A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-23 and is reviewed periodically as new material appears.
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.
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。
| 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 |
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
The resulting Treaty of Córdoba, which was signed on 24 August, kept all existing laws, including the 1812 Constitution, in force until a new constitution for Mexico could be written. O'Donojú became part of the provisional governing junta until his death on 8 October. Both the Spanish Cortes and Ferdinand VII rejected the Treaty of Córdoba, and the final break with the mother country came on 19 May 1822, when the Mexican Congress conferred the throne on Iturbide. Spain initiated attempts to reconquer Mexico and it did not recognize Mexico's independence until 1836. Central America gained its independence along with New Spain. On 15 September 1821, an Act of Independence was signed in Guatemala City which declared Central America (Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica) independent from Spain. The regional elites supported the terms of the Plan of Iguala and orchestrated the union of Central America with the Mexican Empire in January 1822. One years later, following Iturbide's downfall, the region, with the exception of Chiapas, peacefully seceded from Mexico on 1 July 1823, establishing the Federal Republic of Central America. The new state existed for seventeen years, centrifugal forces pulling the individual provinces apart by 1840.
Plantain plantations are vulnerable to destruction by hurricanes, because Musa spp. do not withstand high winds well. An average plantain provides about 920 kilojoules (220 kilocalories) of food energy and is a good source of potassium and dietary fiber. The sap from the fruit peel, as well as the entire plant, can stain clothing and hands, and can be difficult to remove.
Radioactive precursors of DNA and RNA, [3H]-thymidine and [3H]-uridine respectively, may be introduced to living cells to determine the timing of several phases of the cell cycle. RNA or DNA viral sequences can also be located in this fashion. These probes are usually labeled with 32P, 33P, or 35S. In the realm of behavioral endocrinology, autoradiography can be used to determine hormonal uptake and indicate receptor location; an animal can be injected with a radiolabeled hormone, or the study can be conducted in vitro.
Skeletal muscle cells, also called muscle fibers are the individual contractile cells within a muscle. A single muscle such as the biceps in a young adult male contains around 253,000 muscle fibers. Skeletal muscle fibers are multinucleated with the nuclei often referred to as myonuclei. This occurs during myogenesis with the fusion of myoblasts each contributing a nucleus. Fusion depends on muscle-specific proteins known as fusogens called myomaker and myomerger. Many nuclei are needed by the skeletal muscle cell for the large amounts of proteins and enzymes needed to be produced for the cell's normal functioning. A single muscle fiber can contain from hundreds to thousands of nuclei. A muscle fiber for example in the human biceps with a length of 10 cm can have as many as 3,000 nuclei. Unlike in a non-muscle cell where the nucleus is centrally positioned, the myonucleus is elongated and located close to the sarcolemma (membrane). The myonuclei are quite uniformly arranged along the fiber with each nucleus having its own myonuclear domain where it is responsible for supporting the volume of cytoplasm in that particular section of the myofiber. A group of muscle stem cells known as myosatellite cells, also satellite cells are found between the basement membrane and the sarcolemma of muscle fibers. These cells are normally quiescent but can be activated by exercise or pathology to provide additional myonuclei for muscle growth or repair.
Sources: en.wikipedia.org
=== Birth-and-death of MHC class I genes === Birth-and-death evolution asserts that gene duplication events cause the genome to contain multiple copies of a gene which can then undergo separate evolutionary processes. Sometimes these processes result in pseudogenization (death) of one copy of the gene, though sometimes this process results in two new genes with divergent function. It is likely that human MHC class Ib loci (HLA-E, -F, and -G) as well as MHC class I pseudogenes arose from MHC class Ia loci (HLA-A, -B, and -C) in this birth-and-death process.
== Awards == Peak Scientific has received The Queen's Award for Enterprise: International Trade in 2004, 2007, 2011, 2014 and in 2016. In 2016 Peak Scientific Instruments Ltd also received the Queen's Award for Enterprise: Innovation.
Christianity and Druze are Abrahamic religions that share a historical traditional connection with some major theological differences. The two faiths share a common place of origin in the Middle East and are both monotheistic. Christian and Druze communities share a long history of interaction dating back roughly a millennium, particularly in Mount Lebanon. Over the centuries, they have interacted and lived together peacefully, sharing common social and cultural landscapes, despite occasional exceptions. Moreover, Druze beliefs, scriptures and teachings incorporate several elements from Christianity. Historically, the relationship between the Druze and Christians has been characterized by harmony and peaceful coexistence. The divisions within society mainly ran along the lines of class distinction between elites and commoners (alahi) instead of along religious divides in places like Mount Lebanon. Amicable relations between the two groups prevailed throughout history, with the exception of some periods, including 1860 Mount Lebanon civil war. In the Levant region, the conversion of Druze to Christianity was a common practice. Throughout history, there have been instances where prominent members of the Druze community, including some of Shihab dynasty members, as well as the Abi-Lamma clan, embraced Christianity. Bashir Shahib II even presented himself as Druze to Druze populations and as Christian to Christian populations.
