Dioscorea tokoro

SpirostanolS Cardenolides, and Related Compounds.— The biosynthesis of the spirostanols diosgenin (86), yonogenin (87), and tokorogenin (88) has been studiedin Dioscorea tokoro. Cycloartenol (72), cholesterol (75), and its... 

Marker s synthesis was initially based on sarsasapogenin as starting material from root extracts of the Mexican sarsaparilla plant (Smilax aristolochiaefolia), and later on diosgenin. Diosgenin is found as the 3-glycoside (dioscin) in numerous Liliaceae and Dioscoreaceae species, and may be extracted with ethanol from the air-dried rhizomes of Dioscorea tokoro, Dioscorea macrostachya, Dioscorea mexicana, Dioscorea floribunda and Dioscorea composita (Barbasco). The extract is evaporated and heated with dilute hydrochloric or sulfuric acid to cleave the glycosidic bond. Subsequently, diosgenin is filtered off and used as such for the synthesis of steroid hormones. 

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