Wiktionary
diosgenin
n. (context organic compound English) A steroid sapogenin, obtained from certain yams, that has estrogenic activity
Wikipedia
Diosgenin
Diosgenin, a steroid sapogenin, is the product of hydrolysis by acids, strong bases, or enzymes of saponins, extracted from the tubers of Dioscorea wild yam, such as the Kokoro. The sugar-free ( aglycone), diosgenin is used for the commercial synthesis of cortisone, pregnenolone, progesterone, and other steroid products.
Usage examples of "diosgenin".
This always made me suspicious until I learned that diosgenin is identical to the molecule found in the human body.