A practical reference on peptide synthesis: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
| 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. 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.
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.
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
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.
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.
Quantum dots have been gaining interest from the scientific community because of their interesting optical properties, the main being band gap tunability. When an electron is excited to the conduction band, it leaves behind a vacancy in the valence band called hole. These two opposite charges are bound by Coulombic interactions in what is called an exciton and their spatial separation is defined by the exciton Bohr radius. In a nanostructure of comparable size to the exciton Bohr radius, the exciton is physically confined within the semiconductor resulting in an increase of the band gap of the material. This dependence can be predicted using the Brus model.
In May 1945, following its defeat in World War II, Germany was occupied by the United States, Britain, France and the Soviet Union. All four occupation powers reorganised the territories by recreating the Länder (states), the constituting parts of federal Germany. The state of Prussia, whose provinces extended to all four zones and covered two thirds of Germany, was abolished in 1947. Special conditions were assigned to Berlin, which the four powers divided into four sectors. A united German state government existed in the city until it broke apart in 1948. After 1949, both West Berlin and East Berlin (officially only called Berlin) were in effect incorporated into the Federal Republic of Germany and the German Democratic Republic, respectively, despite not legally being part of these countries.
== Biuret test == The biuret test is a chemical test for proteins and polypeptides. It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds. The test and reagent do not actually contain biuret; they are so named because both biuret and proteins have the same response to the test.
Sources: en.wikipedia.org
state of matter The condition of matter existing in a distinct, homogeneous, macroscopic form. Solid, liquid, gas, and plasma are the four traditional states of matter and the most well-known. See also phase.
== Spectroscopy == Both the fluorescence excitation and emission spectrums of wild-type EosFP are shifted ~65 nm to the right upon excitation toward the red end of the spectrum. This spectral change is caused by an extension of the chromophore accompanied by a break in the peptide backbone between Phe-61 and His-62 in an irreversible mechanism. The presence of a crisp isosbestic point at 432 nm also suggests an interconversion between two species. An absorption peak at 280 nm is visible due to aromatic amino acids which transfer their excitation energy to the green chromophore. The quantum yield of the green-emitting form of Eos is 0.7. In the red shifted species, there are pronounced vibronic sidebands separate from the main peak at 533 nm and 629 nm in the excitation spectrum and emission spectrum respectively. There is another peak in the red excitation spectrum at 502 nm likely due to FRET excitation of the red fluorophore. The quantum yield of the red-emitting form is 0.55. EosFPs variants show almost no difference in spectroscopic properties, therefore, it is likely that the structural modifications which arise from separation of interfaces have little to no effect on the structure of the fluorophore-binding site.
=== Hematopoietic stem cell transplant === Bronchiolitis obliterans affects up to 5.5% of people who have received HSCT. One of the biggest risk factors after HSCT is the development of GVHD with a 14% risk. Other risk factors post transplant including tobacco use, age of donor, age of recipient, lower baseline FEV1/FVC ratio, non-caucasian race, peripheral and lower circulating IgG levels. Studies have, however, shown mixed results regarding these other risk factors. There has been an association shown between the increased use of peripheral stem cells and the risk of developing bronchiolitis obliterans. Also, research has shown an increased risk for developing the disease within the first year of transplant if the person is infected with respiratory syncytial virus or parainfluenza virus within the first 100 days post transplant.
