Quingestrone, also known as progesterone 3-cyclopentyl enol ether (PCPE) and sold under the brand name Enol-Luteovis, 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 female sex hormone progesterone in the body. A progestin is a '' synthetic'' progestogen. ...

medication which was previously used in

birth control pill The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. It is the oral form of combined hormonal contra ...

s in

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

but is now no longer marketed. It is taken

by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

. Quingestrone is a progestin, or a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

progestogen Progestogens, also sometimes written progestins, 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 progestoge ...

, and hence is an

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

of 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 resi ...

, the

biological target A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...

of progestogens like

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 ma ...

. It has weak

glucocorticoid Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebra ...

activity. Quingestrone was introduced for medical use by 1962. It is no longer available.

Medical uses

Quingestrone was formerly used in combination with

ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. Ethinylestradiol was widely used for various indications such as the treatment of menopausal symptoms, gynecological ...

mestranol Mestranol, sold under the brand names Enovid, Norinyl, and Ortho-Novum among others, is an estrogen medication which has been used in birth control pills, menopausal hormone therapy, and the treatment of menstrual disorders. It is formulated in ...

in combined

s in

. The medication was studied in the clinical prevention of

miscarriage Miscarriage, also known in medical terms as a spontaneous abortion, is an end to pregnancy resulting in the loss and expulsion of an embryo or fetus from the womb before it can fetal viability, survive independently. Miscarriage before 6 weeks ...

during

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

, but insufficient efficacy was observed at the dosage assessed (100 mg/day orally).

Side effects

Pharmacology

Pharmacodynamics

Along with the

retroprogesterone Retroprogesterone, also known as 9β,10α-progesterone or as 9β,10α-pregn-4-ene-3,20-dione, is a progestin which was never marketed. It is a stereoisomer of the naturally occurring progestogen progesterone, in which the hydrogen atom at the 9 ...

derivative

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

, quingestrone has been described as a "true" progesterone derivative or

due to its close similarity to natural progesterone. Similarly to progesterone, dydrogesterone, and

hydroxyprogesterone caproate Hydroxyprogesterone caproate, sold under the brand name Delalutin among others, is a medication used to reduce the risk of preterm birth in women pregnant with one baby who have a history of spontaneous preterm birth. In March 2023, the manuf ...

, quingestrone is a pure progestogen and lacks any

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

ic effects. As such, it poses no risk of androgenic

side effect In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually use ...

s or virilizing teratogenic effects on female fetuses. Quingestrone is said to influence the

hypothalamic–pituitary–adrenal axis The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland ( ...

similarly to

and

medroxyprogesterone acetate Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in injectable form and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. It is used as a method of ...

, producing

adrenal suppression Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones. The adrenal glands—also referred to as the adrenal cortex—normally secrete glucocorticoids (primarily cortisol), mineraloco ...

at sufficiently high doses, and this suggests that it possesses weak

activity similarly to progesterone. Quingestrone is a very weak progestogen. When administered

orally The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or oral ...

intraperitoneally Intraperitoneal injection or IP injection is the injection of a substance into the peritoneum (body cavity). It is more often applied to non-human animals than to humans. In general, it is preferred when large amounts of blood replacement fluids ...

in animals, the medication showed 1/80 and 1/20 the potency of subcutaneously injected progesterone, respectively. Similarly, oral doses of quingestrone of 10 to 20 times those of subcutaneous progesterone were insufficient to maintain

in animals, and oral or intraperitoneal doses of quingestrone 20 to 40 times those of oral or intraperitoneal progesterone were unable to potentiate

hexobarbital Hexobarbital or hexobarbitone, sold both in acid and sodium salt forms as Citopan, Evipan, and Tobinal, is a barbiturate derivative having hypnotic and sedative effects. It was used in the 1940s and 1950s as an agent for inducing anesthesia for s ...

-induced

anesthesia Anesthesia (American English) or anaesthesia (British English) is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prev ...

in animals (which progesterone does and is thought to do by inhibiting the

hepatic The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

metabolism Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

barbiturate Barbiturates are a class of depressant, depressant drugs that are chemically derived from barbituric acid. They are effective when used medication, medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological a ...

s). With oral administration of equal doses of progesterone and quingestrone in animals, 3 to 4 times less

pregnanediol Pregnanediol, or 5β-pregnane-3α,20α-diol, is an inactive metabolic product of progesterone. A test can be done to measure the amount of pregnanediol in urine, which offers an indirect way to measure progesterone levels in the body. From the ur ...

was recovered from

urine Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (mal ...

with quingestrone. The fact that quingestrone is more potent by intraperitoneal than oral administration in animals suggests that it is transformed into a less active

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

in the

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. T ...

s. The effective dosage of quingestrone in the menstrual delay test has been studied. Quingestrone has no

anesthetic An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into t ...

effect in animals, in contrast to progesterone.

