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Semax Structure And Research Background — Common Mistakes

By Editorial Desk · published 2026-02-10 · last reviewed 2026-03-28 · Blog

Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.

Updated 2026-03-28. Numbers and descriptions here follow the published literature rather than marketing material.

Semax Structure and Research Background

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.

Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.

化学性质与分析表征

稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定,遇到强碱或长时间高温则明显断裂;甲硫氨酸侧链容易被氧化成亚砜,使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间,配制后的水溶液通常需要冷藏并尽快用完。

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。

Semax at a glance

PropertyValueNotes
SequenceMet-Glu-His-Phe-Pro-Gly-ProHeptapeptide; ACTH(4-10) analog extended at C-terminus
Molecular mass~813.9 DaFree peptide, unmodified
AppearanceWhite to off-white powderTypical lyophilized solid
SolubilitySoluble in water and salineAlso soluble in common aqueous buffers
Storage (solid)-20 °C, desiccatedProtect from moisture and repeated thawing

Semax Peptide Structure and Origin

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.

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Semax 的储存、稳定性与分析

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。

常规纯度与身份确认依赖反相高效液相色谱,并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成,肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同,因此各实验室报告的纯度数值不宜直接横向比较。

Chemical Identity and Research Background

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.

Handling, Stability, and Analytical Control

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.

Further detail

3′,5′-cyclic AMP + diphosphate It has key regulatory roles in essentially all cells. It is the most polyphyletic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology. The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues. All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and pyrophosphate. Magnesium ions are generally required and appear to be closely involved in the enzymatic mechanism. The cAMP produced by AC then serves as a regulatory signal via specific cAMP-binding proteins, either transcription factors, enzymes (e.g., cAMP-dependent kinases), or ion transporters.

Nickel-48, discovered in 1999, is the most neutron-poor nickel isotope known. With 28 protons and 20 neutrons 48Ni is "doubly magic" (like 208Pb) and therefore much more stable, with a half-life around 3 milliseconds, than would be expected from its position in the chart of nuclides. It has the highest ratio of protons to neutrons (proton excess) of any known doubly magic nuclide.

The vorticity equation of fluid dynamics describes the evolution of the vorticity ω of a particle of a fluid as it moves with its flow; that is, the local rotation of the fluid (in terms of vector calculus this is the curl of the flow velocity). The governing equation is:where ⁠D/Dt⁠ is the material derivative operator, u is the flow velocity, ρ is the local fluid density, p is the local pressure, τ is the viscous stress tensor and B represents the sum of the external body forces. The first source term on the right hand side represents vortex stretching. The equation is valid in the absence of any concentrated torques and line forces for a compressible, Newtonian fluid. In the case of incompressible flow (i.e., low Mach number) and isotropic fluids, with conservative body forces, the equation simplifies to the vorticity transport equation:

From early 1944, No. 266 Squadron took part in ground attack operations over the Channel and northern France, operating from RAF Harrowbeer in Devon. The squadron also escorted Allied bombers embarking on or returning from raids, protecting them from German fighters. Larger petrol tanks were fitted to the Typhoons to increase their range. In May 1944 the squadron was visited by the Prime Minister, who had been knighted and was now Sir Godfrey Huggins. Over the next month, in preparation for the imminent Allied invasion of Normandy, the Rhodesian aircraft took on a fighter-bomber role, flying sorties across the channel twice a day and participating in the bombing of bridges, roads, railways and the like. Apart from the Southern Rhodesian airmen serving with the RAF in Britain, the colony was sparsely represented in the Normandy landings of 6 June 1944 ("D-Day"). Several men from the colony served aboard cruisers and destroyers that engaged the German shore batteries. A small number of Southern Rhodesians parachuted into Normandy with the 6th Airborne Division during Operation Tonga, and some took part in the amphibious landings. No. 266 Squadron was part of the Allied force that flew over the beaches during the first landings, supporting the infantry. Later that day it took part in sorties to assist the paratroopers holding the bridgeheads north of Caen. No. 266 Squadron, which remained 95% Rhodesian at the start of 1945, thereafter provided air support to the advancing Allied armies through France, the Low Countries and finally Germany.

