heptapeptide 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.
Last reviewed on 2025-08-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
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。
Marc Laidlaw is an American writer. Between 1997 and 2016, he was a writer for the video game company Valve, where he worked on the Half-Life and Portal series. Before joining Valve, Laidlaw was a novelist working in fantasy and horror. In 1996 he won the International Horror Guild Award for his novel The 37th Mandala. In 2025, Laidlaw's 1983 short story "400 Boys" was adapted as an episode of the Netflix series Love, Death & Robots.
=== 1099 reporting === A payor must report payments for goods or services via payment apps, online marketplaces, and payments from credit, debit, or gift cards to the Internal Revenue Service and the payee on Form 1099-K. The law changes the threshold for reporting; now reporting on Form 1099-K is required if a person received at least 200 transactions and received at least $20,000. The law increases the reporting threshold for Form 1099-MISC and Form 1099-NEC from $600 to $2,000 in 2026. The threshold will be adjusted for inflation for future years.
In September 2022, NewsGuard Technologies reported that among the TikTok searches it had conducted and analyzed from the US, 19.4% surfaced misinformation such as questionable or harmful content about COVID-19 vaccines, homemade remedies, the 2020 US elections, the Russian invasion of Ukraine, the Robb Elementary School shooting, and abortion. NewsGuard suggested that in contrast, results from Google were of higher quality. Mashable's own test from Australia found innocuous results after searching for "getting my COVID vaccine" but suggestions such as "climate change is a myth" after typing in "climate change". In November 2023, Singaporean Law and Home Affairs Minister K. Shanmugam applied for court orders requiring TikTok to provide information on the identity of three users that he accuses of spreading false and defamatory information about him. The users had shared on TikTok an article published by celebscritic.com alleging that K. Shanmugam was involved in an extra-marital affair. According to an investigation published in September 2025 by Moldovan newspaper Ziarul de Gardă, before the 2025 Moldovan parliamentary election, hundreds of accounts with false identities were created to spread Russian propaganda in TikTok and Facebook. That month, Bloomberg reported, citing European officials and documents of undisclosed origin, that Russia had prepared a plan to interfere in the election, which would have included a disinformation campaign in both Romanian and Russian on Facebook, Telegram and TikTok.
=== Category:EC 1.7 (act on other nitrogenous compounds as donors) === Category:EC 1.7.1 (with NAD+ or NADP+ as acceptor) Category:EC 1.7.2 (with a cytochrome as acceptor) Category:EC 1.7.3 (with oxygen as acceptor) Urate oxidase EC 1.7.3.3 Category:EC 1.7.7 (with an iron–sulfur protein as acceptor) Category:EC 1.7.99 (with other acceptors) Nitrite reductase EC 1.7.99.3 Nitrate reductase EC 1.7.99.4
Sources: en.wikipedia.org
The plebiscites asked voters whether they wanted their homeland to remain in East Prussia or to become a part of it, as to the Marienwerder Plebiscite Area, which was part of Weimar Germany, or to become part of Poland (the alternatives for the voters were not Poland or Germany but Poland or East Prussia, the latter of which was not a sovereign nation). All inhabitants of the plebiscite areas older than 20 or those who were born in the area before 1 January 1905 were entitled to return to vote.
restitution nucleus A nucleus containing twice the expected number of chromosomes owing to an error in cell division, especially an unreduced, diploid product of meiosis resulting from the failure of the first or second meiotic division.
Muscular dystrophies may be X-linked recessive, autosomal recessive, or autosomal dominant. Diagnosis often involves blood tests and genetic testing. There is no cure for any disorder from the muscular dystrophy group. Several drugs designed to address the root cause are currently available including gene therapy (Elevidys), and antisense drugs (Ataluren, Eteplirsen etc.). Other medications used include glucocorticoids (Deflazacort, Vamorolone); calcium channel blockers (Diltiazem); to slow skeletal and cardiac muscle degeneration, anticonvulsants to control seizures and some muscle activity, and Histone deacetylase inhibitors (Givinostat) to delay damage to dying muscle cells. Physical therapy, braces, and corrective surgery may help with some symptoms while assisted ventilation may be required in those with weakness of breathing muscles. Outcomes depend on the specific type of disorder. Many affected people will eventually become unable to walk and Duchenne muscular dystrophy in particular is associated with shortened life expectancy. Muscular dystrophy was first described in the 1830s by Charles Bell. The word "dystrophy" comes from the Greek dys, meaning "no, un-" and troph- meaning "nourish".
== Derivatives == Coicenals A-C share the common carbon skeleton of 10-(sec-butyl)-6-hydroxy-1,7,9-trimethyl-1,6,7,8,9,9a-hexahydro-1,4-methanobenzo[d]oxepin-2(4H)-ylidene)acetaldehyde. The molecular formulas of each derivative were determined via high-resolution electrospray ionization mass spectrometry. The R group of Coicenal A is a hydrogen. Coicenal B contains a succinate group for its R group. The R group of Coicenal C is a methyl succinate group. Coicenal D contains a different carbon skeleton than A-C and a succinate group for its R group.
