Everything below concerns ACTH analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-09-19. 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. 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.
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.
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。
| 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 |
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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.
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.
When analyte molecules with electronegative / withdrawing elements or functional groups electrons are captured which results in a decrease in current generating a detector response. Nitrogen–phosphorus detector (NPD), a form of thermionic detector where nitrogen and phosphorus alter the work function on a specially coated bead and a resulting current is measured. Dry electrolytic conductivity detector (DELCD) uses an air phase and high temperature (v. Coulsen) to measure chlorinated compounds. Mass spectrometer (MS), also called GC-MS; highly effective and sensitive, even in a small quantity of sample. This detector can be used to identify the analytes in chromatograms by their mass spectrum. Some GC-MS are connected to an NMR spectrometer which acts as a backup detector. This combination is known as GC-MS-NMR. Some GC-MS-NMR are connected to an infrared spectrophotometer which acts as a backup detector. This combination is known as GC-MS-NMR-IR. It must, however, be stressed this is very rare as most analyses needed can be concluded via purely GC-MS. Vacuum ultraviolet (VUV) represents the most recent development in gas chromatography detectors. Most chemical species absorb and have unique gas phase absorption cross sections in the approximately 120–240 nm VUV wavelength range monitored. Where absorption cross sections are known for analytes, the VUV detector is capable of absolute determination (without calibration) of the number of molecules present in the flow cell in the absence of chemical interferences.
The Soviet Union repressed homosexuality. Even during the period when homosexuality was officially legal after the abolition of the Tsarist penal code criminalizing it, Soviet courts attempted to repress non-traditional forms of sexuality, which were widely viewed by Russian revolutionaries as a form of capitalist decadence despite more liberal views on homosexuality from Soviet academic sexologists. After Stalin's consolidation of power, homosexuality became officially recriminalised in 1934. The increased homophobia during this time interval was driven by the economic demands of the First Five-Year Plan, as well as the NKVD's view of homosexuals as "socially harmful elements", although even during this heightened period of repression, a clandestine homosexual subculture was able to persist. Homosexuality remained a criminal offence throughout the remainder of the Soviet Union's existence.
=== International === There are regular regional and international educational medical physics activities. The oldest of these is the International College on Medical Physics at the International Centre for Theoretical Physics (ICTP), Trieste, Italy. This College has educated more than 1000 medical physicists from developing countries.
Targeted mass spectrometry is a mass spectrometry technique that uses multiple stages of tandem mass spectrometry (MSn with n=2 or 3) for ions of specific mass (m/z), at specific time. The values of the m/z and time are defined in an inclusion list which is derived from a previous analysis.
Sources: en.wikipedia.org
=== Music === TikTok has been noted by many media outlets as having a major influence in the music industry. American artist Lil Nas X notably rose to fame after his song "Old Town Road" went viral on TikTok in 2019. He acknowledged the platform's influence in popularizing the song, saying "[TikTok] really boosted the song ... I credit them a lot". Doja Cat has also been noted as an artist who achieved mainstream popularity thanks to her success on TikTok. Insider noted in 2020 that "one of the most popular, pervasive dances of all time" from TikTok was set to Say So, which became her first no.1 hit on the Billboard Hot 100. Pitchfork also noted Doja Cat's "astonishing, unprecedented TikTok reign", saying that before her fame on TikTok, "many people didn't fully register Doja Cat as a star". When it was launched, TikTok allowed users to upload videos that ranged from 3 seconds to 1 minute. The short video length limit led to users making sped-up versions of songs to use in their videos. This allowed them to fit more of the song in their video. Some artists, including SZA and Steve Lacy, released official sped-up versions of their songs after unofficial sped-up remixes of their songs went viral on the platform. TikTok has also helped popularize older songs. Fleetwood Mac's song Dreams re-entered the Billboard Hot 100 over 40 years after its release after a video that featured the song went viral on the platform. Dan Whateley from Insider noted that songs could "rise up organically on the app even if they've been outside the mainstream for decades".
Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent from the first system is transferred onto the second column. Typically the second column has a different separation mechanism, so that bands that are poorly resolved from the first column may be completely separated in the second column. (For instance, a C18 reversed-phase chromatography column may be followed by a phenyl column.) Alternately, the two columns might run at different temperatures. During the second stage of separation the rate at which the separation occurs must be faster than the first stage, since there is still only a single detector. The plane surface is amenable to sequential development in two directions using two different solvents.
==== Corruption ==== There are also cases of corruption amongst customs officers who work for criminal gangs. The amount of corruption amongst customs officers has more than doubled between 2015 and 2017. In October 2017, Tim Deelen, who worked as a customs officer at the Port of Antwerp, was arrested by the Belgian police. He worked for a criminal organisation based in Antwerp. In September 2017, the federal police in Antwerp was sounding the alarm on the increase of cocaine trafficking in the port city, generating a parallel economy and a level of corruption that was never seen before. Customs officers and police officers very often received a large sum of money (up to €100,000 "to relocate containers to avoid police and customs control") by criminal organisations in Antwerp and the Netherlands, to send drugs through the customs controls without being intercepted. The Dutch Ministry of Justice denied that 95% of all the cocaine that arrived at the Port of Antwerp was transported to the Netherlands, and they also denied the relationship of these drugs to the Dutch networks of the Moroccan mafia. However, writer and criminologist Teun Voeten published a book in 2020 called Drugs, where contradictory claims were made in anonymous interviews by Belgian inmates, and by people from certain neighbourhoods in Antwerp. These claims stated that the number of drugs destined for the Netherlands was around 90%. It also stated that criminal organisations based in the Netherlands functioned as distributors for these drugs.
== History == Opioid peptides in the brain were first discovered in 1973 by investigators at the University of Aberdeen, John Hughes and Hans Kosterlitz. They isolated "enkephalins" (from the Greek εγκέφαλος) from pig brain, identified as met-enkephalin and leu-enkephalin. This came after the discovery of a receptor that was proposed to produce the pain-relieving analgesic effects of morphine and other opioids, which led Kosterlitz and Hughes to their discovery of the endogenous opioid ligands. Research during this time was focused on the search for a painkiller that did not have the addictive character or overdose risk of morphine. Rabi Simantov and Solomon H. Snyder isolated morphine-like peptides from calf brain. Eric J. Simon, who independently discovered opioid receptors, later termed these peptides as endorphins. This term was essentially assigned to any peptide that demonstrated morphine-like activity. In 1976, Choh Hao Li and David Chung recorded the sequences of α-, β-, and γ-endorphin isolated from camel pituitary glands for their opioidergic activity. Li determined that β-endorphin produced strong analgesic effects. Wilhelm Feldberg and Derek George Smyth in 1977 confirmed this, finding β-endorphin to be more potent than morphine. They also confirmed that its effects were reversed by naloxone, an opioid antagonist. Studies have subsequently distinguished between enkephalins, endorphins, and endogenously produced true morphine, which is not a peptide.
=== Depression === Pindolol has been investigated as an add-on drug to antidepressant therapy with SSRIs like fluoxetine in the treatment of depression since 1994. The rationale behind this strategy has its basis in the fact that pindolol is an antagonist of the serotonin 5-HT1A receptor. Presynaptic and somatodendritic 5-HT1A receptors act as inhibitory autoreceptors, inhibit serotonin release, and are pro-depressive in their action. This is in contrast to postsynaptic 5-HT1A receptors, which mediate antidepressant effects. By blocking 5-HT1A autoreceptors at doses that are selective for them over postsynaptic 5-HT1A receptors, pindolol may be able to disinhibit serotonin release and thereby improve the antidepressant effects of SSRIs and clomipramine. The results of augmentation therapy with pindolol have been encouraging in early studies of low quality. A 2015 systematic review and meta-analysis of five randomized controlled trials found no overall significant benefit at 2.5 mg although, with regard to patients with SSRI-resistant depression, "once-daily high-dose pindolol (7.5 mg qd) appears to show a promising benefit in these patients". On the other hand, a 2017 systematic review indicated that pindolol's efficacy has been demonstrated in high evidence studies. Initiating pharmacotherapy with an SSRI plus pindolol might accelerate the SSRI's therapeutic impact. Pindolol's antidepressive efficacy may predominantly result from its ability to desensitize 5-HT1A autoreceptors.
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.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。