A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-08-25. Anything still debated is marked as such rather than presented as settled.
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
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.
==== Australia and New Zealand ==== Australia and New Zealand published nutrient reference values including guidelines for dietary vitamin D intake in 2006. About a third of Australians have vitamin D deficiency.
== Awards == In 1980, she was the recipient of a Guggenheim Fellowship. Other honors include the Award for Distinguished Contributions to Psychology in the Public Interest of the American Psychological Association, the NYU Alumni Achievement Award, the Liberty Science Center Genius Award, the Distinguished Contributions of Basic Science to Applied Psychology award from the American Association of Applied and Preventive Psychology, the James McKeen Cattel Award, and the Gordon Allport Intergroup Relations Prize.
=== Metal chelation and antioxidant systems === Trace transition metals, particularly iron and copper, can accelerate oxidative reactions in foods and other sensitive products. Metal-chelating packaging contains compounds that bind these metals and reduce their ability to promote oxidation. Chelating compounds may be immobilised on a polymer surface so that they interact with the product without being directly mixed into it. This approach has been studied as a method for improving oxidative stability and reducing dependence on directly added preservatives. Antioxidants can also be incorporated into films, coatings, labels, or sachets. The active compound may remain immobilised on the package surface or be designed to migrate within regulated limits.
Graphene exhibits high electron mobility at room temperature, with values reported in excess of 15000 cm2⋅V−1⋅s−1. Hole and electron mobilities are nearly identical. The mobility is independent of temperature between 10 K and 100 K, showing minimal change even at room temperature (300 K), suggesting that the dominant scattering mechanism is defect scattering. Scattering by graphene's acoustic phonons intrinsically limits room temperature mobility in freestanding graphene to 200000 cm2⋅V−1⋅s−1 at a carrier density of 1012 cm−2. The corresponding resistivity of graphene sheets is 10−8 Ω⋅m, lower than the resistivity of silver, which is the lowest known at room temperature. However, on SiO2 substrates, electron scattering by optical phonons of the substrate has a more significant effect than scattering by graphene's phonons, limiting mobility to 40000 cm2⋅V−1⋅s−1. Charge transport can be affected by the adsorption of contaminants such as water and oxygen molecules, leading to non-repetitive and large hysteresis I-V characteristics. Researchers need to conduct electrical measurements in a vacuum. Coating the graphene surface with materials such as SiN, PMMA or h-BN has been proposed for protection. In January 2015, the first stable graphene device operation in the air over several weeks was reported for graphene whose surface was protected by aluminum oxide. In 2015, lithium-coated graphene exhibited superconductivity, a first for graphene. Electrical resistance in 40-nanometer-wide nanoribbons of epitaxial graphene changes in discrete steps.
Sources: en.wikipedia.org
=== Advantages === Advantages include low fragmentation: only a small amount of energy is transferred during the ionization process (compared to e.g. electron ionization), therefore fragmentation is suppressed and the obtained mass spectra are easily interpretable. No sample preparation is necessary: VOC-containing air and headspaces over liquids can be analyzed directly, in real time. A typical response time of 100 ms enables online monitoring. Absolute concentrations are obtained directly without previous calibration measurements. Due to the simple design and the low number of parts needed for a PTR-MS instrument, it can be built in into space saving and even mobile housings. PTR-MS operation requires only electric power and a small amount of distilled water. Unlike other techniques, no gas cylinders are needed for buffer gas or calibration standards.
== Research directions == Outside of H. pylori eradication and ulcer management, the broader antimicrobial potential and gastric‑protective roles of bismuth subcitrate are not well studied in clinical trials; this is a potential research direction. Bismuth is also studied on potential antiviral and antileishmanial applications.
