semax 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 2026-01-28. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
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.
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.
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.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
In 2019, the worldwide demand of gelatin was about 620,000 tonnes (1.4×10^9 lb). On a commercial scale, gelatin is made from by-products of the meat and leather industries. Most gelatin is derived from pork skins, pork and cattle bones, or split cattle hides. Gelatin made from fish by-products avoids some of the religious objections to gelatin consumption. The raw materials are prepared by different curing, acid, and alkali processes that are employed to extract the dried collagen hydrolysate. These processes may take several weeks, and differences in such processes have great effects on the properties of the final gelatin products. Gelatin also can be prepared at home. Boiling certain cartilaginous cuts of meat or bones results in gelatin being dissolved into the water. Depending on the concentration, the resulting stock (when cooled) will form a jelly or gel naturally. This process is used for aspic. While many processes exist whereby collagen may be converted to gelatin, they all have several factors in common. The intermolecular and intramolecular bonds that stabilize insoluble collagen must be broken, and also, the hydrogen bonds that stabilize the collagen helix must be broken. The manufacturing processes of gelatin consists of several main stages:
Lemborexant, sold under the brand name Dayvigo, is a medication of the orexin antagonist category. It is indicated for the treatment of insomnia, especially in cases concerning sleep onset or maintenance difficulties, and is taken by mouth. Side effects of lemborexant include somnolence, fatigue, headache, and abnormal dreams. The medication is a dual orexin receptor antagonist (DORA). It acts as a selective dual antagonist of the orexin receptors OX1 and OX2. Lemborexant has a long elimination half-life of 17 to 55 hours and a time to peak of about 1 to 3 hours. It is not a benzodiazepine or Z-drug and does not interact with GABA receptors, instead having a distinct mechanism of action. Lemborexant was approved for medical use in the United States in December 2019. It is considered a controlled substance under most jurisdictions with a low risk of dependency and misuse. Besides lemborexant, other orexin receptor antagonists including suvorexant and daridorexant have also been introduced.
Dufton states that the administration directly ignored the report from the Shafer Commission because of Nixon's personal feelings towards the drug. Nixon told Shafer in a private meeting, "I have very strong feelings about marijuana." He continued, "I want a goddamn strong statement against the drug. One that just tears the ass out of legalization supporters." Marijuana's psychoactive chemical, tetrahydrocannabinol (THC), is still listed as a Schedule 1 drug, despite its legalization in several states. Scholars of criminal justice and drug policy like Antony Loewenstein and James Forman Jr. argued that the CSA was not punitive in nature but targeted marijuana in a demonizing and criminal way. Their argument was based on a belief that targeting marijuana was part of a larger anti-black political strategy. Both intellectuals argue that marijuana was purposefully aligned by conservative politicians with an urban black population, civil rights protests, and the rising crime rates of the late 1960s and the early 1970s. The argument concludes that the political strategy led to disproportionate punitive treatment of the black communities' usage of marijuana.
Sources: en.wikipedia.org
Many of Pauling's critics, including scientists who appreciated the contributions that he had made in chemistry, disagreed with his political positions and saw him as a naïve spokesman for Soviet communism. In 1960, he was ordered to appear before the Senate Internal Security Subcommittee, which termed him "the number one scientific name in virtually every major activity of the Communist peace offensive in this country". A headline in Life magazine characterized his 1962 Nobel Prize as "A Weird Insult from Norway". Pauling was a frequent target of the National Review magazine. In an article entitled "The Collaborators" in the magazine's July 17, 1962, issue, Pauling was referred to not only as a collaborator, but as a "fellow traveler" of proponents of Soviet-style communism. In 1963, Pauling sued the magazine, its publisher William Rusher, and its editor William F. Buckley, Jr for $1 million. He lost both his libel suits and the 1968 appeal (unlike his earlier 1963 libel case against the Hearst Corporation), because in the meantime the landmark case New York Times Co. v. Sullivan had established the actual malice standard for libel lawsuits by public figures, requiring that not only falsehood but deliberate lying should be proved by the plaintiff in such cases. His peace activism, his frequent travels, and his enthusiastic expansion into chemical-biomedical research all aroused opposition at Caltech. In 1958, the Caltech Board of Trustees demanded that Pauling step down as chairman of the Chemistry and Chemical Engineering Division.
==== United Kingdom ==== As of 2025, Dunkin' currently operates 22 sites in the United Kingdom, all in England. This follows what it called an 'aggressive extension plan' in 2023 owing to popular sales.
