A practical reference on Oxidation: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-18. Anything still debated is marked as such rather than presented as settled.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
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.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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.
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.
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.
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。
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。
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。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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。
Like most KWS institute directors, Haber had accrued a large discretionary fund. It was his wish that it be distributed to the dismissed staff to facilitate their emigration. Hahn brokered a deal whereby 10 per cent of the funds would be allocated to Haber's people and the rest to KWS, but the Rockefeller Foundation insisted that the funds be used for their original scientific research or else be returned. In August 1933 the administrators of the KWS were alerted that several boxes of Rockefeller Foundation-funded equipment were about to be shipped to Herbert Freundlich, one of the department heads that Hahn had dismissed, who was now working in England. Ernst Telschow, a Nazi Party member, was in charge while Planck, the president of the KWS since 1930, was on vacation, and he ordered the shipment halted. Hahn complied, but he disagreed with the decision on the grounds that funds from abroad should not be diverted to military research, which the KWS was increasingly undertaking. When Planck returned from vacation, he ordered Hahn to expedite the shipment. Haber died on 29 January 1934. A memorial service was held on the first anniversary of his death. University professors were forbidden to attend, so they sent their wives in their place. Hahn, Planck and Joseph Koeth attended, and gave speeches. The ageing Planck did not seek re-election, and was succeeded in 1937 as president by Carl Bosch, a winner of the Nobel Prize in Chemistry and the chairman of the board of IG Farben, a company which had bankrolled the Nazi Party since 1932. Telschow became Secretary of the KWS.
Ligaments are composed of two different tissues: white and yellow. The white fibrous tissues are not stretchy, but are extremely strong so that even if the bone were fractured the tissue would remain in place. The white tissue allows subjective freedom of movement. The yellow elastic tissue can be stretched considerably and return to its original length.
=== Ionization mechanism === In DESI there are two kinds of ionization mechanism, one that applies to low molecular weight molecules and another to high molecular weight molecules. High molecular weight molecules, such as proteins and peptides show electrospray like spectra where multiply charged ions are observed. This suggests desorption of the analyte, where multiple charges in the droplet can easily be transferred to the analyte. The charged droplet hits the sample, spreads over a diameter greater than its original diameter, dissolves the protein and rebounces. The droplets travel to the mass spectrometer inlet and are further desolvated. The solvent typically used for the electrospray is a combination of methanol and water. For the low molecular weight molecules, ionization occurs by charge transfer: an electron or a proton. There are three possibilities for the charge transfer. First, charge transfer between a solvent ion and an analyte on the surface. Second, charge transfer between a gas phase ion and analyte on the surface; in this case the solvent ion is evaporated before reaching the sample surface. This is achieved when the spray to surface distance is large. Third, charge transfer between a gas phase ion and a gas phase analyte molecule. This occurs when a sample has a high vapour pressure.
(1974), president of the University of the District of Columbia and former president of Southern University Reynold Verret (1976), president of Xavier University of Louisiana Gregory F. Ball (1977), psychologist, dean of the University of Maryland College of Behavioral and Social Sciences Thomas Worcester (1977), Jesuit academic, president of Regis College, Toronto, professor of the University of Toronto Alan Kadish (1977), president of the Touro College and University System Ralph Keen (1979), professor and dean of the honors college at the University of Illinois at Chicago Colin Crawford (1980), 24th dean of the University of Louisville School of Law and incoming dean of the Golden Gate University School of Law Samuel Hoi (1980), president of the Maryland Institute College of Art Daniel Gordis (1981), vice president of Shalem College, Israel's first liberal arts college Mark C. Gordon (1981), first president and dean of the Mitchell Hamline School of Law, former president of Defiance College and dean of the University of Detroit Mercy School of Law Donald S. Siegel (1981), economist and director of the School of Public Affairs at Arizona State University Deborah Waxman (1989), president of Reconstructionist Rabbinical College and Jewish Reconstructionist Communities Jonathan H.
=== Ischemia === Ischemia is an important factor in the formation and persistence of wounds, especially when it occurs repetitively (as it usually does) or when combined with a patient's old age. Ischemia causes tissue to become inflamed and cells to release factors that attract neutrophils such as interleukins, chemokines, leukotrienes, and complement factors. While they fight pathogens, neutrophils also release inflammatory cytokines and enzymes that damage cells. One of their important jobs is to produce Reactive Oxygen Species (ROS) to kill bacteria, for which they use an enzyme called myeloperoxidase. The enzymes and ROS produced by neutrophils and other leukocytes damage cells and prevent cell proliferation and wound closure by damaging DNA, lipids, proteins, the extracellular matrix (ECM), and cytokines that speed healing. Neutrophils remain in chronic wounds for longer than they do in acute wounds, and contribute to the fact that chronic wounds have higher levels of inflammatory cytokines and ROS. Since wound fluid from chronic wounds has an excess of proteases and ROS, the fluid itself can inhibit healing by inhibiting cell growth and breaking down growth factors and proteins in the ECM. This impaired healing response is considered uncoordinated. However, soluble mediators of the immune system (growth factors), cell-based therapies and therapeutic chemicals can propagate coordinated healing.
Sources: en.wikipedia.org
Of his character, he said: "Originally, I was married. I had this kid and I did this research and I didn't know that what I was researching had this effect. And someone got killed and I had these regrets and I'm trying to stop what I'm doing, but they can't let me so they're chasing me. And then all of a sudden I turn into this 24-year-old machinist and I turned to (director) Andrew Davis and I said, 'What happened to the movie I said yes to? What happened to that script? Where did that go?' And he said, 'No, I got something better,' and so I just had to go with it."
