counterion comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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。
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
The different forms of MSH belong to a group called the melanocortins. This group includes ACTH, α-MSH, β-MSH, and γ-MSH; these peptides are all cleavage products of a large precursor peptide called proopiomelanocortin (POMC). α-MSH is the most important melanocortin for pigmentation. The different forms of MSH have the following amino acid sequences:
In the United States, the FDA relaxed rules on prescription drug marketing in 1997, allowing advertisements targeted directly to consumers. Lilly-ICOS hired the Grey Worldwide Agency in New York, part of the Grey Global Group, to run the Cialis advertising campaign. Marketing for Cialis has taken advantage of its greater duration compared to its competitors in advertisements for the drug; Stuart Elliot of The New York Times opined: "The continuous presence of females in Cialis ads is a subtle signal that the drug makes it easier for them to set the pace with males, in contrast to the primarily male-driven imagery for Levitra and Viagra." Iconic themes in Cialis ads include couples side by side in matching bathtubs and the slogan "When the moment is right, will you be ready?" Cialis ads were unique among the ED drugs in mentioning specifics of the drug. As a result, Cialis ads were also the first to describe the side effects in an advertisement, as the FDA requires advertisements with specifics to mention side effects. One of the first Cialis ads aired at the 2004 Super Bowl. Just weeks before the Super Bowl, the FDA required more possible side effects to be listed in the advertisement, including priapism. Although many parents objected to the Cialis ad being aired during the Super Bowl, Janet Jackson's halftime "wardrobe malfunction" overshadowed Cialis. In January 2006, the Cialis ads were tweaked, adding a doctor on screen to describe side effects and only running ads where more than 90 percent of the audience are adults, effectively ending Super Bowl ads.
To realise the vision of "Sahkar se Samriddhi" (prosperity through cooperation). To streamline processes for ‘'Ease of doing business’' for cooperatives and enable development of Multi-State Co-operatives (MSCS) To provide a separate administrative, legal and policy framework for strengthening the cooperative movements in the country. To deepen the cooperative as a true people-based movement reaching up to the grassroot level. Many experts have raised concerns about the new ministry because cooperative societies are subject of State List under the Seventh schedule of the Constitution, and therefore creating such a ministry at the central level would increase the power in the hands of the union government. Kerala's Minister of Co-operation and Registration V. N. Vasavan stated that, "Creation of a new Cooperation ministry is an infringement upon the rights of the state governments.
The steepness of greatest curvature from 'mild' (< 45 D), 'advanced' (up to 52 D) or 'severe' (> 52 D); The morphology of the cone: 'nipple' (small: 5 mm and near-central), 'oval' (larger, below-center and often sagging), or 'globus' (more than 75% of cornea affected); The corneal thickness from mild (> 506 μm) to advanced (< 446 μm). Increasing use of corneal topography has led to a decline in use of these terms.
== External links == Molecular Weight Calculator Calculate molecular weight (molar mass) from chemical formulas Online Molar Mass Calculator with the uncertainty of M and all the calculations shown Molar Mass Calculator Online Molar Mass and Elemental Composition Calculator Stoichiometry Add-In for Microsoft Excel Archived 2011-05-11 at the Wayback Machine for calculation of molecular weights, reaction coefficients and stoichiometry. It includes both average atomic weights and isotopic weights. Molar mass: chemistry second-level course.
Sources: en.wikipedia.org
=== Background and education === Galloway was born in Dundee, Scotland on 16 August 1954, to George Galloway Sr., a Scottish trade unionist, and Sheila O'Reilly, a Scot of Irish descent. Initially raised in Lochee, Dundee, he has described himself as "born in an attic in a slum tenement in the Irish quarter of Dundee, which is known as Tipperary". His father began as an electrician, before studying a degree to become an electromechanical engineer at NCR. After being made redundant, he retrained as a teacher. His mother was a cleaner, and then a factory worker. According to Galloway, his father was patriotic, while his mother had Irish nationalist sympathies, and was critical of perceived British pretensions in the world. He took his mother's side in arguments, and has been a long-time supporter of Sinn Féin and Irish reunification. David Morley, his biographer, has written that people who knew both father and son have said that they had Marxist opinions common in the local Labour Party movement of the time. Galloway grew up in Charleston, Dundee, and attended Charleston Primary and then Harris Academy, in the city's West End, an academically selective and non-denominational state school, which became comprehensive in 1973. Galloway played for the school football team as well as for West End United U12s, Lochee Boys Club U16s and St Columba's U18s.
More recently, the Ethiopian Mineral Resources Development Enterprise has established the existence of 290 million tons of salt at Lake Afrera alone. Some local companies used to produce salt from the lake by pumping the brine into artificial ponds for evaporation and subsequent precipitation. Following the 2011 eruption of Nabro, the lake is contaminated with sulfuric acid, making the salt inedible.
Following the success of Counter-Strike, Valve went on to release multiple installments in the series. The first subsequent game, Counter-Strike: Condition Zero, which used Counter-Strike's GoldSrc engine, was released in 2004. Counter-Strike: Source, a remake of the original Counter-Strike, was the first game in the series to use Valve's Source engine and was also released in 2004, eight months after the release of Condition Zero. The next game in the Counter-Strike series was Counter-Strike: Global Offensive, released for Windows, OS X, Linux, PlayStation 3, and Xbox 360 in 2012. Counter-Strike 2, an updated version of Global Offensive, was released in 2023. The game spawned multiple spin-offs for the Asian gaming market. The first, Counter-Strike Neo, was an arcade game developed by Namco and released in Japan in 2003. In 2008, Nexon Corporation released Counter-Strike Online, a free-to-play installment in the series monetized via microtransactions. Counter-Strike Online was followed by Counter-Strike Online 2 in 2013. In 2014, Nexon released Counter-Strike Nexon: Zombies worldwide via Steam.
Silencing systemin did not affect the ability of black nightshade to resist herbivory and, when competing against normal plants, silenced plants produced more above-ground biomass and berries. Upon herbivory, systemin was down-regulated in black nightshade in contrast to the other peptides which are up-regulated after herbivory. By contrast HypSys were up-regulated and activated the synthesis of protease inhibitors. The down-regulation of systemin was associated with increased root mass but did not decrease shoot mass, demonstrating that systemin can cause developmental changes as a result of herbivory, allowing the plant to tolerate, rather than directly resist attack. Tomato roots were also affected by tomato systemin, with root growth increasing at high tomato systemin concentrations. By allocating more resources to the roots, plants under attack are thought to store carbon and then use it to re-grow when the attack ends. Overexpressing AtPEP1 also increased root and shoot biomass in A. thaliana.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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。