Phytosteroid

[1] Examples include digoxin, digitoxin, diosgenin, and guggulsterone, as well as phytosterols like β-sitosterol and other phytoestrogens like isoflavones.

In 1938–1940, American chemist Russell Earl Marker developed the process known as Marker degradation, which converts diosgenin from Mexican Dioscorea yams into 16-dehydropregnenolone acetate, which has a four-ring structure and can be used to synthesize commonly used steroid hormones.

[2] Also in 1940, American chemist Percy Lavon Julian discovered a process to convert a much more abundant phytosteroid -- stigmasterol from soybean -- into progesterone.

[3] His process was improved by Padmanabhan Sundararaman and Carl Djerassi in 1977, just as stocks of wild Mexican yam became depleted.

[4] Soy stigmasterol soon replaced yam diosgenin as the main starting material for hormone production globally.