Indigenous healers often claim to have learned by observing that sick animals change their food preferences to nibble at bitter herbs they would normally reject. Field biologists have provided corroborating evidence based on observation of diverse species, such as chickens, sheep, butterflies, and chimpanzees. The habit of changing diet has been shown to be a physical means of purging intestinal parasites. Sick animals tend to forage plants rich in secondary metabolites, such as tannins and alkaloids.
oxidized ferredoxin + NADH + H+ Thus, the two substrates of this enzyme are reduced ferredoxin and NAD+, whereas its 3 products are oxidized ferredoxin, NADH, and H+. This enzyme participates in fatty acid metabolism. This enzyme belongs to the family of oxidoreductases, specifically those acting on iron-sulfur proteins as donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme is ferredoxin:NAD+ oxidoreductase. There are a variety of names in common use:
Sources: en.wikipedia.org
The American film critic Pare Lorentz defines a documentary film as "a factual film which is dramatic." Others further state that a documentary stands out from the other types of non-fiction films for providing an opinion, and a specific message, along with the facts it presents. Scholar Betsy McLane asserted that documentaries are for filmmakers to convey their views about historical events, people, and places which they find significant. Therefore, the advantage of documentaries lies in introducing new perspectives which may not be prevalent in traditional media such as written publications and school curricula. Documentary practice is the complex process of creating documentary projects. It refers to what people do with media devices, content, form, and production strategies to address the creative, ethical, and conceptual problems and choices that arise as they make documentaries. Documentary filmmaking can be used as a form of journalism, advocacy, or personal expression.
During the 1970s, the expansion of Arby's took place at a rate of 50 stores per year. During this time it created several menu items, including the Beef 'n Cheddar, Jamocha Shakes, chicken sandwiches, curly fries, and two signature sauces: Arby's Sauce and Horsey Sauce. Baked potatoes were added to the menu in 1985. Curly fries were initially introduced as Curly-Q Fries in 1988. It became the first restaurant in the fast food industry to offer a complete "lite" menu in 1991 with several sandwiches and salads under 300 calories and 94 percent fat-free. The family-owned business tried converting into a public company in 1970 by offering the sale of stock, but the IPO never went through when the stock market subsequently fell. Arby's filed for reorganization with the United States bankruptcy court in February 1971, owing to a large number of debts accrued in expansion, as well as a nationwide recession and relatively high price point compared to other fast-food chains of the time. In 1976, the family sold the company to RC Cola for $18 million and Leroy Raffel remained as CEO until his retirement three years later. In 1984, Victor Posner obtained Arby's via a hostile takeover of its then parent Royal Crown through his DWG Corporation. Nine years later, with a new owner of DWG Corporation and a new name, Triarc Companies, Inc., a former PepsiCo executive, Don Pierce, was brought in to "resurrect" Arby's. With $100 million additional funding, Pierce moved to a new "Roast Town" concept, similar in format to Boston Market, in 1996.
=== Marketing === It may be used in generic labels and store brands, Benylin DM, Mucinex DM, Camydex-20 tablets, Komix DT, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, TheraFlu, Charcoal D, Medicon Cinfatós and others.
== Endurance sports == The use of performance-enhancing drugs in sport has become an increasing problem across a wide range of sports. It is defined as any substance or drug that, when taken, gives an athlete an unfair advantage relative to a "clean" athlete. The banning of these drugs promotes a level playing field and equality among athletes. The use of 'the suit' in swimming, which gives athletes an advantage in the way of hydrodynamics, has been banned from international competition due to the unfair advantage it delivered. The drugs taken by athletes differ widely based on the performance needs of the sport. Erythropoietin (EPO) is largely taken by endurance athletes who seek a higher level of red blood cells, which leads to more oxygenated blood, and a higher VO2 max. An athlete's VO2 max is highly correlated with success within endurance sports such as swimming, long-distance running, cycling, rowing, and cross-country skiing. EPO has recently become prevalent amongst endurance athletes due to its potency and low degree of detectability when compared to other methods of doping such as blood transfusion. While EPO is believed to have been widely used by athletes in the 1990s, there was not a way to directly test for the drug until 2002 as there was no specific screening process to test athletes. Athletes at the Olympic Games are tested for EPO through blood and urine tests. Stringent guidelines and regulations can lessen the danger of doping that has existed within some endurance sports. A notable case being TJ Dillashaw.
The L-type amino acid transporter (LAT1) is a uniporter that mediates the transport of neutral amino acids like L-tryptophan, leucine, histidine, proline, alanine, etc. LAT1 favors the transport of amino acids with large branched or aromatic side chains. The amino acid transporter functions to move essential amino acids into the intestinal epithelium, placenta, and blood-brain barrier for cellular processes such as metabolism and cell signaling. The transporter is of particular significance in the central nervous system as it provides the necessary amino acids for protein synthesis and neurotransmitter production in brain cells. Aromatic amino acids like phenylalanine and tryptophan are precursors for neurotransmitters like dopamine, serotonin, and norepinephrine. LAT1 is a membrane protein of the SLC7 family of transporters and works in conjunction with the SLC3 family member 4F2hc to form a heterodimeric complex known as the 4F2hc complex. The heterodimer consists of a light chain and a heavy chain covalently bonded by a disulfide bond. The light chain is the one that carries out transport, while the heavy chain is needed to stabilize the dimer. There is some controversy over whether LAT1 is an uniporter or an antiporter. The transporter has uniporter characteristics of transporting amino acids into cells in a unidirectional manner down the concentration gradient. However, recently it has been found that the transporter has antiporter characteristics of exchanging neutral amino acids for abundant intracellular amino acids.
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.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。