Pharmacokinetics

Quingestrone has been suggested to act as a

prodrug A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be ...

of progesterone via slow

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

in the body. Indeed, it produces similar

s (e.g.,

s and

allopregnanediol Allopregnanediol, or 5α-pregnane-3α,20α-diol, is an endogenous metabolite of progesterone and allopregnanolone and an isomer of pregnanediol (5β-pregnan-3α,20α-diol). It has been found to act like a partial agonist of an allosteric site of ...

s) as progesterone, although with differing ratios, and notably is the only progestin that is known to produce pregnanediol as a metabolite. Subsequent research has cast doubt on the notion that quingestrone is a prodrug of progesterone however, and indicates that it instead is directly

metabolized Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

into pregnanediols without intermediate conversion into progesterone. Based on its

chemical structure A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target m ...

, quingestrone may be transformed into 3α-dihydroprogesterone and/or 3β-dihydroprogesterone and then further metabolized into

pregnanolone Pregnanolone, also known as eltanolone, is an endogenous inhibitory neurosteroid which is produced in the body from progesterone. It is closely related to allopregnanolone, which has similar properties. Biological activity Pregnanolone is a pos ...

s and pregnanediols. 3β-Dihydroprogesterone has been reported to possess about the same

potency Potency may refer to: * Potency (pharmacology), a measure of the activity of a drug in a biological system * Virility * Cell potency, a measure of the differentiation potential of stem cells * In homeopathic dilutions, potency is a measure of ho ...

in the

Clauberg test Carl Clauberg (28 September 1898 – 9 August 1957) was a German gynecologist who conducted medical experiments on (mostly Jewish) human subjects at Auschwitz concentration camp. He worked with Horst Schumann in X-ray sterilization experime ...

, whereas 3α-dihydroprogesterone was not assessed. Relative to progesterone, quingestrone shows improved

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to describing how the body affects a specific su ...

, including higher

, oral activity, and a longer

terminal half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma. ...

and hence

duration of action Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms (fo ...

. This is considered to be due to its higher

lipophilicity Lipophilicity (from Greek λίπος "fat" and φίλος "friendly") is the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such compounds are called lipophilic (translated ...

, being stored into and slowly released from

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

. Quingestrone also shows slower

and more stable blood levels, with a longer time to peak concentrations and a less intense peak compared to progesterone. The

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...

of quingestrone is highest when it is given as a sesame seed oil solution (compared to an oil suspension (~2-fold less) or

micronization Micronization is the process of reducing the average diameter of a solid material's particles. Traditional techniques for micronization focus on mechanical means, such as milling and grinding. Modern techniques make use of the properties of superc ...

(~7-fold less)). The C3 enol ethers of progesterone are less suited for use via

depot injection A depot injection, also known as a long-acting injectable (LAI), is a term for an injection formulation of a medication which releases slowly over time to permit less frequent administration of a medication. They are designed to increase medic ...

relative to

progestogen ester A progestogen ester is an ester of a progestogen or progestin (a synthetic progestogen). The prototypical progestogen is progesterone, an endogenous sex hormone. Esterification is frequently employed to improve the pharmacokinetics of steroids, i ...

s like

due to their susceptibility to

oxidative Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

. The

of quingestrone have been reviewed.

Chemistry

Quingestrone, also known as progesterone 3-cyclopentyl enol ether (PCPE) or as 3-cyclopentyloxypregna-3,5-dien-20-one, is a

pregnane Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5α-pregnane (originally all ...

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

and a

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

. It is specifically the 3-

cyclopentyl Cyclopentane (also called C pentane) is a highly flammable alicyclic hydrocarbon with chemical formula C5H10 and CAS number 287-92-3, consisting of a ring of five carbon atoms each bonded with two hydrogen atoms above and below the plane. It is a ...

enol ether In organic chemistry an enol ether is an alkene with an alkoxy substituent. The general structure is R2C=CR-OR where R = H, alkyl or aryl. A common subfamily of enol ethers are vinyl ethers, with the formula ROCH=CH2. Important enol ethers incl ...

of progesterone. Quingestrone is closely related to

progesterone 3-acetyl enol ether Progesterone 3-acetyl enol ether, also known as progesterone acetate, as well as 3-acetoxypregna-3,5-dien-20-one, is a progestin which was never marketed.Rao, P. N., & Edwards, B. E. (1967). ''U.S. Patent No. 3,321,495.'' Washington, DC: U.S. Pat ...

and pentagestrone acetate (17α-acetoxyprogesterone 3-cyclopentyl enol ether).

Synthesis

Chemical syntheses of quingestrone have been published.

History

Quingestrone appears to have been first synthesized in 1936. It was introduced for medical use in

by 1962.

Society and culture

Generic names

''Quingestrone'' is the generic name of the drug and its and . It is also known by its developmental code name ''W-3399''.

Brand names

Quingestrone was marketed under the brand name Enol-Luteovis.

Availability

Quingestrone is no longer marketed and hence is no longer available in any country.http://www.micromedexsolutions.com/micromedex2/ It was previously available in

References

{{Navboxes , title =

Pharmacodynamics Pharmacodynamics (PD) is the study of the biochemistry, biochemical and physiology, physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or comb ...

, titlestyle = background:#ccccff , list1 = {{Glucocorticoid receptor modulators {{Progesterone receptor modulators {{Xenobiotic-sensing receptor modulators Abandoned drugs Cyclopentyl ethers Conjugated dienes Ethers Glucocorticoids Hormonal contraception Ketones Pregnanes Progestogen ethers Progestogens