This is a working overview of alpha-MSH, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-15 and is reviewed periodically as new material appears.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
Identity testing for a cyclic peptide of this size usually relies on reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The mass spectrum confirms molecular weight, while the chromatographic trace indicates the proportion of related impurities. Tandem mass spectrometry can provide sequence-level information when fragmentation data are compared against a reference standard. Nuclear magnetic resonance is sometimes used to confirm the lactam bridge, although it requires more material and greater operator expertise than routine chromatographic methods.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
=== Dicastery for the Causes of Saints === As part of his 2022 reorganization of the Curia in Praedicate evangelium, Pope Francis renamed the congregation to the Dicastery for the Causes of Saints. It is working on about 1,600 causes, some dating from the 15th century.
Paracetamol is available in oral, suppository, and intravenous forms. Intravenous paracetamol is sold under the brand name Ofirmev in the United States. In some formulations, paracetamol is combined with the opiate codeine, sometimes referred to as co-codamol (BAN) and Panadeine in Australia. In the U.S., this combination is available only by prescription. As of 1 February 2018, medications containing codeine also became prescription-only in Australia. Paracetamol is also combined with other opioids such as dihydrocodeine, referred to as co-dydramol (British Approved Name (BAN)), oxycodone or hydrocodone. Another very commonly used analgesic combination includes paracetamol in combination with propoxyphene napsylate. A combination of paracetamol, codeine, and the doxylamine succinate is also available. Paracetamol is also available combined with butalbital and caffeine as a treatment for tension and migraine headaches. Paracetamol is sometimes combined with phenylephrine hydrochloride. Sometimes a third active ingredient, such as ascorbic acid, caffeine, chlorpheniramine maleate, or guaifenesin is added to this combination.
A cryoEM structure of the 50S subunit from the archaeon Methanothermobacter thermautotrophicus has been determined. It shares the 50S size/sedimentation rate and the two rRNA count, but its 23S expansion segments have more in common with eukaryotes. A cryoEM reconstruction of the native 50S subunit of the extremely halophilic Archaean Halococcus morrhuae (classified under Euryarchaeota; Stenosarchaea group) is available. The 50S subunit contains a 108‐nucleotide insertion in its 5S rRNA, which at subnanometer resolution, is observed to emerge from a four‐way junction without affecting the parental canonical 5S rRNA structure. Due to the differences, archaeal 50S are less sensitive to some antibiotics that target bacterial 50S.
These occur at asparagine (Asn) amino acid numbers 96, 135, 155, and 192 in humans and at similar amino acid numbers in other species. All these sites are occupied by covalently attached oligosaccharide side-chains in the predominant form of human antithrombin, α-antithrombin, resulting in a molecular weight for this form of antithrombin of 58,200. The potential glycosylation site at asparagine 135 is not occupied in a minor form (around 10%) of antithrombin, β-antithrombin (see Figure 1). Recombinant antithrombins with properties similar to those of normal human antithrombin have been produced using baculovirus-infected insect cells and mammalian cell lines grown in cell culture. These recombinant antithrombins generally have different glycosylation patterns to normal antithrombin and are typically used in antithrombin structural studies. For this reason many of the antithrombin structures stored in the protein data bank and presented in this article show variable glycosylation patterns. Antithrombin begins in its native state, which has a higher free energy compared to the latent state, which it decays to on average after 3 days. The latent state has the same form as the activated state – that is, when it is inhibiting thrombin.
Sources: en.wikipedia.org
==== Discovery of the Redfield relaxation theory and equation ==== Redfield's original article published in the IBM Journal in 1957, and then in the first issue of Advanced Magnetic Resonance in 1965, "The Theory of Relaxation Processes" explained observations that molecules excited with RF in a magnetic field did not relax as expected in terms of classical thermodynamics but could be explained in terms of quantum physics, yielding a semi-classic explanation of nuclear spin in metals. The theory continues to be useful not only in NMR but in optics and computational quantum mechanics as well. The theory streamlined analysis of atomic relationships and explained observations that NMR scientists had not fully theorized. The theory helped explain spin temperature, rotating frame, nuclear spin relaxation, and predicted adiabatic demagnetization and remagnetization in a spin-locked state, and short correlation time.
The two substrates of this enzyme are D-xylose and oxidised nicotinamide adenine dinucleotide phosphate (NADP+). Its products are D-xylono-1,5-lactone, reduced NADPH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is D-xylose:NADP+ 1-oxidoreductase. Other names in common use include D-xylose (nicotinamide adenine dinucleotide phosphate), dehydrogenase, D-xylose-NADP+ dehydrogenase, D-xylose:NADP+ oxidoreductase, and D-xylose 1-dehydrogenase (NADP+).