Sources: en.wikipedia.org
49 Squadron RAF in October 1956 in Operation Buffalo at Maralinga; Project Dazzle and its research on re-entry vehicles enabled the Mercury-Atlas 6 launch to happen in February 1962; the Australian government built four launch pads for the Blue Streak in 1959, but it was cancelled in 1960, the redesignated satellite launcher Blue Streak first launched on 5 June 1964, and satellites would be launched by 1966, but only WRESAT was launched in November 1967, on a Redstone rocket instead; Woomera launched over 4000 missiles and cost the Australian government £900m; the site was demolished by the Australian government at the end of the 1960s; part of the former site is now the secret Joint Defense Facility Nurrungar 17 September Not in the Stars, making mathematical models for predictions; Robert May, Baron May of Oxford of Imperial College; William Phillips and his 1949 MONIAC economic model; a British Airways 747 flight simulator; computer models of epidemics - the R number, and vaccination policies; the UK fishing industry had quotas imposed in 1983, due to mathematical models of fish stocks; John Shepherd of the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) laboratory in Lowestoft; computer models of warfare were developed by the Defence Operational Analysis Establishment in West Byfleet with deputy director David Faddy, which closed six years later, superseded in function by CORDA (UK); Irving Mintzer of the World Resources Institute; the NASA Goddard Space Flight Center had developed computer models of the Earth's atmosphere, such as rainfall; the hole in the Ozone layer and phytoplankton, with Norman Myers; Ian Riley of the Economist Intelligence Unit. Narrated by Bob Peck. Written, produced and directed by Chris Haws, made by InCA 24 September Race for the Top, CERN versus Fermilab; in 1983 CERN discovered the W and Z bosons, it and Fermilab were looking for the top quark; Leon M. Lederman, director of Fermilab; Andy Parker of CERN; CERN had 80 scientists led by Luigi Di Lella on its UA2 experiment, and Fermilab had its Collider Detector at Fermilab (CDF); Roy Schwitters; Fermilab had discovered the bottom quark in 1977; John Ellis of CERN; each team prepared for an annual physics conference at La Thuile, Aosta Valley in north-west Italy; UA2 had a meeting in July 1989 in Cambridge; the top quark would be discovered in 1995 with 175 GeV by Fermilab. Narrated by Carole Boyd, known for playing Lynda Snell in The Archers, joint production InCA and WGBH 1 October Walk on Wheels, a half-million disabled people have a wheelchair in the UK; NHS wheelchairs were made by Carter's; the quick-release axle was developed in World War II, for releasing munitions; the residential Treloar School in Alton, Hampshire, which was funded by individual LEAs, with charity funding as well; Bill Walmsley of the Department of Health's wheelchair research centre in Blackpool, now part of the Disability and Carers Service at DWP Peel Park at the end of the M55 motorway, on the A5230 in Westby-with-Plumptons. 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Narrated by John Benson, produced by Mike Johnstone, directed by Ed Newstead, made by VATV (Video Arts) 15 October Wheels of War, about the early 1990s Leyland 4-tonne truck and defence procurement; James Adams, journalist; military historian Correlli Barnett; general service (GS) cargo vehicles, and a RE vehicle carrying a Medium Girder Bridge; a youthful-looking Mark Francois; the Austin Champ, designed in the 1950s; the British Aerospace Nimrod AEW3 was cancelled in 1986 at a cost of £860m; cost-plus contracts were replaced by competitive; Sir Peter Levine was brought in as Chief of Defence Procurement; the Leyland 4-tonne truck would replace the Bedford MK, made by Bedford Vehicles; journalist John Parsons; each vehicle would cost around £23,000 each; the Leyland 5-tonne was developed from its Comet and Roadrunner vehicles (developed into the DAF LF) under project director Stuart Hayes; the equivalent German vehicle, the MAN KAT1, had cost £75,000 each; the Panavia Tornado; Leyland design engineer Colin Ingram; the three vehicle prototypes were punishingly tested at the Royal Armament Research and Development Establishment (RARDE). Narrated by Anthony Valentine, produced by Patrick Uden made by Uden Associates 22 October Three Score Years and Then? 29 October Robotopia, advances of robotics in Japan, and bizarre contraptions; Frederik L. Schodt, author of the 1988 book Inside the Robot Kingdom - for hundreds of years until 1853, Japan was a fairly backward country; Joseph Engelberger, who developed the first industrial robot, Unimate, made by his company Unimation from 1961 - there were around 200,000 industrial robots, with around 130,000 of those in Japan; Japanese robot artist Hajime Sorayama, who drew lurid female robots; automated mannequins; nineteen universities in Japan were developing ungainly humanoid robots, notably Ichiro Kato at Waseda University; Seiuemon Inaba of FANUC, produced by Mike Wallington, made by Kai Productions 5 November Fly-by-wire, the new Airbus 320; software engineer Mike Hennell of the University of Liverpool; Roger Beteille, managing director of Airbus from 1967–85, and Henri Ziegler; John Knight of the University of Virginia; software engineer Bev Littlewood of City University; the A320 was the first fly-by-wire airliner; Blind Landing Experimental Unit testing at RAE Bedford in the 1960s, and developing the automatic pilot with a Vickers Valetta; testing Concorde in a wind tunnel; the Apollo project had depended on computers - it couldn't be done otherwise; Paul Ceruzzi of the Air and Space Museum; Philip Felleman of the Draper Laboratory; testing the F-16 in the early 1970s; Joe Sutter, head of Boeing from 1981–86; Boeing