If you have been reading about ACTH analog 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 2026-06-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
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.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
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.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
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.
The revived Mannerist sphinx of the late 15th century is sometimes thought of as the "French sphinx". Her coiffed head is erect and she has the breasts of a young woman. Often she wears ear drops and pearls as ornaments. Her body is naturalistically rendered as a recumbent lioness. Such sphinxes were revived when the grottesche or "grotesque" decorations of the unearthed Domus Aurea of Nero were brought to light in late 15th-century Rome, and she was incorporated into the classical vocabulary of arabesque designs that spread throughout Europe in engravings during the 16th and 17th centuries. Sphinxes were included in the decoration of the loggia of the Vatican Palace by the workshop of Raphael (1515–20), which updated the vocabulary of the Roman grottesche. The first appearances of sphinxes in French art are in the School of Fontainebleau in the 1520s and 1530s and she continues into the Late Baroque style of the French Régence (1715–1723). From France, she spread throughout Europe, becoming a regular feature of the outdoors decorative sculpture of 18th-century palace gardens, as in the Upper Belvedere Palace in Vienna, Sanssouci Park in Potsdam, La Granja in Spain, Branicki Palace in Białystok, or the late Rococo examples in the grounds of the Portuguese Queluz National Palace (of perhaps the 1760s), with ruffs and clothed chests ending with a little cape.
Falx cerebri: This sickle-shaped fold is the largest of the dural reflections. It separates the two cerebral hemispheres, and is anchored to the crista galli of the ethmoid bone and the internal occipital protuberance. Tentorium cerebelli. The second largest fold is also crescent-shaped. It separates the occipital lobes of the cerebrum from the cerebellum. The falx cerebri attaches to it to form the roof of the posterior cranial fossa, which gives it a tentlike appearance. Falx cerebelli: This vertical infolding is located inferior to the tentorium cerebelli. It partially separates the cerebellar hemispheres. Diaphragma sellae: The smallest of the infoldings, it forms a roof over the sella turcica and seals the pituitary gland from the subarachnoid space.
== Use == The first publication on vinylene carbonate described its Diels-Alder reaction using the example of its addition reaction with 2,3-dimethylbutadiene to a bicyclic carbonate and subsequent hydrolysis to cis-4,5-dihydroxy-1,2-cyclohexene:
Burrows (1960), author and journalist; founder of the Alliance to Rescue Civilization Thomas Lippman (1961), journalist and author specializing in the Middle East, correspondent for The Washington Post Lars-Erik Nelson (1962), New York Daily News columnist Allen Young (1962), journalist, author, political activist Bernard L. Stein (1963), journalist and winner of the Pulitzer Prize for Editorial Writing in 1998 Michael Drosnin (1966), journalist and author on the Bible code Juan Gonzalez (1969), New York Daily News columnist Jeffrey Bruce Klein (1969), investigative journalist and co-founder of Mother Jones James Simon Kunen (1970), author of articles for Newsday, People, The New York Times Magazine and the novel The Strawberry Statement Glenn Frankel (1971), journalist for The Washington Post, winner of the 1989 Pulitzer Prize for International Reporting Juris Kaža (1971), journalist for Latvian News Agency LETA Jonathan Freedman (1972), journalist and winner of the 1987 Pulitzer Prize for Editorial Writing John Brecher (1973), journalist and wine critic for The Wall Street Journal Michael Wolff (1975), media columnist for New York Magazine and Vanity Fair, author of controversial book Fire and Fury on Donald Trump Bill Minutaglio (1976), journalist, biographer of George W. Bush D. D.
Sources: en.wikipedia.org
Risk factors for opioid overdose include opioid dependence, injecting opioids, using high doses of opioids, and use together with alcohol, benzodiazepines, or cocaine. The risk is particularly high following detoxification. Dependence on prescription opioids can occur from their use to treat chronic pain. In young children, an overdose is usually due to opioids that are intended for their parents, older siblings, or grandparents. In mothers who take codeine during breastfeeding, opioid overdoses have occurred in their baby. Codeine is, therefore, not recommended for those who are breastfeeding.