The need for fuel declined in the Soviet Union from the 1970s to the 1980s, both per ruble of gross social product and per ruble of industrial product. The decline was very rapid between 1965 and 1970, then slowed between 1970 and 1975. From 1975 to 1980, the decline continued at an even slower rate, with fuel requirements per ruble of gross social product decreasing by only 2.6%. David Wilson, a historian, believed that the gas industry would account for 40% of Soviet fuel production by the end of the century. His theory did not come to fruition because of the USSR's collapse. According to Wilson, the Soviet Union was, in theory, well-positioned to avoid an energy crisis and could have sustained economic growth rates of 2–2.5% during the 1990s, supported by its energy resources. However, the energy sector faced many difficulties, among them the country's high military expenditure and hostile relations with the First World. In 1991, the Soviet Union had a pipeline network of 82,000 kilometres (51,000 mi) for crude oil and another 206,500 kilometres (128,300 mi) for natural gas. Petroleum and petroleum-based products, natural gas, metals, wood, agricultural products, and a variety of manufactured goods, primarily machinery, arms and military equipment, were exported. In the 1970s and 1980s, the USSR heavily relied on fossil fuel exports to earn hard currency. At its peak in 1988, it was the largest producer and second-largest exporter of crude oil, surpassed only by Saudi Arabia.
Sources: en.wikipedia.org
The economic effects of organized crime have been approached from a number of both theoretical and empirical positions, however the nature of such activity allows for misrepresentation. The level of taxation taken by a nation-state, rates of unemployment, mean household incomes and level of satisfaction with government and other economic factors all contribute to the likelihood of criminals to participate in tax evasion. As most organized crime is perpetrated in the liminal state between legitimate and illegitimate markets, these economic factors must adjusted to ensure the optimal amount of taxation without promoting the practice of tax evasion. As with any other crime, technological advancements have made the commission of tax evasion easier, faster and more globalized. The ability for organized criminals to operate fraudulent financial accounts, utilize illicit offshore bank accounts, access tax havens or tax shelters, and operating goods smuggling syndicates to evade importation taxes help ensure financial sustainability, security from law enforcement, general anonymity and the continuation of their operations. Al Capone became a notorious example of tax evasion. In 1931, he was sentenced to 11 years in federal prison and ordered to pay $215,000 in back taxes, along with accrued interest
=== Selected books === Diagnosis and Management of Renal Disease and Hypertension (1988) ISBN 9780812111293 Immunohistology in Diagnostic Pathology (1989) ISBN 9780849349874 Non-neoplastic Kidney Diseases (2005) ISBN 9781881041962 Primer on Kidney Diseases (2009) ISBN 9781416051855 Fundamentals of Renal Pathology (2013) ISBN 9783642390791 Heptinstall's Pathology of the Kidney (2024) ISBN 9781975161538
==== Ketoacid ==== Currently, the best available evidence suggests that the ketoacid is originally attached to the chromophore core (as L-glutamate) when it is synthesized from D-tyrosine, L-2,4-diaminobutyric acid, and L-glutamate. It is unclear how this is later altered to the other congenerate (i.e., a-ketoglutarate, succinate/succinamide, etc.) forms.
PCP is well known for its primary action on the NMDA receptor, an ionotropic glutamate receptor. As such, PCP is a non-competitive NMDA receptor antagonist. The role of NMDAR antagonism in the effect of PCP, ketamine, and related dissociative agents was first published in the early 1980s by David Lodge and colleagues. Other NMDA receptor antagonists include ketamine, tiletamine, dextromethorphan, nitrous oxide, and dizocilpine (MK-801). Research also indicates that PCP inhibits nicotinic acetylcholine receptors (nAChRs) among other mechanisms. Analogues of PCP exhibit varying potency at nACh receptors and NMDA receptors. Findings demonstrate that presynaptic nAChRs and NMDA receptor interactions influence the postsynaptic maturation of glutamatergic synapses and consequently impact synaptic development and plasticity in the brain. These effects can lead to inhibition of excitatory glutamate activity in certain brain regions such as the hippocampus and cerebellum thus potentially leading to memory loss as one of the effects of prolonged use. Acute effects on the cerebellum manifest as changes in blood pressure, breathing rate, pulse rate, and loss of muscular coordination during intoxication. PCP, like ketamine, also acts as a potent dopamine D2High receptor partial agonist in rat brain homogenate and has affinity for the human cloned D2High receptor. This activity may be associated with some of the other more psychotic features of PCP intoxication, which is evidenced by the successful use of D2 receptor antagonists (such as haloperidol) in the treatment of PCP psychosis.
Sources: en.wikipedia.org
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.