Gaseous ammonia is generally referred to as anhydrous ammonia, to distinguish it from its solution in water, household ammonia solution, also known as ammonium hydroxide. Gaseous hydrogen chloride is generally referred to as anhydrous, to distinguish it from its solution in water, hydrochloric acid. Reactions which produce water can be kept dry using a Dean–Stark apparatus.
In ancient India, various teachings about well-being are found in the Hindu tradition, formulated in the first two millennia BCE in the Vedas, Upanishads, and the Smriti literature. They include the ideas that a person should fulfill their duty relative to their social role and stage of life, and that one should attain knowledge about how the self and the world are ultimately one. A central element of the Buddhist conception of well-being is the avoidance of suffering. The Buddha (roughly 6th century BCE) identified craving as the root cause of suffering, proposing a set of practical recommendations, such as right conduct and mindfulness, to overcome it. In ancient China, Confucius (6th to 5th century BCE) emphasized the role of social virtues in leading a good life, with a particular focus on benevolence or humaneness. In the Taoist tradition, Laozi (6th century BCE) saw living in harmony with the natural order of the universe through effortless, spontaneous action as the ideal form of life. During the medieval period in the West, Christian thinkers associated well-being with spiritual salvation. Augustine (354–430 CE) argued that humans are not fully in control of their well-being and instead depend on divine grace. He maintained that true happiness is achievable only in the afterlife. Thomas Aquinas (1225–1274 CE) similarly emphasized the role of the divine, proposing that a beatific vision of God is the highest form of well-being.
Bristol was made a city in 1542, with the former Abbey of St Augustine becoming Bristol Cathedral, following the Dissolution of the Monasteries by Henry VIII. The Dissolution also saw the surrender to the king of all of Bristol's friaries and monastic hospitals, together with St James' Priory, St Mary Magdalen nunnery and the college at Westbury on Trym. In the case of the friaries at Greyfriars and Whitefriars, the priors had fled before the arrival of the royal commissioners, and at Whitefriars a succession of departing priors had plundered the friary of its valuables. Although the commissioners had not been able to point to as much religious malpractice in Bristol as elsewhere, there is no record of Bristolians raising any objections to the royal seizures. In 1541 Bristol's civic leaders took the opportunity of buying up lands and properties formerly belonging to St Mark's Hospital, St Mary Magdalen, Greyfriars and Whitefriars for a total of a thousand pounds. Bristol thereby became the only municipality in the country which has its own chapel, at St Mark's. Bristol Grammar School was established in 1532 by the Thorne family and in 1596 John Carr established Queen Elizabeth's Hospital, a bluecoat school charged with 'the education of poor children and orphans'. Trade continued to grow: by the mid-16th century imports from Europe included, wine, olive oil, iron, figs and other dried fruits and dyes; exports included cloth (both cotton and wool), lead and hides.
Sources: en.wikipedia.org
The Horizontal Working Party on Drugs (better known as Horizontal Drug Group or HDG) is a Council Working Party, a preparatory body of the Council of the European Union established in 1997, responsible for the lead and management of the work of the council and of the European Union (EU) on drug policy. The HDG meets monthly in Brussels's Europa building or in the Justus Lipsius building, and prepares all relevant legislation and political documents to be adopted by EU's Committee of Permanent Representatives (COREPER II) and subsequently by the Council, such as EU drugs strategies, action plans on drugs, and statements on drug-related aspects to be presented at international fora like the United Nations Commission on Narcotic Drugs. Since 2018, the HDG is also responsible to establish the imperative mandate for the vote on international scheduling by member state of the EU at the Commission on Narcotic Drugs. The HDG engages and closely collaborates with other EU institutions like the European Monitoring Centre for Drugs and Drug Addiction and Europol. There are frequent meetings of EU countries' national drugs coordinators held as part of HDG meetings. In addition, the HDG regularly meets with delegates from other regions and third countries within the EU's area of interest (Russia, Turkey, the Western Balkans, the United States within a so-called "Transatlantic Dialogue", Western Africa, Andes Community, and with countries from Latin America and the Caribbean within the "Technical Committee EU/LAC").
=== Climate change === Ectomycorrhizal communities can be affected by increased CO2 and the consequent effects of climate change. In some studies, elevated CO2 levels increased fungal mycelium growth and increased EcM root colonization. Other EcM associations showed little response to elevated CO2. Increased temperatures also give a range of responses, some negative, and others positive. The EcM response to drought is complex since many species provide protection against root desiccation and improve the ability of the roots to take up water. Thus, EcMs protect their host plants during times of drought, although they may themselves be affected over time.
The core routing protocol on the Internet, BGP, has to maintain a routing table in order to remember the paths a packet can be deviated to. When one of these paths repeatedly changes its state from available to not available (and vice versa), the BGP router controlling that path has to repeatedly add and remove the path record from its routing table (flaps the path), thus spending local resources such as CPU and RAM and, even more, broadcasting useless information to peer routers. To prevent this undesired behavior, an algorithm named route flapping damping assigns each route a weight that gets bigger each time the route changes its state and decays exponentially with time. When the weight reaches a certain limit, no more flapping is done, thus suppressing the route.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
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.