A new steroidal saponin from Dioscorea cayenensis.
The new 26-O-beta-D-glucopyranosyl-3beta,26-dihydroxy-20,22-seco-25(R)-furost-5-en-20,22-dione-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-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 microg/ml, respectively), whereas saponins 1-3 were inactive.
Sautour
Marc
M
Laboratoire de Pharmacognosie, Unité UMIB, EA 3660, Faculté de Pharmacie, Université de Bourgogne, 7 Boulevard Jeanne d'Arc, BP 87900, 21079 Dijon Cedex, France.
Mitaine-Offer
Anne-Claire
AC
Miyamoto
Tomofumi
T
Dongmo
Alain
A
Lacaille-Dubois
Marie-Aleth
MA
D002176:Candida albicans / Q000187:drug effects / Q000502:physiology; D027742:Dioscorea; D006801:Humans; D010840:Phytosterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D027343:Rhizome; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
D010840:Phytosterols; D010936:Plant Extracts; D012503:Saponins