5α-Androstane

5α-Androstane is a steroid and, more specifically, a androstane. It is one of the most basic structures for steroid hormones in the body.

Structure and Nomenclature

5α-Androstane is a 19-carbon structure, which is made up of three cyclohexane rings and a single cyclopentane ring. The carbon atoms are numbered from 1 to 19, with the 5α position referring to the configuration of the hydrogen atom on the 5th carbon atom in the molecule.

The term "androstane" is derived from Androstanolone, the 5α-reduced metabolite of Testosterone. The "5α" prefix indicates that the hydrogen atom is on the same side of the molecule as the methyl groups at positions 10 and 13.

Biological Importance

5α-Androstane serves as a key structural component of many biologically active steroids, including corticosteroids, glucocorticoids, mineralocorticoids, and sex steroids. It is also a precursor to more potent androgens such as dihydrotestosterone (DHT).

In addition to its role in steroid biosynthesis, 5α-androstane is also involved in the metabolism of other steroids. For example, it is a substrate for the enzyme 5α-reductase, which converts testosterone into DHT.

Synthesis

5α-Androstane can be synthesized from pregnenolone via a series of enzymatic reactions. The first step is the conversion of pregnenolone to progesterone by the enzyme 3β-hydroxysteroid dehydrogenase. Progesterone is then converted to 5α-pregnane by the enzyme 5α-reductase. Finally, 5α-pregnane is converted to 5α-androstane by the enzyme 17α-hydroxylase.

See Also

• Steroid
• Androstane
• Testosterone
• Dihydrotestosterone
• 5α-reductase