lyophilized powder 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.
Last reviewed on 2026-07-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
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.
| 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 |
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
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.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
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.
=== Obesity === Studies have shown that Ffar3 gene knockout mice fed a high fat diet have significant increases in their food intake and body weights compared to wild-type (i.e., genetically unaltered) mice. These and other studies in animals suggest that the activation of FFAR3 and FFAR2 on L cells by SC-FAs triggers the release of PYY and GLP-1, both of which, among various other activities, inhibit gastric emptying and thereby suppress appetite and the development of obesity. Further studies are needed to determine if FFAR3 plays a similar role in human satiety and obesity. Semaglutide, also called Wegovy, is a peptide with a modified GLP-1-like structure. It strongly stimulates GLP-1 receptors and thereby suppresses appetite and promotes weight loss in obese individuals.
Firstly, chemical reactions have been used to introduce tags into specific sites or proteins for the purpose of probing specific protein functionalities. The isolation of phosphorylated peptides has been achieved using isotopic labeling and selective chemistries to capture the fraction of protein among the complex mixture. Secondly, the ICAT technology was used to differentiate between partially purified or purified macromolecular complexes such as large RNA polymerase II pre-initiation complex and the proteins complexed with yeast transcription factor. Thirdly, ICAT labeling was recently combined with chromatin isolation to identify and quantify chromatin-associated proteins. Finally ICAT reagents are useful for proteomic profiling of cellular organelles and specific cellular fractions. Another quantitative approach is the accurate mass and time (AMT) tag approach developed by Richard D. Smith and coworkers at Pacific Northwest National Laboratory. In this approach, increased throughput and sensitivity is achieved by avoiding the need for tandem mass spectrometry, and making use of precisely determined separation time information and highly accurate mass determinations for peptide and protein identifications.
== Functions == Lpp, along with another OmpA-like lipoprotein called Pal/OprL (P0A912), maintains the stability of the cell envelope by attaching the outer membrane to the cell wall. Lpp has been proposed as a virulence factor of Yersinia pestis, the cause of plague. Y. pestis needs lpp for maximum survival in macrophages and to efficiently kill mouse models of bubonic and pneumonic plague.
Sebastião de Araújo Melo (born 24 July 1958) is a Brazilian lawyer and politician. He has been the mayor of Porto Alegre since 2021. A member of the Brazilian Democratic Movement (MDB) since 1981, he had been a member of the city council from 2001 to 2012 and was the vice-mayor of the city during the mayorship of José Fortunati. In 2018, he was elected as a state deputy to the Legislative Assembly of the state of Rio Grande do Sul, a position he held until 2021. Melo has run for mayor of Porto Alegre on three occasions. The first time, in 2016, he advanced to the second round, but was defeated by Nelson Marchezan Júnior. In 2020, he ran again and advanced once again to the second round, this time winning against Manuela d'Ávila. He would be reelected in 2024 against Maria do Rosário.
Sources: en.wikipedia.org
=== Death === De Duve died on 4 May 2013, at his home in Nethen, Belgium, aged 95. He decided to end his life by legal euthanasia, performed by two doctors and in the presence of his four children. He had been long suffering from cancer and atrial fibrillation, and his health problems were exacerbated by a recent fall in his home. De Duve was cremated as he had willed, and his ashes were distributed among family members and friends.
