A practical reference on synthetic heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-01-05 and is reviewed periodically as new material appears.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
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。
perform both visual and digital oral health examinations. treatment by using removable oral appliances directly to patient prescribe oral prosthetics to dental technicians. Provide and fit other dental devices (including mouthguards). Supervise auxiliary personnel in the performance of their delegated duties. Take a detailed medical and dental history. Perform technical and clinical procedures related to providing removable dental appliances. Carry out clinical examinations within their scope of practice to examine for details such as space and retention. Take and process radiographs and other images related to providing removable dental appliances. Distinguish between normal and abnormal consequences of ageing. Give appropriate patient advice. Recognize abnormal oral mucosal lesions and related underlying structures and refer patients to other healthcare professionals if necessary. Vary the detail but not the direction of a prescription according to patient needs. Additional skills which CDTs in the UK could develop include:
== Traditional use == Skullcaps are used in traditional medicine, such as in traditional Chinese medicine. The root of Scutellaria baicalensis – a common component of many preparations – is marketed in volumes that have led to the overexploitation of the wild plant. Its rarity has led to an increase in price, and encouraged the adulteration of the product with other species of Scutellaria. In 1773, Scutellaria lateriflora became a common treatment in North America for the hysteria and hydrophobia caused by rabies. Today it is still a popular medicinal herb. It is widely available as a commercial product used in western herbalism. The plant reportedly commands prices of $16 to $64 per pound dry weight.
Cancer immunotherapy (immuno-oncotherapy) is the stimulation of the immune system to treat cancer, improving the immune system's natural ability to fight the disease. It is an application of the basic science of cancer immunology (immuno-oncology) and a growing subspecialty of oncology. Cancer immunotherapy exploits the fact that cancer cells often have tumor antigens, molecules on their surface that can bind to antibody proteins or T-cell receptors, triggering an immune system response. The tumor antigens are often proteins or other macromolecules (e.g., carbohydrates). Normal antibodies bind to external pathogens, but the modified immunotherapy antibodies bind to the tumor antigens marking and identifying the cancer cells for the immune system to inhibit or kill. The clinical success of cancer immunotherapy is highly variable between different forms of cancer; for instance, certain subtypes of gastric cancer react well to the approach whereas immunotherapy is not effective for other subtypes. Major types of cancer immunotherapy include immune checkpoint inhibitors, which block inhibitory pathways such as PD-1/PD-L1 and CTLA-4 to enhance T cell activity against tumors. These therapies have shown effectiveness in treating cancers such as melanoma and lung cancer. Adoptive cell therapies, including chimeric antigen receptor (CAR) T cell therapy, involve modifying a patient's immune cells to recognize cancer-specific antigens. These therapies have been particularly effective in certain blood cancers.
The freedoms include the ability to leave the Culture when desired, often forming new associated but separate societies with Culture ships and Minds, most notably the Zetetic Elench and the ultra-pacifist and non-interventionist Peace Faction.
Sources: en.wikipedia.org
If the identity of the protein is desired, usually the method of in-gel digestion is applied, where the protein spot of interest is excised, and digested proteolytically. The peptide masses resulting from the digestion can be determined by mass spectrometry using peptide mass fingerprinting. If this information does not allow unequivocal identification of the protein, its peptides can be subject to tandem mass spectrometry for de novo sequencing. Small changes in mass and charge can be detected with 2D-PAGE. The disadvantages with this technique are its small dynamic range compared to other methods, some proteins are still difficult to separate due to their acidity, basicity, hydrophobicity, and size (too large or too small). The second method, high performance liquid chromatography is used to fractionate peptides after enzymatic digestion. Characterization of protein mixtures using HPLC/MS is also called shotgun proteomics and MuDPIT (Multi-Dimensional Protein Identification Technology). A peptide mixture that results from digestion of a protein mixture is fractionated by one or two steps of liquid chromatography. The eluent from the chromatography stage can be either directly introduced to the mass spectrometer through electrospray ionization, or laid down on a series of small spots for later mass analysis using MALDI.
== Interactions == A number of drugs add to the low blood pressure caused by nitrovasodilators: for example, other vasodilators, antihypertensive drugs, tricyclic antidepressants, antipsychotics, general anaesthetics, as well as ethanol. Combination with PDE5 inhibitors, including sildenafil (Viagra), is contraindicated because potentially life-threatening hypotension may occur. Nitrates increase the bioavailability of dihydroergotamine (DHE). High DHE levels may result in coronary spasms in patients with coronary disease. This interaction is not described for non-nitrate nitrovasodilators.
