Retroprogesterone, also known as 9β,10α-progesterone or as 9β,10α-pregn-4-ene-3,20-dione, is a

progestin A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural product, natural female sex hormone progesterone in the body. A progestin is a ''synthetic co ...

which was never marketed. It is a

stereoisomer In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...

of the

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 ...

progestogen Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. ...

progesterone Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...

, in which the

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

atom at the 9th carbon is in the α-position (below the plane) instead of the β-position (above the plane) and the

methyl group In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

at the 10th carbon is in the β-position instead of the α-position. In other words, the atom positions at the two carbons have been reversed relative to progesterone, hence the name ''retro''progesterone. This reversal results in a "bent" configuration in which the plane of rings A and B is orientated at a 60° angle below the rings C and D. This configuration is ideal for interaction with the

progesterone receptor The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene resid ...

, with retroprogesterone binding with high

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Par ...

to this receptor. However, the configuration is not as ideal for binding to other

steroid hormone receptor Steroid hormone receptors are found in the nucleus, cytosol, and also on the plasma membrane of target cells. They are generally intracellular receptors (typically cytoplasmic or nuclear) and initiate signal transduction for steroid hormones which ...

s, and as a result, retroprogesterone derivatives have increased

selectivity Selectivity may refer to: Psychology and behaviour * Choice, making a selection among options * Discrimination, the ability to recognize differences * Socioemotional selectivity theory, in social psychology Engineering * Selectivity (radio), a ...

for the progesterone receptor relative to progesterone. Retroprogesterone is the

parent compound In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized. Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one o ...

of a group of progestins consisting of the marketed progestins

dydrogesterone Dydrogesterone, sold under the brand name Duphaston & Dydroboon among others, is a progestin medication which is used for a variety of indications, including threatened or recurrent miscarriage during pregnancy, dysfunctional bleeding, infertil ...

(6-dehydroretroprogesterone) and

trengestone Trengestone, sold under the brand names Reteroid, Retroid, and Retrone, is a progestin medication which was formerly used to treat menstrual disorders but is now no longer marketed.http://www.micromedexsolutions.com It is taken oral administrati ...

(1,6-didehydro-6-chlororetroprogesterone) and the never-marketed progestin

Ro 6-3129 Ro 6-3129, also known as 16α-ethylthio-6-dehydroretroprogesterone or as 16α-ethylthio-9β,10α-pregna-4,6-diene-3,20-dione, as well as 16α-ethylthiodydrogesterone, is a progestogen of the retroprogesterone group which was developed by Roche ...

, as well as the

active metabolite An active metabolite is an active form of a drug after it has been processed by the body. Metabolites of drugs An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...

s of these progestins like 20α-dihydrodydrogesterone and 20α-dihydrotrengestone (i.e., the 20α-

hydroxylated In chemistry, hydroxylation can refer to: *(i) most commonly, hydroxylation describes a chemistry, chemical process that introduces a hydroxyl group () into an organic compound. *(ii) the ''degree of hydroxylation'' refers to the number of OH gr ...

analogues).

Chemistry

References

Abandoned drugs Diketones Pregnanes Progestogens {{Genito-urinary-drug-stub

Chemistry

See also

References