Steroid (source code)

= Steroid

A <steroid> is a member of a structural family based on a characteristic fused-ring <carbon> framework, usually three six-membered rings and one five-membered ring. <Cholesterol>, bile-derived compounds and many signalling <molecules> share variations of this skeleton.

Substituents, <oxidation states> and especially ring-junction <stereochemistry> change molecular shape and function. Thus “steroid” is a structural classification, not a synonym for one hormone or one biological effect. Removing or modifying a side chain can preserve the underlying steroid framework while changing biochemical behaviour substantially.