials: CE
authors.lastname: Olsen
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Kharazmi
authors.forename: T
authors.initials: T
authors.lastname: Theander
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000302:isolation & purification* / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D018320:Leishmania major / Q000187:drug effects; D017705:Lignans; D019668:Liliaceae / Q000737:chemistry*; D008214:Lymphocytes / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010636:Phenols / Q000302:isolation & purification* / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000187:drug effects; D012502:Sapogenins / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000981:Antiprotozoal Agents; D017705:Lignans; D010636:Phenols; D012502:Sapogenins; C109392:muzanzagenin; C109393:nyasol