If you have been reading about ACTH(4-10) and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
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.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
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。
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。
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.
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.
== Taxonomy and phylogeny == Pholcus phalangioides was first described in 1775 by the Swiss entomologist Johann Kaspar Füssli. A member of the genus Pholcus in the family Pholcidae, P. phalangioides shares ancestry with roughly 1,340 similar cellar-spiders. All of these spiders are known for their characteristic long legs, which can range from 5 to 6 times the size of their bodies. This is not to be confused with organisms with similar physical appearances, such as the crane fly – an insect – and harvestmen of the arachnid order Opiliones.
FedEx Express maintains its world hub at the Memphis airport. The company refers to Memphis as its "Superhub". Launched in 1973, the hub has sorting facilities, a cold-storage building, and a command center. A separate control tower manages traffic to and from the ramp. The hub is capable of sorting 484,000 shipments per hour and serves 250 daily flights, most of which operate between 10 p.m. and 5 a.m. FedEx contributes the most toward the airport's operating costs, excluding those related to the passenger terminal. In addition, United Parcel Service has had a regional hub at the airport since 1999.
=== Elevation and pinecone production === Some growers claim that the elevation of the pinyon pine is an important determinant of the quantity of pine cone production and, therefore, will largely determine the number of pine nuts the tree will yield. The US Department of Agriculture notes that variation in cone production between trees growing on identical sites is often observed. American pinyon pine cone production is most commonly found at an elevation between 1,800 and 2,600 m (6,000 and 8,500 ft), and ideally at 2,100 m (7,000 ft). This is due to higher temperatures at elevations lower than 1,800 m (6,000 ft) during the spring, which dry up humidity and moisture content (particularly snow packs) that provide for the tree throughout the spring and summer, causing little nourishment for pine cone maturity. Although several other environmental factors determine the conditions of the ecosystem (such as clouds and rain), the trees tend to abort cones without sufficient water. High humidity encourages cone development. There are certain topographical areas found in lower elevations, such as shaded canyons, where the humidity remains constant throughout the spring and summer, allowing pine cones to fully mature and produce seed. At elevations above 2,600 m (8,500 ft), the temperature substantially drops, drastically affecting the state of the dormant cone. During the winter, frequent dramatic changes in temperature, drying, and gusty winds make the cones susceptible to freeze-drying that permanently damages them; in this case, growth is stunted, and the seeds deteriorate.
Sources: en.wikipedia.org
MacLeod was overseeing the work of Banting, who had no experience in physiology, and his assistant Best. In December 1921, when Banting and Best were having difficulties in refining the pancreatic extract and monitoring glucose levels, MacLeod assigned the biochemist James Collip to the team. In January 1922, while Collip was working on insulin purification, Best and Banting administered prematurely their pancreatic extracts to 14-year-old Leonard Thompson, who suffered a severe allergic reaction. Eventually, Collip succeeded in preparing insulin in a more pure, usable form. Banting, Best and Collip shared the patent for insulin, which they sold to the University of Toronto for one dollar. In 1923, the Nobel Prize Committee honoured Banting and John Macleod with the Nobel Prize in Medicine for the discovery of insulin, ignoring Best and Collip. Banting chose to share half of the prize money with Best. The key contribution by Collip was recognised in the Nobel speech of MacLeod, who also gave one-half of his prize money to Collip. However, "if Banting was hoping that this might offer Best some consolation for not having shared in the prize, he was mistaken. Best’s resentment at having been overlooked began to irritate Banting", to the point that Banting stated in 1941 "If I don’t come back and they give my [Professorial] Chair to that son-of-a-bitch Best, I’ll never rest in my grave", shortly before Banting boarded a plane for the UK which crashed and killed him.
The waning loyalty of the Cossacks, and the szlachta's arrogance towards them, resulted in several Cossack uprisings against the Polish–Lithuanian Commonwealth in the early 17th century. Finally, the King's adamant refusal to accede to the demand to expand the Cossack Registry prompted the largest and most successful of these: the Khmelnytsky Uprising, that began in 1648. Some Cossacks, including the Polish szlachta in Ukraine, converted to Eastern Orthodoxy, divided the lands of the Ruthenian szlachta, and became the Cossack szlachta. The uprising was one of a series of catastrophic events for the Commonwealth, known as The Deluge, which greatly weakened the Polish-Lithuanian Commonwealth and set the stage for its disintegration 100 years later. Influential relatives of the Ruthenian and Lithuanian szlachta in Moscow helped to create the Russian–Polish alliance against Khmelnitsky's Cossacks, portrayed as rebels against order and against the private property of the Ruthenian Orthodox szlachta. Don Cossacks' raids on Crimea left Khmelnitsky without the aid of his usual Tatar allies. From the Russian perspective, the rebellion ended with the 1654 Treaty of Pereyaslav, in which, in order to overcome the Russian–Polish alliance against them, the Khmelnitsky Cossacks pledged their loyalty to the Russian Tsar. In return, the Tsar guaranteed them his protection; recognized the Cossack starshyna (nobility), their property, and their autonomy under his rule; and freed the Cossacks from the Polish sphere of influence and the land claims of the Ruthenian szlachta.
