Everything below concerns lyophilised powder. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-21. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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。
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
==== AMPA receptor trafficking to the PSD in response to LTP ==== Once AMPA receptors are transported to the perisynaptic region through PKA or SAP97 phosphorylation, receptors are then trafficked to the postsynaptic density (PSD). However, this process of trafficking to the PSD still remains controversial. One possibility is that, during LTP, there is lateral movement of AMPA receptors from perisynaptic sites directly to the PSD. Another possibility is that exocytosis of intracellular vesicles is responsible for AMPA trafficking to the PSD directly. Recent evidence suggests that both of these processes are happening after an LTP stimulus; however, only the lateral movement of AMPA receptors from the perisynaptic region enhances the number of AMPA receptors at the PSD. The exact mechanism responsible for lateral movement of AMPA receptors to the PSD remains to be discovered; however, research has discovered several essential proteins for AMPA receptor trafficking. For example, overexpression of SAP97 leads to increased AMPA receptor trafficking to synapses. In addition to influencing synaptic localization, SAP97 has also been found to influence AMPA receptor conductance in response to glutamate. Myosin proteins are calcium sensitive motor proteins that have also been found to be essential for AMPA receptor trafficking. Disruption of myosin Vb interaction with Rab11 and Rab11-FIP2 blocks spine growth and AMPA receptor trafficking. Therefore, it is possible that myosin may drive the lateral movement of AMPA receptors in the perisynaptic region to the PSD.
Solvent extraction is used to extract individual lanthanoid elements from the mixtures found in nature in ores such as monazite. In one process, the metal ions in aqueous solution are made to form complexes with tributylphosphate (TBP), which are extracted into an organic solvent such as kerosene. Complete separation is effected by using a countercurrent exchange method. A number of cells are arranged as a cascade. After equilibration, the aqueous component of each cell is transferred to the previous cell and the organic component is transferred to the next cell, which initially contains only water. In this way the metal ion with the most stable complex passes down the cascade in the organic phase and the metal with the least stable complex passes up the cascade in the aqueous phase. If solubility in the organic phase is not an issue, a selectivity coefficient is equal to the ratio of the stability constants of the TBP complexes of two metal ions. For lanthanoid elements which are adjacent in the periodic table this ratio is not much greater than 1, so many cells are needed in the cascade.
In 1914, Lipton's tea was one of the sponsors for the first flight from Melbourne, Australia to Sydney, Australia by French aviator Maurice Guillaux, at the time the longest air mail and air freight flight in the world. Sponsor Lipton printed 250,000 copies of a letter Guillaux wrote saying "I found it the most delicious tea I have ever tasted. ... I found it very soothing to the nerves", and these could be had by sending Lipton a one-penny stamp. For a threepenny stamp, Lipton would send out a quarter-pound pack of tea. In an attempt to change the negative perception of iced tea in the United Kingdom – as 60% claimed they did not like the taste before even trying it – the Unilever PepsiCo joint venture carried out a London-based marketing campaign in 2010 under the slogan "Don't knock it 'til you’ve tried it!"; roaming demonstrators handed out 498,968 samples over the 58-day run. After the campaign, 87% of consumers claimed to enjoy Lipton Ice Tea, while 73% said they were more likely to purchase in the future. A similar campaign, with slogan "Let's Go!", was carried out in mid-2017. Lipton also made commercials starring the Muppets for the 2014 The Walt Disney Company film Muppets Most Wanted.
Also in 1893, Édouard Laguesse suggested that the islet cells of the pancreas, described as "little heaps of cells" by Paul Langerhans in 1869, might play a regulatory role in digestion. These cells were named Islets of Langerhans after the original discoverer. Soon after, it was established that the role of the pancreas in carbohydrate metabolism could be localized to the islets; Eugene Lindsay Opie (1901) confirmed this connection in relation to diabetes mellitus. In 1909, Belgian physician Jean de Mayer hypothesized that the islets secrete a substance that plays this metabolic role, and termed it insulin, from the Latin insula ('island'). Sir Edward Albert Sharpey-Schafer independently proposed the same in 1916, not knowing at the time that de Meyer had made the same suggestion a few years prior. The endocrine role of the pancreas in metabolism, and indeed the existence of insulin, was further clarified between 1921 and 1922 when a group of researchers in Toronto, including Frederick Banting, Charles Best, John MacLeod, and James Collip, were able to isolate and purify the extract.
Sources: en.wikipedia.org
=== Classification of antivirals based on target === Classifying antivirals based on their target of action, the protein or process that they interact with, serves to create two broad categories of antivirals: direct-acting antivirals (DAAs) and host-targeting antivirals (HTAs).
=== Laboratory tests === Laboratory tests including urea and creatinine levels, liver enzymes, glucose, thyroid function, full blood count, and clotting tests. The analysis of serum and urine for presence of monoclonal immunoglobulin is also done through immunofixation for detection of the monoclonal band. Presence of the monoclonal band would be consistent with light chain amyloidosis. For light chain amyloidosis, serum immunoglobulin free light chain assay can be used for diagnosis and following of the amyloidosis. In light-chain amyloidosis, a low paraprotein level can be present.
== Metabolism == The exact metabolic pathways of dimethocaine have not been researched, but the different metabolites have been examined in Wistar rats. After administration of dimethocaine, different metabolites have been found and identified in their urine. Due to these metabolites, different metabolic pathways could have been postulated. The main phase I reactions are ester hydrolysis, deethylation, hydroxylation of the aromatic system, or a combination of these three. The main phase II reactions are N-acetylation, glucuronidation and a combination of both. Different cytochrome P450 isozymes are involved in the initial steps of human metabolism. The N-acetylation is catalyzed by the NAT2 isozyme.
24 June NASA publishes images showing an unexpected and unexplained double crater from what is thought to be the first time human space debris – likely by a spent rocket body – unintentionally hit the lunar surface on 4 March. Early 2022 monkeypox outbreak research:A study reports phylogenomic characterization of the first monkeypox (MP) virus outbreak genome sequences, finding the "presumably slow-evolving" DNA virus has evolved roughly 6–12-fold more mutations than one would expect and 15 SNP mutations since the beginning of the outbreak. The WHO announces that MP is not yet a global public health emergency but a cause for deep concern (25 June). Early overviews and reviews, including about current knowledge about MP prevention and treatment, are published. Scientists are investigating circulating lineages (and potential variants) of the MP virus and compare them to the African endemic lineages. A preprint suggests that cases "where a small fraction of individuals have disproportionately large numbers of partners, can explain the sustained growth of monkeypox cases among the MSM population" (13 June). The MP incubation period is estimated to be 8.5 days on average and up to 21 days (16 June). The 3D-folded structures of the whole proteome of the current DNA virus are predicted, which may be useful for the development of (better or updated) vaccines and drugs (28 June). A study indicates MP contaminated surfaces within hospitals and households could be infectious (30 June).
=== Doctoral students === His doctoral students at the University of California included Roy Elwood Clausen, Carl L. A. Schmidt, and Selman Waksman (the 1952 Nobel Prize in Physiology or Medicine for the discovery of streptomycin).
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.