A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-03 and is reviewed periodically as new material appears.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
== Pull down time == The pull down time is defined as the necessary time to cool down the ULT freezer from ambient temperatures to the selected temperature of −80 to −86 °C (−112 to −123 °F). The time strongly depends on the type of insulation, the efficiency of the compressor system as well as the installed metal shelves within the freezer. At the start of the twenty-first century, ULT freezers were able to cool down within 3 to 5 hours. Warm up time is typically 1/8 °C per minute.
November 17, 2008: Japan The world's second-biggest economy slides into recession, its first in seven years. Its GDP contracts 0.1% in the July–September quarter, as the 2008 financial crisis curbs demand for its exports. It shrank 0.9% in the previous quarter.
Uhthoff's phenomenon, a reversible exacerbation of symptoms following a rise in body temperature, and Lhermitte's sign, an electrical sensation that runs down the back when flexing the neck, are particularly characteristic of MS, although may not always be present. 60–80% of MS patients find that symptoms, such as fatigue, are affected by changes in body temperature. MS may also present with eye movement impairments, such as internuclear ophthalmoplegia or sixth nerve palsy.
== History == In literature from ancient Rome there are complaints of foul air, while in 1273 the inhabitants of London were discussing the prohibition of coal burning to improve air quality. However, the measurement and analysis of aerosols only became established in the second half of the 19th century. In 1847 Henri Becquerel presented the first concept of particles in the air in his condensation nuclei experiment and his ideas were confirmed in later experiments by Coulier in 1875. These ideas were expanded on between 1880 and 1890 by meteorologist John Aitken who demonstrated the fundamental role of dust particles in the formation of clouds and fogs. Aitken's method for aerosol analysis consisted of counting and sizing particles mounted on a slide, using a microscope. The composition of the particles was determined by their refractive index. In the 1920s aerosol measurements, using Aitken's simple microscopic method, became more common place because the negative health effects of industrial aerosols and dust were starting to be recognized by health organizations. Technological and instrumentation advancements, including improved filters, led to improvement in the aerosol measurement methods in the 1960s. The introduction of polycarbonate filters, called nucleopore filters, enhanced the collection, storage, and transportation of samples without disturbing the physical and chemical state of the particles. On-line aerosol measurements methods took a little longer than off-line to be developed and perfected. It wasn't till 1973 with W.D.
Sources: en.wikipedia.org
Hunger is a sensation that motivates the consumption of food. The sensation of hunger typically manifests after only a few hours without eating and is generally considered to be unpleasant. Satiety occurs between 5 and 20 minutes after eating. There are several theories about how the feeling of hunger arises. The desire to eat food, or appetite, is another sensation experienced with regard to eating. The term hunger is also the most commonly used in social science and policy discussions to describe the condition of people who suffer from a chronic lack of sufficient food and constantly or frequently experience the sensation of hunger, and can lead to malnutrition. A healthy, well-nourished individual can survive for weeks without food intake (see fasting), with claims ranging from three to ten weeks. Satiety is the opposite of hunger; it is the sensation of feeling full.
They can be used in machinery, auto-industry, and medical applications. For example, the cockpit canopy of the F-22 Raptor is made of high-optical-quality polycarbonate. Polysulfides have outstanding oil and solvent resistance, good gas impermeability, and good resistance to aging and ozone. However, they smell bad, and they shows low tensile strength as well as poor heat resistance. They can be used in gasoline hoses, gaskets, and places that require solvent resistance and gas resistance. Polyether shows good thermoplastic behavior, water solubility, generally good mechanical properties, and moderate strength and stiffness. It is applied in sizing for cotton and synthetic fibers, stabilizers for adhesives, binders, and film formers in pharmaceuticals. Phenol formaldehyde resin (Bakelite) have good heat resistance and dimensional stability as well as good resistance to most solvents. It also shows good dielectric properties. These materials are typically used in molding applications, electrical, radio, televisions, and automotive parts, where their good dielectric properties are of use. Some other uses include impregnating paper, varnishes, and decorative laminates for wall coverings. Polytriazole polymers are produced from monomers which bear both an alkyne and azide functional group. The monomer units are linked to each other by the a 1,2,3-triazole group, which is produced by the 1,3-dipolar cycloaddition, also called the azide-alkyne Huisgen cycloaddition. These polymers can take on the form of a strong resin or a gel.
