A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-04-27. Anything still debated is marked as such rather than presented as settled.
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.
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.
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
One possible explanation is that freezing causes the loss of hydroxyl groups on the Alum, destabilizing its association with the antigen. Another explanation is the agglomeration of adjuvant-antigen complexes, forming larger particles of lower surface area. In either case, there are a number of cryoprotectants such as glycerine that can be added to the typical vial of aluminum liquid suspension vaccine to reduce the loss of potency. Some scientists are also working on making Alum-containg vaccines suitable for freeze-drying. Freeze-dried vaccines exist as a stable dry powder containing nothing to freeze.
=== Proteomics === ETD is widely used in the analysis of protein and large peptides. Important post translational modifications including phosphorylation, glycosylation and disulfide linkages are all analyzed using ETD.
dolichyl diphosphate + a glycoprotein with the oligosaccharide chain attached by N-glycosyl linkage to protein L-asparagine Thus, the two substrates of this enzyme are dolichyl diphosphooligosaccharide and protein L-asparagine, whereas its 3 products are dolichyl diphosphate, glycoprotein with the oligosaccharide chain attached by N-glycosyl, and linkage to protein L-asparagine. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is dolichyl-diphosphooligosaccharide:protein-L-asparagine oligopolysaccharidotransferase. Other names in common use include dolichyldiphosphooligosaccharide-protein glycosyltransferase, asparagine N-glycosyltransferase, dolichyldiphosphooligosaccharide-protein oligosaccharyltransferase, dolichylpyrophosphodiacetylchitobiose-protein glycosyltransferase, oligomannosyltransferase, oligosaccharide transferase, dolichyldiphosphoryloligosaccharide-protein, and oligosaccharyltransferase. This enzyme participates in n-glycan biosynthesis and glycan structures - biosynthesis 1.
=== 1977–1981: Peak progressive era === After the conclusion of the 2112 tour, Rush recorded A Farewell to Kings (1977) and Hemispheres (1978) at Rockfield Studios in Monmouthshire, Wales. The albums had the band members expanding the progressive elements in their music. "As our tastes got more obscure", Lee said in an interview, "we discovered more progressive rock-based bands like Yes, Van der Graaf Generator, and King Crimson, and we were very inspired by those bands. They made us want to make our music more interesting and more complex, and we tried to blend that with our own personalities to see what we could come up with that was indisputably us." Increased synthesizer use, lengthy songs, and highly dynamic playing featuring complex time signature changes became a staple of Rush's compositions. To achieve a broader, more progressive sound, Lifeson began to experiment with classical and twelve-string guitars, and Lee added bass-pedal synthesizers and Minimoog. Likewise, Peart's percussion became diversified in the form of triangles, glockenspiel, wood blocks, cowbells, timpani, gong, and chimes. Beyond instrument additions, the band kept in stride with progressive rock trends by continuing to compose long, conceptual songs with science fiction and fantasy overtones. As the new decade approached, Rush gradually began to dispose of their older styles of music in favour of shorter and sometimes softer arrangements, due in part to the band's exhaustion from recording Hemispheres.
Sources: en.wikipedia.org
The most stable and dense form of selenium is gray and has a chiral hexagonal crystal lattice (space group 152 or 154 depending on the chirality) consisting of helical polymeric chains, where the Se–Se distance is 237.3 pm and Se–Se–Se angle is 103.1°. The minimum distance between chains is 343.6 pm. Gray selenium is formed by mild heating of other allotropes, by slow cooling of molten selenium, or by condensing selenium vapor just below the melting point. Whereas other selenium forms are insulators, gray selenium is a semiconductor showing appreciable photoconductivity. Unlike the other allotropes, it is insoluble in CSs. It resists oxidation by air and is not attacked by nonoxidizing acids. With strong reducing agents, it forms polyselenides. Selenium does not exhibit the changes in viscosity that sulfur undergoes when gradually heated.
Sinecatechins (Veregen) was the first botanical drug approved in the US in 2006; a green tea extract, for genital warts Crofelemer (Mytesi), approved by the FDA in 2012, an extract of "dragon's blood" sap of the Croton lechleri plant, for diarrhea in people with HIV/AIDS Nabiximols (USAN, trade name Sativex) is a specific extract of Cannabis approved as a botanical drug in the United Kingdom as a mouth spray for people with multiple sclerosis, who can use it to alleviate neuropathic pain, spasticity, overactive bladder, and other symptoms; it was developed by the UK company GW Pharmaceuticals Menerba is a botanical drug candidate consisting of 22 herbs that have been used historically in traditional Chinese medicine that act as a selective estrogen receptor modulator. As of 2015 the FDA had approved Bionovo's chemical manufacturing and controls and Menerba was in a Phase III clinical trial as a potential treatment to relieve hot flashes associated with menopause.
== External links == The Nuclear Science web portal Nucleonica The Karlsruhe Nuclide Chart National Nuclear Data Center Portal to large repository of free data and analysis programs from NNDC National Isotope Development Center Coordination and management of the production, availability, and distribution of isotopes, and reference information for the isotope community Isotope Development & Production for Research and Applications (IDPRA) U.S. Department of Energy program for isotope production and production research and development International Atomic Energy Agency Homepage of International Atomic Energy Agency (IAEA), an Agency of the United Nations (UN) Atomic Weights and Isotopic Compositions for All Elements Static table, from NIST (National Institute of Standards and Technology) Atomgewichte, Zerfallsenergien und Halbwertszeiten aller Isotope Exploring the Table of the Isotopes at the LBNL Current isotope research and information isotope.info Emergency Preparedness and Response: Radioactive Isotopes by the CDC (Centers for Disease Control and Prevention) Chart of Nuclides Archived 2018-10-10 at the Wayback Machine Interactive Chart of Nuclides (National Nuclear Data Center) Interactive Chart of the nuclides, isotopes and Periodic Table Archived 2008-09-30 at the Wayback Machine The LIVEChart of Nuclides – IAEA with isotope data. Annotated bibliography for isotopes from the Alsos Digital Library for Nuclear Issues The Valley of Stability (video) – a virtual "flight" through 3D representation of the nuclide chart, by CEA (France)
== Contraindications == The use of valsartan in pregnancy is avoided due to the potential risk of fetal toxicity. The U.S. Food and Drug Administration has a black box warning for valsartan/hydrochlorothiazide use during pregnancy. The use of hydrochlorothiazide is avoided in those with anuria or severe kidney disease.
