If you have been reading about ACTH fragment 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.
Updated 2026-07-30. Numbers and descriptions here follow the published literature rather than marketing material.
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。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
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.
| 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 |
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。
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。
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.
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.
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.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
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.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
In March 2023, TikTok announced default screen time limits for users under the age of 18. The Wall Street Journal has reported that doctors experienced a surge in reported cases of tics, tied to an increasing number of TikTok videos from content creators with Tourette syndrome. Doctors suggested that the cause may be a social one as users who consumed content showcasing various tics would sometimes develop tics of their own, akin to mass psychogenic illness. In May 2024, Nebraska Attorney General Mike Hilgers filed a lawsuit against TikTok for allegedly harming minors' mental health through an algorithm designed to be cultivate compulsive behavior. In October 2024, US senators Richard Blumenthal and Marsha Blackburn requested that TikTok turn over "all documents and information" related to child safety disclosures that were uncovered by NPR and Kentucky Public Radio. As of March 2025, strong scientific understanding of TikTok's effects on user's mental health "remains elusive". A 2025 meta-analysis found that use of TikTok was correlated with symptoms of anxiety and depression, with stronger links in females and users under 24 years old. In November 2025, French prosecutors opened a probe into TikTok, citing concerns that its algorithms could push vulnerable young people to suicide. The Ministry of Education (Taiwan) has warned against the harmful impact of TikTok and related app RedNote on body image and ensuing self harm related to weight loss especially in teenagers.
=== Category:EC 1.13 (act on single donors with incorporation of molecular oxygen) === Category:EC 1.13.11 (With incorporation of two atoms of oxygen) 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27) Category:EC 1.13.12 (With incorporation of one atom of oxygen (internal monooxygenases or internal mixed function oxidases)) Renilla-luciferin 2-monooxygenase EC 1.13.12.5 Cypridina-luciferin 2-monooxygenase EC 1.13.12.6 Firefly luciferase EC 1.13.12.7 Watasenia-luciferin 2-monooxygenase EC 1.13.12.8 Oplophorus-luciferin 2-monooxygenase EC 1.13.12.13
== Structure == The inactive form of Limulus clotting enzyme, referred to as proclotting enzyme, consists of a single chain glycoprotein. The enzyme is activated upon cleavage at the Arg98-Ile99 bond by Limulus clotting factor B or Limulus clotting factor G. The active clotting enzyme consists of a light and heavy chain linked together by a disulfide bridge. The active site of the clotting enzyme is located in the heavy chain and contains the His-Asp-Ser catalytic triad that is common among serine proteases. The sequence of the heavy chain in the serine protease region is 34.1% homologous to that of human clotting factor X, and four disulfide linkages are found in the same locations in both enzymes (and in prothrombin). These similarities indicate a relationship between serine protease structure and function. Limulus clotting enzyme also has substrate specificity similar to mammalian factor X. The crystal structure of the enzyme is unknown. The enzyme’s light chain contains a clip-like disulfide-knotted structure. Sequence homology in this region to the precursor of serine protease easter in Drosophila suggests that this structure may be common in invertebrate serine protease zymogens. Structural similarity of the light chain clip domain to horseshoe crab defensin suggests that the clip domain may have some antimicrobial activity. The amino acid sequences of Limulus clotting enzyme and Limulus clotting factor B are 35.9% similar.
3 spot in Entrepreneur magazine's 31st Annual Franchise 500, "the first and most comprehensive ranking in the world". This was the 17th year 7-Eleven was named in the top 10. In February 2010, 7-Eleven opened a concept store in DeLand, Florida, across from Stetson University, designed to meet LEED environmental standards. In 2017 they bought 1,110 C-Stores convenience stores from Sunoco in a deal valued at $3.3 billion and in 2024 acquired 204 Stripes convenience stores from Sunoco in a deal valued at $1 billion and finished integrating them in 2026. By 2015, 7-Eleven had over 55,000 stores across the world. In 2020, 7-Eleven announced it would purchase Speedway, 23,000 stores, for $21 billion. In 2021, 7-Eleven rolled out a $70 million ad campaign, their largest investment in advertising in years, doubling their market spending from the previous year. The commercials, directed by Harmony Korine, were to reflect the "evolution" of the chain's store format, drawing attention to, in part, the fact that "this isn't just gas station food, there's real restaurant quality food at 7-Eleven", according to CMO Marissa Jarrantt. On August 19, 2024, it was reported that Alimentation Couche-Tard—owner of competitor Circle K—had made a buyout offer for Seven & i Holdings. Later, on September 6, 2024, Seven & i Holdings rejected this offer as too low and rife with regulatory risk, although a "sweetened offer" might be considered. In October, a revised bid of $47 billion, 22% increase of the previous one, was presented.
