ACTH 片段 raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-03-06 and is reviewed periodically as new material appears.
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.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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。
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。
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.
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.
== Probe design == The basic unit of ABPP is the activity-based probe (ABP), which are small-molecule probes engineered to profile enzymatic activities of a range of related enzymes within a complex proteome. Although specific architectures vary, most ABPs share three modular components: (1) a reactive group (RG, sometimes called a "warhead"), (2) a linker or binding element, and (3) a tag used for detection or enrichment. This modularity allows probes to achieve broad yet mechanistically meaningful coverage of an enzyme class while minimizing off-target reactivity.
The Spanish navy had been totally dismantled by a disastrous naval policy and relegated to the background by the urgency of the war against Napoleon itself. To 1817, Tsar Alexander supported reactionary governments. Ferdinand VII applied to the Tsar to purchase vessels. The Tsar agreed to this request with the offer of the sale of some of his own vessels. The agreement was finally negotiated at Madrid, between Dmitry Tatishchev, Russian ambassador, and Eguia, Minister of war. It was apparently known only to these two, and to the king himself. The text of the treaty of sale has not been found in the Spanish naval archives. This diplomatic transaction was veiled in the deepest secrecy against Spanish Navy and Minister of Navy. The requested fleet would consist of 5 warships and 3 frigates. The squadron would be delivered to Cadiz, duly armed, and supplied. The arrival of the Russian fleet in Cadiz in February 1818 was not to the liking of the Spanish navy, which was dissatisfied with the state of deterioration in which some supposedly new ships were found: between 1820 and 1823 all the warships were scrapped as being useless. This fiasco put an end to the whole plan to reconquer the Rio de la Plata, which would end with the uprising of the Spanish Army in Cadiz (Trienio Liberal). In 1818 one of the frigates (Maria Isabel aka Patrikki) was captured in the Pacific, after the uprising of one of the Spanish troop transports that went over to the side of the American rebels delivering all the keys, routes and signals for the capture of the frigate.
Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the fifth-most populous country, with a population of over 241.5 million, having the second-largest Muslim population in the world as of 2023. Islamabad is the nation's capital, while Karachi is its largest city and financial centre. Pakistan is the 33rd-largest country by area. Bounded by the Arabian Sea on the south, the Gulf of Oman on the southwest, and the Sir Creek on the southeast, it shares land borders with India to the east; Afghanistan to the west; Iran to the southwest; and China to the northeast. It shares a maritime border with Oman in the Gulf of Oman, and is separated from Tajikistan in the northwest by Afghanistan's narrow Wakhan Corridor. Pakistan is the site of several ancient cultures, including the 8,500-year-old Neolithic site of Mehrgarh in Balochistan, the Indus Valley Civilisation of the Bronze Age, and the ancient Gandhara civilisation. The regions that compose the modern state of Pakistan were the realm of multiple empires and dynasties, including the Achaemenid, the Maurya, the Kushan, the Gupta; the Umayyad Caliphate in its southern regions, the Hindu Shahis, the Ghaznavids, the Delhi Sultanate, the Samma, the Shah Miris, the Mughals, and finally, the British Raj from 1858 to 1947.
=== Ecuador intervention === On March 6, 2026, the Operation was expanded militarily in Ecuador when the United States participated in bombing Comandos de la Frontera, during the Ecuadorian conflict (2024–present).
=== N-Alkylation === Intramolecular amide N-alkylation of alpha-haloacetamide amides 8 with ethanolic potassium hydroxide using ultrasonication gave the 2,5-diketopiperazines 9, where 8 was obtained by an Ugi reaction between amines, aldehydes, isocyanides, and chloroacetic acid. However this route is limited by epimerization at the stereogenic centre and failure to obtain the 2,5-diketopiperazine ring if R1 = Alkyl.
Sources: en.wikipedia.org
==== Gastrointenstinal tract ==== Age-related changes in OPRK1 gene expression were observed in mouse gastrointestinal tract, with mRNA expression significantly decreased in the distal ileum in 12-month-old mice compared to 6-month-old animals, though no statistically significant differences were detected in the stomach and colon. Protein expression of dynorphin in the colon was lower in older mice.
Horsepox is extinct in the wild, and the only known sample was collected in 1976. Because the sample was collected at the end of the smallpox eradication campaign, scientists considered the possibility that horsepox is a strain of vaccinia that had escaped into the wild. However, as more smallpox vaccines were sequenced, older vaccines were found to be more similar to horsepox than modern vaccinia strains. A smallpox vaccine manufactured by Mulford in 1902 is 99.7% similar to horsepox, closer than any previously known strain of vaccinia. Modern Brazilian vaccines with a documented introduction date of 1887, made from material collected in an 1866 outbreak of "cowpox" in France, are more similar to horsepox than other strains of vaccinia. Five smallpox vaccines manufactured in the United States in 1859–1873 are most similar to each other and horsepox, as well as the 1902 Mulford vaccine. One of the 1859–1873 vaccines was identified as a novel strain of horsepox, containing a complete gene from the 1976 horsepox sample that has deletions in vaccinia.
The citation description "For exceptionally meritorious conduct in the performance of outstanding services to the Government of the United States from June 1944 to August 1945. He has made an essential contribution to Pan-American Solidarity in further strengthening the bond and understanding between the United States of America and Ecuador. Under his able guidance and direction, the Navy of Ecuador, cooperating with the Armed Forces of the United States, assisted in consolidating Western Hemispheric Defense during the critical period of the war." In 1948, then Brigadier General John Frederick Boyce Combe was made an Officer of the Legion for his contribution "to the over-all success Allied forces in Italy" during World War II. In 1948, Air Chief Marshal Donald Perera VSV, USP, Sri Lanka Air Force. In 1950 Air Commodore Leonard Birchall (Royal Canadian Air Force) was made an officer of the Legion for his life imperiling heroic actions as a Japanese POW in WWII: "His exploits became legendary throughout Japan and brought renewed faith and strength to many hundreds of ill and disheartened prisoners." – U.S. President Harry S. Truman. In 1953, The President of the United States of America, authorized by Act of Congress, 20 July 1942, takes pleasure in presenting the Legion of Merit, in the Degree of Officer to Major General [then Brigadier General] Ham Byong Sun, Republic of Korea Army, for exceptionally meritorious conduct in the performance of outstanding services to the Government of the United States from 28 April 1951 to 3 April 1952.
== External links == Hepatocyte+growth+factor at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Hepatocyte growth factor on the Atlas of Genetics and Oncology UCSD Signaling Gateway Molecule Page on HGF Overview of all the structural information available in the PDB for UniProt: P14210 (Hepatocyte growth factor) at the PDBe-KB.
Sources: en.wikipedia.org
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.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.