The short version of Melanocortin receptor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-07-29. Anything still debated is marked as such rather than presented as settled.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
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.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
Instead, the Buddha taught that sentient experience is dependently originated and that whatever is dependently originated is conditioned, impermanent, subject to change, and lacking independent selfhood.
== Other uses == Chart Rulership or Chart Ruler, in astrology Comfort room, another name for a public toilet Consciousness raising, in social activism Continuing resolution, a type of appropriations legislation in the US Councillor, a title for a public servant, used in Australia and New Zealand Cree language (ISO 639 alpha-2 code CR) Critical reading, a skill measured by the Scholastic Aptitude Test (SAT) Crore, a number representing 10,000,000 in the Hindu-Arabic numeral system Cr$ or ₢, symbol for Brazilian cruzeiro
β-pleated sheet structures are made from extended β-strand polypeptide chains, with strands linked to their neighbours by hydrogen bonds. Due to this extended backbone conformation, β-sheets resist stretching. β-sheets in proteins may carry out low-frequency accordion-like motion as observed by the Raman spectroscopy and analyzed with the quasi-continuum model. A β-helix is formed from repeating structural units consisting of two or three short β-strands linked by short loops. These units "stack" atop one another in a helical fashion so that successive repetitions of the same strand hydrogen-bond with each other in a parallel orientation. See the β-helix article for further information. In lefthanded β-helices, the strands themselves are quite straight and untwisted; the resulting helical surfaces are nearly flat, forming a regular triangular prism shape, as shown for the 1QRE archaeal carbonic anhydrase at right. Other examples are the lipid A synthesis enzyme LpxA and insect antifreeze proteins with a regular array of Thr sidechains on one face that mimic the structure of ice.
Tranexamic acid is frequently used following major trauma. Tranexamic acid is used to prevent and treat blood loss in a variety of situations, such as dental procedures, heavy menstrual bleeding, and surgeries with high risk of blood loss. Tranexamic acid has been found to decrease the risk of death due to any cause in people who have significant bleeding due to trauma. It is most effective if taken within the first three hours following major trauma. It also decreases the risk of death if given within the first three hours of brain injury.
Sources: en.wikipedia.org
Troglitazone was developed by Daiichi Sankyo (Japan). In the United States, it was introduced and manufactured by Parke-Davis in the late 1990s but turned out to be associated with an idiosyncratic reaction leading to drug-induced hepatitis. The Food and Drug Administration (FDA) medical officer assigned to evaluate troglitazone, John Gueriguian, did not recommend its approval due to potentially high liver toxicity; Parke-Davis complained to the FDA, and Gueriguian was subsequently removed from his post. A panel of experts approved it in January 1997. Once the prevalence of adverse liver effects became known, troglitazone was withdrawn from the British market in December 1997, from the United States market in 2000, and from the Japanese market soon afterwards. It did not get approval in the rest of Europe. Troglitazone was developed as the first anti-diabetic drug having a mechanism of action involving a decrease in insulin resistance. At the time, it was widely believed that such drugs, by addressing the primary metabolic defect associated with Type 2 diabetes, would have numerous benefits including avoiding the risk of hypoglycemia associated with insulin and earlier oral antidiabetic drugs. It was further believed that reducing insulin resistance would potentially reduce the very high rate of cardiovascular disease that is associated with diabetes. Parke-Davis/Warner Lambert submitted the diabetes drug Rezulin for FDA review on July 31, 1996. The medical officer assigned to the review, Dr. John L.
=== Since 2014 === In 2014, Daniel Fata, who served as deputy assistant secretary of defense for European and NATO policy in Pentagon from September 2005 to September 2008, said that Putin pledged to the United States in 2008 that his limited intervention in Georgia intended to defend Russian citizens, however Putin "lied" since he really wanted to topple the government of President Mikheil Saakashvili. Fata said that the reasons behind Russia's actions is that "Putin wants to be seen as a player," to be "a great power like France, Germany, and the UK". According to Fata, events in Crimea "is in many ways a redux" of the August 2008.
Qualification of machinery/equipment is venue dependent, in particular items that are shock sensitive and require balancing or calibration, and re-qualification needs to be conducted once the objects are relocated. The full scales of some equipment qualifications are even time dependent as consumables are used up (i.e. filters) or springs stretch out, requiring recalibration, and hence re-certification is necessary when a specified due time lapse. Re-qualification of machinery/equipment should also be conducted when replacement of parts, or coupling with another device, or installing a new application software and restructuring of the computer which affects especially the pre-settings, such as on BIOS, registry, disk drive partition table, dynamically-linked (shared) libraries, or an ini file etc., have been necessary. In such a situation, the specifications of the parts/devices/software and restructuring proposals should be appended to the qualification document whether the parts/devices/software are genuine or not. Some have discussed the suitability of non-genuine parts for clinical use and provided guidelines for equipment users to select appropriate substitutes which are capable of avoiding adverse effects. In the case when genuine parts/devices/software are demanded by some of regulatory requirements, then re-qualification does not need to be conducted on the non-genuine assemblies. Instead, the asset has to be recycled for non-regulatory purposes.