10 December – Foreign Secretary David Cameron threatens to withdraw co-operation with Scottish ministers following a meeting between Humza Yousaf, the First Minister of Scotland, and Turkish President Recep Tayyip Erdogan at the 2023 United Nations Climate Change Conference, which took place without the presence of a UK official and was consequently a breach of protocol. In response, Yousaf calls the threat "petty" and "misguided". 11 December – New modernised trains are introduced on the Glasgow Subway as part of a £288m upgrade of the city's underground rail system. The Foreign and Commonwealth Office is to move from its Abercrombie House offices in East Kilbride to an undisclosed location in Glasgow some time after 2025, it is announced, with His Majesty's Revenue and Customs moving from Queensway House to replace the FCO at Abercrombie House. 12 December – Five men are charged in connection with historic sexual abuse at Edinburgh Academy. Perth and Kinross Council provisionally approves a 100% increase in Council Tax on second homes. 13 December – Nuns Sister Sarah McDermott, 79, and Sister Eileen Igoe, 79, and carer Margaret Hughes, 76, are convicted of mistreating children at Smyllum Park, an orphanage in Lanark, from 1969 until its closure in 1981. 14 December – Robert O'Brien, aged 45, Andrew Kelly, 44, and Donna Marie Brand, also aged 44, are convicted of the 1996 murder of Caroline Glachan following a trial at the High Court in Glasgow. All three were teenagers at the time the crime was committed.
Sources: en.wikipedia.org
== Publications == Robertson published widely over a range of scientific subjects, including his life-long interest in the biochemical processes underlying higher nervous functions and cognition. In 1932, the Australian biochemist, Mary Campbell Dawbarn, compiled an extensive list of Robertson's publications for The Robertson Memorial Volume. She cited 7 books, 174 articles, and 26 other items, published between 1904 and 1929 of which Robertson was joint author. His publications included an early (1914) work, especially written for children; and, later, three significant textbooks, one of which had two editions:
A phosphorimidazolide is a chemical compound in which a phosphoryl mono-ester is covalently bound to a nitrogen atom in an imidazole ring. They are a type of phosphoramidate. These phosphorus (V) compounds are encountered as reagents used for making new phosphoanhydride bonds with phosphate mono-esters, and as reactive intermediates in phosphoryl transfer reactions in some enzyme-catalyzed transformations. They are also being studied as critical chemical intermediates for the polymerization of nucleotides in pre-biotic settings. They are sometimes referred to as phosphorimidazolidates, imidazole-activated phosphoryl groups, and P-imidazolides.
==== Drug delivery ==== Block copolymers are a well-studied and versatile class of self-assembling materials characterized by chemically distinct polymer blocks that are covalently bonded. This molecular architecture of the covalent bond enhancement is what causes block copolymers to spontaneously form nanoscale patterns. In block copolymers, covalent bonds frustrate the natural tendency of each individual polymer to remain separate (in general, different polymers, do not like to mix), so the material assembles into a nano-pattern instead. These copolymers offer the ability to self-assemble into uniform, nanosized micelles and accumulate in tumors via the enhanced permeability and retention effect. Polymer composition can be chosen to control the micelle size and compatibility with the drug of choice. The challenges of this application are the difficulty of reproducing or controlling the size of self-assembly nano micelle, preparing predictable size-distribution, and the stability of the micelle with high drug load content.
Plaid Cymru expels Senedd member Rhys ab Owen after he was found to have inappropriately touched and sworn at two women while drunk at a party. Former Chancellor Nadhim Zahawi, who stood down from Parliament at the general election, is reported to be seeking financial backers in order to bid for the Daily Telegraph and The Spectator. 23 July – Seven Labour MPs, including former shadow chancellor John McDonnell and former shadow minister Rebecca Long-Bailey, have the Labour whip suspended for six months after voting against the government and in favour of an SNP amendment to scrap the two-child benefit cap. McDonnel said, "I'm following Keir Starmer's example as he said put country before party". The Home Office confirms that contract for the Bibby Stockholm, the vessel used to house asylum seekers, will not be renewed after January 2025. Documents released by The National Archives reveal that former prime minister Harold Wilson agreed to sell his private papers late in life in order to provide funds for his care. A deal agreed with Canada's McMaster University in 1990 attracted concern from the Cabinet Office because documents relating to his time in office remained private under the thirty year rule, which would not apply if they went to Canada. They were eventually sold to Oxford's Bodleian Library. 2024 Conservative Party leadership election: James Cleverly, who served as home secretary and foreign secretary in the Sunak government, announces his intention to run for the post of Conservative Party leader. 24 July – Starmer attends his first PMQs as prime minister.
=== Detection in biological specimens === Polonium-210 may be quantified in biological specimens by alpha particle spectrometry to confirm a diagnosis of poisoning in hospitalized patients or to provide evidence in a medicolegal death investigation. The baseline urinary excretion of polonium-210 in healthy persons due to routine exposure to environmental sources is normally in a range of 5–15 mBq/day. Levels in excess of 30 mBq/day are suggestive of excessive exposure to the radionuclide.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。