Dislocations or subluxations (that is, partial dislocations) Sprains, tendinitis, or bursitis from activities. However, a 2018 study reports that while hypermobile individuals are more likely to suffer dislocations doing sports than non-hypermobile individuals, they are less likely to suffer muscle and tendon sprains. The overall chances of sports injury are not significantly different. Joint pain Back pain Joints that make clicking noises Chance of nerve compression disorders in the joints (such as carpal tunnel syndrome) "Growing pains" (as described in children in late afternoon or night)
== Education == Daly attended Hunter College High School, a laboratory high school for girls run by Hunter College faculty, where she was also encouraged to pursue chemistry. She then enrolled in Queens College, a small, fairly new school in Flushing, New York. She lived at home to save money and graduated magna cum laude from Queens College with her bachelor's degree in chemistry in 1942. Upon graduation, she was named a Queens College Scholar, an honor that is awarded to the top 2.5% of the graduating class. Labor shortages and the need for scientists to support the war effort enabled Daly to garner fellowships to study at New York University and Columbia University for her master's and Ph.D. degrees, respectively. Daly worked as a laboratory assistant at Queens College while studying at New York University for her master's degree in chemistry, which she completed in 1943. She became a chemistry tutor at Queens College and enrolled in the doctoral program at Columbia University, where she was supervised by Mary Letitia Caldwell, for a Ph.D. thesis titled, "A Study of the Products Formed By the Action of Pancreatic Amylase on Corn Starch" and received her Ph.D. in chemistry in 1947.
The C-terminal domain binds to NADPH. It has a special structure, a Rossmann fold, whereby six-stranded twisted and parallel beta sheet with loops and alpha helices surrounding the core beta sheet. The Structure of Shikimate dehydrogenase is characterized by two domains, two alpha helices and two beta sheets with a large cleft separating the domains of the monomer. The enzyme is symmetrical. Shikimate dehydrogenase also has an NADPH binding site that contains a Rossmann fold. This binding site normally contains a glycine P-loop. The domains of the monomer show a fair amount of flexibility suggesting that the enzyme can open in close to bind with the substrate 3-Dehydroshikimate. Hydrophobic interactions occur between the domains and the NADPH binding site. This hydrophobic core and its interactions lock the shape of the enzyme even though the enzyme is a dynamic structure. There is also evidence to support that the structure of the enzyme is conserved, meaning the structure takes sharp turns in order to take up less space.
Sources: en.wikipedia.org
. The azide side chains of L-Aha allow highly specific and efficient site-specific conjugation to a lot different of functional molecules via Staudinger ligation with phosphine reagents, and Copper (I)-catalysed azide-alkyne cycloaddition (CuAAC) or Strain promoted azide-alkyne cycloaddition (SPAAC) in click reactions.
== Acquisitions == In July 2016, Relief acquired FirstString Research, a clinical-stage biotech firm based in Charleston, South Carolina, US. In January 2021, Relief acquired German-based firm AdVita in a €25 million agreement to further their research into inhaled treatments for Acute respiratory distress syndrome. In May 2021, Relief acquired Swiss biotech firm Applied Pharma Research (APR), including its existing portfolio and all pipeline products, for CHF 72 million ($79 million).
== Demographics and geographical distribution == Bektashis are mainly found throughout Anatolia, the Balkans and among Ottoman-era Greek Muslim communities. According to a 2005 estimate by Dedebaba Reshat Bardhi, there are over seven million Bektashis worldwide, though more recent studies put the figure as high as 20 million. According to Albania's latest census in September 2023, Bekhtashis number slightly make up 9% of the Muslim population and 5% of the country's population. An additional 12.5 million Bektashis are estimated to live in Turkey. The term Alevi–Bektashi is used frequently in current Turkish religious discourse as an umbrella term for Alevism and Bektashism, despite their distinct origins and separate belief systems. Alevi/Bektashi is officially recognized through Ministry of Culture and Tourism under the 'Presidency of Alevi/Bektashi Culture'. There are also important Bektashi communities among the Albanian communities of North Macedonia and Kosovo, the most important being the Arabati Baba Teḱe in the city of Tetovo, which was until recently under the guidance of Baba Tahir Emini (1941–2006). Following the death of Baba Tahir Emini, the dedelik of Tirana appointed Baba Edmond Brahimaj (known as Baba Mondi), formerly head of the Turan Tekke of Korçë, to oversee the Harabati baba tekke. A splinter branch of the order has recently sprung up in the North Macedonian town of Kičevo which has ties to the Turkish Bektashi community under Haydar Ercan Dede rather than the order's headquarters in Tirana.
== Bibliography == Touati, Sylvie (1976). Discrimination en France à l'égard des femmes dans l'emploi [Discrimination against women in employment in France] (in French). Mémoire DES. Boutillier, Sophie; Lestrade, Brigitte (2004). Le travail des femmes: axes d'émancipation [Women's work: paths to empowerment] (in French). Harmattan. Cova, A (1997). Maternité et droits des femmes en France, XIXe et XXe siècles [Motherhood and women's rights in France, 19th and 20th centuries] (in French). Paris: Anthropos. Milewski, Françoise; Périvier, Hélène (2011). Les discriminations entre les femmes et les hommes [Discrimination between women and men] (in French). Les Presses de Sciences Po. Fortino, Sabine (1999). "De la ségrégation sexuelle des postes à la mixité au travail : étude d'un processus" [From gender segregation in the workplace to gender diversity: a study of a process]. Sociologie du Travail (in French). 41 (4): 363–384. Maruani, Margaret (2011). Travail et emploi des femmes [Women's work and employment] (in French). La Découverte. Moreau, Marie-Pierre (2011). Les enseignants et le genre [Teachers and gender] (in French). Presses Universitaires de France.
Sources: en.wikipedia.org
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
Mass spectrometry combined with liquid chromatography provides both molecular weight confirmation and a measure of related impurities. Tandem mass spectrometry adds sequence information. A purity percentage reported without a mass measurement does not confirm what the material is.