2004 Volume 52 Issue 11 Pages 1353-1355
The new 26-O-β-D-glucopyranosyl-3β,26-dihydroxy-20,22-seco-25(R)-furost-5-en-20,22-dione-3-O-α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (1), along with the known methyl protodioscin (2), asperoside (3) and prosapogenin A of dioscin (4) were isolated from the rhizomes of Dioscorea cayenensis LAM.-HOLL (Dioscoreaceae). Their structures were established mainly on the basis of 600 MHz 2D-NMR spectral data. 4 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs of 20.8, 6.25, 25 μg/ml, respectively), whereas saponins 1—3 were inactive.
