A practical reference on Melanocortin receptor: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-14 and is reviewed periodically as new material appears.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
"History of the Laboratory". LLNL. July 14, 2002. Archived from the original on October 12, 2006. Serving the Nation for Fifty Years: 1952–2002 Lawrence Livermore National Laboratory [LLNL], Fifty Years of Accomplishments (PDF) (Report). LLNL. 2002. UCRL-AR-148833. Archived from the original (PDF) on October 15, 2011. Retrieved August 26, 2013. LLNL Industrial Partnerships and Commercialization (IPAC) (official website)
=== Other incidents === On 13 September 1999, six people tried to steal 60Co rods from a chemical plant in the city of Grozny, Chechen Republic, Russia. During the theft, the suspects opened the radioactive material container and handled it, resulting in the deaths of three of the suspects and injury of the remaining three. The suspect who held the material directly in his hands died of radiation exposure 30 minutes later. This incident is described as an attempted theft, but some of the rods are reportedly still missing.
== Trelagliptin versus Vildagliptin in Indian patients == Dewan et al. (2025) conducted a phase 3 randomized trial comparing once-weekly trelagliptin with twice-daily vildagliptin in Indian patients with type 2 diabetes. Trelagliptin was found to be non-inferior to vildagliptin in reducing HbA1c over 16 weeks. Both treatments showed comparable efficacy in improving glycemic parameters. Notably, a slightly higher proportion of patients on trelagliptin achieved HbA1c <7% compared to vildagliptin. Adverse events were mild and similar between groups. Trelagliptin demonstrated effective glycemic control with a favorable safety profile and the added benefit of convenient once-weekly dosing.
Because silent mutations do not alter protein function they are often treated as though they are evolutionarily neutral. Many organisms are known to exhibit codon usage biases, suggesting that there is selection for the use of particular codons due to the need for translational stability. Transfer RNA (tRNA) availability is one of the reasons that silent mutations might not be as silent as conventionally believed. There is a different tRNA molecule for each codon. For example, there is a specific tRNA molecule for the codon UCU and another specific for the codon UCC, both of which code for the amino acid serine. In this instance, if there was a thousand times less UCC tRNA than UCU tRNA, then the incorporation of serine into a polypeptide chain would happen a thousand times more slowly when a mutation causes the codon to change from UCU to UCC. If amino acid transport to the ribosome is delayed, translation will be carried out at a much slower rate. This can result in lower expression of a particular gene containing that silent mutation if the mutation occurs within an exon. Additionally, if the ribosome has to wait too long to receive the amino acid, the ribosome could terminate translation prematurely.
Sources: en.wikipedia.org
α-Tocopherol-Binding Protein: Vitamin E is transported in plasma mainly by lipoproteins, but little is known about how it is transported intracellularly. Duttaroy identified a new α-tocopherol-binding protein with a molecular mass of 14.2 kDa found in the cytosol of the heart and liver. This protein specifically binds α-tocopherol more than δ- and γ-homologues but does not bind oleate. The binding is quick, reversible, and saturable, indicating a specialized role in the intracellular transport and metabolism of α-tocopherol.1–4 The discovery of these binding proteins is vital for understanding how α-tocopherol is distributed within cells and tissues. Since α-tocopherol is a powerful antioxidant, proper localization is crucial for protecting cellular membranes from oxidative damage. Disruptions in the function of these binding proteins could weaken the protective effects of α-tocopherol, potentially leading to cellular problems and contributing to various diseases. Duttaroy serves as Editor-In-Chief of the peer-reviewed journal Food & Nutrition Research, which has an Impact factor of 4.5 (2025). Duttaroy serves on the editorial boards of several other journals, including Prostaglandins Leukotrienes and Essential Fatty Acids, Nutrients, and European Journal of Lipid Science and Technology. Since 2022, Professor Duttaroy has been consistently ranked among the world's top 2% of scientists each year on Stanford/Elsevier's list.
== Artwork == The album cover features an award-winning photograph by Spanish-born Catalan photojournalist and photographer Samuel Aranda. It shows a mother, Fatima al-Qaws embracing her son Zayed who is suffering from the effects of tear gas after taking part in a street demonstration against the then-ruling President Ali Abdullah Saleh in Sana'a, Yemen, on October 15, 2011. The photo was awarded the World Press Photo of the Year 2012 in February, 2012.
