Polypodosides

Three steroidal saponins, polypodosides, were isolated from the rhizomes of Polypodium glycyrrbiza DC. Eaton (Polypodiaceae).37,38 According to the corrected structure of osladin, the structure of polypodoside was also revised.39 Polypodoside A was shown to be highly sweet (600 times sweeter than sucrose). 

Polypodoside A Polypodium glycyrrhiza (licorice fern) Sweet (600 X >sucrose... 

Steroidal Saponins The fern genus, Polypodium, has so far yielded three sweet steroidal saponins, namely, osladin (45) and polypodosides A and B (46, 47). The first-named of these compounds was structurally determined without full stereochemistry as an isolate of P. 

Another sweet-tasting saponin, osladin (17), occurs at rather low concentrations (about 0.03%) in the roots of the fern Polypodium vulgare (Hodge and Inglett, 1974). Similar steroidal glycosides have been isolated from the rhizomes of Polypodium glycyrrhiza (Kim et al., 1988 Kim and Kinghom, 1989). The major intensely sweet compound of that plant is polypodoside A, a 26-0-a-L-rhamnopyranosyl-pol-... 

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