The Scottish Government loses a non-binding vote calling for the rollout of free school meals to all primary school pupils, with MSPs voting 64–2 for the motion. 13 September – Former nurse Adele Rennie is sentenced to two years and four months in prison and placed on the sex offenders' register for ten years after pleading guilty to stalking a woman online, while posing as a man, after the dating app Tinder matched them. 15 September – The A83 road in Argyll is reopened with a slight diversion after heavy rain caused a 500 tonne landslide. 17 September – Glasgow is formally selected as the host city of the Commonwealth Games in 2026. 18 September – Scotland experiences its warmest September day since 2019, with temperatures reaching 25 °C. 19 September – The Scottish Government temporarily pauses a ban on wood burning stoves in new properties and property conversions following a review of the legislation. Greenock Morton F.C. dismisses player Jay Emmanuel-Thomas after he appeared in court accused of attempting to orchestrate the smuggling of drugs into the UK. 20 September – A woman juror who used the Right Move app to research the floorplan of a house similar to one that was the scene of a rape during a trial is fined for contempt of court. 24 September – Official figures show the number of households living in temporary accommodation has reached a record high, with 16,300 households in the system as of March 2024, the highest since records began in 2002.
== Theoretical, actual, and percent yields == The percent yield is a comparison between the actual yield—which is the weight of the intended product of a chemical reaction in a laboratory setting—and the theoretical yield—the measurement of pure intended isolated product, based on the chemical equation of a flawless chemical reaction, and is defined as,
Lepirudin is an anticoagulant that functions as a direct thrombin inhibitor. Brand name: Refludan, Generic: Lepirudin rDNA for injection. Lepirudin is a recombinant hirudin derived from yeast cells. Lepirudin is almost identical to hirudin extracted from Hirudo medicinalis, having the amino acid sequence LTYTDCTESGQNLCLCEGSNVCGQGNKCILGSDGEKNQCVTGEGTPKPQSHNDGDFEEIPEEYLQ with disulfide bridges at Cys6-Cys14, Cys16-Cys28 and Cys22-Cys39, and differs from by the substitution of leucine for isoleucine at the N-terminal end of the molecule and the absence of a sulfate group on the tyrosine at position 63. Lepirudin may be used as an anticoagulant when heparins (unfractionated or low-molecular-weight) are contraindicated because of heparin-induced thrombocytopenia.
Sources: en.wikipedia.org
ionophore Any chemical compound or macromolecule that facilitates the movement of ions across biological membranes, or more specifically, any chemical species that reversibly binds electrically charged atoms or molecules. Many ionophores are lipid-soluble proteins that catalyze the transport of monovalent and divalent cations across the hydrophobic lipid bilayers surrounding cells and vesicles.
Thus, a high ratio of [NADH] to [NAD+] or a high ratio of [ADP] [Pi] to [ATP] imply a high amount of reduced cytochrome c and a high level of cytochrome c oxidase activity. An additional level of regulation is introduced by the transport rates of ATP and NADH between the mitochondrial matrix and the cytoplasm.
After having conferred with the Transvaal leaders, de Wet returned to the Orange Free State, where he inspired successful attacks and raids in the western part of the country, though he suffered a defeat at Bothaville in November 1900. Many Boers who had returned to their farms and towns, sometimes after being given parole by the British, took up arms again. In late January 1901, De Wet led a renewed invasion of Cape Colony. This was less successful, because there was no general uprising among the Cape Boers, and De Wet's men were hampered by bad weather and pursued by British forces. They narrowly escaped across the Orange River. From then until the final days of the war, De Wet remained comparatively quiet, rarely attacking British army camps and columns partly because the Orange Free State was effectively left desolate by British sweeps. In December 1901, De Wet attacked and overran an isolated British detachment at Groenkop, inflicting heavy casualties and capturing over 200 British soldiers. This prompted Kitchener to launch the first of the "New Model" drives against him. De Wet escaped the first such drive but lost 300 of his fighters. This was a severe loss, and a portent of further attrition, although sweep attempts to round up De Wet were badly handled, and De Wet's forces avoided capture for the rest of the war.
=== Alternative to autograft in long bone nonunions === In 2001, the Food and Drug Administration (FDA) approved rhBMP-7 (a.k.a. OP-1; Stryker Biotech) for a humanitarian device exemption as an alternative to autograft in long bone nonunions. In 2004, the humanitarian device exemption was extended as an alternative to autograft for posterolateral fusion. In 2002, rhBMP-2 (Infuse; Medtronic) was approved for anterior lumbar interbody fusions (ALIFs) with a lumbar fusion device. In 2008 it was approved to repair posterolateral lumbar pseudarthrosis, open tibia shaft fractures with intramedullary nail fixation. In these products, BMPs are delivered to the site of the fracture by being incorporated into a bone implant, and released gradually to allow bone formation, as the growth stimulation by BMPs must be localized and sustained for some weeks. The BMPs are eluted through a purified collagen matrix which is implanted in the site of the fracture. rhBMP-2 helps grow bone better than any other rhBMP so it is much more widely used clinically. There is "little debate or controversy" about the effectiveness of rhBMP-2 to grow bone to achieve spinal fusions, and Medtronic generates $700 million in annual sales from their product.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.