This is a working overview of semax, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-20 and is reviewed periodically as new material appears.
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
| 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 |
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.
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.
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。
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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According to the first option, the spent nuclear fuel is considered complete waste. After an interim storage (wet and dry), all the used fuel is directly disposed of in a deep geological repository. Several geological media and repository designs are being studied according to different natures of fuel and their burnup, radioactive inventory and decay heat generation. The assessment of a geological disposal is based on the multi-barrier approach, which combines multiple effects of engineered and natural barriers in order to delay potential long-lived radionuclide migrations to the biosphere over time. Reprocessing is the alternative option for the spent fuel after a long interim storage. The used fuel is not considered waste anymore but a future energy resource. A large amount of fertile uranium (
=== Glucose transporter (GLUTs) === The glucose transporter (GLUTs) is a type of uniporter responsible for the facilitated diffusion of glucose molecules across cell membranes.Glucose is a vital energy source for most living cells, however, due to its large size, it cannot freely move through the cell membrane. The glucose transporter is specialized in transporting glucose specifically across the membrane. The GLUT proteins have several types of isoforms, each distributed in different tissues and exhibiting different kinetic properties.
The total ion current chromatogram (TICC) represents the summed intensity across the entire range of masses being detected at every point in the analysis. The range is typically several hundred mass-to-charge units or more. In complex samples, the TICC often provides limited information as multiple analytes elute simultaneously, obscuring individual species.
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Medical syringes include disposable and safety syringes, injection pens, needleless injectors, insulin pumps, and specialty needles. Hypodermic syringes are used with hypodermic needles to inject liquid or gases into body tissues, or to remove from the body. Injecting of air into a blood vessel is hazardous, as it may cause an air embolism; preventing embolisms by removing air from the syringe is one of the reasons for the familiar image of holding a hypodermic syringe pointing upward, tapping it, and expelling a small amount of liquid before an injection into the bloodstream. The barrel of a syringe is made of plastic or glass, usually has graduated marks indicating the volume of fluid in the syringe, and is nearly always transparent. Glass syringes may be sterilized in an autoclave. Plastic syringes can be constructed as either two-part or three-part designs. A three-part syringe contains a plastic plunger/piston with a rubber tip to create a seal between the piston and the barrel, where a two-part syringe is manufactured to create a perfect fit between the plastic plunger and the barrel to create the seal without the need for a separate synthetic rubber piston. Two-part syringes have been traditionally used in European countries to prevent introduction of additional materials such as silicone oil needed for lubricating three-part plungers. Most modern medical syringes are plastic because they are cheap enough to dispose of after being used only once, reducing the risk of spreading blood-borne diseases.
Wiechelman, K.; Braun, R. & Fitzpatrick, J. (1988). "Investigation of the bicinchoninic acid protein assay: Identification of the groups responsible for color formation". Anal. Biochem. 175 (1): 231–7. doi:10.1016/0003-2697(88)90383-1. PMID 3245570. Stoscheck, CM. (1990). "6". Quantitation of Protein. Methods in Enzymology. Vol. 182. pp. 50–69. doi:10.1016/0076-6879(90)82008-P. ISBN 9780121820831. PMID 2314256.
The transition from capitalism to socialism was signified by the introduction of the first five-year plan and the 1936 Soviet Constitution. By the late 1920s, Stalin established ideological orthodoxy in the CPSU, Soviet Union, and Communist International to establish universal Marxist–Leninist praxis. The formulation of the Soviet version of dialectical and historical materialism by Stalin and his associates, such as in Stalin's text Dialectical and Historical Materialism, became the official Soviet interpretation of Marxism, and was taken as example by Marxist–Leninists in other countries. This text became the foundation philosophy of Marxism–Leninism. In 1938, Stalin's textbook History of the Communist Party of the Soviet Union (Bolsheviks) popularised Marxism–Leninism. The internationalism of Marxism–Leninism was expressed in supporting revolutions in other countries, initially through the Communist International, then through the concepts of national democratic states and states of socialist orientation after de-Stalinisation. The establishment of other communist states after World War II resulted in Sovietisation, and these states tended to follow the Marxist–Leninist model of five-year plans and rapid industrialisation, political centralisation, and repression. During the Cold War, Marxist–Leninist countries like the Soviet Union were a major force in international relations.
