Most reports of progestagens from plants are probably not valid however. Progestagens are mostly C 21 - compounds. Ecdysteroids Ecdysteroids are hormonal substances in insects, molluscs, and crustaceans. They are involved in moulting. Various developmental processes require change in the ratios of ecdysones and juvenile hormones.
Many plants synthesize ecdysteroids.
Although these are called phytoecdysteroids, some are identical in structure to the compounds from animals. Chemotaxis in fungi A series of sterols including antheridiol and oogoniols, derived from fucosterol, are involved in attraction of gametes and concomitant developmental changes in members of the genus Achlya . Cucurbitacins Cucurbitacins are triterpenes. They are extremely bitter compounds and also are highly toxic. Although they are common in the family Cucurbitaceae, they also are the bitter principles in at least 20 other families.