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.
Updated 2025-09-07. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
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.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
== External links == https://www.bruker.com/fileadmin/user_upload/8-PDF-Docs/Separations_MassSpectrometry/InstructionForUse/8702557_IFU_Bruker_Guide_MALDI_Sample_Preparation_Revision_E.pdf http://www.matrixscience.com/help/pmf_help.html http://www.matrixscience.com/cgi/search_form.pl?FORMVER=2&SEARCH=PMF https://www.youtube.com/watch?v=xh8GGzsc2r4
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscles and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square metres, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that forms the dermis and subcutaneous tissues. The epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers by diffusion from the dermis since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95 percent of the epidermis.
== Types == There are mainly two types of granules based on the presence or absence of a membrane: membrane-bound granules, and non-membrane-bound granules. Eosinophilic granules, basophilic granules, and secretory granules are examples of membrane-bound granules, while P-granules and stress granules are examples of non-membrane-bound granules.
At the 1922 and 1923 elections, the Liberals won barely a third of the vote and only a quarter of the seats in the House of Commons as many radical voters abandoned the divided Liberals and went over to Labour. In 1922, Labour became the official opposition. A reunion of the two warring factions took place in 1923 when the new Conservative prime minister Stanley Baldwin committed his party to protective tariffs, causing the Liberals to reunite in support of free trade. The party gained ground in the 1923 general election but made most of its gains from Conservatives whilst losing ground to Labour—a sign of the party's direction for many years to come. The party remained the third largest in the House of Commons, but the Conservatives had lost their majority. There was much speculation and fear [by whom?] about the prospect of a Labour government and comparatively little about a Liberal government, even though it could have plausibly presented an experienced team of ministers compared to Labour's almost complete lack of experience as well as offering a middle ground that could obtain support from both Conservatives and Labour in crucial Commons divisions. However, instead of trying to force the opportunity to form a Liberal government, Asquith decided instead to allow Labour the chance of office in the belief that they would prove incompetent, and this would set the stage for a revival of Liberal fortunes at Labour's expense, but it was a fatal error.
Sources: en.wikipedia.org
Asparagine peptide lyase are one of the seven groups in which proteases, also termed proteolytic enzymes, peptidases, or proteinases, are classified according to their catalytic residue. The catalytic mechanism of the asparagine peptide lyases involves an asparagine residue acting as nucleophile to perform a nucleophilic elimination reaction, rather than hydrolysis, to catalyse the breaking of a peptide bond. The existence of this seventh catalytic type of proteases, in which the peptide bond cleavage occurs by self-processing instead of hydrolysis, was demonstrated with the discovery of the crystal structure of the self-cleaving precursor of the Tsh autotransporter from E. coli.
Some species of starfish can reproduce asexually as adults either by fission of their central discs or by autotomy (self-amputation) of one or more of their arms. Single arms that regenerate a whole individual are called comet forms. The larvae of several species of starfish can reproduce asexually before they reach maturity. They do this by autotomising some parts of their bodies or by budding. Larvae increase asexual reproduction when they sense that food is plentiful. Though this costs time and energy and delays maturity, it allows a single larva to give rise to multiple adults when the conditions are appropriate.
== Production of biopharmaceuticals == Lemna has been transformed by molecular biologists to express proteins of pharmaceutical interest. Expression constructs were engineered to cause Lemna to secrete the transformed proteins into the growth medium at high yield. Since the Lemna is grown on a simple medium, this substantially reduces the burden of protein purification in preparing such proteins for medical use, promising substantial reductions in manufacturing costs. In addition, the host Lemna can be engineered to cause secretion of proteins with human patterns of glycosylation, an improvement over conventional plant gene-expression systems. Several such products are being developed, including monoclonal antibodies.
Generally, gold nanoparticles are produced in a liquid ("liquid chemical methods") by reduction of chloroauric acid (H[AuCl4]). To prevent the particles from aggregating, stabilizing agents are added. Citrate acts both as the reducing agent and colloidal stabilizer. They can be functionalized with various organic ligands to create organic-inorganic hybrids with advanced functionality.
Just as Augustus's Domus on the Palatine was connected to the Temple of Apollo Palatinus, Hitler's palace was to have been connected by a cryptoporticus to the Volkshalle, which filled the entire north side of the forum. This truly enormous building was, according to Speer, inspired by Hadrian's Pantheon, which Hitler visited privately on May 7, 1938. But Hitler's interest in and admiration for the Pantheon predated this visit, since his sketch of the Volkshalle dates from about 1925. Hermann Giesler records a conversation he had with Hitler in the winter of 1939–40, when Hitler was recalling his “Roman Impressions” (Römische Impressionen):
Sources: en.wikipedia.org
The heart has four valves, which separate its chambers. One valve lies between each atrium and ventricle, and one valve rests at the exit of each ventricle. The valves between the atria and ventricles are called the atrioventricular valves. Between the right atrium and the right ventricle is the tricuspid valve. The tricuspid valve has three cusps, which connect to chordae tendinae and three papillary muscles named the anterior, posterior, and septal muscles, after their relative positions. The mitral valve lies between the left atrium and left ventricle. It is also known as the bicuspid valve due to its having two cusps, an anterior and a posterior cusp. These cusps are also attached via chordae tendinae to two papillary muscles projecting from the ventricular wall. The papillary muscles extend from the walls of the heart to valves by cartilaginous connections called chordae tendinae. These muscles prevent the valves from falling too far back when they close. During the relaxation phase of the cardiac cycle, the papillary muscles are also relaxed and the tension on the chordae tendineae is slight. As the heart chambers contract, so do the papillary muscles. This creates tension on the chordae tendineae, helping to hold the cusps of the atrioventricular valves in place and preventing them from being blown back into the atria. Two additional semilunar valves sit at the exit of each of the ventricles. The pulmonary valve is located at the base of the pulmonary artery. This has three cusps which are not attached to any papillary muscles.
Several genera, including Asian coral snakes (Calliophis), burrowing asps (Atractaspis), and night adders (Causus), are remarkable for having exceptionally long venom glands, extending along each side of the body, in some cases extending posterially as far as the heart. Instead of the muscles of the temporal region serving to press out the venom into the duct, this action is performed by those of the side of the body. Considerable variability in biting behavior is seen among snakes. When biting, viperid snakes often strike quickly, discharging venom as the fangs penetrate the skin, and then immediately release. Alternatively, as in the case of a feeding response, some viperids (e.g. Lachesis) bite and hold. A proteroglyph or opisthoglyph may close its jaws and bite or chew firmly for a considerable time. Differences in fang length between the various venomous snakes are likely due to the evolution of different striking strategies. Additionally, it has been shown that the fangs of different species of venomous snakes have different sizes and shapes depending on the biomechanical properties of the snake's prey.
== Evolution == OATPs are present in many animals, including fruit flies, zebrafish, dogs, cows, rats, mice, monkeys and horses. OATPs are not present in bacteria, indicating their evolution from the animal kingdom. However homologs do not correlate well with the human OATPs and therefore it is likely that isoforms arose by gene duplication. OATPs have however been found in insects, suggesting that their evolution was early in the formation of the animal kingdom.
== See also == List of coffeehouse chains List of ice cream parlor chains List of pizza chains List of restaurant chains List of revolving restaurants Lists of restaurants List of defunct restaurants of the United States
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.