The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-09 and is reviewed periodically as new material appears.
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.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
| 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 |
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
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.
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 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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
The likelihood of developing a new biopharmaceutical successfully is significantly greater than in traditional drug development. 25% of biopharmaceuticals that enter Phase I of the regulatory process eventually are granted approval. The corresponding figure for conventional drugs is less than 6%. The traditionally large share of outsourcing. Small number of custom manufacturers with industrial-scale manufacturing capabilities in this demanding technology. In the Western hemisphere, primarily Boehringer-Ingelheim of Germany and Lonza of Switzerland; in the Eastern hemisphere, Nicholas Piramal of India (through the acquisition of a former Avecia operation) and the joint ventures between AutekBio and Beijing E-Town Harvest International in China and between Biocon in India and Celltrion in South Korea. Same customer category: life science, especially the pharmaceutical industry. Similar business types: custom manufacturing of proprietary drugs; opportunities for generic versions, called biosimilars. Similar regulatory environment: FDA regulations, especially GMP. Existing infrastructure (utilities, etc.) can be used. Cons:
=== Sites of hematopoiesis === The principal site of extramedullary hematopoiesis in myelofibrosis is the spleen, which is usually markedly enlarged, sometimes weighing as much as 4000 g. As a result of massive enlargement of the spleen, multiple subcapsular infarcts often occur in the spleen, meaning that due to interrupted oxygen supply to the spleen partial or complete tissue death happens. On the cellular level, the spleen contains red blood cell precursors, granulocyte precursors and megakaryocytes, with the megakaryocytes prominent in their number and in their bizarre shapes. Megakaryocytes are believed to be involved in causing the secondary fibrosis seen in this condition, as discussed under "Mechanism" above. Sometimes unusual activity of the red blood cells, white blood cells, or platelets is seen. The liver is often moderately enlarged, with foci of extramedullary hematopoiesis. Microscopically, lymph nodes also contain foci of hematopoiesis, but these are insufficient to cause enlargement. There are also reports of hematopoiesis taking place in the lungs. These cases are associated with hypertension in the pulmonary arteries. The bone marrow in a typical case is hypercellular and diffusely fibrotic. Both early and late in disease, megakaryocytes are often prominent and are usually dysplastic.
== Signs and symptoms == These descriptions refer to 'classic' Alport syndrome, which usually causes significant disease from young adult or late childhood life. Some individuals, usually with milder mutations or 'carrier' status, develop disease later, or show only some of the features of classic disease.
=== Oxides === Two oxides of berkelium are known, with the berkelium oxidation state of +3 (Bk2O3) and +4 (BkO2). Berkelium(IV) oxide is a brown solid, while berkelium(III) oxide is a yellow-green solid with a melting point of 1920 °C and is formed from BkO2 by reduction with molecular hydrogen:
Sources: en.wikipedia.org
In the spring of 1948, Liu Wenhui's son Yuanyan, who was studying at West China University and had secretly come into contact with the Communist Youth League, came to Liu to act as an intermediary for negotiations with the Communist Party. However, Liu Wenhui told his son that he had already been in contact with the communists. This contact had happened in 1942, when Liu met with Zhou Enlai in Chongqing to discuss forming an anti-Chiang Kai-shek pact. Liu and Zhou reportedly agreed to jointly resist Chiang and to share intelligence; in a concession to the Xikang warlord, the communists also promised not to organize within Liu's 24th Army. This pact was exemplified by the existence of a covert communist radio station in Ya'an, established in June 1942 under the leadership of Wang Shaochun. This radio station provided Liu with pro-communist battle reports and propaganda, and operated continuously until 1949, helping coordinate the Chengdu Uprising. In 1947, after the Nationalists captured Yan'an and put the communist forces on the backfoot, Liu temporarily stopped providing funding to the radio station; however, he resumed support soon after. Zhou Enlai described Liu as a "political thermometer", who was "sometimes hot, sometimes cold" in his dealings with the Communist Party.
