Everything below concerns peptidase cleavage. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C37H51N9O10S | 游离碱形式 |
| 等电点 | 约 6.5 | 估算值，随缓冲体系变化 |
| 主要降解途径 | 水解与氧化 | 侧链氧化最为常见 |
| 溶液储存 | 2 至 8 摄氏度避光 | 避免反复冻融 |
| 常规分析手段 | 反相色谱与质谱联用 | 氨基酸分析辅助核对 |
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
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.
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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
In Syria, an Israeli airstrike on a copper plant near Aleppo killed 16 members of Iran-backed militias. Hezbollah said that it fired drones at the IDF's headquarters in the Galilee. It also claimed a drone attack in Metula. The IDF confirmed that two drones crashed in northern Israel while a third was intercepted. Acting Minister of Foreign Affairs of Iran made his first overseas visit as foreign minister to Lebanon, during which he confirmed that the Iranian government was engaged in negotiations with the United States hosted by Oman. Forest fires in northern Israel were erupted the entire week which reportedly resulted in 2,500 acres of land burnt and the hospitalization of six Israeli soldiers and five civilians due to smoke inhalation. On 11 June, an Israeli strike on a command and control center in Jwaya killed senior Hezbollah commander Taleb Abdallah and three other militants. The next day, in response to Taleb's killing, Hezbollah launched a barrage of about 90 rockets into Israel targeting an IDF factory, military headquarters in Ein Zeitim and Ami'ad, and an air surveillance station in Meron. It later fired another 70 at the Mount Meron area, and then ten more at Zar'it, bringing the total number of launches to 170. It increased to 215 by the late afternoon. On 13 June, Hezbollah fired 150 rockets and 30 UAVs at 15 targets in northern Israel and the Golan Heights. Amos Hochstein, a senior advisor to US President Joe Biden, arrived in Israel on 17 June to attempt to de-escalate tensions between Israel and Lebanese militias.
The back-end of the nuclear fuel cycle, mostly spent fuel rods, contains fission products that emit beta and gamma radiation, and actinides that emit alpha particles, such as uranium-234 (half-life 245 thousand years), neptunium-237 (2.144 million years), plutonium-238 (87.7 years) and americium-241 (432 years), and even sometimes some neutron emitters such as californium (half-life of 898 years for californium-251). These isotopes are formed in nuclear reactors. It is important to distinguish the processing of uranium to make fuel from the reprocessing of used fuel. Used fuel contains the highly radioactive products of fission (see high-level waste below). Many of these are neutron absorbers, called neutron poisons in this context. These eventually build up to a level where they absorb so many neutrons that the chain reaction stops, even with the control rods completely removed from a reactor. At that point, the fuel has to be replaced in the reactor with fresh fuel, even though there is still a substantial quantity of uranium-235 and plutonium present. In the United States, this used fuel is usually "stored", while in other countries such as Russia, the United Kingdom, France, Japan, and India, the fuel is reprocessed to remove the fission products, and the fuel can then be re-used. The fission products removed from the fuel are a concentrated form of high-level waste as are the chemicals used in the process. While most countries reprocess the fuel carrying out single plutonium cycles, India is planning multiple plutonium recycling schemes and Russia pursues closed cycle.
== Pharmaceutical variants == The recombinant human G-CSF (rhG-CSF) synthesised in an E. coli expression system is called filgrastim. The structure of filgrastim differs slightly from the structure of the natural glycoprotein. Most published studies have used filgrastim. The Food and Drugs Administration (FDA) first approved filgrastim on February 20, 1991, marketed by Amgen with the brand name Neupogen. It was initially approved to reduce the risk of infection in patients with non-myeloid malignancies who are taking myelosuppressive anti-cancer drugs associated with febrile neutropenia with fever. Several bio-generic versions are now also available in markets such as Europe and Australia. Filgrastim (Neupogen) and PEG-filgrastim (Neulasta), or pegylated form of filgratim, are two commercially available forms of rhG-CSF. The pegylated form of filgratim form has a much longer half-life, reducing the necessity of daily injections. The FDA approved the first biosimilar of Neulasta in June 2018. It is made by Mylan and sold as Fulphila. Another form of rhG-CSF called lenograstim is synthesised in Chinese hamster ovary cells (CHO cells). As this is a mammalian cell expression system, lenograstim is indistinguishable from the 174-amino acid natural human G-CSF. No clinical or therapeutic consequences of the differences between filgrastim and lenograstim have yet been identified, but there are no formal comparative studies.
