This is a working overview of melanocortin receptor, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
Published human data come mostly from small, short studies rather than large controlled trials. Reported outcomes include increased skin pigmentation and, in some reports, effects on appetite and libido, but sample sizes are small and follow-up is limited. Whether long-term use produces durable pigment changes or adverse effects is not established. Because products sold outside pharmacies are not standardized, the actual content of any given vial is often unknown. Independent testing of such material is uncommon.
Melanotan II is a synthetic cyclic heptapeptide analog derived from the core sequence of alpha-melanocyte-stimulating hormone. Researchers at the University of Arizona synthesized it during the 1980s while studying pigmentation and appetite signaling. The compound is not an approved medicine in any major jurisdiction and appears mainly in laboratory and research-chemical settings. Its structure incorporates a lactam bridge between side chains, which constrains the ring and slows enzymatic breakdown relative to the natural hormone.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Synthetic cyclic heptapeptide |
| Molecular mass | Approximately 1024 g/mol | Depends on counter-ion content |
| Appearance | White to off-white powder | Commonly supplied as a lyophilised solid |
| Solubility | Freely soluble in water | Also dissolves in common aqueous buffers |
| Typical storage | -20 degrees Celsius, desiccated | Protect from light and repeated freeze-thaw |
Metformin - widely used in treatment of diabetes mellitus type 2 Phenformin - withdrawn from the market in most countries due to toxic effects Buformin - withdrawn from the market due to toxic effects
=== Proteins === Proteins present in the hemolymph vary in quantity during the course of development. These proteins are classified by their functions: chroma proteins, protease inhibitors, storage, lipid transport, enzymes, the vitellogenins, and those involved in the immune responses of arthropods. Some hemolymphic proteins incorporate carbohydrates and lipids into the structure.
An offshoot of the Zulu, the amaNdebele, better known to history as the Matabele, created an even larger empire under their king Mzilikazi, including large parts of the highveld and modern-day Zimbabwe.
Fabrication and coating of nanodevices and medical implants to increase biocompatibility. Emulsifiers in food industry and personal care products. Hydrophobins' high stability can be very useful in the coating of surfaces of prolonged use or under harsh conditions. The easy dissociation of a class II hydrophobin monolayer might be desirable and this can easily be achieved by the use of detergents and alcohols. The use of hydrophobins in protein purification, drug delivery and cell attachment has been reported. For more about the potential biotechnological applications of hydrophobins see Hektor & Scholtmeijer (2005) and Cox & Hooley (2009).
== Styrene derivatives == This group contains a benzene and also an ethylene group, being derived from styrene. Coniferin (C16H22O8) occurs in the cambium of conifer wood. Emulsin converts it into glucose and coniferyl alcohol. Oxidation of coniferin gives glucovanillin, which yields upon treatment with emulsin glucose and vanillin. Syringin, which occurs in the bark of Syringa vulgaris, is a methoxyconiferin. Phloridzin occurs in the root-bark of various fruit trees; it hydrolyses to glucose and phloretin, which is the phloroglucin ester of paraoxyhydratropic acid. It is related to the pentosides naringin (C27H32O14), which hydrolyzes to rhamnose and naringenin, the phloroglucin ester of p-coumaric acid, and hesperidin, which hydrolyzes to rhamnose and hesperetin, the phloroglucin ester of isoferulic acid (C10H10O4).
Sources: en.wikipedia.org
7 January Hunt for the Death Star, about lethal energy bursts across the universe; Ray Klebesadel; music from the opening of You Only Live Twice; Bohdan Paczyński of Princeton University and unknown gamma-ray bursts; Stan Woosley of the University of California, Santa Cruz; the Compton Gamma Ray Observatory was deployed from 1991; Canadian Dale Frail of the Very Large Array in Socorro, New Mexico, and the W. M. Keck Observatory; the High Energy Transient Explorer 1 (HETE), launched incorrectly by a Northrop Grumman Pegasus on 4 November 1996, due to a faulty battery; music from Moonraker- Flight Into Space; Dutch researchers from the Anton Pannekoek Institute for Astronomy; the Italian BeppoSAX satellite, launched in April 1996; HETE 2 was launched on 9 October 2000.