=== Institutional review boards (IRBs) === Approval by an Institutional Review Board (IRB), or Independent Ethics Committee (IEC), is necessary before all but the most informal research can begin. In commercial clinical trials, the study protocol is not approved by an IRB before the sponsor recruits sites to conduct the trial. However, the study protocol and procedures have been tailored to fit generic IRB submission requirements. In this case, and where there is no independent sponsor, each local site investigator submits the study protocol, the consent(s), the data collection forms, and supporting documentation to the local IRB. Universities and most hospitals have in-house IRBs. Other researchers (such as in walk-in clinics) use independent IRBs. The IRB scrutinizes the study both for medical safety and for protection of the patients involved in the study, before it allows the researcher to begin the study. It may require changes in study procedures or in the explanations given to the patient. A required yearly "continuing review" report from the investigator updates the IRB on the progress of the study and any new safety information related to the study.
Emapunil (AC-5216, XBD-173) is an anxiolytic drug which acts as a selective agonist at the peripheral benzodiazepine receptor, also known as the mitochondrial 18 kDa translocator protein or TSPO. This protein has multiple functions, among which is regulation of steroidogenesis, particularly the production of neuroactive steroids such as allopregnanolone in the brain. In both animal and human trials, emapunil produced fast acting anxiolytic and anti-panic effects, without producing sedation or withdrawal symptoms following cessation of use. Emapunil is also used in its 11C radiolabelled form to map the distribution of TSPO receptors in the brain.
== Operations and technology == By 2015, Lineage's facility network was ranked the second-largest in the world by the International Association of Refrigerated Warehouses. With 111 facilities in 21 states, Lineage also ranked as the second largest temperature-controlled warehousing and logistics company in the United States. In September 2020, Lineage raised $1.6 billion in equity for technology and expansion. In March 2021, Lineage raised $1.9 billion in equity for global greenfield developments, facility expansions, M&A and research and development. In July 2021, Lineage partnered with 8VC logistics technology venture capital firm, to further invest in the transportation and logistics technology sector.
=== Recovery from trauma === Bemethyl has also been shown to prevent permanent hearing loss and facilitate recovery of hearing after mine-explosion trauma, when treatment is initiated immediately after injury.
Sources: en.wikipedia.org
=== Mechanism of action === Thrombin is an enzyme that splits fibrinogen into fibrin monomers in 10 to 60 seconds, which aggregate to form a three-dimensional gel-like structure. Thrombin also activates factor XIII from the human body to factor XIIIa, which then cross-links the fibrin monomers to form a stable clot. Both these processes need calcium to work. As the wound heals, the clot is slowly degraded by the enzyme plasmin.
To improve child health and nutrition through regular milk intake. To develop sustainable demand for dairy products among Thai consumers. To provide stable income for local dairy farmers and cooperatives. To ensure that milk distributed under the scheme is produced locally and meets safety standards.
===== Inhibiting interferon response in some cancer cells ===== In HeLa cells SeV (in contrast to vesicular stomatitis virus) can counteract IFN-α pretreatment and keep a viral protein translation level similar to that in IFN-untreated cells.
A spider positioned in the middle of the web makes for a highly visible prey for birds and other predators, even without web decorations; many day-hunting orb-web spinners reduce this risk by hiding at the edge of the web with one foot on a signal line from the hub or by appearing to be inedible or unappetizing. Spiders do not usually adhere to their own webs, because they are able to spin both sticky and non-sticky types of silk, and are careful to travel across only non-sticky portions of the web. However, they are not immune to their own glue. Some of the strands of the web are sticky, and others are not. For example, if a spider has chosen to wait along the outer edges of its web, it may spin a non-sticky prey or signal line to the web hub to monitor web movement. However, in the course of spinning sticky strands, spiders have to touch these sticky strands. They do this without sticking by using careful movements, dense hairs and nonstick coatings on their feet to prevent adhesion.
=== Industrial === Fatty acids are usually produced industrially by the hydrolysis of triglycerides, with the removal of glycerol (see oleochemicals). Phospholipids represent another source. Some fatty acids are produced synthetically by hydrocarboxylation of alkenes.
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.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.