16α-Hydroxyandrostenedione (16α-OH-A4), also known as 16α-hydroxyandrost-4-ene-3,17-dione, is an endogenous and

naturally occurring A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

steroid and

metabolic intermediate Metabolic intermediates are molecules that are the precursors or metabolites of biologically significant molecules. Although these intermediates are of relatively minor direct importance to cellular function, they can play important roles in the ...

in the biosynthesis of

estriol Estriol (E3), also spelled oestriol, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estrone. Levels of estriol in women who are not pregnant are almost ...

during

pregnancy Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occur ...

. It is produced from

dehydroepiandrosterone Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans. DHEA is produced in the adrenal glands, the gonads, and the brain. It fun ...

(DHEA), which is converted into 16α-hydroxy-DHEA sulfate, then desulfated and

aromatized Aromatization is a chemical reaction in which an aromaticity, aromatic system is formed from a single nonaromatic precursor. Typically aromatization is achieved by dehydrogenation of existing cyclic compounds, illustrated by the conversion of cycl ...

into 16α-hydroxyestrone, and finally converted into estriol by

17β-hydroxysteroid dehydrogenase A hydroxysteroid is a molecule derived from a steroid with a hydrogen replaced with a hydroxy group. When the hydroxy group is specifically at the C3 position, hydroxysteroids are referred to as sterols, with an example being cholesterol. See ...

References

Androstanes Steroid hormones {{steroid-stub

See also

References