The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-15 and is reviewed periodically as new material appears.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
=== Phase 1 === (R)-MDMA ((R)-midomafetamine; MM-402) – serotonin, norepinephrine, and dopamine releasing agent and weak serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptor agonist (entactogen and weak psychedelic hallucinogen) STP-1 (STALICLA Therapeutic Package 1) – phosphoric diester hydrolase inhibitor and sodium–potassium–chloride symporter inhibitor Sulforafan alfadex (sulforaphane alfadex; sulforafan α-cyclodextrin; SFX-01, STP-2; broccoli sprout extract) – various actions
==== High resolution melting analysis (HRM) ==== A further method to differentiate converted from unconverted bisulfite-treated DNA is using high-resolution melting analysis (HRM), a quantitative PCR-based technique initially designed to distinguish SNPs. The PCR amplicons are analyzed directly by temperature ramping and resulting liberation of an intercalating fluorescent dye during melting. The degree of methylation, as represented by the C-to-T content in the amplicon, determines the rapidity of melting and consequent release of the dye. This method allows direct quantitation in a single-tube assay, but assesses methylation in the amplified region as a whole rather than at specific CpG sites.
DNA can be manipulated in the laboratory. Restriction enzymes are commonly used enzymes that cut DNA at specific sequences, producing predictable fragments of DNA. DNA fragments can be visualized through use of gel electrophoresis, which separates fragments according to their length. The use of ligation enzymes allows DNA fragments to be connected. By binding ("ligating") fragments of DNA together from different sources, researchers can create recombinant DNA, the DNA often associated with genetically modified organisms. Recombinant DNA is commonly used in the context of plasmids: short circular DNA molecules with a few genes on them. In the process known as molecular cloning, researchers can amplify the DNA fragments by inserting plasmids into bacteria and then culturing them on plates of agar (to isolate clones of bacteria cells). "Cloning" can also refer to the various means of creating cloned ("clonal") organisms. DNA can also be amplified using a procedure called the polymerase chain reaction (PCR). By using specific short sequences of DNA, PCR can isolate and exponentially amplify a targeted region of DNA. Because it can amplify from extremely small amounts of DNA, PCR is also often used to detect the presence of specific DNA sequences.
Report ITU-R BT.2246-3 (2014) The present state of ultra-high definition television Draft New Report ITU-R BT.[UHDTV-DTT TRIALS] (Sub-Working Group 6A-1) Collection of field trials of UHDTV over DTT networks
== Disease relevance == Diseases have been linked to R5P imbalances in cells. Cancers and tumors show upregulated production of R5P correlated to increased RNA and DNA synthesis. Ribose 5-phosphate isomerase deficiency, the rarest disease in the world, is also linked to an imbalance of R5P. Although the molecular pathology of the disease is poorly understood, hypotheses included decreased RNA synthesis. Another disease linked to R5P is gout. Higher levels of G6P lead to a buildup of glycolytic intermediates, that are diverted to R5P production. R5P converts to PRPP, which forces an overproduction of purines, leading to uric acid build up. Accumulation of PRPP is found in Lesch-Nyhan Syndrome. The build up is caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT), which leads to decreased nucleotide synthesis and an increase of uric acid production. Superactivity in PRPS1, the enzyme that catalyzes the R5P to PRPP, has also been linked to gout, as well as neurodevelopmental impairment and sensorineural deafness.
Sources: en.wikipedia.org
== Career == Larsen worked for more than 35 years at DuPont. In her research in mass spectrometry, she worked with a number of ionization sources, from electrospray ionization, matrix-assisted laser desorption/ionization, solid probe introduction with corona discharge ionization, to laserspray ionization. Her fluorinated polymer extraction method, the Larsen method, is required by the Environmental Protection Agency for consumer safety. She is a consultant at Larsen Scientific Consulting. She serves on the editorial advisory board of Spectroscopy. She was an editor for the Journal of the American Society for Mass Spectrometry. She served on a number of board positions for the American Society for Mass Spectrometry: treasurer (1992-1994), vice president for programs (2004-2006), president (2006-2008), and past president (2008-2010). She was elected as an American Chemical Society Fellow in 2017.