Sources: en.wikipedia.org

Background from the literature

For services to British Business in South-East Asia. John Worsley Knagg, Director, British Council English Language Centre, Singapore. Lam Shiu-kum. For services to medicine in Hong Kong. Gerald John Laving. For services to British business interests, and to the community, in Russia. Ranee Lee Pui-Leung, . For public and community service in Hong Kong. Shelly Lau Lee Lai-kuen, . Director of Home Affairs, Hong Kong. Edmund Kwong Ho Leung. For services to engineering in Hong Kong. Jurek Martin, Washington Bureau Chief, Financial Times. Patrick Joseph McGuinness, lately First Secretary, British Embassy, Abu Dhabi. Evelyn Hugh Norie. For services to British business interests in Hong Kong. Alan Richardson, , Director, Accounting Services, Hong Kong. Rolf Schild. For public and industrial services. Michael John Steere. For services to British engineering in Norway. Ian Robert Strachan, , Director of Social Welfare, Hong Kong. Robert Wallace. For services to British commercial interests overseas. Michael David Williams, Rabbi to the Copernic community in Paris. David Wong Shou-yeh, . For services to business and the community, Hong Kong. The Honourable Samuel Wong Ping-wai, . For public services, Hong Kong. William John Woods. For services to community health care in Brazil. Raymond Wu Wai-yung. For services to psychiatric rehabilitation in Hong Kong. Helen Yu Lai Ching-ping, , Director of Education, Hong Kong.

The story ends with the poet writing of Akkad's fate, mirroring the words of the gods' curse earlier on: Its chariot roads grew nothing but the 'wailing plant, Moreover, on its canalboat towpaths and landings, No human being walks because of the wild goats, vermin, snakes, and mountain scorpions, The plains where grew the heart-soothing plants, grew nothing but the 'reed of tears, Akkad, instead of its sweet-flowing water, there flowed bitter water, Who said "I would dwell in that" found not a good dwelling place, Who said "I would lie down in Akkad" found not a good sleeping place.

She had formerly had the same symptoms of arsenical poison herself, and it was some time before she discovered it to be the mesmeric work of an enemy. Soon after her marriage her husband began to manifest the same symptoms and had since shown them from time to time; but was, with her help, always able to overcome them. A few weeks ago she observed that he did not look well, and when questioned he said that he was unable to get the idea of this arsenical poison out of his mind. He had been steadily growing worse ever since, but still had hoped to overcome the trouble until the last. After the death the body had turned black. A doctor performed an autopsy and showed Eddy her husband's diseased heart, but she responded by giving more interviews about mesmerism. Fraser wrote that the articles made Eddy a household name, a real-life version of the charismatic and beautiful Verena Tarrant in Henry James's The Bostonians (1885–1886), with her interest in spiritualism, women's rights and the mind cure. Shortly after the death, Eddy moved next door to 571 Columbus Avenue with several students. The following year, 1883, she founded the Journal of Christian Science (later called the Christian Science Journal), which spread news of her ideas across the United States.

David eventually returns to Lanford and tells Darlene he wants to reenter his children's lives. After sleeping together, both Darlene and David consider reconciling until Roseanne tells Darlene the reason David said he left their marriage. She says it would be bad for their children, who resent David being an absent father. At Dan's urging, David agrees to get his life settled before seeing the kids again. In The Conners, David is working at Trader Joe's and has moved in with a free-spirited woman named Blue. Darlene is furious to discover that during the kids' first weekend staying with David, Blue allowed Harris' boyfriend to sleep over and she lost her virginity. David defensively says he was working and was unaware, but Darlene demands he be a more attentive father. David eventually breaks up with Blue because she wants children. David and Darlene began sleeping together again while Darlene is also in a relationship with Ben. Darlene decides she wants to be with Ben, and she and David finally agree to divorce. Ben, already knowing the two were seeing each other, breaks up with Darlene, though he eventually forgives her. David began seeing a therapist, and, during a joint session with Darlene, reveals he feels Darlene never treated him as an equal and caused him to leave her. When David was first introduced to the series, his name was Kevin, though it was subsequently changed to David. While applying for college, he uses his full name, David Maurice Healy. As a show inside joke, Roseanne comments in Season 6, "David's not even his real name.

Three zoos, the Paris Zoological Park (Parc zoologique de Paris, also known as the Zoo de Vincennes), at the Bois de Vincennes in the 12th arrondissement, the Cleres Zoological Park (Parc zoologique de Clères), at a medieval manor in Clères (Seine-Maritime) and the Haute Touche Zoological Park in Obterre (Indre), the largest in France, Three botanical parks, the Arboretum de Chèvreloup in Rocquencourt next to the Château de Versailles, the Jardin botanique exotique de Menton and the Jardin alpin de La Jaÿsinia in Samoëns, Two museums, the Musée de l'abri Pataud in Les Eyzies-de-Tayac and the Harmas de Fabre in Sérignan-du-Comtat, Four scientific sites, the Institut de Paléontologie humaine in Paris, the Centre d'Écologie générale de Brunoy, the Station de Biologie marine et Marinarium de Concarneau and the CRESCO (Centre de Recherche et d'Enseignement sur les Systèmes Côtiers) in Dinard.

