Cortone

Cortisone is a pregnane (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug; it is not synthesized in the adrenal glands. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase isozyme 2 into the inactive metabolite cortisone, particularly in the kidneys. Cortisone is converted back to the active steroid cortisol by the action of the enzyme 11β-Hydroxysteroid dehydrogenase type 1,... [wikipedia]