ACTH(4–10) is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-06-04. Numbers and descriptions here follow the published literature rather than marketing material.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
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 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
=== Choosing an adhesive === Adhesives are selected based on archival properties and compatibility with textiles and treatment goals. The following criteria are evaluated: age-test performance, flexibility, bond strength, heat sealing temperature, pH, solubility, color stability, volatile emissions, and glass transition temperature (Tg). Display and storage orientation and conditions are also factored in because adhesives with high glass transition temperatures can tend to creep when applied to hanging textiles. Adhesives fall into four categories:
Bradford East MP Imran Hussain resigns as Shadow Minister for the New Deal for Working People from the opposition frontbench citing Keir Starmer's response to the Gaza war. 8 November Possession of nitrous oxide, commonly known as "laughing gas" or "NOS", is categorised as a Class C drug, making its possession illegal in the UK. Sunak says he will hold the Commissioner of the Metropolitan Police "accountable" over a pro-Palestinian march planned for Armistice Day, and meets with Sir Mark Rowley to discuss the demonstration. Members of the National Union of Rail, Maritime and Transport Workers are to vote on a revised pay offer and guarantee of job security that could end the railway strikes. The Mounjaro injection for treating obesity is approved for use in the UK by the Medicines and Healthcare products Regulatory Agency. 9 November Home Secretary Suella Braverman faces questions about her future after writing an article for The Times questioning the impartiality of the police over the way they deal with demonstrations, claiming that aggressive right-wing protesters are "rightly met with a stern response", while "pro-Palestinian mobs" are "largely ignored". The article was not cleared by Downing Street, while she ignored suggested changes to the piece made by officials. Data from NHS England shows waiting lists in England reached a record high in September 2023, with 7.77 million people waiting for treatment in England, including over a million on more than one waiting list.
The ATP synthase of mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane proton gradient as an energy source for adding an inorganic phosphate group to a molecule of adenosine diphosphate (ADP) to form a molecule of adenosine triphosphate (ATP). This enzyme works when a proton moves down the concentration gradient, giving the enzyme a spinning motion. This unique spinning motion bonds ADP and P together to create ATP. ATP synthase can also function in reverse, that is, use energy released by ATP hydrolysis to pump protons against their electrochemical gradient.
Sources: en.wikipedia.org
== Flow types == Microfluidic flows need only be constrained by geometrical length scale – the modalities and methods used to achieve such a geometrical constraint are highly dependent on the targeted application. Traditionally, microfluidic flows have been generated inside closed channels with the channel cross section being in the order of 10 μm x 10 μm. Each of these methods has its own associated techniques to maintain robust fluid flow which have matured over several years.
== Structure == Alpha 2-antiplasmin (α2AP) is a member of the serine protease inhibitor (serpin) superfamily and is structurally characterized by a central serpin domain flanked by unique N- and C-terminal extensions. The mature human α2AP protein consists of 452 amino acids, with a 12-residue N-terminus, a central serpin domain, and a C-terminal tail of approximately 55 residues. The reactive center loop, which is crucial for its inhibitory function, protrudes from the central serpin domain and contains the Arg364-Met365 peptide bond that is specifically targeted and cleaved by plasmin. There are two main circulating forms: Met-α2AP, which has methionine at the N-terminus, and Asn-α2AP, which is N-terminally shortened and starts with asparagine; the latter form constitutes about 70% of plasma α2AP and is more efficiently cross-linked to fibrin. The C-terminal region, rich in lysine residues, mediates the initial non-covalent binding to plasmin, facilitating the formation of a stable 1:1 stoichiometric complex. This structural arrangement allows α2AP to efficiently interact with plasmin and be incorporated into fibrin clots via cross-linking by factor XIIIa.
To ensure the accuracy of what they are reporting, forensic chemists routinely check and verify that their instruments are working correctly and are still able to detect and measure various quantities of different substances.
Sources: en.wikipedia.org
==== Removal of the signal sequence ==== Proteins that are to be targeted to a particular organelle or for secretion have an N-terminal signal peptide that directs the protein to its final destination. This signal peptide is removed by proteolysis after their transport through a membrane.
==== Wittig-Still rearrangement ==== The 2,3-Wittig rearrangement is a useful carbon-carbon bond forming reaction that transforms an allyl ether into a homoallylic alcohol. However, a significant limitation of this reaction is the difficulty in forming the alkoxy-substituted carbanion which initiates the 2,3-sigmatropic rearrangement. Traditionally, this required the use of a strong base and the presence of a stabilizing group to enable deprotonation of the ether substrate. In 1978, Still dramatically increased the scope of the 2,3-Wittig rearrangement by introducing an organotin-substituted ether as a precursor to the alkoxy-substituted carbanion. In this procedure, transmetalation of the organotin group can be achieved chemoselectively at low temperature using n-butyllithium to form an alpha-lithiated ether that undergoes the desired 2,3-sigmatropic rearrangement. This variation of the traditional 2,3-Wittig reaction is known as the Wittig-Still rearrangement.
These peptides result from partial proteolysis of intracellular or extracellular protein precursors performed by several processing enzymes or protease complexes (rennin, kallikreins, calpains, prohormone convertases, proteasomes, endosomes, lysosomes), which convert proteins into peptides, including those with biological activities. The resulting protein fragments of various sizes are either readily degraded into free amino acids, or captured by oligopeptidases, whose peculiar binding and/or catalytic properties allow them to fulfill their physiological roles by trimming inactive peptide precursors leading to their active form, converting bioactive peptides into novel ones., inactivating them, thus restraining the continuous activation of specific receptors, or protecting the newly generated bioactive peptide from further degradation, suggesting a peptide chaperon-like activity. TOP, a ubiquitous cytosolic oligopeptidase, is a remarkable example of how this enzyme could play an essential role in immune defense against cancer cells. It has also been successfully used as a hook to fish novel bioactive peptides from cytosol of cells. The involvement of peptides in cell-cell interactions and in neuropsychiatric, autoimmune, and neurovegetative diseases are waiting for peptidomics and gene silencing approaches, which will expedite the formation of new concepts in an emerging era for oligopeptidases. The participation of oligopeptidases in a number of pathologies has long been reported.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
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.