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.
Last reviewed on 2025-11-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
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.
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。
== Occurrence == The compound is produced by human pathogens such as Aspergillus fumigatus, and also by species of Trichoderma and Penicillium. Gliotoxin has also been reported from yeasts of the genus Candida, but results from other studies have cast doubt on the production of this metabolite by Candida fungi. Gliotoxin is not produced by nonpathogenic A. fischeri although A.fischeri contains a gene cluster that is homologous to the gliotoxin gene cluster found in the pathogenic A. fumigatus. Gliotoxin contributes to the pathogenicity of opportunistic fungi by suppressing the immune system response of its host. Gliotoxin additionally possesses fungicidal and bacteriostatic properties, which indicates that it likely plays an important self defense role against bacteria and other fungi for the fungi that produce gliotoxin. Exposure of A. fumigatus to exogenous gliotoxin resulted in aberrant protein expression, especially in those strains that lacked the self-protection protein GliT. There is additional evidence for differential gliotoxin sensitivities amongst fungi including Aspergillus flavus, Fusarium graminearum, and Aspergillus oryzae.
The Christian Science movement is a religious movement within Christianity founded by Mary Baker Eddy that arose in the mid to late 19th century and that led to the founding of The First Church of Christ, Scientist.
In an interview to Italian newspaper Corriere della Sera on 20 June, Lula asserted that Italy is a priority for Brazil, especially because Brazil has "30 million Brazilians of Italian descent and great relations with Italian trade unions, intellectuals and companies". On 20 June, Lula met with left-wing sociologist and professor emeritus at the Sapienza University of Rome Domenico De Masi during his visit to Rome. On 21 June, Lula met with General Secretary of the Democratic Party (PD), Elly Schlein, and former Prime Minister Massimo D'Alema, with whom he reportedly had talks about "democracy, world peace, climate change, inequality and challenges common to several countries". Brazilian government officials also said that Lula and Schlein had a talk about "gender violence and sexism in politics". Lula also met and dined with Italian president Sergio Mattarella at the Quirinal Palace to reportedly discuss about the relations between Brazil and Italy, as well as the Mercosur-European Union deal. Upon returning from his visit to the Vatican, he also had a meeting with Italian Prime Minister Giorgia Meloni at the Chigi Palace. During an interview to the press after the meeting, he praised Meloni, saying that "ideological differences wouldn't end diplomacy" between the two countries. Lula also had a meeting and private dinner with Rome mayor Roberto Gualtieri.
Sources: en.wikipedia.org
Within the immune system, prolactin acts to promote lymphocyte differentiation, proliferation, and function through the activation of protein kinase C signaling pathway. Prolactin has immunomodulatory and anti-inflammatory effects within the immune system, contributing to immune system maintenance. Stress also acutely stimulates prolactin production, as dopamine (a prolactin inhibitor) levels are reduced under stress, the pituitary gland is in turn expressed more leading to higher prolactin levels.
=== Greek === Greek critic Dimitris Danikas gave Dogtooth a rating of eight out of ten ("with enthusiasm"), calling it "black, surreal, nightmarish" and writing that Dogtooth is as important for Greek cinema as Theodoros Angelopoulos's 1970 film Reconstitution. Danikas added, "Lanthimos composes and goes from one level to another like a wildcat-creator, constantly and continuously maintaining the same rigorous style. Hence the aphasia; hence the uniformity; hence the submission and the scheduled mass culture; hence also the serial killer; hence, however, the disobedience, the anarchy. As I said at the beginning: Dogtooth has the surrealism of Buñuel, the scalpel of Haneke, the underground horror of a thriller without the splatter. Perfect." Danikas characterized Dogtooth's Academy Award nomination as "the greatest Greek triumph of recent years." Columnist Dimitris Bouras, writing for Kathimerini, mentioned "the beneficial effects that the prestigious award could have" and wrote that the nomination reveals three interesting facts: "1) in Greece we need to be extroverts (and not only in cinema), 2) exportable product is whatever has an identity, 3) Dogtooth's nomination is like an investment— manna from the heaven of Hollywood for the developing Greek cinema."
=== Chronic poisoning === Prolonged exposure to high levels of nitrogen dioxide can have an inflammatory effect that principally targets the respiratory tracts leading to chronic nitrogen dioxide poisoning which can occur within days or weeks after the threshold limit value is excessively exceeded. This condition causes fever, rapid breathing coupled with rapid heart rate, labored breathing and severe shortness of breath. Other effects include diaphoresis, chest pain, and persistent dry cough, all of which may result in weight loss, anorexia and may also lead to right-side heart enlargement and heart disease in advanced cases. Prolonged exposure to relatively low levels of nitrogen (II) oxide may cause persistent headaches and nausea. Like chlorine gas poisoning, symptoms usually resolve themselves upon removal from further nitrogen dioxide exposure, unless there had been an episode of severe acute poisoning. Treatment and management vary with symptoms. Patients are often observed for hypoxemia for a minimum of 12 hours if there are no initial symptoms and if the patient is hypoxemic, oxygen may be administered but high-dose steroids are recommended for patients with pulmonary manifestations. Patients may also be hospitalized for 12 to 24 hours or longer for observation if the gaseous exchange is impaired.
In conventional nomenclature, the carbons to which the phosphate groups attach are the 3'-end and the 5'-end carbons of the sugar. This gives nucleic acids directionality, and the ends of nucleic acid molecules are referred to as 5'-end and 3'-end. The nucleobases are joined to the sugars via an N-glycosidic linkage involving a nucleobase ring nitrogen (N-1 for pyrimidines and N-9 for purines) and the 1' carbon of the pentose sugar ring. Non-standard nucleosides are also found in both RNA and DNA and usually arise from modification of the standard nucleosides within the DNA molecule or the primary (initial) RNA transcript. Transfer RNA (tRNA) molecules contain a particularly large number of modified nucleosides.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
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.