Pro-Gly-Pro tail comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-04-19. Numbers and descriptions here follow the published literature rather than marketing material.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
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。
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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
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.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
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.
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.
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.
They described MDMA as inducing "an easily controlled altered state of consciousness with emotional and sensual overtones" comparable "to marijuana, to psilocybin devoid of the hallucinatory component, or to low levels of MDA". While not finding his own experiences with MDMA particularly powerful, Shulgin was impressed with the drug's disinhibiting effects and thought it could be useful in therapy. Believing MDMA allowed users to strip away habits and perceive the world clearly, Shulgin called the drug window. Shulgin occasionally used MDMA for relaxation, referring to it as "my low-calorie martini", and gave the drug to friends, researchers, and others who he thought could benefit from it. One such person was Leo Zeff, a psychotherapist who had been known to use psychedelic substances in his practice. When he tried the drug in 1977, Zeff was impressed with the effects of MDMA and came out of his semi-retirement to promote its use in therapy. Over the following years, Zeff traveled around the United States and occasionally to Europe, eventually training an estimated four thousand psychotherapists in the therapeutic use of MDMA. Zeff named the drug Adam, believing it put users in a state of primordial innocence. Psychotherapists who used MDMA believed the drug eliminated the typical fear response and increased communication. Sessions were usually held in the home of the patient or the therapist. The role of the therapist was minimized in favor of patient self-discovery accompanied by MDMA induced feelings of empathy.
=== Gott ist schön (dissertation 1998) === In his dissertation Gott ist schön (God is Beautiful), which focuses on reception aesthetics and philology, Kermani shows how prominently Islamic tradition perceives the aesthetic dimension of the Koran. The Koran is described as a beguiling, captivating work of art, its beauty capturing people's hearts with an irresistible appeal. The beauty and clarity of the Koran is thus proof of its divine inspiration. According to this conception, God communicates in the Koran in an aesthetically mediated way in hopes to be understood accordingly by those whom the Koran addresses. If God seeks understanding recognition rather than blind obedience, he must encounter receptive people in an aesthetic way. For—at least according to Navid Kermani's thesis informed by his analytical view of Islamic tradition—religious recognition in Islam is conveyed aesthetically as the thrilling, goose bump-inducing hearing of a language described as beautiful, i.e. as an experience of beauty. Kermani is therefore concerned with appreciating the power of aesthetics on a religious level. He views this mystical insight as being entirely in line with the more recent Western aesthetics since Hegel. In almost all philosophical theories of art in the modern tradition, aesthetic experience is about truth. Indeed, contrary to Kant, aesthetic experience need not be about enjoyment or disinterested pleasure. It may simply be about discovering the truth, whatever the cost.
=== Industry growth === The global blood testing market was valued at approximately USD 96.62 billion in 2024 and is projected to reach USD 160.50 billion by 2030, growing at a compound annual growth rate (CAGR) of 8.83%. The DTC segment represents a rapidly growing portion of this market, fueled by increasing consumer health awareness and technological innovations in sample collection and analysis. North America dominates the market with the largest revenue share (approximately 44.83% in 2024), driven by well-established healthcare infrastructure, favorable regulatory environments in many states, and high consumer acceptance of self-directed healthcare services.
The CompTox Chemicals Dashboard is a freely accessible online database created and maintained by the U.S. Environmental Protection Agency (EPA). The database provides access to multiple types of data including physicochemical properties, environmental fate and transport, exposure, usage, in vivo toxicity, and in vitro bioassay. EPA and other scientists use the data and models contained within the dashboard to help identify chemicals that require further testing and reduce the use of animals in chemical testing. The Dashboard is also used to provide public access to information from EPA Action Plans, e.g. around perfluorinated alkylated substances. Originally titled the Chemistry Dashboard, the first version was released in 2016. The latest release of the database (version 3.0.5) contains manually curated data for over 875,000 chemicals and incorporates the latest data generated from the EPA's Toxicity Forecaster (ToxCast) high-throughput screening program. The Chemicals Dashboard incorporates data from several previous EPA databases into one package including the ToxCast Dashboard, the Endocrine Disruption Screening Program (EDSP) Dashboard and the Chemical and Products Database (CPDat).
Sources: en.wikipedia.org
He officially declared Rhaenyra as the Princess of Dragonstone and his living heir over Daemon at a grand ceremony, with hundreds of lords and knights swearing allegiance to her claim while Daemon fled the capital in anger. Following Aemma's death, various members of Viserys' court suggested that he remarry. Though several suggested that he marry the young Laena to stabilize relations between House Targaryen and House Velaryon, Viserys ultimately chose to wed Otto's daughter Lady Alicent Hightower. The two were married in 106 AC, as Rhaenyra poured wine for her new stepmother while Alicent referred to Rhaenyra as her "daughter". This relationship soon soured, as Alicent bore Viserys three children in the next four years: Prince Aegon in 107 AC, Princess Helaena in 109 AC, and Prince Aemond Targaryen in 110 AC. Rhaenyra viewed the births of Aegon and Aemond as being dangerous to her claim to the throne, though Viserys did not change the order of succession even with male heirs. This decision upset Otto, which led to Viserys sending Otto back to his family's seat in Oldtown, after which he appointed Lord Lyonel Strong as his replacement. Two factions began to form within the court, one of which was friendly to Alicent and supportive of her sons' claims to the throne, while the other was supportive of Rhaenyra's claim. On the fifth anniversary of Viserys and Alicent's wedding in 111 AC, Alicent wore a green gown representative of her family's colors, while Rhaenyra wore a black and red dress.
1908: George W. McCoy's discovery that rodents were a reservoir of bubonic plague. 1911: George W. McCoy, Charles W. Chapin, William B. Wherry, and B. H. Lamb described the previously unknown tularemia. 1924: Roscoe R. Spencer and Ralph R. Parker developed a vaccine against Rocky Mountain spotted fever. 1930: Sanford M. Rosenthal developed a treatment for mercury poisoning used widely before the development of dimercaptoethanol. 1943: Wilton R. Earle pioneered the cell culture process and published a paper describing the production of malignancy in vitro, Katherine K. Sanford developed the first clone from an isolated cancer cell, and Virginia J. Evans devised a medium that supported growth of cells in vitro. 1940s–1950s: Bernard Horecker and colleagues described the pentose phosphate pathway. 1950s: Julius Axelrod discovered a new class of enzymes, cytochrome P450 monooxygenases, a fundamental of drug metabolism. 1950: Earl Stadtman discovered phosphotransacetylose, elucidating the role of acetyl CoA in fatty acid metabolism. 1960s: Discovered the first human slow virus disease, kuru, which is a degenerative, fatal infection of the central nervous system. This discovery of a new mechanism for infectious diseases revolutionized thinking in microbiology and neurology. 1960s: Defined the mechanisms that regulate noradrenaline, one of the most important neurotransmitters in the brain. 1960s: Developed the first licensed rubella vaccine and the first test for rubella antibodies for large scale testing.
Heterolytic fragmentation is bond cleavage where the bonding electrons remain with only one of the fragment species. In CID, charge remote fragmentation is a type of covalent bond breaking that occurs in a gas phase ion in which the cleaved bond is not adjacent to the location of the charge. This fragmentation can be observed using tandem mass spectrometry.
Sources: en.wikipedia.org
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。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.