Sources: en.wikipedia.org

Reference notes

Gabe Logan Newell (born November 3, 1962), known by his nickname Gaben, is an American video game developer and businessman who is the co-founder and president of the video game company Valve. Newell was born in Aspen, Colorado, and grew up in Davis, California. He attended Harvard University in the early 1980s but dropped out to join Microsoft, where he helped create the first versions of the Windows operating system. He also led development on a port of the game Doom for Windows 95. In 1996, Newell and Mike Harrington left Microsoft to found Valve and fund the development of their first game, Half-Life (1998). After the success of Half-Life, Harrington sold his stake in Valve to Newell and left in 2000. Newell led development of Valve's digital distribution service, Steam, which launched in 2003 and controlled most of the market for downloaded PC games by 2011. Forbes estimated that Newell owned at least half of Valve as of 2025. He is also the owner of the marine research organization Inkfish, the neuroscience company Starfish Neuroscience, and the custom yacht manufacturer Oceanco. Newell has been estimated as one of the wealthiest people in the United States and the wealthiest person in the video games industry, with an estimated net worth of $11 billion as of 2025.

Many physicians operate by the World Professional Association of Transgender Health (WPATH) Standards of Care (SoC) model and require psychotherapy and a letter of recommendation from a psychotherapist in order for a transgender person to obtain hormone therapy. Other physicians operate by an informed consent model and have no requirements for transgender hormone therapy aside from consent. Medications used in transgender hormone therapy are also sold without a prescription on the Internet by unregulated online pharmacies, and some transgender women purchase these medications and treat themselves using a do-it-yourself (DIY) or self-medication approach. One reason that many transgender people turn to DIY hormone therapy is due to long waiting lists of up to years for standard physician-based hormone therapy in some parts of the world such as the United Kingdom, as well as due to the often high costs of seeing a physician and the restrictive criteria that make some ineligible for treatment, or simply medical malpractice by physicians that are not adequately trained. The accessibility of transgender hormone therapy differs throughout the world and throughout individual countries.

=== H. G. Wells === Author H. G. Wells was born in Bromley on 21 September 1866, to Sarah and Joseph Wells; his father was the founder of the Bromley Cricket Club and the proprietor of a shop that sold cricket equipment. Wells spent the first 13 years of his life in Bromley. From 1874 to 1879 he attended Tomas Morley's Bromley Academy, at 74 High Street. There was a 'H. G. Wells Centre' in Masons Hill near the southern end of the High Street which housed the Bromley Labour Club (the building was demolished in 2017). In August 2005, the wall honouring Wells in Market Square was repainted; the current wall painting features a rich green background with the same Wells reference and the evolutionary sequence of Homo sapiens featured in Origin of Species by Charles Darwin, a former resident of nearby Downe Village. Wells wrote about Bromley in an early unsigned article in the Pall Mall Gazette in which he expressed satisfaction that he had been born in an earlier, more rural Bromley. A blue plaque marks Wells' birthplace in Market Square, on the wall of what is now a Primark store. A marble plaque appears above the door of 8 South Street, the location of Mrs Knott's Dame school where "Bertie", as he was called as a child, learned to read and write. H. G. Wells featured Bromley in two of his novels: The War in the Air (which refers to Bromley as Bunhill) and The New Machiavelli (in which Bromley is referred to as Bromstead). However, H. G.

The human body subjects most, but not all, compounds to various chemical processes (i.e. metabolism) to make them suitable for elimination. This involves chemical transformations to (a) reduce fat solubility and (b) to change biological activity. Although almost all tissues in the body have some ability to metabolize chemicals, smooth endoplasmic reticulum in the liver is the principal "metabolic clearing house" for both endogenous chemicals (e.g., cholesterol, steroid hormones, fatty acids, proteins) and exogenous substances (e.g., drugs, alcohol). The central role played by liver in the clearance and transformation of chemicals makes it susceptible to drug-induced injury. Drug metabolism is usually divided into two phases: phase 1 and phase 2. Phase 1 reaction is generally speaking to prepare a drug for phase 2. However, many compounds can be metabolized by phase 2 directly or be excreted without any phase 2 reactions occurring. Phase 1 reaction involves oxidation, reduction, hydrolysis, hydration and many other rare chemical reactions. These processes tend to increase water solubility of the drug and can generate metabolites that are more chemically active and/or potentially toxic. Most of phase 2 reactions take place in cytosol and involve conjugation with endogenous compounds via transferase enzymes. Phase 1 are typically more suitable for elimination. A group of enzymes located in the endoplasmic reticulum, known as cytochrome P-450, is the most important family of metabolizing enzymes in the liver.

Sources: en.wikipedia.org

Frequently asked questions

What is semax?

Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.

How is semax related to ACTH?

Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.

Is semax an approved drug?

It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.

用什么方法确认分子量?

电喷雾或基质辅助激光解吸电离质谱是常用手段,测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内,才支持结构一致的判断。

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