If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-09-20. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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 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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
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。
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。
=== Religious alignment === Since 1660, nonconformist Protestants have played a major role in English politics. Relatively few MPs were Dissenters. However the Dissenters were a major voting bloc in many areas, such as the East Midlands. They were very well organised and highly motivated and largely won over the Whigs and Liberals to their cause. Down to the 1830s, Dissenters demanded removal of political and civil disabilities that applied to them (especially those in the Test and Corporation Acts). The Anglican establishment strongly resisted until 1828. Numerous reforms of voting rights, especially that of 1832, increased the political power of Dissenters. They demanded an end to compulsory church rates, in which local taxes went only to Anglican churches. They finally achieved the end of religious tests for university degrees in 1905. Gladstone brought the majority of Dissenters around to support for Home Rule for Ireland, putting the dissenting Protestants in league with the Irish Roman Catholics in an otherwise unlikely alliance. The Dissenters gave significant support to moralistic issues, such as temperance and sabbath enforcement. The nonconformist conscience, as it was called, was repeatedly called upon by Gladstone for support for his moralistic foreign policy. In election after election, Protestant ministers rallied their congregations to the Liberal ticket. In Scotland, the Presbyterians played a similar role to the Nonconformist Methodists, Baptists and other groups in England and Wales.
%) is also used as aquarium plants fertilizer. The more soluble form of iron, Fe(II), is a micronutrient needed by aquatic plants. By binding to Fe2+ ions DTPA prevents their precipitation as Fe(OH)3, or Fe2O3·nH2O poorly soluble oxy-hydroxides after their oxidation by dissolved oxygen. It increases the solubility of Fe2+ and Fe3+ ions in water, and therefore the bioavailability of iron for aquatic plants. It contributes so to maintain iron under a dissolved form (probably a mix of Fe(II) and Fe(III) DTPA complexes) in the water column. It is unclear to what extent does DTPA really contribute to protect dissolved Fe2+ against air oxidation and if the Fe(III)-DTPA complex cannot also be directly assimilated by aquatic plants simply because of its enhanced solubility. Under natural conditions, that is, in the absence of complexing DTPA, Fe2+ is more easily assimilated by most organisms, because of its 100-fold higher solubility than that of Fe3+. In pulp and paper mills DTPA is also used to remove dissolved ferrous and ferric ions (and other redox-active metal ions, such as Mn or Cu) that otherwise would accelerate the catalytic decomposition of hydrogen peroxide (H2O2 reduction by Fe2+ ions according to the Fenton reaction mechanism). This helps preserving the oxidation capacity of the hydrogen peroxide stock which is used as oxidizing agent to bleach pulp in the chlorine-free process of paper making. Several thousand tons of DTPA are produced annually for this purpose in order to limit the non-negligible losses of H2O2 by this mechanism.
== Research examples == In 2012 research was published where genes and proteins were found in a model organism that could not have been found without GFS because they had not been previously annotated. The planarian Schmidtea mediterranea has been used in research for over 100 years. This planarian is capable of regenerating missing body parts and is therefore emerging as potential model organism for stem cell research. Planarians are covered in mucus which aids in locomotion, in protecting them from predation, and in helping their immune system. The genome of Schmidtea mediterranea is sequenced but mostly un-annotated making it a prime candidate for genome-based peptide fingerprint scanning. When the proteins were analyzed with GFS 1,604 proteins were identified. These proteins had mostly not been annotated before they were found with GFS They were also able to find the mucous subproteome (all the genes associated with mucus production). They found that this proteome was conserved in the sister species Schmidtea mansoni. The mucous subproteome is so conserved that 119 orthologs of planarians are found in humans. Due to the similarity in these genes the planarian can now be used as a model to study mucous protein function in humans. This is relevant for infections and diseases related to mucous aberrancies such as cystic fibrosis, asthma, and other lung diseases. These genes could not have been found without GFS because they had not been previously annotated.
Sources: en.wikipedia.org
Vaginitis An infection of the vagina usually caused by a fungus. A woman with this condition may have itching or burning and may notice a discharge. Women who have diabetes may develop vaginitis more often than women who do not have diabetes. Vascular Relating to the body's blood vessels (arteries, veins, and capillaries). Vein Visceral neuropathy Vitrectomy Removing the gel from the center of the eyeball because it has blood and scar tissue in it that blocks sight. An eye surgeon replaces the clouded gel with a clear fluid. See also: Diabetic retinopathy. Vitreous humor The clear jelly (gel) that fills the center of the eye.
