Trypanocidal withanolides and withanolide glycosides from Dunalia brachyacantha.

J A Bravo B, M Sauvain, A Gimenez T, E Balanza, L Serani, O Laprévote, G Massiot, C Lavaud

Laboratorio de Productos Naturales, Instituto de Investigaciones Químicas, CP 303, Universidad Mayor de San Andrés, La Paz, Bolivia.

Journal of natural products 2001 Jun

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Two new withanolide glycosides, (20R,22R)-O-(3)-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl-1 alpha,12 beta-diacetoxy-20-hydroxywitha-5,24-dienolide (3) and (20R,22R)-O-(3)-beta-D-xylopyranosyl(1-->3)-[beta-D-xylopyranosyl(1-->4)]-beta-D-glucopyranosyl-1 alpha-acetoxy-12 beta,20-dihydroxywitha-5,24-dienolide (4), were isolated from the leaves and root of Dunalia brachyacantha. Their aglycones, (20R,22R)-1 alpha,12 beta-diacetoxy-3 beta,20-dihydroxywitha-5,24-dienolide (or 1 alpha,12 beta-diacetyldunawithagenine) and (20R,22R)-1 alpha-acetoxy-3 beta,12 beta,20-trihydroxywitha-5,24-dienolide (or 1 alpha-acetyl-12 beta-hydroxydunawithagenine), are novel. The known 18-acetoxywithanolide D (1) and 18-acetoxy-5,6-deoxy-5-withenolide D (2) were also isolated from the leaves. These last two compounds were shown to be responsible for the trypanocidal, leishmanicidal, and bactericidal activities manifested by the crude ethanolic extract. The structures were deduced from spectroscopic data and on the basis of chemical evidence.

Citation

J A Bravo B, M Sauvain, A Gimenez T, E Balanza, L Serani, O Laprévote, G Massiot, C Lavaud. Trypanocidal withanolides and withanolide glycosides from Dunalia brachyacantha. Journal of natural products. 2001 Jun;64(6):720-5