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Semax Peptide Structure And Origin — Hands-On Walkthrough

By Editorial Desk · published 2025-09-16 · last reviewed 2025-10-27 · News

ACTH(4-10) 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.

Updated 2025-10-27. Numbers and descriptions here follow the published literature rather than marketing material.

Semax Peptide Structure and Origin

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.

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.

化学性质与分析表征

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。

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。

Semax at a glance

PropertyValueNotes
Chemical classSynthetic heptapeptideACTH(4-7) analogue
SequenceMet-Glu-His-Phe-Pro-Gly-ProFree N terminus, unmodified side chains
Molecular weight813.9 DaFree base; salt forms differ
AppearanceWhite to off-white powderLyophilised solid
SolubilityFreely soluble in waterHydrophilic; polar solvents preferred

Semax Structure and Research Background

Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.

Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.

Related pages on this site

Mechanism and Research

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.

Semax Background and Chemistry

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.

Handling, Stability, and Analytical Control

Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.

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.

Reference notes

==== Member of the Order of the British Empire (MBE) ==== Civil Division Sotaga Paape. For services to education and the community. Filoimea Telito. For community and public services, especially to education.

== Laboratory use == Pentanes are relatively inexpensive and are the most volatile liquid alkanes at room temperature, so they are often used in the laboratory as solvents that can be conveniently and rapidly evaporated. However, because of their nonpolarity and lack of functionality, they dissolve only nonpolar and alkyl-rich compounds. Pentanes are miscible with most common nonpolar solvents such as chlorocarbons, aromatics, and ethers. They are often used in liquid chromatography.

== Physiology == Human sweat glands are primarily classified as either eccrine or apocrine glands. Eccrine glands open directly onto the surface of the skin, while apocrine glands open into hair follicles. Eccrine glands are the predominant sweat gland in the human body with numbers totaling up to 4 million. They are located within the reticular dermal layer of the skin and distributed across nearly the entire surface of the body with the largest numbers occurring in the palms and soles. Eccrine sweat is secreted in response to both emotional and thermal stimulation. Eccrine glands are primarily innervated by small-diameter, unmyelinated class C-fibers from postganglionic sympathetic cholinergic neurons. Increases in body and skin temperature are detected by visceral and peripheral thermoreceptors, which send signals via class C and Aδ-fiber afferent somatic neurons through the lateral spinothalamic tract to the preoptic nucleus of the hypothalamus for processing. In addition, there are warm-sensitive neurons located within the preoptic nucleus that detect increases in core body temperature. Efferent pathways then descend ipsilaterally from the hypothalamus through the pons and medulla to preganglionic sympathetic cholinergic neurons in the intermediolateral column of the spinal cord. The preganglionic neurons synapse with postganglionic cholinergic sudomotor (and to a lesser extent adrenergic) neurons in the paravertebral sympathetic ganglia.

When chronic granulomatous disease (CGD) is suspected, neutrophil-function testing should be carried out, and positive findings should be confirmed by genotyping. The p47phox mutation is due to a pseudogene conversion, hence it may not be detectable by standard sequencing; in these cases, an immunoblot or gene dose determination may be needed to confirm p47phox deficiency. Infections caused by the pathogens commonly associated with CGD should prompt functional or genetic screening; neonatal or early postnatal screening of potentially affected children is essential with a family history of CGD. Neutrophil function tests: These include nitroblue tetrazolium (NBT) reduction test, dihydrorhodamine (DHR) 123 test, direct measurement of superoxide production, cytochrome c reduction assay, and chemiluminescence. DHR test is usually preferred because it is easy to use, objective, and it is able to distinguish between X-linked and autosomal forms of CGD; furthermore, it allows to detect gp91phox carriers.

Sources: en.wikipedia.org

Reference notes

While the role of rain water δD as the fundamental control on the final δD of lipids is well documented, the importance of fractionation effects from rain water to soil water and leaf water on εl/w is appreciated but remains poorly understood. Organic biomolecules are generally depleted relative to the δD of leaf water. However, differences between organisms, biosynthetic pathways, and biological roles of different molecules can lead to huge variability in fractionation; the diversity of lipid biomarkers spans a 600‰ range of δD values. Lipid biosynthesis is biochemically complex, involving multiple enzyme-dependent steps that can lead to isotope fractionations. There are three major pathways of lipid biosynthesis, known as the mevalonate pathway, the acetogenic pathway, and the 1-deoxyD-xylulose-5-phosphate/2-methylerythroyl-4-phosphate pathway. The acetogenic pathway is responsible for the production of n-alkyl lipids like leaf waxes, and is associated with a smaller δD depletion relative to source water than the other two lipid biosynthesis pathways. While leaf water is the main source of hydrogen in leaf biomolecules, relatively depleted hydrogen from acetate or NADPH is often added during biosynthesis, and contributes to the HIC of the final molecule. Secondary hydrogen exchange reactions, meaning hydrogenation and dehydrogenation reactions outside of the primary biosynthetic pathway, also contribute substantially to the variability of lipid HIC.