introduced flight management systems, so not needing a flight engineer; David Learmount of Flight International, and how Airbus had more commercial need to be innovative; the A300 was the first two-engined wide body aircraft; the A310 had electrical hydraulics and electronic control of some flight surfaces; John Cullyer of the University of Warwick; the A320 had five master computers; Gordon Corps, the Airbus test pilot, later to fly on Thai Airways International Flight 311 in 1992; Gilles Pichon, chief engineer of the A320; Jacques Troyes, head of Flight Control at Airbus; there was emergency mechanical control to the rudder and tail trim; the June 1988 Air France Flight 296Q - Michel Asseline, the pilot, said the aircraft had tried to land, when he tried to raise the aircraft; Alain Monnier of the DGAC said it was pilot error; Greg Holt of the FAA and Brian Perry of the CAA; the four-engined A330 would be manufactured from 1992; a prototype fly-by-wire relaxed stability Saab JAS 39 Gripen tumbles on 2 February 1989 at Linköping/Saab Airport, piloted by Lars Rådeström. Narrated by James Bellini, produced by Ben Shephard (historian), directed by John Longley, made by Box Television with WGBH 12 November Deadly Force, aerial shots of Miami; the WINZ Miami broadcaster; the Miami SWAT response team; the 1980 Miami riots; Sgt Louis Battle, Bernie Gonzalez and the Heckler & Koch MP5; Tom Salerno and the Remington Model 870 pump action shotgun, the M1911 pistol and Beretta M9; Ted Bradley; a WSVN news broadcast with Jane Akre; two thirds of Miami's population were Latin-American, and had many exiled citizens; the 1980 Mariel boatlift, from Cuba, added to the population and much to the crime; Miami had two murders a day in the 1980s; Robert Waller; Edna Buchanan of the Miami Herald; severed limbs washed up on Miami beach; the Colt Python; the Beretta 92; the Colt AR-15 semi-automatic rifle; 80% of SWAT call-outs were connected to the drug trade; two thirds of illegal drugs went through Miami; Sgt Louis Philips and negotiation techniques; SWAT negotiator Eric Caspener; 95% of SWAT negotiations work. Produced by David Jones, directed by Catherine Bailey, made by Buffalo Pictures 19 November Faster than a Speeding Bullet, and the quest for supersonic flight, eventually resulting in Concorde. The programme features former Concorde pilot Christopher Orlebar, who wrote The Concorde Story. The history of supersonic research dates back to the 18th Century, but supersonic flight only became achievable after the development of the jet engine. Featured aircraft include: the wartime Messerschmitt Me 262; the innovative de Havilland DH 108; the Messerschmitt Me 163 Komet; the Fairey Delta 2, the Bell X1 and numerous experimental "X Planes". After the war, the world's fastest non-experimental aircraft was the Lockheed SR-71 Blackbird, which could fly at 95,000 ft at 2,300 mph. The programme interviews key figures in the development of supersonic military aircraft and second generation SST (Supersonic Transport) aircraft. Narrated by Tony Anholt, written, produced and directed by Chris Haws, made by InCA
=== Studies in vitro === Epitalon appears to induce telomere elongation via increased telomerase activity in human somatic cells in vitro, based on a study in human fibroblast cell cultures. Elongation of telomeres by epitalon was sufficient to surpass the Hayflick limit in a cell culture of human fetal fibroblast cells, extending their proliferative potential from termination at the 34th passage in the control cell population to beyond the 44th passage in the treated cell population, while increasing the lengths of their telomeres to levels comparable to those of cells in the original culture. Epitalon induces decondensation of heterochromatin near the centromeres in cultured lymphocytes originating from samples taken from humans of ages 76 to 80 years. Epitalon appears to inhibit the synthesis of the MMP9 protein in vitro in aging skin fibroblasts.
Hydromorphone, also known as dihydromorphinone, and sold under the brand name Dilaudid among others, is a morphinan opioid used to treat moderate to severe pain. Typically, long-term use is only recommended for pain due to cancer. It may be used by mouth or by injection into a vein, muscle, or under the skin. Effects generally begin within half an hour and last for up to five hours. A 2016 Cochrane review (updated in 2021) found little difference in benefit between hydromorphone and other opioids for cancer pain. Common side effects include dizziness, euphoria, sleepiness, nausea, itchiness, and constipation. Serious side effects may include abuse, low blood pressure, seizures, respiratory depression, and serotonin syndrome. Rapidly decreasing the dose may result in opioid withdrawal. Generally, use during pregnancy or breastfeeding is not recommended. Hydromorphone exerts its effects by activating opioid receptors, mainly in the brain and spinal cord. Hydromorphone 2 mg IV is equivalent to approximately 10 mg morphine IV. Hydromorphone was patented in 1923. Hydromorphone is made from morphine. Hydromorphone is a therapeutic alternative on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2022, it was the 233rd most commonly prescribed medication in the United States, with more than 1 million prescriptions.
In women with polycystic ovary syndrome (PCOS), a condition of androgen excess, testosterone levels are typically around 50 to 80 ng/dL, with a range of about 30 to 140 ng/dL. Total testosterone levels are about 20-fold and free testosterone levels about 40-fold higher in men than in women on average. Similarly, testosterone production is approximately 30 times higher in men than in women.
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.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.