Article: Progesterone

Progesterone
Systematic (IUPAC) name
17-acetyl-10,13-dimethyl-1,2,6,7,8,9,10,11,12,13,14,15,16,17- tetradecahydrocyclopenta[a]phenanthren-3-one
Identifiers
CAS number	57-83-0
ATC code	G03DA04
PubChem	5994
DrugBank	APRD00700
Chemical data
Formula	C21H30O2
Mol. weight	314.47
Synonyms	4-pregnene-3,20-dione
Physical data
Melt. point	126°C (259°F)
Spec. rot	[α]D
Pharmacokinetic data
Bioavailability	prolonged absorption, half-life approx 25-50 hours
Protein binding	96%-99%
Metabolism	hepatic to pregnanediols and pregnanolones
Half life	34.8-55.13 hours
Excretion	renal
Therapeutic considerations
Pregnancy cat.	B (USA)
Legal status
Routes	oral, implant

Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other species. Progesterone belongs to a class of hormones called progestagens, and is the major naturally occurring human progestagen.

It is important that Progesterone not be confused with progestins, which are synthetically produced progestagens.

Other terms for progesterone include lutren, lutein, flavolutan, corporin, and luteal hormone.

Chemistry

Like other steroids, progesterone consists of four interconnected cyclic hydrocarbons. Progesterone contains ketone and oxygenated functional groups, as well as two methyl branches. Like all steroid hormones, it is hydrophobic. This is mostly due to its lack of very polar functional groups.

Synthesis

Progesterone, like all other steroid hormones, is synthesized from pregnenolone, a derivative of cholesterol. This conversion takes place in two steps. The 3-hydroxyl group is converted to a keto group and the double bond is moved to C-4, from C-5.

Conversion of Pregnenolone to Progesterone

Progesterone is the precursor of the mineralocorticoid aldosterone, and after conversion to 17-hydroxyprogesterone (another natural progestogen) of cortisol and androstenedione. Androstenedione can be converted to testosterone, estrone and estradiol.

Progesterone is important for aldosterone (mineralocorticoid) synthesis, as 17-hydroxyprogesterone is for cortisol (glucocorticoid), and androstenedione for sex steroids.