In China nearly all universities and research institutions are public. Typically, provincial governments run public universities. However, some are administered by municipal governments or are national, which the central government directly administers. Private undergraduate colleges exist but are primarily vocational colleges sponsored by private entities. Private universities can award bachelor's degrees. Public universities tend to enjoy a higher reputation domestically and globally.
Coleoids, a shell-less subclass of cephalopods (squid, cuttlefish, and octopuses), have complex pigment containing cells called chromatophores which are capable of producing rapidly changing color patterns. These cells store pigment within an elastic sac which produces the color seen from these cells. Coleoids can change the shape of this sac, called the cytoelastic sacculus, which then causes changes in the translucency and opacity of the cell. By rapidly changing multiple chromatophores of different colors, cephalopods are able to change the color of their skin at astonishing speeds, an adaptation that is especially notable in an organism that sees in black and white. Chromatophores are known to only contain three pigments, red, yellow, and brown, which cannot create the full color spectrum. However, cephalopods also have cells called iridophores, thin, layered protein cells that reflect light in ways that can produce colors chromatophores cannot. The mechanism of iridophore control is unknown, but chromatophores are under the control of neural pathways, allowing the cephalopod to coordinate elaborate displays. Together, chromatophores and iridophores are able to produce a large range of colors and pattern displays.
Genetic pathology involving incest Economics of peasant families Varying rules of legal inheritance Village ecology Class basis of family sizes Migration Urbanization Age at marriage Social mobility Household structure Sociology of the family Microhistory Catholic-Protestant comparisons Sociobiology
Sources: en.wikipedia.org
Among marine animals, eels are resistant to sea snake venoms, which contain complex mixtures of neurotoxins, myotoxins, and nephrotoxins, varying according to species. Eels are especially resistant to the venom of sea snakes that specialise in feeding on them, implying coevolution; non-prey fishes have little resistance to sea snake venom. Clownfish always live among the tentacles of venomous sea anemones (an obligatory symbiosis for the fish), and are resistant to their venom. Only 10 known species of anemones are hosts to clownfish and only certain pairs of anemones and clownfish are compatible. All sea anemones produce venoms delivered through discharging nematocysts and mucous secretions. The toxins are composed of peptides and proteins. They are used to acquire prey and to deter predators by causing pain, loss of muscular coordination, and tissue damage. Clownfish have a protective mucus that acts as a chemical camouflage or macromolecular mimicry preventing "not self" recognition by the sea anemone and nematocyst discharge. Clownfish may acclimate their mucus to resemble that of a specific species of sea anemone.
== Causes == Leptomeningeal carcinomatosis occurs when the cancer cells invade the cerebrospinal fluid and spread throughout the central nervous system. The metastatic tumor cells grow either attached to the pia mater covering the brain and spinal cord or floating unattached to the subarachnoid space. Tumors of diverse origins and hematologic cancers may spread to this space. Some patients may develop leptomeningeal cancer while receiving chemotherapy for their primary tumour, partly because the blood-brain barrier serves as a protective filter that shields the central nervous system from toxins and pathogens circulating in the blood. While essential for protection, this barrier also complicates treatment, as many chemotherapy agents and biopharmaceuticals struggle to cross into the brain and spinal cord.
Exposure to harmful products such as cigarette smoke. Exposure to an atmospheric pollutant, primary air pollutants (nitrogen oxides [NOx], sulfur dioxide [SO2], volatile organic compounds [VOCs], hydrocarbons and certain metals [such as lead or cadmium]) or secondary (created in the atmosphere through chemical reactions between pollutants). Exposure to UV light.
=== Enterocytes and incretin === While glucokinase has been shown to occur in certain cells (enterocytes) of the small intestine and stomach, its function and regulation have not been worked out. It has been suggested that here, also, glucokinase serves as a glucose sensor, allowing these cells to provide one of the earliest metabolic responses to incoming carbohydrates. It is suspected that these cells are involved in incretin functions.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.