Saponins And Sapogenins Of Paris Species

Extracts of P. polyphylla rhizome are known to have a depressant effect on the CNS of rats and an excitory effect on isolated guinea pig ileum, Two components of such an extract have been isolated and identified as: I) Diosgenin 3-0-(o(-L-rhamnopyranosyl-1-2) ( O&(-L-rhamnopyranosyl -1-) -D-glucopyranoside, e = Tt) Diosgenin 3-0-(¢ -L-arabinofuranosyl-1-2) ((-L-rhamnopyranosyl-1-}) ee oneenosiae B 2 Identification relied on comparison of mass spectra and carbon-14 nmr of these natural products and a series of synthesised model diosgenin glycosides containing glucose and rhamnose. These included two monoglucosides, two diglycosides with sugars linked (1-6), and four linked (1-4). A linear (1-4) triglucoside and two substituted branched glycosides were also made. The synthetic routes used were a modified version of that originally developed by Koenigs and Knorr. Carbon-14 chemical shift values permitted a) the identification of the aglycone, b) the configuration at the anomeric carbon once the sugars were identified (by paper and gas chromatography) , c) the position of attachment of a second and third sugar moiety (although some ambiguity in the latter remained)