1 August 1919: Sejm Ustawodawczy votes on a resolution on the "Temporary Organisation of Government in the former Prussian Partition" (O tymczasowej organizacji zarządu byłej dzielnicy pruskiej), creating the Ministry of the Former Prussian Partition and a plan of gradual unification of Greater Poland with the rest of the country. 12 August 1919: Władysław Seyda becomes the first minister of the Former Prussian Partition. 19 August 1919: The NRL is dissolved. 28 August 1919: The headquarters of the Polish Army decides that the Greater Polish Army will join the Polish Army and that its headquarters will be transferred to the headquarters of the Seventh Corps. 6 November 1919: The Commission of the NRL is dissolved. 10 January 1920: Ratification of Treaty of Versailles, which has Polish forces in Greater Poland take control over small amounts of Greater Poland's territories given to Poland that are resisting German control and Eastern Pomerania. 13 January 1920: The headquarters of the Greater Poland front orders preparations for implementing the treaty. 17 January 1920: beginning of the occupation of the remaining German-held territories assigned to Poland by the treaty. 8 March 1920: The Greater Poland front is dissolved.
Sources: en.wikipedia.org
Working at the newly relocated Institute for Social Research, Adorno collaborated on influential studies of authoritarianism, antisemitism, and propaganda that would later serve as models for sociological studies the institute carried out in post-war Germany. Upon his return to Frankfurt, Adorno was involved with the reconstitution of German intellectual life through debates with Karl Popper on the limitations of positivist science, critiques of Martin Heidegger's language of authenticity, writings on German responsibility for the Holocaust, and continued interventions into matters of public policy. As a writer of polemics in the tradition of Friedrich Nietzsche and Karl Kraus, Adorno delivered scathing critiques of contemporary Western culture. Adorno's posthumously published Aesthetic Theory (1970), which he had planned to dedicate to Samuel Beckett, is the culmination of a lifelong commitment to modern art, which seeks to revoke the "fatal separation" of feeling and understanding long demanded by the history of philosophy and explode the privilege aesthetics accords to content over form and contemplation over immersion. Adorno was nominated for the 1965 Nobel Prize in Literature by Helmut Viebrock.
After the incident, Marine Catering Services issued a reminder to seafarers that the UK Food Act makes it illegal for crews to fish for food from their vessels. In September 2016, a British holidaymaker died while on honeymoon in Mexico after consuming fish contaminated with the toxins. During October 2016, more than 100 people suffered from ciguatera poisoning after eating fish heads supplied by an export firm in Mangalore, India.
In people with sIBM, the muscle cells display "flags" telling the immune system that they are infected or damaged (the muscles ubiquitously express MHC class I antigens) and this immune process leads to the death of muscle cells. The chronic stimulation of these antigens also causes stress inside the muscle cell in the endoplasmic reticulum (ER) and this ER stress may be enough to cause a self-sustaining T cell response (even after a virus has dissipated). In addition, this ER stress may cause the misfolding of protein. The ER is in charge of processing and folding molecules carrying antigens. In IBM, muscle fibers are overloaded with these major histocompatibility complex (MHC) molecules that carry the antigen protein pieces, leading to more ER stress and more protein misfolding. A self-sustaining T cell response would make sIBM a type of autoimmune disorder. When studied carefully, it has not been possible to detect an ongoing viral infection in the muscles. One theory is that a chronic viral infection might be the initial triggering factor setting IBM in motion. There have been a handful of IBM cases – approximately 15 – that have shown clear evidence of a virus called HTLV-1. The HTLV-1 virus can cause leukemia, but in most cases lies dormant and most people end up being lifelong carriers of the virus. One review says that the best evidence points towards a connection with some type of retrovirus and that a retroviral infection combined with immune recognition of the retrovirus is enough to trigger the inflammation process.
Sources: en.wikipedia.org
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。
甲硫氨酸侧链含硫醚，在氧气、光照或金属离子存在时容易被氧化。氧化产物极性略增，常在色谱图上表现为主峰之前的肩峰或前伸峰。
通常建议冷藏避光，并在较短时间内使用。不存在适用于所有配方的统一期限，具体取决于浓度、缓冲体系与容器材质。
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.