== Biological function == When expressed in nitrogen-fixing organisms, azurin serves as the electron donor to nitrite reductase, an enzyme in the denitrification pathway of the nitrogen cycle. Azurins support oxidative deamination of primary amines by passing electrons from aromatic amine dehydrogenase to cytochrome oxidase, as well as from some c-type cytochromes to nitrite reductases.
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As seen in Fig. 1, the engineered aldehyde tag consists of six amino acids. A set of organisms from all domains of life was chosen and the sequence homology of the sulfatase motif was determined. The sequence used is the best consensus for sequences found in bacteria, archaea, worms and higher vertebrates.
The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. This pericardial sac is filled with a serous fluid for lubrication. The heart itself is divided into a right and left half, each with an atrium and ventricle. The atrium and ventricles of each side are separated by atrioventricular valves which prevent back flow from one chamber to the next during contraction. Being myogenic, the heart's pace is maintained by pacemaker cells found in the sinoatrial node, located on the right atrium. The sinoatrial node uses calcium to cause depolarisation of the signal transduction pathway from the atrium through right and left atrioventricular bundle which communicates contraction to the ventricles. The avian heart also consists of muscular arches that are made up of thick bundles of muscular layers. Much like a mammalian heart, the avian heart is composed of endocardial, myocardial and epicardial layers. The atrium walls tend to be thinner than the ventricle walls, due to the intense ventricular contraction used to pump oxygenated blood throughout the body. Avian hearts are generally larger than mammalian hearts when compared to body mass. This adaptation allows more blood to be pumped to meet the high metabolic need associated with flight.
Analysis of the insect os-d-like gene family. J Chem Ecol. 2004; 30: 889-911. 41. Forêt S, Wanner KW, Maleszka R. Chemosensory proteins in the honeybee: Insights from the annotated genome, comparative analysis and expression profiling. Insect Biochem Mol Biol. 2007; 37: 19-28. 42. Ozaki K, Utoguchi A, Yamada A, Yoshikawa H. Identification and genomic structure of chemosensory proteins (CSP) and odorant binding proteins (OBP) genes expressed in foreleg tarsi of the swallowtail butterfly Papilio xuthus. Insect Biochem Mol Biol. 2008; 38: 969-76. 43. Liu GX, Arnaud P, Offmann B, Picimbon JF. Genotyping and bio-sensing chemosensory proteins in insects. Sensors 2017; 17: 1801. 44. Mei T, Fu WB, Li B, He ZB, Chen B. Comparative genomics of chemosensory protein genes (CSPs) in twenty-two species (Diptera: Culicidae): identification, characterization, and evolution. PLoS ONE 2018; 13: e0190412. 45. Kulmuni J, Wurm Y, Pamilo P. Comparative genomics and chemosensory protein genes reveals rapid evolution and positive selection in ant-specific duplicates. Heredity 2013; 110: 538-547. 46. Pikielny CW, Hasan G, Rouyer F, Rosbach M. Members of a family of Drosophila putative odorant-binding proteins are expressed in different subsets of olfactory hairs. Neuron (1994) 12: 35-49. 47. McKenna MP, Hekmat-Scafe DS, Gaines P, Carlson JR. Putative Drosophila pheromone-binding-proteins expressed in a subregion of the olfactory system. J Biol Chem (1994) 269: 16340-16347. 48. Robertson HM, Martos R, Sears CR, Todres EZ, Walden KK, Nardi JB.
Cannabichromene (CBC) is a minor non-psychotic phytocannabinoid that is capable of anti-inflammatory, anti-nociceptive, and anti-convulsant properties. Research further indicates that CBC induces programmed cell death via apoptosis and ferroptosis in pancreatic cancer cells by serving as a potent agonist of TRPV1 and CB2 receptors. Also, CBC helps the brain to stay healthy by preventing the Neural Stem Progenitor Cells (NSPCs) from turning into reactive astrocytes, which can cause inflammation that can damage the brain.
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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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.