=== Therapy === Intravenous magnesium is recommended by the ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death for patients with ventricular arrhythmia associated with torsades de pointes who present with long QT syndrome; and for the treatment of patients with digoxin-induced arrhythmias. Intravenous magnesium sulfate is used for the management of pre-eclampsia and eclampsia. Hypomagnesemia, including that caused by alcoholism, is reversible by oral or parenteral magnesium administration depending on the degree of deficiency. There is limited evidence that magnesium supplementation may play a role in the prevention and treatment of migraine.
=== Risk modifiers === Environmental factors such as infections, geographic latitude, birth weight, antibiotic use, intestinal microbiota, socioeconomic status, hygiene, breastfeeding, and the timing of introduction of gluten into an infant's diet are theorised to contribute to the development of coeliac disease in genetically predisposed individuals. The consumption of gluten and timing of introduction, in a baby's life does not appear to increase the risk of coeliac disease, however in those who are genetically predisposed to coeliac disease, large amounts of gluten early in life may increase the risk of developing coeliac disease.
Sources: en.wikipedia.org
Ghiorso and co-workers analyzed filter papers which had been flown through the explosion cloud on airplanes (the same sampling technique that had been used to discover 244Pu). Larger amounts of radioactive material were later isolated from coral debris of the atoll, and these were delivered to the U.S. The separation of suspected new elements was carried out in the presence of a citric acid/ammonium buffer solution in a weakly acidic medium (pH ≈ 3.5), using ion exchange at elevated temperatures; fewer than 200 atoms of einsteinium were recovered in the end. Nevertheless, element 99, einsteinium, and in particular 253Es, could be detected via its characteristic high-energy alpha decay at 6.6 MeV. It was produced by the capture of 15 neutrons by uranium-238 nuclei followed by seven beta decays, and had a half-life of 20.5 days. Such multiple neutron absorption was made possible by the high neutron flux density during the detonation, so that newly generated heavy isotopes had plenty of available neutrons to absorb before they could disintegrate into lighter elements. Neutron capture initially raised the mass number without changing the atomic number of the nuclide, and the concomitant beta-decays resulted in a gradual increase in the atomic number:
=== „Gott ist schön“ (Dissertation 1998) === A parallel (including excursions into the scholarly realm) is discernable here with Kermani's narratively oriented 1999 dissertation „Gott ist schön“ (God is Beautiful). The dissertation, after all, investigates the (musical) aesthetics of the Koran and contains a subchapter entitled “Those Killed by the Koran“.
== OECD's Mutual Acceptance of Data (MAD) == Sources: The chemicals industry, which includes industrial chemicals, pharmaceuticals, pesticides, biocides, food and feed additives, and cosmetics, ranks as one of the largest industrial sectors in the world. Harmonizing national approaches (the OECD's key mission) to chemical regulation offers several benefits: it streamlines requirements for industry, provides governments with a common framework for collaboration, and reduces trade barriers. Simultaneously, the OECD adopted 1) the Mutual Acceptance of Data (MAD) Directive system; and 2) the OECD Guidelines for Testing Chemicals and OECD Principles of Good Laboratory Practice (GLP), to be required by regulators globally (and to which the MAD Directive applies). These two simultaneous acts were instrumental in achieving this global harmonization. The MAD system aims to avoid conflicting or redundant national regulations, foster cooperation among national authorities, and eliminate trade barriers. Under this system, OECD countries and full adherents agree that safety tests conducted according to OECD Test Guidelines and Good Laboratory Practice in one country should be accepted by others for assessment purposes—a principle known as "tested once, accepted for assessment everywhere." This approach saves the chemicals industry from the expense of duplicative testing for products marketed in multiple countries. Crucially, though a receiving government must accept a TG-performed study, it retains the discretion to rely on other data (e.g.
In the coupling of amino acids, frequently occurring secondary reactions largely suppressed, which would be the formation of symmetrical acid anhydrides, racemization and epimerization and the cyclization to oxazolinones or - especially for dipeptides - to 2,5-diketopiperazines.
Similarly, in Asian adults homozygous for the hypoactive CYP2D6*10 allele, atomoxetine peak levels were about 1.5-fold higher and total exposure 2-fold higher compared to extensive metabolizers. There is little accumulation of atomoxetine with repeated administration in CYP2D6 extensive metabolizers, but significant accumulation in CYP2D6 poor metabolizers. The pharmacokinetics of atomoxetine, for instance elimination half-life, volume of distribution, and clearance, are similar with a single dose versus at steady state.
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
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.