The ACS International Activities is the birthplace of the ACS International Center, an online resource for scientists and engineers looking to study abroad or explore an international career or internship. The site houses information on hundreds of scholarships and grants related to all levels of experience to promote scientific mobility of researchers and practitioners in STEM fields. The Society grants membership to undergraduates as student members provided they can pay the $25 yearly dues. Any university may start its own ACS Student Chapter and receive benefits of undergraduate participation in regional conferences and discounts on ACS publications. The American Chemical Society administers 64 national awards, medals and prizes based on scientific contributions at various career levels that promote achievement across the chemical sciences. The ACS national awards program began in 1922 with the establishment of the Priestley Medal, the highest award offered by the ACS, which is given for distinguished services to chemistry.
Lactobacillales (order) as the most abundant; primarily upstream of pnuC, and sometimes pncB or pnuC–nadR operons. Notable organisms include species of Fructobacillus and many other lactic acid bacteria. Planctomycetota (phylum), commonly upstream of nadA. Pseudomonadota, found in Pseudomonas laurylsulfatiphila and related species, upstream of an annotated nucleoside transporter. Actinobacteriota, in isolated instances from metagenome-assembled genomes. The prevalence of mini-NAD⁺-II riboswitches in lactic acid bacteria is thought to be functionally significant, as these organisms rely on various anaerobic fermentation strategies (e.g., lactic acid or ethanol production) to maintain a balanced NAD⁺/NADH ratio. The prevalence of mini-NAD⁺-II riboswitches in lactic acid bacteria is thought to be functionally significant, as these organisms rely on various anaerobic fermentation strategies (e.g., lactic acid or ethanol production) to maintain a balanced NAD⁺/NADH ratio.
Sources: en.wikipedia.org
Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in cartilage, bones, tendons, ligaments, and skin. Vitamin C is vital for collagen synthesis. Depending on the degree of mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and dentin. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes 1% to 2% of muscle tissue and 6% by weight of skeletal muscle. The fibroblast is the most common cell creating collagen in animals. Collagen is used in numerous food products, such as in gelatin employed to thicken or flavor a food matrix. Although marketed as a dietary supplement and skincare product, there is little evidence it is beneficial for skin health. In biomaterials used in medicine, collagen has useful properties for artificial skin and healing of severe burns and wounds.
No flerovium atoms were detected; this was thought to be because the compound nucleus 288Fl only has 174 neutrons instead of the supposed magic 184, and this would have significant impact on the reaction cross section (yield) and half-lives of nuclei produced. It was then 30 more years before flerovium was first made. Later work suggests the islands of stability around hassium and flerovium occur because these nuclei are respectively deformed and oblate, which make them resistant to spontaneous fission, and that the true island of stability for spherical nuclei occurs at around unbibium-306 (122 protons, 184 neutrons). In the 1970s and 1980s, theoretical studies debated whether element 114 would be a more volatile metal like lead, or an inert gas.
Hannibal had a history of the Punic Wars produced, and ordered it to be kept in the temple of Juno Lacinia in Crotone so that the Romans could not falsify the history of the war. Plutarch drew from that source. In the summer of 204 BCE the Romans arrived in Calabria and enslaved the Bruttians to punish their rebellion. Vast estates were requisitioned and assigned to members of the Roman aristocracy. During the Second Punic War (218–201 BCE) the Bruttii allied with Hannibal, who sent Hanno, one of his commanders, to Calabria. Hanno twice marched toward Capua (in Campania) with Bruttian soldiers to take them to Hannibal's headquarters there, but he was twice defeated. When his campaign in Italy came to an end, Hannibal took refuge in Calabria, whose steep mountains provided protection against the Roman legions. He set up his headquarters in Kroton and stayed there for four years until he was recalled to Carthage. The Romans fought a battle with him near Kroton, but its details are not recorded. Many Calabrian cities surrendered to the Romans and Calabria was put under a military commander.
Sources: en.wikipedia.org
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。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
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.