== Amino-acid sequences == Analysis of the suite of known cyclotides reveals many sequence similarities that are important for understanding their unique physico-chemical properties, bioactivities and homology. The cyclotides fall into two main structural subfamilies. Moebius cyclotides, the less common of the two, contain a cis-proline in loop 5 that induces a local 180° backbone twist (hence likening it to a Möbius strip), whereas bracelet cyclotides do not. There is smaller variation in sequences within these subfamilies than between them. A third subfamily of cyclotides are trypsin inhibitors and are more homologous to a family of non-cyclic trypsin inhibitors from squash plants known as knottins or inhibitor cystine knots than they are to the other cyclotides. It is convenient to discuss sequences in terms of the backbone segments, or loops, between successive cysteine residues. The six cysteine residues are absolutely conserved throughout the cyclotide suite and presumably contribute to preserving the CCK motif. Although the cysteines appear essential to maintaining the overall fold, several other residues highly conserved in cyclotides are thought to provide additional stability. Throughout the known cyclotides loop 1 is the most conserved. Apart from the six cysteine residues, the glutamic acid and serine/threonine residues of loop 1 are the only residues to have 100% identity across the bracelet and Möbius subfamilies. Furthermore, the remaining residue of this loop exhibits only a conservative change i.e. glycine/alanine.
Clomipramine is the only TCA that has been shown to be effective in the treatment of OCD and that is approved by the FDA for the treatment of OCD; the other TCAs failed clinical trials for this indication, likely due to insufficient serotonergic activity.
=== Extrapulmonary === Very rarely, the primary site for small-cell carcinoma is outside of the lungs and pleural space; in these cases, it is referred to as extrapulmonary small-cell carcinoma (EPSCC). Outside of the respiratory tract, small-cell carcinoma can appear in the cervix, prostate, liver, pancreas, gastrointestinal tract, or bladder. It is estimated to account for 1,000 new cases a year in the U.S. Histologically similar to small-cell lung cancer, therapies for small-cell lung cancer are usually used to treat EPSCC. First-line treatment is usually with cisplatin and etoposide. In Japan, first-line treatment is shifting to irinotecan and cisplatin. When the primary site is in the skin, it is referred to as a Merkel-cell carcinoma.
Sources: en.wikipedia.org
Morgan's athletic teams are known as the Bears, and they compete in the Mid-Eastern Athletic Conference (MEAC). Between 1926 and 1928, a young Charles Drew served as Athletic Director. During this time he made great improvements in the school's teams' records. From the 1930s through 1960s, led by coach and then athletic director Edward P. Hurt, Morgan's athletic teams were legendary. More than thirty of its football players were drafted by and played in the NFL and many of its track athletes competed internationally and received world-class status. By the late 1960s most white colleges and universities ended their segregation against black high school students and many top black high school students and athletes started matriculating to schools from which they had previously been barred. While achieving a national goal of desegregation, integration depleted the athletic strength of schools like Morgan State and Grambling State University. For example, the annual contest between Morgan State and Grambling played in New York City in the late 1960s drew more than 60,000 fans. Morgan State's rivals are the Howard University Bison (the matchup is often called the Battle of the Beltway) and the Coppin State Eagles.
== Emergence == The drug made many news headlines when it appeared in several public middle and high schools in Dallas, Texas. The United States Drug Enforcement Administration, some police agencies and the Dallas Independent School District (DISD) dubbed the mixture "starter heroin." The district handled fifty-four property cases and found twenty-four felony offenses involving "cheese" between August 15, 2005 and March 1, 2006, at eleven schools. On February 24, 2007, United Press International reported that DISD would increase drug-sniffing dog patrols in order to eliminate Cheese from its schools. As of mid-2007, police records for the northwest quadrant of Dallas showed almost daily arrests for and confiscations of the drug. According to Dallas school district authorities, Hispanic teenagers are the demographic group most frequently charged with possession of the drug; Hispanics also constitute a majority (60 percent) of all DISD students. By February 1, 2007, usage of Cheese was reported in the fourth-grade level at several elementary schools; By February 2007, Monty Moncibais, a detective of the Dallas Police Narcotics Division, noted 71 cheese-related arrests in children aged 10 through 16. Dallas-area treatment centers have noted that the drug's growing use has led to a lowering in the age of teens admitted to their programs. From a typical clientele of 15- to 17-year-olds admitted under court order, one Dallas-area center noted it had begun to admit 11, 12, and 13-year-olds voluntarily or at a parent's request.
Equilin is a naturally occurring estrogen sex hormone found in horses as well as a medication. It is one of the estrogens present in the estrogen combination drug preparations known as conjugated estrogens (CEEs; e.g. Premarin) and esterified estrogens (EEs; e.g. Estratab, Menest). CEEs is the most commonly used form of estrogen medications in hormone replacement therapy (HRT) for menopausal symptoms in the United States. Estrone sulfate is the major estrogen in CEEs (about 50%) while equilin sulfate is the second major estrogen in the formulation, present as about 25% of the total.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.
It is shorter than the native hormone and carries a cyclic constraint that improves stability. These changes raise receptor potency and slow breakdown relative to the naturally occurring peptide.
Published accounts date its development to the 1980s, when researchers were generating analogues of melanocyte-stimulating hormone. That work aimed to produce more stable compounds for studying pigmentation biology.
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.