If you have been reading about Semax 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 2026-07-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
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.
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.
== External links == "Corticotropin-releasing Factor Receptors: CRF1". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2015-11-20. Retrieved 2008-12-04. Corticotropin-releasing+hormone+receptors at the U.S. National Library of Medicine Medical Subject Headings (MeSH) CRF+receptor+type+1 at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P34998 (Corticotropin-releasing factor receptor 1) at the PDBe-KB.
=== Amanda: Two Girls, One Cage === First aired: 18 November 2010 Meet Amanda, Bully Beatdown's first female bully with a bad attitude. She stands at 5'7 and makes life miserable for her victim, Keiko. Keiko is the second female victim to appear on the show, the first being Linda. Amanda calls herself "the queen" so Mayhem Miller brings in female MMA fighter Michelle Waterson who's done kickboxing since she was 10 years old to teach her a lesson. In the first round, she tapped out five times. In the second round, Amanda got KO'd with a brutal punch to her stomach. Keiko won $10,000 and an apology from Amanda.
== Challenges in Tendon Cell Research == Source: Despite their importance in tendon function and repair, expanding tenocytes in vitro for therapeutic purposes remains a significant challenge. The main hurdle in this area is the phenotypic drift that occurs during the in-vitro culture of tenocytes. These cells tend to lose their characteristic elongated morphology and tenogenic properties when grown in culture for extended periods. This drift complicates their use in regenerative medicine and tendon tissue engineering, as it limits the cells' ability to maintain their functional and structural roles in tendon repair. One of the primary reasons for the phenotypic drift of tenocytes in culture is the loss of their characteristic elongated shape. Under normal conditions, tenocytes are elongated to facilitate the interaction with surrounding collagen fibers. This morphology is important for maintaining their function in the tendon tissue. However, when cultured in conventional conditions, tenocytes often undergo a morphological shift, adopting a more rounded shape and losing their specialized functionality. This drift in phenotype can be detrimental to their ability to effectively regenerate tendon tissue. Given the challenges associated with in vitro tenocyte expansion and autologous tenocyte availability, alternative strategies need to be explored. Some of the promising approaches include:
Sources: en.wikipedia.org
== In popular culture == The Gulf War has been the subject of several video games including Conflict: Desert Storm, Conflict: Desert Storm II, Gulf War: Operation Desert Hammer, and Call of Duty: Black Ops 6, which was banned in Kuwait. Depictions in film include Jarhead (2005), which is based on US Marine Anthony Swofford's 2003 memoir of the same name. The 2016 Bollywood movie Airlift is based on the 1990 airlift of stranded Indian citizens from Kuwait during the Gulf War. As for music, Gil Scott-Heron's song "Work for Peace" from the 1994 album Spirits was a response to the war. Additionally, the 2002 audio documentary The Fire This Time features contemporaneous interviews and media selections set to electronic music by various artists.
=== Fl–Fu === Louis B. Flexner (1902–1996). American biochemist at the University of Pennsylvania, who worked on the biochemistry of memory and brain function. Member Natl. Acad. Sci. USA. Otto Folin (1867–1934). Swedish-American chemist at Harvard, best known for developing methods for the determination of the constituents of protein-free blood filtrates. Member Natl. Acad. Sci. USA. Karl August Folkers (1906–1997). American biochemist at Merck, known for work on the antibiotics cathomycin and cycloserine. Ivar Asbjørn Følling (1888–1973). Norwegian biochemist and geneticist who first described phenylketonuria. Sidney W. Fox (1912–1998). American biochemist at the University of Miami who worked on the production of amino acids in abiotic conditions. Heinz Fraenkel-Conrat (1910–1999). German-American biochemist at UC Berkeley, known for research on viruses such as tobacco mosaic virus. Member Natl. Acad. Sci. USA. Rosalind Franklin (1920–1958). British X-ray crystallographer at King's and Birkbeck Colleges, London, who worked on the structure of DNA Perry A. Frey (b. 1935). American biochemist at the University of Wisconsin known for work on enzyme mechanisms. Member Natl. Acad. Sci. USA. Irwin Fridovich (1929–2019). American biochemist at Duke University, who discovered superoxide dismutase and studied its mechanisms and superoxide toxicity. Member Natl. Acad. Sci. USA. Joseph S. Fruton (1912–2007). Polish-American biochemist at the Rockefeller Institute.