==== S ==== Salami – cured sausage, fermented and air-dried meat, originating from one or a variety of animals. Historically, salami was popular among Southern European peasants because it can be stored at room temperature for periods of up to 30–40 days once cut, supplementing a possibly meager or inconsistent supply of fresh meat. Varieties of salami are traditionally made across Europe. Salumi – Italian cured meat products that are predominantly made from pork. It comes from the Italian word salume, pl. salumi "salted meat", derived from Latin sal "salt". The term salumi also encompasses bresaola, which is made from beef, and also cooked products such as mortadella and prosciutto cotto. Secca de bœuf – a type of dried salted beef made in Entrevaux. Similar to the Swiss Bindenfleisch, it is typically eaten as a starter. Skerpikjøt – a type of wind-dried mutton, is a delicacy of the Faroe Islands which is traditionally eaten at Christmas but also at other times of the year. Slinzega – a type of air-dried meat produced in Valtellina, in the Italian Alps. It is made in a similar manner to Bresaola, with smaller pieces of meat, which therefore bear a stronger taste. Smithfield ham – a specific form of the country ham, A 1926 Statute of Virginia (passed by the Virginia General Assembly) first regulated the usage of the term "Smithfield Ham".

== Marketing == Little Caesars is legally prevented from using its “Pizza! Pizza!” slogan in Canada since the unaffiliated Pizza Pizza restaurant chain holds the countrywide trademark for its name. Instead, Little Caesars uses other slogans such as "Two Pizzas!" and "Delivery! Delivery!".

This activity is usually attributed to the role of proteasomes in the activation of NF-κB which further regulates the expression of pro inflammatory cytokines such as TNF-α, IL-β, IL-8, adhesion molecules (ICAM-1, VCAM-1, P-selectin) and prostaglandins and nitric oxide (NO). Additionally, the UPS also plays a role in inflammatory responses as regulators of leukocyte proliferation, mainly through proteolysis of cyclines and the degradation of CDK inhibitors. Lastly, autoimmune disease patients with SLE, Sjögren syndrome and rheumatoid arthritis (RA) predominantly exhibit circulating proteasomes which can be applied as clinical biomarkers.

melting point Also liquefaction point. The temperature at which a substance changes state from a solid to a liquid. It depends on pressure and is usually specified for a given substance under standard conditions. The melting point of a substance is identical to its freezing point.

Sources: en.wikipedia.org

Reference notes

Washington's resignation as Commander-in-Chief after the Revolutionary War and his later refusal to run for a third term as the country's first president established a precedent for the supremacy of civil authority in the United States and the peaceful transfer of power.

== Cell-surface receptor binding == While traditionally reported for its protease-inhibiting ability, the C-terminal domain of TIMP1 has been shown to bind to cell-surface receptors including the tetraspanins CD63 and CD82. These interactions can activate downstream signaling pathways including the MAPK pathway.

An old qualitative test for the presence of the alkene functional group is that alkenes turn brown aqueous bromine solutions colourless, forming a bromohydrin with some of the dibromoalkane also produced. The reaction passes through a short-lived strongly electrophilic bromonium intermediate. This is an example of a halogen addition reaction.

=== Jcom radio libel case === In November 2007, Jewish radio station Jcom aired a satirical segment in which a character named 'Georgie Galloway' used the anti-Semitic catchphrase "kill the Jews, kill the Jews". Galloway sued the station for libel and won the case in the High Court. Galloway was awarded £15,000 in damages and around £5,000 in costs. The radio station closed after losing the case. Galloway said the judgment had "categorically crushed the slur of anti-Semitism" against him.

Through the Luebering–Rapoport pathway bisphosphoglycerate mutase catalyzes the transfer of a phosphoryl group from C1 to C2 of 1,3-BPG, giving 2,3-BPG. 2,3-bisphosphoglycerate, the most concentrated organophosphate in the erythrocyte, forms 3-PG by the action of bisphosphoglycerate phosphatase. The concentration of 2,3-BPG varies proportionately with the pH, since it is inhibitory to catalytic action of bisphosphoglycerate mutase. Under physiological conditions, the flux through the Rapoport-Luebering shunt is 19% of the main glycolytic flux.

Sources: en.wikipedia.org

Frequently asked questions

What is Semax chemically?

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.

How does it relate to ACTH?

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.

Does it occur naturally?

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.

用什么方法确认分子量?

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。

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