ACTH(4-10) is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-01-11. Numbers and descriptions here follow the published literature rather than marketing material.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
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。
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。
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。
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。
Gunman Chronicles is a 2000 first-person shooter game originally created as a mod by the now-defunct Rewolf Software. It was originally a Quake deathmatch mod named Gunmanship 101, then it was moved to Quake II's engine before becoming a Half-Life mod. Gunman Chronicles was popular at the Half-Life Mod Expo in 1999, and Sierra approached Rewolf to make a retail version. After significant work, it was released as a standalone game. Plans were drawn to release Gunman Chronicles on GameCube, but it was never released.
Sauvagine is a neuropeptide from the corticotropin-releasing factor (CRF) family of peptides and is orthologous to the mammalian hormone, urocortin 1, and the teleost fish hormone, urotensin 1. It is 40 amino acids in length, and has the sequence XGPPISIDLSLELLRKMIEIEKQEKEKQQAANNRLLLDTI-NH2, with a pyrrolidone carboxylic acid modification at the N-terminal and amidation of the C-terminal isoleucine residue. It was originally isolated from the skin of the frog Phyllomedusa sauvagii. Given its relation to other CRF-related peptides, it exerts similar physiological effects as corticotropin-releasing hormone. Sauvagine belongs to the corticotropin-releasing factor (CRF) family that also includes CRF, urocortin l/urotensin l, urocortin II and urocortin III.
==== Endogenous ==== Endogenous pyrogens are cytokines released from monocytes (which are part of the immune system). In general, they stimulate chemical responses, often in the presence of an antigen, leading to a fever. Whilst they can be a product of external factors like exogenous pyrogens, they can also be induced by internal factors like damage associated molecular patterns such as cases like rheumatoid arthritis or lupus. Major endogenous pyrogens are interleukin 1 (α and β) and interleukin 6 (IL-6). Minor endogenous pyrogens include interleukin-8, tumor necrosis factor-β, macrophage inflammatory protein-α and macrophage inflammatory protein-β as well as interferon-α, interferon-β, and interferon-γ. Tumor necrosis factor-α (TNF) also acts as a pyrogen, mediated by interleukin 1 (IL-1) release. These cytokine factors are released into general circulation, where they migrate to the brain's circumventricular organs where they are more easily absorbed than in areas protected by the blood–brain barrier. The cytokines then bind to endothelial receptors on vessel walls to receptors on microglial cells, resulting in activation of the arachidonic acid pathway. Of these, IL-1β, TNF, and IL-6 are able to raise the temperature setpoint of an organism and cause fever. These proteins produce a cyclooxygenase which induces the hypothalamic production of PGE2 which then stimulates the release of neurotransmitters such as cyclic adenosine monophosphate and increases body temperature.
Sources: en.wikipedia.org
RGD was identified as the minimal recognition sequence within fibronectin required for cell attachment by Ruoslahti and Pierschbacher in the early 1980s. To do this, the authors synthesized various peptides based on the hypothesized cell attachment site of fibronectin. They then coupled those peptides to protein-coated plastic and tested each for cell attachment-promoting activity. Only those that contained the RGD sequence were found to enhance cell attachment. Further, they showed that peptides containing RGD were able to inhibit cell attachment to fibronectin-coated substrates, whereas peptides not containing RGD did not. These foundational studies also identified the cellular receptors that recognize the sequence. These studies utilized a synthetic RGD-containing peptide to isolate the putative receptors, and then demonstrated that liposomes containing the isolated proteins could bind to fibronectin, in much the same way as cells with surface receptors. The discovered receptors were later named integrins. The RGD motif is presented in slightly different ways in different proteins, making it possible for the many RGD-binding integrins to selectively distinguish individual adhesion proteins.
=== Sampling calorimeters for detectors in high-energy particle physics === Depleted uranium has been used in a number of sampling calorimeters (such as in the D0 and ZEUS detectors) because of its high density and natural radioactivity.
Although canagliflozin produces beneficial effects on HDL cholesterol, it has also been shown to increase LDL cholesterol to produce no change in total cholesterol. Evidence shows that apart from positive effects on glycemic levels, canagliflozin also reduces the risk of heart attacks and heart failures. SGLT2 inhibitors, including canagliflozin, reduce the likelihood of hospitalization for congestive heart failure or progression of renal disease in persons with diabetes mellitus type 2 and reduce the likelihood of stroke and heart attack in persons with diabetes mellitus type 2 who have known atherosclerotic vascular disease.
=== Georgia === Georgia first said that its military operation responded to Ossetian artillery attack on Georgian villages, and it intended to "restore constitutional order" in South Ossetia. Later, Georgia also said it aimed to resist a Russian invasion. President of Georgia Mikheil Saakashvili told journalists that around 23:00 on 7 August, Russian tanks had begun entering Georgia, causing the Georgians to respond with artillery weapons. Georgia made intercepted telephone calls public. The calls allegedly proved that entry of Georgian troops into Tskhinvali was preceded by movement of a Russian armoured regiment into South Ossetia nearly a day earlier.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
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.