A practical reference on Neurotrophic signalling: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-27. Anything still debated is marked as such rather than presented as settled.
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 is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
| 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 |
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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 was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
From 1899 to 1901 the six separate self-governing colonies in Australia sent contingents to serve in the war. That much of the population had originated from Britain explains a desire to support it. After the colonies formed the Commonwealth of Australia in 1901, the new Government of Australia sent "Commonwealth" contingents to the war. The Boer War was thus the first war in which the Commonwealth of Australia fought. A few Australians fought on the Boer side. The most famous and colourful character was Colonel Arthur Alfred Lynch, formerly of Ballarat, Victoria, who raised the Second Irish Brigade. The Australian climate and geography were far closer to that of South Africa than most other parts of the empire, so Australians adapted quickly, with troops serving mostly among the army's "mounted rifles". Enlistment in official Australian contingents totalled 16,463. Another five to seven thousand Australians served in "irregular" regiments raised in South Africa. Perhaps 500 Australian irregulars were killed. In total about 20,000 Australians served and about 1,000 were killed. 267 died from disease, 251 were killed in action or from wounds sustained in battle; 43 men were reported missing. When the war began some Australians, like some Britons, opposed it. As the war dragged on some Australians became disenchanted, in part because of the sufferings of Boer civilians reported in the press.
==== MeSH D12.125.070 – amino acids, branched-chain ==== MeSH D12.125.070.075 – aminoisobutyric acids MeSH D12.125.070.577 – isoleucine MeSH D12.125.070.637 – leucine MeSH D12.125.070.950 – valine MeSH D12.125.070.950.100 – 2-amino-5-phosphonovalerate
The crab is defined as the intensity of X-rays emitted from the Crab Nebula at a given photon energy up to 30 kiloelectronvolts. The Crab Nebula is often used for calibration of X-ray telescopes. For measuring the X-ray intensity of a less energetic source, the milliCrab (mCrab) may be used. One crab is approximately 24 pW/m2.
=== Primer extension === Primer extension is a two step process that first involves the hybridization of a probe to the bases immediately upstream of the SNP nucleotide followed by a ‘mini-sequencing’ reaction, in which DNA polymerase extends the hybridized primer by adding a base that is complementary to the SNP nucleotide. This incorporated base is detected and determines the SNP allele. Because primer extension is based on the highly accurate DNA polymerase enzyme, the method is generally very reliable. Primer extension is able to genotype most SNPs under very similar reaction conditions making it also highly flexible. The primer extension method is used in a number of assay formats. These formats use a wide range of detection techniques that include MALDI-TOF mass spectrometry (see Sequenom) and ELISA-like methods. Generally, there are two main approaches which use the incorporation of either fluorescently labeled dideoxynucleotides (ddNTP) or fluorescently labeled deoxynucleotides (dNTP). With ddNTPs, probes hybridize to the target DNA immediately upstream of SNP nucleotide, and a single, ddNTP complementary to the SNP allele is added to the 3’ end of the probe (the missing 3'-hydroxyl in didioxynucleotide prevents further nucleotides from being added). Each ddNTP is labeled with a different fluorescent signal allowing for the detection of all four alleles in the same reaction. With dNTPs, allele-specific probes have 3’ bases which are complementary to each of the SNP alleles being interrogated.
Sources: en.wikipedia.org
=== Famous patients === UPMC has provided care to many celebrities, including Pennsylvania two-term governor and 1992 Presidential candidate Robert P. Casey for cancer, 10,000 Maniacs guitarist and founder Robert Buck for liver disease, sportscaster Bob Prince, publisher William Block, MCI CEO William G. McGowan, transplant recipient Stormie Jones and Pittsburgh mayors Bob O'Connor for lymphoma and Richard Caliguiri for amyloidosis. Pittsburgh Steelers quarterback Ben Roethlisberger was rushed to UPMC Mercy after his 2006 motorcycle crash and NASCAR driver Dale Earnhardt Jr. was treated for concussions in 2012. Pittsburgh Steelers running back, James Conner was treated at UPMC Hillman Cancer Center. The golfer Arnold Palmer, a native of Latrobe, Pennsylvania, died at UPMC Shadyside on September 25, 2016. In 2017, Manchester United striker Zlatan Ibrahimović traveled to a UPMC facility to have surgery to repair his torn anterior cruciate ligament.
An exceptional case appears with the benzylideneprotecting group, which also admits reductive cleavage. This proceeds either through catalytic hydrogenation or with the hydride donor diisobutyl aluminum hydride (DIBAL). The cleavage with DIBAL deprotects one alcohol group, for the benzyl moiety stays as a benzyl ether on the second, sterically hindered hydroxy group.
Binge drinking, or heavy episodic drinking, is drinking alcoholic beverages with an intention of becoming intoxicated by heavy consumption of alcohol over a short period of time. Specific definitions vary considerably. Binge drinking is associated with risks such as suicide, sexual assault, cardiovascular issues, and brain damage, more acutely than alcohol use in general.
Dexrazoxane hydrochloride, sold under the brand name Zinecard among others, is a cardioprotective agent. It was discovered in 1972. The IV administration of dexrazoxane is in acidic condition with HCl adjusting the pH.
=== Serotonin receptors === The serotonin receptors are located on the cell membrane of nerve cells and other cell types in animals, and mediate the effects of serotonin as the endogenous ligand and of a broad range of pharmaceutical and psychedelic drugs. There are currently 14 known serotonin receptors, including the serotonin 5-HT1 (1A, 1B, 1D, 1E, 1F), 5-HT2 (2A, 2B, 2C), 5-HT3, 5-HT4, 5-HT5 (5A, 5B), 5-HT6, and 5-HT7 receptors. Except for the serotonin 5-HT3 receptor, a ligand-gated ion channel, all other 5-HT receptors are G-protein-coupled receptors (also called seven-transmembrane, or heptahelical receptors) that activate an intracellular second messenger cascade. The 5-HT5B receptor is present in rodents but not in humans. In addition to the serotonin receptors, serotonin is an agonist of the trace amine-associated receptor 1 (TAAR1) in some species. It is a weak TAAR1 partial agonist in rats, but is inactive at the TAAR1 in mice and humans. The cryo-EM structures of the serotonin 5-HT2A receptor with serotonin, as well as with various serotonergic psychedelics, have been solved and published by Bryan L. Roth and colleagues.
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.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.