Antimalarial and vasorelaxant constituents of the leaves of Allanblackia monticola (Guttiferae).
Ann Trop Med Parasitol
; 101(1): 23-30, 2007 Jan.
Article
em En
| MEDLINE
| ID: mdl-17244407
ABSTRACT
Phytochemical investigation of the leaves of Allanblackia monticola led to the isolation and characterisation of five prenylated xanthones [1,6-dihydroxy-3,7-dimethoxy-2-(3-methylbut-2-enyl)xanthone 1, alpha-mangostin 2, tovophyllin A 3, allanxanthone C 4 and 1,7-dihydroxy-3-methoxy-2-(3-methylbut-2-enyl)xanthone 5], two biflavonoid derivatives (amentoflavone 6 and podocarpusflavone A 7) and one pentacyclic triterpene (friedelan-3-one 8). The structures of these compounds were established on the basis of homo- and hetero-nuclear, one- and two-dimensional, nuclear magnetic resonance. Compounds 2-8 and a crude methanolic extract of A. monticola leaves were each tested for antimalarial activity in vitro, using the chloroquine-sensitive F32 and chloroquine-resistant FcM29 strains of Plasmodium falciparum; the median inhibitory concentrations (IC(50)) recorded varied from 0.7 to 83.5 mug/ml. The cytotoxicities of the compounds and crude extract, against cultures of human melanoma cells (A375), were then investigated, and cytotoxicity/antimalarial IC(50) ratios of 0.6-16.75 were recorded. In tests involving aortic rings from guinea pigs, a crude extract of the leaves of A. monticola was found to induce concentration-dependent vasorelaxation, causing up to 82% and 42% inhibition of noradrenaline- and KCl-induced contractions, respectively. The corresponding values for compounds 2 and 6 when tested against noradrenaline-induced contractions were approximately 18% and 35%, respectively.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vasodilatadores
/
Folhas de Planta
/
Clusiaceae
/
Antimaláricos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Ann Trop Med Parasitol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Camarões