pregnane

Parent hydrocarbon of two series of steroids stemming from 5α-p. (originally allopregnane) and 5β-p. (17β-ethyletiocholane). 5β-P. is the parent of the progesterones, p. alcohols, ketones, and several adrenocortical hormones and is found largely in urine as a metabolic product of 5β-p. compounds. For structure, see steroids.

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preg·nane 'preg-.nān n a crystalline steroid C₂₁H₃₆ that is related to cholane and is the parent compound of the corticosteroid and progestational hormones

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preg·nane (pregґnān) a type of saturated 21-carbon steroid hydrocarbon nucleus that is the parent structure of many steroids; two groups of steroids are distinguished as those stemming from 5α-pregnane and those stemming from 5β-pregnane. In the latter group are progesterones, ketones, and several corticosteroids.