Trypanocidal withanolides and withanolide glycosides from Dunalia brachyacantha

Bravo, BJA Sauvain, M Gimenez, TA Balanza, E Serani, L Laprevote, O Massiot, G Lavaud, C

Bja. Bravo et al., Trypanocidal withanolides and withanolide glycosides from Dunalia brachyacantha, J NAT PROD, 64(6), 2001, pp. 720-725

18

INGLESE

Article

Agricultural Chemistry","Pharmacology & Toxicology

JOURNAL OF NATURAL PRODUCTS

0163-3864 → ACNP

64

6

2001

720 - 725

ISI

0163-3864(200106)64:6<720:TWAWGF>2.0.ZU;2-M

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)-0-(3)-O-D-xylopyranosyl(1 -->3)-[beta -D-xy lo- pyranosyl(1 -->4)]-beta -D-glucopyranosyl-1 alpha -acetoxy-12 beta ,20- dihydroxywitha-5,24-dienolide (4), were isolated from the leaves and root o f Dunalia brachyacantha. Their aglycones, (20R,22R)-1 alpha ,12 beta -diace toxy-3 beta ,20-dihydroxywitha-5,24-dienolide (or 1 alpha ,12 beta -diacety ldunawithagenine) and (20R,22R)-1 alpha -acetoxy-3 beta ,12 beta,- 20-trihy droxywitha-5,24-dienolide (or 1 alpha -acetyl-12 beta -hydroxydunawithageni ne), are novel. The known 18-acetoxywithanolide D (1) and 18-acetoxy-5,6-de oxy-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. Th e structures were deduced from spectroscopic data and on the basis of chemi cal evidence.