Sources: en.wikipedia.org
Iodine will kill all principal pathogens and, given enough time, even spores, which are considered to be the most difficult form of microorganisms to be inactivated by disinfectants and antiseptics. Octenidine dihydrochloride, currently increasingly used in continental Europe, often as a chlorhexidine substitute. Peroxides, such as hydrogen peroxide and benzoyl peroxide. Commonly, 3% solutions of hydrogen peroxide have been used in household first aid for scrapes, etc. However, the strong oxidization causes scar formation and increases healing time during fetal development. Phenols such as phenol itself (as introduced by Lister) and triclosan, hexachlorophene, chlorocresol, and chloroxylenol. The fact that the more substituted and more lipophylic phenols are less toxic, less irritant and more powerful was gradually discovered in late 19th century. Nowadays comparatively more water-soluble phenols such as chlorocresol are commonly used as preservatives in personal care products while less soluble such as chloroxylenol – as topical antiseptics. Both can be encountered in household disinfectants. Quat salts such as benzalkonium chloride/lidocaine (trade name Bactine among others), cetylpyridinium chloride, or cetrimide. These surfactants disrupt cell walls. Quinolines such as hydroxyquinolone, dequalium chloride, or chlorquinaldol. 4-Hexylresorcinol, or S.T.37
sulfur amino acid metabolic processes DNA methylation methionine metabolic processes methionine biosynthetic processes methylation S-adenosylmethionine (SAM) cycle homocysteine catabolic processes folic acid metabolic processes oxidation-reduction processes negative regulation of cystathionine beta-synthase activity.
=== Maps === Poland and West-Slavs 800–950 Archived 2017-10-25 at the Wayback Machine Poland 990–1040 Archived 2017-12-13 at the Wayback Machine Poland 1040–1090 Archived 2017-12-13 at the Wayback Machine Poland 1090–1140 Archived 2017-08-11 at the Wayback Machine Poland 1140–1250 Archived 2017-12-13 at the Wayback Machine Poland 1250–1290 Archived 2017-02-12 at the Wayback Machine Poland 1290–1333 Archived 2017-02-12 at the Wayback Machine Poland 1333–1350 Archived 2007-12-24 at the Wayback Machine Poland 1350–1370 Archived 2017-08-11 at the Wayback Machine Poland 1773 Poland 2004
Sources: en.wikipedia.org
== Structure-activity relationships == There is a rather large homology in structure between arenobufagin and cardiac glycosides. Cardiac glycosides are natural compounds found in plants which cause inactivation of the sodium potassium pump like arenobufagin. The specific steroidic structure binds to the pump in a way it inhibits the process of pumping potassium into the cell and sodium out of the cell. The exact way of binding to the Na-K-Pump is not yet documented.
=== Alleviation of dysphoria theory === The alleviation of dysphoria theory suggests that people with severe mental illness commonly have a negative self-image, which makes them vulnerable to using psychoactive substances to alleviate these feelings. Despite the existence of a wide range of dysphoric feelings (anxiety, depression, boredom, and loneliness), the literature on self-reported reasons for use seems to lend support for the experience of these feelings being the primary motivator for alcohol use disorder and other drug misuse.
Plants produce chemicals at the injury site that signal the presence of damage and may help to reduce further damage. The chemicals involved depend to some extent on the plant species, though several of them are shared among species; and the signals given depend on the cause of the injury. Plants injured by spider mites release volatile chemicals that attract predatory mites, serving to reduce the attack on the plants. As another example, maize plants damaged by the caterpillars of noctuid moths release a mixture of terpenoid substances which attract the parasitoid wasp Cotesia marginiventris, which kills caterpillars. Many plants give off such herbivory-induced signals.
== References == Arsdel, Wallace, B. Van, Michael, J Copley, and Robert, L. Olson. Quality and Stability of Frozen Foods: Time-Temperature Tolerance and its Significance. New York, NY: John Wiley & Sons, INC, 1968. "Clarence Birdseye." Encyclopedia of World Biography. Vol. 19. 2nd ed. Detroit: Gale, 2004. 25–27. Gale Virtual Reference Library. Gale. Brigham Young University – Utah. 3 November 2009. (subscription required) Copson, David. Microwave Heating. 2nd ed.. Westport, CT: The AVI Publishing Company, INC., 1975. Decareau, Robert. Microwave Foods: New Product Development. Trumbull, CT: Food & Nutrition Press, INC., 1992. Gould, Grahame. New Methods of Food Preservation. New York, NY: Chapman & Hall, 2000. Mathlouthi, Mohamed. Food Packaging and Preservation. New York, NY: Chapman & Hall, 1994.*^Robinson, Richard. Microbiology of Frozen Foods. New York, NY: Elsevier Applied Science Publishers LTD, 1985. Russell, Nicholas J., and Grahame W. Gould. Food Preservatives. 2nd ed. New York, NY: Kluwer Academic/Plenum Publishers, New York, 2003. Sun, Da-Wen. Handbook of Frozen Food Processing and Packaging. Boca Raton, Fl: Taylor & Francis Group, LLC, 2006. Tressler, Donald K., Clifford F. Evers, and Barbara, Hutchings Evers. Into the Freezer – and Out. 2nd ed. New York, NY: The AVI Publishing Company, INC., 1953. Tressler, Donald K., and Clifford F. Evers. The Freezing Preservation of Foods. 3rd ed. 1st volume. Westport, CT: The AVI Publishing Company, INC., 1957. Whelan, Elizabeth M., and Fredrick J. Stare. Panic in the Pantry: Facts and Fallacies About the Food You Buy.
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 registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.