ACTH fragment comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-05-10. Numbers and descriptions here follow the published literature rather than marketing material.
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 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 of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
| 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 |
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
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。
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.
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.
==== Finance and monetary policy ==== In 2008 and 2009, Sanders voted against the Troubled Asset Relief Program (TARP), a program to purchase toxic banking assets and provide loans to banks that were in free-fall. On February 4, 2009, he sponsored an amendment to ensure that TARP funds would not displace US workers. The amendment passed and was added to the American Recovery and Reinvestment Act of 2009. Among his proposed financial reforms is auditing the Federal Reserve, which would reduce its independence in monetary policy deliberations; Federal Reserve officials say that "Audit the Fed" legislation would expose the Federal Reserve to undue political pressure from lawmakers who do not like its decisions.
Andrews, Richard Mowery. "Social Structures, Political Elites and Ideology in Revolutionary Paris, 1792–94: A Critical Evaluation of Albert Soboul's' Les sans-culottes parisiens en l'an II'," Journal of Social History (1985) 19#1 pp. 71–112. in JSTOR Furet, François and Mona Ozouf, eds. A Critical Dictionary of the French Revolution (1989), pp. 393–99 Palmer, Robert Roswell (1958), Twelve Who Ruled. The Making of the Sans-culottes: Democratic Ideas and Institutions in Paris ...by R.B. Rose (1983) Salmon, Jean (1975), Curés Sans-culottes En Province : 1789-1814. Langres: Diffusion Museé Saint-Didier. Sonenscher, Michael. Sans-Culottes: An Eighteenth-Century Emblem in the French Revolution (Princeton University Press, 2008). Pp. 493. Williams, Gwyn A (1969), Artisans and Sans-culottes: Popular Movements in France and Britain during the French Revolution. Foundations of Modern History. New York: Norton. Woloch, Isser, and Peter McPhee. "A Revolution in Political Culture" in McPhee, ed., A Companion to the French Revolution (2012) pp. 435–453
Arby's promoted their announcement by breaking two Guinness World Records. The first record, "world's smallest advertisement", measured 38.3 microns by 19.2 microns on a sesame seed and was printed at Georgia Tech. The second record, "largest advertising poster", took up approximately 5 acres of land and was placed in Monowi, Nebraska, America's smallest town. Toasted Subs, sandwiches served on a toasted ciabatta roll, were first introduced in September 2007. The initial line-up included the French Dip & Swiss Toasted Sub, Philly Beef Toasted Sub, Classic Italian Toasted Sub, and Turkey Bacon Club. Three months later, the Toasted Subs product line was extended to include the Meatball Toasted Sub and the Chicken Parmesan Toasted Sub. In October 2013, Arby's introduced a Smokehouse Brisket sandwich. In September 2014, Arby's introduced gyros to its menu for a limited time. Gyros were previously offered in 2006. They have since become a permanent menu fixture on the menu in April 2016. On an almost annual basis, Arby's had offered some sort of a flatbread melt sandwich for a limited time. In 2007 and again in 2008, it was the Philly Cheesesteak and the Fajita Beef. The Beef Fajita returned with the new Chicken Fajita in 2009. After a six-year hiatus, Steak Fajita Flatbreads were offered for a limited time in 2015. The following year, Steak Fajita returned in 2016 with Chicken Fajita along with a choice between a hot and mild sauce. After a nine-year hiatus, a pork-beef mixture meatball sandwich was reintroduced in July 2016.
Sources: en.wikipedia.org
Endocrine signals are called hormones. Hormones are produced by endocrine cells and they travel through the blood to reach all parts of the body. Specificity of signaling can be controlled if only some cells can respond to a particular hormone. Endocrine signaling involves the release of hormones by internal glands of an organism directly into the circulatory system, regulating distant target organs. In vertebrates, the hypothalamus is the neural control center for all endocrine systems. In humans, the major endocrine glands are the thyroid gland and the adrenal glands. The study of the endocrine system and its disorders is known as endocrinology.
Aquileia was founded as a colony by the Romans in 180/181 BC along the Natiso River, on land south of the Julian Alps but about 13 kilometres (8 mi) north of the lagoons. The colony served as a strategic frontier fortress at the north-east corner of transpadane Italy (on the far side of the Po river) and was intended to protect the Veneti, faithful allies of Rome during the invasion of Hannibal in the Second Punic War and during the Illyrian Wars. The colony would serve as a citadel to check the advance into Cisalpine Gaul of other warlike peoples, such as the hostile Carni to the northeast in what is now Carnia and Histri tribes to the southeast in what is now Istria. In fact, the site chosen for Aquileia was about 6 km (3.7 mi) from where an estimated 12,000 Celtic Taurisci had attempted to settle in 183 BC. However, since the thirteenth century BC, the site, on the river and at the head of the Adriatic, had also been of commercial importance as the end of the Baltic amber (sucinum) trade. It is, therefore, theoretically not unlikely that Aquileia had been a Gallic oppidum even before the coming of the Romans. However, few Celtic artefacts have been discovered from 500 BC to the Roman arrival. The colony was established with Latin Rights by the triumvirate of Publius Cornelius Scipio Nasica, Caius Flaminius, and Lucius Manlius Acidinus, two of whom were of consular and one of praetorian rank. Each of the men had first-hand knowledge of Cisalpine Gaul. Nasica had conquered the Boii in 191.
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In 1991, Japanese scientists created the first milk-based ACE inhibitor, in the form of a fermented milk drink, using specific cultures to liberate the tripeptide isoleucine-proline-proline (IPP) from the dairy protein. Valine-proline-proline (VPP) is also liberated in this process—another milk tripeptide with a very similar chemical structure to IPP. Together, these peptides are now often referred to as lactotripeptides. In 1996, the first human study confirmed the blood pressure-lowering effect of IPP in fermented milk. Although twice the amount of VPP is needed to achieve the same ACE-inhibiting activity as the originally discovered IPP, VPP also is assumed to add to the total blood pressure lowering effect. Since the first lactotripeptides discovery, more than 20 human clinical trials have been conducted in many different countries.
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 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.