The four substrates of the enzyme are carbazole, reduced nicotinamide adenine dinucleotide (NADH), oxygen, and a proton. Its products are 2'-aminobiphenyl-2,3-diol and oxidised NAD+. It is an oxidoreductase that uses molecular oxygen as oxidant and incorporates both its atoms into the starting material. It catalyses the first reaction in the pathway of carbazole degradation.
Sources: en.wikipedia.org
=== 1950–2000 === In the 1950s, thiazide diuretics were developed by Merck scientists Karl H. Beyer, James M. Sprague, John E. Baer, and Frederick C. Novello and led to the marketing of the first drug of this class, chlorothiazide, under the trade name Diuril in 1958. The research leading to the discovery of chlorothiazide, leading to "the saving of untold thousands of lives and the alleviation of the suffering of millions of victims of hypertension" was recognized by a special Public Health Award from the Lasker Foundation in 1975. In 1953, Merck & Co. merged with Philadelphia-based Sharp & Dohme, Inc., becoming the largest U.S. drugmaker. Sharp and Dohme had acquired H. K. Mulford Company in 1929, adding smallpox vaccines to its portfolio. The combined company kept the trade name Merck in the United States and Canada, and as Merck Sharp & Dohme (MSD) outside these two countries. In 1965, Merck & Co. acquired Charles Frosst Ltd. of Montreal (founded 1899), creating Merck-Frosst Canada, Inc., as its Canadian subsidiary and pharmaceutical research facility. Merck & Co. closed this facility in July 2010 but reemerged in 2011 as Merck Canada. Maurice Hilleman, a scientist at Merck, developed the first mumps vaccine in 1967, the first rubella vaccine in 1969, and the first trivalent measles, mumps, rubella (MMR vaccine) in 1971. The incidence of rubella-associated birth defects fell from up to 10,000 per year in the U.S. to zero in the aftermath of the rubella vaccine's development.
coli and Salmonella typhimurium and has since been demonstrated in many other bacterial cells. It was found that bacteria use histidine and aspartate phosphorylation as a model for bacterial signaling transduction. Serine, threonine and tyrosine phosphorylation are also present in bacteria. Bacteria carry kinases and phosphatases similar to that of their eukaryotic equivalent and have also developed unique kinases and phosphatases not found in eukaryotes.
=== Infrastructure === As Minister, McNaughton introduced Bill 32, the Access to Natural Gas Act, in the fall of 2018. It was passed into law that December. Bill 32 was intended to make it possible to expand access to natural gas throughout rural and Northern Ontario, including First Nations communities. Premier Ford said in a statement released on September 17, 2018, that "cancelling the cap-and-trade carbon tax" had caused the price of natural gas to decrease in Ontario. Premier Ford announced the new legislation and explained how it differed from the previous government's 2017 taxpayer-funded $100 million Natural Gas Grant Program—through which—according to Premier Ford, "private sector companies were limited from participating in natural gas expansion, portions of which were instead managed by the [Natural Gas Grant Program]." Bill 32, the Access to Natural Gas Act passed into law in 2018 to "encourage more private gas distributors to partner with communities to develop projects that expand access to affordable and efficient natural gas." On September 18, 2018, the city of North Bay learned that the Natural Gas Grant Program funding of over $8.6 million had been cancelled for a natural gas project that would have extended "services to as many as 350 homes in the north shore area of Trout Lake." In January 2019, Minister McNaughton announced that the Ford government would provide $27 million to Northeast Midstream towards the construction of their Nipigon LNG gas plant.
== In cancer research == In Cullen's paper "Granzymes in Cancer and Immunity" he describes the process of "immune surveillance [as] the process whereby precancerous and malignant cells are recognized by the immune system as damaged and are consequently targeted for elimination". For a tumor to progress it requires conditions within the body and surrounding area to be growth-promoting. Almost all people have suitable immune cells to fight off tumors in the body. Studies have shown that the immune system even has the ability to prevent precancerous cells from growing and arbitrate the regression of established tumors. The dangerous thing about cancer cells is they have the ability to inhibit the function of the immune system. Although a tumor may be in its beginning stage and very weak, it may be giving off chemicals that inhibit the function of the immune system allowing it to grow and become harmful. Tests have shown that mice without granzymes and perforins are at high risk to have tumors spread throughout their body. Tumors have the ability to escape from immune surveillance by secreting immunosuppressive TGF-β. This inhibits proliferation and activation of T cells. TGF-β production is the most potent mechanism of immune avoidance used by tumors. TGF-β inhibits expression of five different cytotoxic genes including perforin, granzyme A, and granzyme B, which then inhibits T cell-mediated tumor clearance.
The Artificial Intelligence Cold War (AI Cold War) is a narrative in which geopolitical tensions between the United States of America (USA) and the People's Republic of China (PRC) could lead to a Second Cold War waged in the area of artificial intelligence technology rather than in the areas of nuclear capabilities or ideology. The context of the AI Cold War narrative is the AI arms race, which involves a build-up of military capabilities using AI technology by the US and China and the usage of increasingly advanced semiconductors which power those capabilities. According to a February 2019 publication by the Center for a New American Security, General Secretary of the Chinese Communist Party Xi Jinping – believes that being at the forefront of AI technology will be critical to the future of China's global military and economic power competition.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.