ChEBI: Protodioscin is a spirostanyl glycoside that consists of the trisaccharide alpha-L-Rha-(1->4)-[alpha-L-Rha-(1->2)]-beta-D-Glc attached to position 3 of 26-(beta-D-glucopyranosyloxy)-3beta,22-dihydroxyfurost-5-ene via a glycosidic linkage. Found in several plant species including yams, asparagus and funugreek. It has a role as a metabolite. It is a steroid saponin, a trisaccharide derivative, a beta-D-glucoside, a pentacyclic triterpenoid and a cyclic hemiketal. It is functionally related to a diosgenin. It derives from a hydride of a spirostan.