Selegiline is available in forms for use by multiple different routes of administration and its pharmacokinetics vary by route. The bioavailability of the oral form of selegiline is 4–10%, of the ODT is 5 to 8 times that of the oral form, and of the transdermal patch is 75%. The time to peak levels of selegiline with oral administration is about 0.5 to 1.5 hours. The plasma protein binding of selegiline is 85–90%. It is metabolized extensively in the liver by the cytochrome P450 enzyme CYP2B6 among other enzymes. Metabolites of selegiline include desmethylselegiline (DMS), levomethamphetamine (L-MA), and levoamphetamine (L-A). The oral form of selegiline is subject to strong first-pass metabolism and levels of the metabolites of selegiline are much lower with the ODT and transdermal patch forms than with the oral form. The elimination half-lives of selegiline and its metabolites range from 1.2 to 10 hours for selegiline, 2.2 to 9.5 hours for DMS, 14 to 21 hours for levomethamphetamine, and 16 to 18 hours for levoamphetamine. Selegiline and its metabolites are eliminated mainly in urine (87% in urine and 15% in feces via oral administration), with its metabolites accounting for virtually all of the eliminated material in the case of the oral form. Hepatic impairment and renal impairment have been found to dramatically increase exposure to selegiline.
=== Association and dissociation constants === When discussing the properties of acids it is usual to specify equilibrium constants as acid dissociation constants, denoted by Ka, with numerical values given the symbol pKa.
Sources: en.wikipedia.org
== Reaction mechanism == In the first part of the reaction process, the carbonyl is converted to an iminium, to which a cyanide ion adds. First, the carbonyl oxygen of an aldehyde is protonated, followed by a nucleophilic attack of ammonia to the carbonyl carbon. After subsequent proton exchange, water is cleaved to form the iminium ion intermediate. A cyanide ion then attacks the iminium carbon yielding an aminonitrile.
On April 5, the Iraqi government announced "the complete crushing of acts of sedition, sabotage and rioting in all towns of Iraq." An estimated 25,000 to 100,000 Iraqis were killed in the uprisings. In Kuwait, the Emir was restored, and suspected Iraqi collaborators were repressed. Eventually, over 400,000 people were expelled from the country, including a large number of Palestinians, because of PLO support of Saddam. Yasser Arafat did not apologize for his support of Iraq, but after his death Mahmoud Abbas formally apologized in 2004 on behalf of the PLO. This came after the Kuwaiti government formally forgave the group. There was some criticism of the Bush administration, as they chose to allow Saddam to remain in power instead of pushing on to capture Baghdad and overthrowing his government. In their co-written 1998 book, A World Transformed, Bush and Brent Scowcroft argued that such a course would have fractured the alliance, and would have had many unnecessary political and human costs associated with it. In 1992, the US defense secretary during the war, Dick Cheney, made the same point:
== Mechanism == The accumulation of hyperphosphorylated tau in neurons is associated with neurofibrillary degeneration. The actual mechanism of how tau propagates from one cell to another is not well identified. Also, other mechanisms, including tau release and toxicity, are unclear. As tau aggregates, it replaces tubulin, which in turn enhances fibrilization of tau. Several propagation methods have been proposed that occur by synaptic contact such as synaptic cell adhesion proteins, neuronal activity and other synaptic and non-synaptic mechanisms. The mechanism of tau aggregation is still not completely elucidated, but several factors favor this process, including tau phosphorylation and zinc ions. Moreover, recent studies show that tau can coordinate up to three Zn²⁺ ions via distinct sites in the N-terminal, repeat, and C-terminal regions; occupancy of two Zn²⁺ sites is sufficient to promote liquid–liquid phase separation (LLPS) of tau in vitro, linking zinc homeostasis to condensate-driven aggregation pathways.
Dimethyltryptamine (DMT), also known as N,N-dimethyltryptamine (N,N-DMT), is a serotonergic hallucinogen and investigational drug of the tryptamine family that occurs naturally in many plants and animals. DMT is used as a psychedelic drug and prepared by various cultures for ritual purposes as an entheogen. DMT has a rapid onset, intense effects, and a relatively short duration of action. For those reasons, DMT was known as the "businessman's trip" during the 1960s in the United States, as a user could access the full depth of a psychedelic experience in considerably less time than with other substances such as LSD or psilocybin mushrooms. DMT can be inhaled or injected and its effects depend on the dose, as well as the mode of administration. When inhaled or injected, the effects last about five to fifteen minutes. Effects can last three hours or more when orally ingested along with a monoamine oxidase inhibitor (MAOI), such as the ayahuasca brew of many native Amazonian tribes. DMT induces intense, often indescribable subjective experiences involving vivid visual hallucinations, altered sensory perception, ego dissolution, and encounters with seemingly autonomous entities. DMT is generally considered non addictive with low dependence and having little to no tolerance build-up with short-acting routes, but it may cause acute psychological distress or cardiovascular effects, especially in predisposed individuals. DMT was first synthesized in 1931.
Sources: en.wikipedia.org
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.