Phytosteroid

See also: Phytosterol

Digitoxin, a phytosteroid and cardiac glycoside found in digitalis.

Phytosteroids, also known as plant steroids, are naturally occurring steroids that are found in plants.^[1] Examples include digoxin, digitoxin, diosgenin, and guggulsterone, as well as phytosterols like β-sitosterol and other phytoestrogens like isoflavones.^[1]

Industrial use

Steroid pharmaceuticals that are identical or similar to human steroid hormones are very widely used in medicine. However, the four-ring structure of a steroid is quite expensive to replicate using direct synthetic methods.

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. Marker's process reduced the price of progesterone from $80/gram in early 1944 to $2/gram in 1951.^[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.^[5]

References

1. Hugh L. J. Makin; D.B. Gower; B. Kirk (29 June 2013). Steroid Analysis. Springer Science & Business Media. pp. 621–. ISBN 978-94-017-3078-5.
2. "Russell Marker and the Mexican Steroid Hormone Industry". American Chemical Society. Retrieved June 5, 2012.
3. "Giants of the Past". lipidlibrary.aocs.org. Archived from the original on 15 April 2012.
4. Sundararaman P, Djerassi C (October 1977). "A convenient synthesis of progesterone from stigmasterol". The Journal of Organic Chemistry. 42 (22): 3633–4. doi:10.1021/jo00442a044. PMID 915584.
5. Soto Laveaga, Gabriela (2009). Jungle Laboratories: Mexican peasants, National Projects and the Making of the Pill. Duke University. ISBN 9780822346050.