Melengestrol acetate (MLGA), sold under the brand names Heifermax and MGA among others, 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 ...
medication which is used in
animal reproduction
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
.
/ref> It is not approved for use in humans, and is instead used as an implantable contraceptive
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...
for captive animals in zoos and other refuges, and is also used as a feed additive A feed additive is an additive of extra nutrient or drug for livestock. Such additives include vitamins, amino acids, fatty acids, minerals, pharmaceutical, fungal products and steroidal compounds. The additives might impact feed presentation, hygi ...
to promote growth in cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...
, a purpose it is licensed for in the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
and Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
.
Uses
Animal reproduction
MLGA is used in animal reproduction
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
.
Pharmacology
Pharmacodynamics
MLGA is a 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. ...
, and hence is an agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
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 resid ...
. It has been found to possess 73% of the 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 ...
of 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 ...
for the progesterone receptor in rhesus monkey
The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies that are split between two groups, the Chinese-derived and the Indian-derived. Generally b ...
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
.
Chemistry
MLGA, also known as 17α-acetoxy-16-methylene-6-dehydro-6-methylprogesterone or as 17α-acetoxy-16-methylene-6-methylpregna-4,6-diene-3,20-dione, is a synthetic 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 allop ...
steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
and a derivative
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. F ...
of 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 ...
. It is specifically a derivative of 17α-hydroxyprogesterone
17α-Hydroxyprogesterone (17α-OHP), also known as 17-OH progesterone (17-OHP), or hydroxyprogesterone (OHP), is an endogenous progestogen steroid hormone related to progesterone. It is also a chemical intermediate in the biosynthesis of many ot ...
with a 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 C6 position, a methylene group
In organic chemistry, a methylene group is any part of a molecule that consists of two hydrogen atoms bound to a carbon atom, which is connected to the remainder of the molecule by two single bonds. The group may be represented as , where the '< ...
at the C16 position, a double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
between the C6 and C7 positions, and an acetate
An acetate is a salt (chemistry), salt formed by the combination of acetic acid with a base (e.g. Alkali metal, alkaline, Alkaline earth metal, earthy, Transition metal, metallic, nonmetallic or radical Radical (chemistry), base). "Acetate" als ...
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
at the C17α position. As such, it is also a derivative of 16-methylene-17α-hydroxyprogesterone acetate
16-Methylene-17α-hydroxyprogesterone acetate is a progestin of the 17α-hydroxyprogesterone group which was never marketed. Given orally, it shows about 2.5-fold the progestogenic activity of parenteral progesterone in animal bioassays. It i ...
. MLGA is the acetate
An acetate is a salt (chemistry), salt formed by the combination of acetic acid with a base (e.g. Alkali metal, alkaline, Alkaline earth metal, earthy, Transition metal, metallic, nonmetallic or radical Radical (chemistry), base). "Acetate" als ...
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
of melengestrol
Melengestrol (INN, BAN) is a steroidal progestin of the 17α-hydroxyprogesterone group and an antineoplastic drug which was never marketed. An acylated derivative, melengestrol acetate, is used as a growth promoter in animals.
While ''me ...
, which in contrast, has never been marketed. Analogues of MLGA include other 17α-hydroxyprogesterone derivatives such as chlormadinone acetate
Chlormadinone acetate (CMA), sold under the brand names Belara, Gynorelle, Lutéran, and Prostal among others, is a progestin and antiandrogen medication which is used in birth control pills to prevent pregnancy, as a component of menopausal hor ...
, chlormethenmadinone acetate
Chlormethenmadinone acetate (CMMA), also known as chlorsuperlutin, is a progestin medication which was developed in Czechoslovakia in the 1960s.Sterba, R. (1968). New biological application of contraceptive steroids. Endocrinologia Experimentali ...
, cyproterone acetate
Cyproterone acetate (CPA), sold alone under the brand name Androcur or Ethinylestradiol/cyproterone acetate, with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the treat ...
, delmadinone acetate
Delmadinone acetate (DMA), sold under the brand name Tardak among others, is a progestin and antiandrogen which is used in veterinary medicine to treat androgen-dependent conditions such as benign prostatic hyperplasia. It must be used with care ...
, hydroxyprogesterone caproate
Hydroxyprogesterone caproate (OHPC), sold under the brand names Proluton and Makena among others, is a progestin medication which is used to prevent preterm birth in pregnant women with a history of the condition and to treat gynecological dis ...
, 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 bi ...
, megestrol acetate
Megestrol acetate (MGA), sold under the brand name Megace among others, is a progestin medication which is used mainly as an appetite stimulant to treat wasting syndromes such as cachexia.https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/ ...
, methenmadinone acetate, and osaterone acetate
Osaterone (developmental code name TZP-5258), also known as 17α-hydroxy-6-chloro-2-oxa-6-dehydroprogesterone, as well as 2-oxachloromadinone, is a steroidal antiandrogen and progestin that was never marketed. The C17α acetate ester
In chem ...
. The only structural difference between MLGA and megestrol acetate
Megestrol acetate (MGA), sold under the brand name Megace among others, is a progestin medication which is used mainly as an appetite stimulant to treat wasting syndromes such as cachexia.https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/ ...
is the presence of the C16 methylene group in the former.
Society and culture
Generic names
''Melengestrol acetate'' is the generic name of the drug and its and . ''Melengestrol'' is the and of the unesterified free alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
form.
Brand names
MLGA is marketed under the brand names Heifermax and MGA among others.
References
{{Progesterone receptor modulators
Acetate esters
Antineoplastic drugs
Pregnanes
Progestogen esters
Progestogens
Veterinary drugs
Vinylidene compounds