Coordinates were measured in grades on official French terrestrial ordnance charts from the French revolution well into the 20th century. 1 grade (or in modern symbology, 1 gon) = 0.9° or 0.01 right angle. One advantage of this measure is that the distance between latitude lines 0.01 gon apart at the equator is almost exactly 1 kilometre. It would be exactly 1 km if the original definition of 1 metre = 1⁄10,000 quarter-meridian had been adhered to. One disadvantage is that common angles like 30° and 60° are expressed by fractional values (33+1⁄3 and 66+2⁄3 respectively) so this "decimal" unit failed to displace the "sexagesimal" units equilateral-vertex – degree – minute – second invented by Babylonian astronomers.
Sources: en.wikipedia.org
The National Association of Newspapers spoke about the case in a statement:The ANJ follows with concern and expresses its repudiation of attempts at intimidation against O Estado de S.Paulo and its Politics editor, Andreza Matais, after the newspaper disclosed the access of the wife of a leader of organized crime in Amazonas to offices of the Ministry of Justice. The use of intimidation methods against outlets and journalists is not consistent with democratic values and demonstrates blatant disrespect for freedom of the press. It also shows a practice characteristic of autocratic regimes of, with the support of political leaders, pro-government sites and influencers, attempting to divert attention from uncomfortable reporting by attacking those who investigate and disclose it. The ANJ expects such intimidation methods, especially against women journalists already employed in the recent past, to cease immediately, in the name of respect for freedom of the press and the free exercise of journalism and communication outlets.
== Adverse events == The safety of benzhydrocodone/APAP was evaluated in a total of 200 healthy adults in six phase 1 studies. The subjects received at least one oral dose of benzhydrocodone/APAP. The most common adverse events in these studies were nausea (21.5%), somnolence (18.5%), vomiting (13.0%), constipation (12.0%), pruritus (11.5%), dizziness (7.5%) and headache (6.0%). Benzhydrocodone/APAP use with serotonergic drugs can cause serotonin syndrome. Mixed agonist/antagonist and partial agonist opioids may reduce the analgesic effect of benzhydrocodone/APAP or cause withdrawal symptoms. MAOIs can increase the effects of benzhydrocodone/APAP.
In 1961, Peter Mitchell proposed chemiosmosis as a cell's primary system of energy conversion. The mechanism, now ubiquitous in living cells, powers energy conversion in micro-organisms and in the mitochondria of eukaryotes, making it a likely candidate for early life. Mitochondria produce adenosine triphosphate (ATP), the energy currency of the cell used to drive cellular processes such as chemical syntheses. The mechanism of ATP synthesis involves a closed membrane in which the ATP synthase enzyme is embedded. The energy required to release strongly bound ATP has its origin in protons that move across the membrane. In modern cells, those proton movements are caused by the pumping of ions across the membrane, maintaining an electrochemical gradient. In the first organisms, the gradient could have been provided by the difference in chemical composition between the flow from a hydrothermal vent and the surrounding seawater, or perhaps meteoric quinones that were conducive to the development of chemiosmotic energy across lipid membranes if at a terrestrial origin.
No paralogs of c7orf26 have been found in the human genome, however, six unique isoforms have been identified. They are c7orf26 isoform (X1, X2, X3, X4) and isoform 2 (two sub-isoforms identified). Below is a table of a variety of orthologs of the human c7orf26. The table include closely, intermediately and distantly related orthologs. Orthologs of the human protein c7orf26 are listed above in descending order of the date of divergence. c7orf26 is highly conserved throughout all orthologs, this is demonstrated with a 65% identity in the least similar ortholog. c7orf26 has evolved slowly and evenly over time. Below is a phylogenetic tree showing the evolutionary history of c7orf26 and its nearest orthologs.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。