ChEBI: Ecdysone is a 6-oxo steroid that is 5beta-cholest-7-en-6-one substituted by hydroxy groups at positions 2, 3, 14, 22 and 25 respectively (the 2beta, 3beta, 22R stereoisomer). It is a steroid prohormone of the major insect moulting hormone 20-hydroxyecdysone. It has a role as a prohormone. It is a 2beta-hydroxy steroid, a 14alpha-hydroxy steroid, a 22-hydroxy steroid, a 25-hydroxy steroid, a 6-oxo steroid, a 3beta-sterol and an ecdysteroid. It derives from a hydride of a 5beta-cholestane.