In 2009, the PLA held its first military exercise in Africa, a humanitarian and medical training practice conducted in Gabon. For the past 10 to 20 years, the PLA has acquired some advanced weapons systems from Russia, including Sovremenny-class destroyers, Sukhoi Su-27 and Kilo-class diesel-electric submarines. It has also started to produce several new classes of destroyers and frigates including the Type 052D class guided-missile destroyer. In addition, the PLAAF has designed its very own Chengdu J-10 fighter aircraft and a new stealth fighter, the Chengdu J-20. The PLA launched the new Jin class nuclear submarines on 3 December 2004 capable of launching nuclear warheads that could strike targets across the Pacific Ocean and have three aircraft carriers, with the latest, the Fujian, launched in 2022. From 2014 to 2015, the PLA deployed 524 medical staff on a rotational basis to combat the Ebola virus outbreak in Liberia, Sierra Leone, Guinea, and Guinea-Bissau. As of 2023, this was the PLA's largest medical assistance mission in another country. China re-organized its military from 2015 to 2016. In 2015, the PLA formed new units including the PLA Ground Force, the PLA Rocket Force, and the PLA Strategic Support Force. In 2016, the CMC replaced the four traditional military departments with a number of new bodies. China replaced its system of seven military regions with newly established Theater Commands: Northern, Southern, Western, Eastern, and Central. In the prior system, operations were segmented by military branch and region.
== In drug discovery == Identification of active sites is crucial in the process of drug discovery. The 3-D structure of the enzyme is analysed to identify active site residues and design drugs which can fit into them. Proteolytic enzymes are targets for some drugs, such as protease inhibitors, which include drugs against AIDS and hypertension. These protease inhibitors bind to an enzyme's active site and block interaction with natural substrates. An important factor in drug design is the strength of binding between the active site and an enzyme inhibitor. If the enzyme found in bacteria is significantly different from the human enzyme then an inhibitor can be designed against that particular bacterium without harming the human enzyme. If one kind of enzyme is only present in one kind of organism, its inhibitor can be used to specifically wipe them out. Active sites can be mapped to aid the design of new drugs such as enzyme inhibitors. This involves the description of the size of an active site and the number and properties of sub-sites, such as details of the binding interaction. Modern database technology called CPASS (Comparison of Protein Active Site Structures) however allows the comparison of active sites in more detail and the finding of structural similarity using software.
During the course of the symposium a semantic difficulty became apparent. To some of the participants, "microsomes" mean the ribonucleoprotein particles of the microsome fraction contaminated by other protein and lipid material; to others, the microsomes consist of protein and lipid contaminated by particles. The phrase "microsomal particles" does not seem adequate, and "ribonucleoprotein particles of the microsome fraction" is much too awkward. During the meeting, the word "ribosome" was suggested, which has a very satisfactory name and a pleasant sound. The present confusion would be eliminated if "ribosome" were adopted to designate ribonucleoprotein particles in sizes ranging from 35 to 100S. Albert Claude, Christian de Duve, and George Emil Palade were jointly awarded the Nobel Prize in Physiology or Medicine, in 1974, for the discovery of the ribosome. The Nobel Prize in Chemistry 2009 was awarded to Venkatraman Ramakrishnan, Thomas A. Steitz, and Ada E. Yonath for determining the detailed structure and mechanism of the ribosome.
Slavery in Korea existed since before the Three Kingdoms of Korea period, in the first century BCE. Slavery has been described as "very important in medieval Korea, probably more important than in any other East Asian country, but by the 16th century, population growth was making [it] unnecessary". Slavery went into decline around the 10th century but came back in the late Goryeo period when Korea also experienced multiple slave rebellions. In the Joseon period of Korea, members of the slave class were known as nobi. The nobi were socially indistinct from freemen (i.e., the middle and common classes) other than the ruling yangban class, and some possessed property rights, and legal and civil rights. Hence, some scholars argue that it is inappropriate to call them "slaves", while some scholars describe them as serfs. The nobi population could fluctuate up to about one-third of the total, but on average the nobi made up about 10% of the total population. In 1801, the majority of government nobi were emancipated, and by 1858, the nobi population stood at about 1.5 percent of the Korean population. During the Joseon period, the nobi population could fluctuate up to about one-third of the population, but on average the nobi made up about 10% of the total population. The nobi system declined beginning in the 18th century. Since the outset of the Joseon dynasty and especially beginning in the 17th century, there was harsh criticism among prominent thinkers in Korea about the nobi system.
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.
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.