== Principle == The assay principle of peptide microarrays is similar to an ELISA protocol. The peptides (up to tens of thousands in several copies) are linked to the surface of a glass chip typically the size and shape of a microscope slide. This peptide chip can directly be incubated with a variety of different biological samples like purified enzymes or antibodies, patient or animal sera, cell lysates and then be detected through a label-dependent fashion, for example, by a primary antibody that targets the bound protein or modified substrates. After several washing steps a secondary antibody with the needed specificity (e.g. anti IgG human/mouse or anti phosphotyrosine or anti myc) is applied. Usually, the secondary antibody is tagged by a fluorescence label that can be detected by a fluorescence scanner. Other label-dependent detection methods includes chemiluminescence, colorimetric or autoradiography. Label-dependent assays are rapid and convenient to perform, but risk giving rise to false positive and negative results. More recently, label-free detection including surface plasmon resonance (SPR) spectroscopy, mass spectrometry (MS) and many other optical biosensors have been employed to measuring a broad range of enzyme activities. Peptide microarrays show several advantages over protein microarrays:
== Causes and risk factors == The etiology of Peyronie's disease is multifactorial. The most widely held hypothesis is that recurrent microtrauma to the erect penis (e.g., during intercourse) leads to localized inflammation and abnormal wound healing in genetically predisposed men. This pathway initiates a cascade of pro-inflammatory and pro-fibrotic cytokines such as transforming growth factor beta 1 (TGF-β1), resulting in abnormal collagen deposition and plaque formation. Risk factors include advancing age, penile trauma, diabetes mellitus, Dupuytren's contracture, and tobacco smoking. Familial aggregation and linkage with other fibrosing disorders suggest a genetic basis. Peyronie's disease is seen most frequently in men over 40 years of age, with a prevalence in the general male population estimated at between 1% and 20%, and with higher prevalence in those with erectile dysfunction.
Sources: en.wikipedia.org
== Function == Gamma-glutamyltransferase is a membrane-associated protein involved in both glutathione metabolism and the transpeptidation of amino acids. Changes in gamma-glutamyltransferase activity may signal preneoplastic or toxic conditions in the liver or kidney. The protein encoded by this gene is similar in sequence to gamma-glutamyltransferase, but its function is unknown.
Large quantities of both adenoviruses are produced by HEK 293 cells that have the E1 gene necessary for viral replication. Rarely, Ad5 can acquire the E1 gene from the HEK 293 cells, restoring its ability to replicate. Gamaleya has set an acceptable limit of 5,000 replicating virus particles per vaccine dose, and quality control documents state that tested batches contain less than 100 replicating virus particles per dose. The production of the frozen liquid formulation was developed for large-scale use, it is cheaper and easier to manufacture. The production of the freeze-dried formulation takes much more time and resources, although it is more convenient for storage and transportation. It was developed with vaccine delivery to hard-to-reach regions of Russia in mind. According to Russian media, the mass production of the Gam-COVID-Vac was launched by 15 August. By that moment, the Russian Federation has already received applications from 20 countries for the supply of 1 billion doses of vaccine. Three facilities were able to produce about a million doses per month at each with a potential doubling of capacity by winter. By the end of 2020, Gamaleya Research Institute's production, according to an interview with the organization's spokesperson, was planned to produce 3–5 million doses. As of March 2021, the Russian Direct Investment Fund (RDIF) has licensed production in India, China, South Korea and Brazil. In the EU, RDIF has signed production agreements.
Gen'en (減塩; 'reduced salt'): This version contains 50% less salt than regular soy sauce for consumers concerned about heart disease. Usujio (薄塩; 'light salt'): This version contains 20% less salt than regular soy sauce. All of these varieties are sold in three different grades according to how they were made:
== Later life and recognition == Smolková-Keulemansová became one of the leading experts in the field of chromatography. She was the first professor of chemistry in the Czech Republic and one of the first in Europe. Not only did she continue her studies in chemistry, but she also focused on polarography, a PhD focused on gas chromatography and a DrSc concentrated on inclusion compounds in chromatography. In the early 1970s, inclusion complex formations in selective analytical separations became a major focus of Smolková-Keulemansová's, her first choice being cyclodextrins, but moving on with urea and thiourea for the separation of isomers. Her research on cyclodextrins started soon after her methods focused on gas chromatography, high-performance liquid chromatography and electromigration. Her research became more widespread and she was asked to add many monographs on cyclodextrins, one of them being for a compendium on supramolecular chemistry edited by Jean-Marie Lehn. She has written and co-written 140 original papers and numerous reviews and has contributed to many books, including her work in Journal of High-Resolution Chromatography, "A Few Milestones on the Journey of Chromatography", and an article in the journal Chromatographia, "Study of retention of isomeric aromatic hydrocarbons on GTCB and cyclodextrins". Smolková-Keulemansová died on 27 February 2024, at the age of 96.
Reptiles generally reproduce sexually, though some are capable of asexual reproduction. All reproductive activity occurs through the cloaca, the single exit/entrance at the base of the tail where waste is also eliminated. Most reptiles have copulatory organs, which are usually retracted or inverted and stored inside the body. In turtles and crocodilians, the male has a single median penis, while squamates, including snakes and lizards, possess a pair of hemipenes, only one of which is typically used in each session. Tuatara, however, lack copulatory organs, and so the male and female simply press their cloacas together as the male discharges sperm. Most reptiles lay amniotic eggs covered with leathery or calcareous shells. An amnion (5), chorion (6), and allantois (8) are present during embryonic life. The eggshell (1) protects the crocodile embryo (11) and keeps it from drying out, but it is flexible to allow gas exchange. The chorion (6) aids in gas exchange between the inside and outside of the egg. It allows carbon dioxide to exit the egg and oxygen gas to enter the egg. The albumin (9) further protects the embryo and serves as a reservoir for water and protein. The allantois (8) is a sac that collects the metabolic waste produced by the embryo. The amniotic sac (10) contains amniotic fluid (12) which protects and cushions the embryo. The amnion (5) aids in osmoregulation and serves as a saltwater reservoir.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.