=== Retail editions === Half-Life 2 was simultaneously released through Steam, CD, and on DVD in several editions. Customers could order three versions: the" bronze" version includes only Half-Life 2 and Counter-Strike: Source, whereas the "silver" and "gold" editions also include Half-Life: Source and Day of Defeat: Source (ports of the original Half-Life and the Day of Defeat mod to the new engine). The "Gold Edition" additionally includes merchandise, such as a baseball cap, a strategy guide and a CD containing the soundtrack. The boxed retail copies come as standard and collector's editions. The collector's edition includes a T-shirt and sample of the Prima strategy guide. Both the disc and Steam versions require Steam to be installed and active for play to occur. None of the 2004 releases came with an instruction manual, though a reference card was included to guide people through installation and setup. In September 2005, Electronic Arts distributed a "Game of the Year Edition" of Half-Life 2, including Half-Life: Source.
=== Elderly === Valproate may cause increased somnolence in the elderly. In a trial of valproate in elderly patients with dementia, a significantly higher portion of valproate patients had somnolence compared to placebo. In approximately one-half of such patients, there was associated reduced nutritional intake and weight loss.
== Overview == A sequence begins with a greater-than character (">") followed by a description of the sequence (all in a single line). The lines immediately following the description line are the sequence representation, with one letter per amino acid or nucleic acid, and are typically no more than 80 characters in length. For example:
Sources: en.wikipedia.org
== Pharmacokinetics == Absorption of orally administered levothyroxine from the gastrointestinal tract ranges from 40 to 80%, with the majority of the drug absorbed from the jejunum and upper ileum. Levothyroxine absorption is increased by fasting and decreased in certain malabsorption syndromes, by certain foods, and with age. Dietary fiber decreases the bioavailability of the drug. Greater than 99% of circulating thyroid hormones are bound to plasma proteins including thyroxine-binding globulin, transthyretin (previously called thyroxine-binding prealbumin), and albumin. Only free hormone is metabolically active. The primary pathway of thyroid hormone metabolism is through sequential deiodination. The liver is the main site of T4 deiodination, and along with the kidneys, are responsible for about 80% of circulating T3. In addition to deiodination, thyroid hormones are also excreted through the kidneys and metabolized through conjugation and glucuronidation and excreted directly into the bile and the gut, where they undergo enterohepatic recirculation. Half-life elimination is 6–7 days for people with normal lab results; 9–10 days for people with hypothyroidism; 3–4 days for people with hyperthyroidism. Thyroid hormones are primarily eliminated by the kidneys (about 80%), with urinary excretion decreasing with age. The remaining 20% of T4 is eliminated in the stool.
=== Non-surgical === Indicated for people with exposed bone with symptoms of infection. This treatment modality may also be utilised for patients with other co-morbidities which precludes invasive surgical methods. This approach requires antimicrobial mouthwashes, systemic antibiotics and antifungal medication and analgesics.
traffic in refrigerated fruit hit 600,000 short tons (544,311 t; 535,714 long tons). 1908: Japan's first refrigerator cars entered service. The cars were used for seafood transport, as with most other Japanese reefers. 1913: The number of thermally insulated railcars (most of which were cooled by ice) in the U.S. topped 100,000. 1920: The Fruit Growers Express (or FGE, a former subsidiary of the Armour Refrigerator Line) was formed using 4,280 reefers acquired from Armour & Co. 1923: FGE and the Great Northern Railway form the Western Fruit Express (WFE) to compete with the Pacific Fruit Express and Santa Fe Refrigerator Despatch in the West. 1925 to 1930: Mechanically refrigerated trucks enter service and gain public acceptance, particularly for the delivery of milk and ice cream. 1926: The FGE expanded its service into the Pacific Northwest and the Midwest through the WFE and the Burlington Refrigerator Express Company (BREX), its other partly owned subsidiary. FGE purchased 2,676 reefers from the Pennsylvania Railroad. 1928: The FGE formed the National Car Company as a subsidiary to service the meat transportation market. Customers include Kahns, Oscar Mayer, and Rath. 1930: The number of refrigerator cars in the United States reached its maximum of approximately 183,000. 1931: The SFRD reconfigured seven reefers to use dry ice as a cooling agent. 1932: Japanese Government Railways built vehicles specially made for dry ice coolant. 1934: The Interstate Commerce Commission (ICC) regulation #201 came into effect, banning billboard advertisements on freight cars.
Sources: en.wikipedia.org
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
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.