16α-Hydroxyprogesterone

16α-Hydroxyprogesterone (16α-OHP) is a steroid and a metabolite of progesterone. It is formed in the body by the enzyme cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) and is a precursor to androstenedione, which is a key intermediate in the production of estrogens and androgens.

Structure and Properties

16α-Hydroxyprogesterone is a steroid with a molecular formula of C₂₁H₃₀O₃. It has a molecular weight of 330.461 g/mol. The structure of 16α-Hydroxyprogesterone consists of a cyclopentanoperhydrophenanthrene core, with a hydroxyl group at the 16α position and a ketone group at the 3 position.

Biosynthesis

16α-Hydroxyprogesterone is synthesized from progesterone in the body. The enzyme CYP17A1 catalyzes the conversion of progesterone to 16α-Hydroxyprogesterone. This reaction is part of the steroidogenesis pathway, which is responsible for the production of all steroid hormones.

Biological Role

16α-Hydroxyprogesterone is a precursor to androstenedione, which is a key intermediate in the production of estrogens and androgens. It is also a potent progestogen, meaning it can bind to and activate the progesterone receptor.

Clinical Significance

Abnormal levels of 16α-Hydroxyprogesterone can be indicative of certain medical conditions. Elevated levels can be seen in congenital adrenal hyperplasia (CAH), a group of inherited disorders affecting the adrenal glands. Measurement of 16α-Hydroxyprogesterone levels can be used as a diagnostic tool for CAH.

See Also

• Progesterone
• Androstenedione
• Congenital adrenal hyperplasia