=== Hormone signals === The hormones insulin and cholecystokinin (CCK) are released from the GI tract during food absorption and act to suppress the feeling of hunger. CCK is key in suppressing hunger because of its role in inhibiting neuropeptide Y. Glucagon and epinephrine levels rise during fasting and stimulate hunger. Ghrelin, a hormone produced by the stomach, is an appetite stimulant.
Sources: en.wikipedia.org
=== High Voltage Power Corporation === In July 1968, High Voltage Engineering Corporation and Reynolds Metals Company announced they would form a joint venture partnership to develop, produce, and sell gas-insulated systems for transmission of electric power. The venture, High Voltage Power Corporation, aimed to commercialize technology for underground electric power transmission. HVEC president Denis Robinson noted increasing need by bury transmission lines underground for technological, economic, and aesthetic reasons, and emphasizing that compressed gas offered unique advantages for transmitting large amounts of power at high voltages with increased reliability at lower cost. Each company held a 50% interest in the venture, with Reynolds providing funds and technical research while HVEC contributed its patents, licenses, and know-how. The development work was carried out at HVEC's Burlington factory. The subsidiary's products included insulating-core reactors for nuclear power plants and gas-insulated transmission systems for electrical utilities, based on Van de Graaff's insulating-core transformer invention. However, by 1974, High Voltage Power Corp. losses were consuming 60-75% of HVEC's cash flow despite generating only $1.5-2 million in annual sales, leading HVEC to divest from the subsidiary.
. The simulation first updates the infected from the susceptible and then the removed category is updated from the infected category for the next time point (t=1). This describes the flow persons between the three categories. During an epidemic the susceptible category is not shifted with this model,
=== October === 1 October – The Government confirms it will not sell its shares in the electrical generation sector but will instead increase capital investments and the enforcement powers of the Electricity Authority. 2 October: The Police and Serious Fraud Office (SFO) end their criminal investigation into alleged electoral misconduct at the Manurewa Marae during the 2023 New Zealand general election, citing insufficient evidence of corruption. Māori activist group Toitū Te Tiriti, led by Eru Kapa-Kingi, severs its formal relationship with Te Pāti Māori, citing leadership differences and a desire for independence. Three new measles cases are reported in the Northland Region, bringing the total number of cases nationwide to ten. 4 October — The Presbyterian Church of Aotearoa New Zealand issues its second apology to survivors of historical abuse in Auckland. 6 October: Mike Davidson is elected as a list MP for the Green Party following the resignation of Benjamin Doyle. The New Zealand government agrees to pay Samoa 10 million tala ($3.6 million) in compensation for the sinking of HMNZS Manawanui in 2024. 7 October — ASB Bank agrees to pay NZ$135.6 million to settle a lawsuit relating to alleged breaches of the Credit Contracts and Consumer Finance Act. ANZ Bank New Zealand declines to settle the lawsuit with plaintiffs. 8 October — Over 100 pro-Palestinian protesters attempt to disrupt the New Zealand Aerospace Summit 2025 at Christchurch's Te Pae Convention Centre. Police arrest 22 protesters.
Centrifugation is a process that uses centrifugal force to separate mixtures of particles of varying masses or densities suspended in a liquid. When a vessel (typically a tube or bottle) containing a mixture of proteins or other particulate matter, such as bacterial cells, is rotated at high speeds, the inertia of each particle yields a force in the direction of the particles velocity that is proportional to its mass. The tendency of a given particle to move through the liquid because of this force is offset by the resistance the liquid exerts on the particle. The net effect of "spinning" the sample in a centrifuge is that massive, small, and dense particles move outward faster than less massive particles or particles with more "drag" in the liquid. When suspensions of particles are "spun" in a centrifuge, a "pellet" may form at the bottom of the vessel that is enriched for the most massive particles with low drag in the liquid. Non-compacted particles remain mostly in the liquid called "supernatant" and can be removed from the vessel thereby separating the supernatant from the pellet. The rate of centrifugation is determined by the angular acceleration applied to the sample, typically measured in comparison to the g-force. If samples are centrifuged long enough, the particles in the vessel will reach equilibrium wherein the particles accumulate specifically at a point in the vessel where their buoyant density is balanced with centrifugal force. Such an "equilibrium" centrifugation can allow extensive purification of a given particle.
Sources: en.wikipedia.org
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.