As a consequence of the exchange rate policy, the bank must always adjust its interest rates to ensure a stable exchange rate and consequently cannot at the same time conduct monetary policy to stabilize e.g. domestic inflation or unemployment rates. This makes the conduct of stabilization policy fundamentally different from the situation in Denmark's neighbouring countries like Norway, Sweden, Poland and the United Kingdom, in which the central banks have a central stabilizing role. Denmark is presently the only OECD member country maintaining an independent currency with a fixed exchange rate. Consequently, the Danish krone is the only currency in the European Exchange Rate Mechanism II (ERM II), before Bulgaria and Croatia joined in 2020 (the latter uses the euro since 2023) In the first months of 2015, Denmark experienced the largest pressure against the fixed exchange rate for many years because of very large capital inflows, causing a tendency for the Danish krone to appreciate. Danmarks Nationalbank reacted in various ways, chiefly by lowering its interest rates to record low levels. On 6 February 2015 the certificates of deposit rate, one of the four official Danish central bank rates, was lowered to −0.75%. In January 2016 the rate was raised to −0.65%, at which level it has been maintained since then. Inflation in Denmark as measured by the official consumer price index of Statistics Denmark was 1.1% in 2017. Inflation has generally been low and stable for the last decades.
Other compounds other than radiolabelled somatostatin receptor antagonists have also been studied. Cyclosomatostatin is one such compound. Contrary to previously discussed compounds, cyclosomatostatin does not contain a radionuclide. It is a non-selective somatostatin receptor antagonist, inhibiting the effects of somatostatin on target cells in the gastrointestinal tract, pancreas, hypothalamus, and central nervous system. Cyclosomatostatin is used as a research chemical to investigate the effects of somatostatin on different cell types by antagonizing its receptors. However it acts as an agonist in SH-SY5Y neuroblastoma cells. Cyclosomatostatin is also known by the following names:
=== United States of America === In the US, home sleep testing is increasingly being preferred by private insurance carriers. For individuals who have high co-pays or deductibles, a home sleep test can be done for a fraction of the cost of polysomnography. Radiofrequency ablation was recognized by the American Academy of Otolaryngology as a somnoplasty treatment option in selected situations for mild to moderate OSA, but the evidence was judged insufficient for routine adoption by the American College of Physicians.
Sources: en.wikipedia.org
== Classification == The term nevus is applied to a number of conditions caused by neoplasias and hyperplasias of melanocytes, as well as a number of pigmentation disorders, both hypermelanotic (containing increased melanin, the pigment responsible for skin color) and hypomelanotic (containing decreased melanin). Suspicious skin moles which are multi-colored or pink may be a finding in skin cancer.
The recent patent literature describes the synthesis of glycocyamine by catalytic oxidation of ethanolamine to glycine and subsequent reaction with cyanamide in aqueous solution in high yield, analogous to the synthesis of creatine starting from 2-methylaminoethanol via sarcosine.
Danny Gutwein, Professor of Jewish History at the University of Haifa, proposes a twist on an old idea, asserting that Sykes's February 1917 approach to the Zionists was the defining moment, and that it was consistent with the pursuit of the government's wider agenda to partition the Ottoman Empire.
MRI has the advantages of having very high spatial resolution and is very adept at morphological imaging and functional imaging. MRI does have several disadvantages though. First, MRI has a sensitivity of around 10−3 mol/L to 10−5 mol/L, which, compared to other types of imaging, can be very limiting. This problem stems from the fact that the population difference between the nuclear spin states is very small at room temperature. For example, at 1.5 teslas, a typical field strength for clinical MRI, the difference between high and low energy states is approximately 9 molecules per 2 million. Improvements to increase MR sensitivity include increasing magnetic field strength and hyperpolarization via optical pumping or dynamic nuclear polarization. There are also a variety of signal amplification schemes based on chemical exchange that increase sensitivity. To achieve molecular imaging of disease biomarkers using MRI, targeted MRI contrast agents with high specificity and high relaxivity (sensitivity) are required. To date, many studies have been devoted to developing targeted-MRI contrast agents to achieve molecular imaging by MRI. Commonly, peptides, antibodies, or small ligands, and small protein domains, such as HER-2 affibodies, have been applied to achieve targeting. To enhance the sensitivity of the contrast agents, these targeting moieties are usually linked to high payload MRI contrast agents or MRI contrast agents with high relaxivities.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。