Semax raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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。
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.
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.
| 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 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.
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.
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。
=== Overexpression === Mayford and colleagues engineered transgenic mice that express CaMKII with a point mutation of Thr-286 to aspartate, which mimics autophosphorylation and increases kinase activity. These mice failed to show LTP response to weak stimuli, and failed to perform hippocampus-dependent spatial learning that depended on visual or olfactory cues. Researchers speculate these results could be due to lack of stable hippocampal place cells in these animals. However, because genetic modifications might cause unintentional developmental changes, viral vector delivery allows the mice's genetic material to be modified at specific stages of development. It is possible with viral vector delivery to inject a specific gene of choice into a particular region of the brain in an already developed animal. This, in fact, has been done by Tonegawa group in early 1990s and by Poulsen and colleagues in 2007. Both groups used this method to inject CaMKII into the hippocampus. They found that overexpression of CaMKII resulted in slight enhancement of acquisition of new memories.
This method involves coating LEDs of one color (mostly blue LEDs made of InGaN) with phosphors of different colors to form white light; the resultant LEDs are called phosphor-based or phosphor-converted white LEDs (pcLEDs). A fraction of the blue light undergoes the Stokes shift, which transforms it from shorter wavelengths to longer. Depending on the original LED's color, various color phosphors are used. Using several phosphor layers of distinct colors broadens the emitted spectrum, effectively raising the color rendering index (CRI). Phosphor-based LEDs have efficiency losses due to heat loss from the Stokes shift and other phosphor-related issues. Their luminous efficacies compared to normal LEDs depend on the spectral distribution of the resultant light output and the original wavelength of the LED itself. For example, the luminous efficacy of a typical YAG yellow phosphor based white LED ranges from 3 to 5 times the luminous efficacy of the original blue LED because of the human eye's greater sensitivity to yellow than to blue (as modeled in the luminosity function). Due to the simplicity of manufacturing, the phosphor method is still the most popular method for making high-intensity white LEDs. The design and production of a light source or light fixture using a monochrome emitter with phosphor conversion is simpler and cheaper than a complex RGB system, and the majority of high-intensity white LEDs presently on the market are manufactured using phosphor light conversion.
=== 29 July === Russian forces took the villages of Novoselivka Persha, 20 kilometers northwest of Avdiivka, and Vovche in Donetsk Oblast. The Russian defence ministry claimed to have intercepted 39 Ukrainian drones over five oblasts. Local media and officials claimed power failures along the western border due to damage caused by drone strikes. A fire occurred at an electrical substation in Tomarovka, Belgorod Oblast, and a power station in Glazunovka, Oryol Oblast was reported damaged, while falling debris damaged a “critical infrastructure facility” in Ostrogozhsky, Voronezh Oblast. Ukrainian authorities announced the arrest of six people in Odesa on suspicion of burning 15 military vehicles on behalf of Russia.
Sources: en.wikipedia.org
== Biography == Robert Allan Humphreys was born on October 16, 1930, in Chickasha, Oklahoma, to Ira Denver Humphreys and Stella Bernice Humphreys. "Laud" was chosen as his first name when he was baptized again upon entering the Episcopal Church.
=== Magnetic droplets === The micro-magnetofluidic method is the control of magnetic fluids by an applied magnetic field on a microfluidic platform, offering wireless and programmable control of the magnetic droplets. Hence, the magnetic force can also be used to perform various logical operations, in addition to the hydrodynamic force and the surface tension force. The magnetic field strength, type of the magnetic field (gradient, uniform or rotating), magnetic susceptibility, interfacial tension, flow rates, and flow rate ratios determine the control of the droplets on a micro-magnetofluidic platform. Magnetic droplets, in the context of droplet-based microfluidics, are microliter size droplets that are either composed of ferrofluids or contain some magnetic component that allows for manipulation via an applied magnetic field. Ferrofluids are homogenous mixtures of colloidal solutions of magnetic nanoparticles in a liquid carrier. Two applications of magnetic droplets are the control and manipulation of microfluidic droplets in a microenvironment and the fabrication, transport, and utilization of nanomaterial constructs in the microdroplets. Manipulating magnetic droplets can be used to perform tasks such as arranging droplets into an ordered array for applications in cell culture studies, while the use of magnetic droplets for nanostructure fabrication can be used in drug delivery applications.
The cycle is present in microorganisms that cause disease but is absent in mammals, for example humans. There is a strong plausibility of the development of antibiotics that would attack the glyoxylate cycle, which would kill the disease-causing microorganisms that depend on the cycle for their survival, yet would not harm humans where the cycle, and thus the enzymes that the antibiotic would target, are absent.
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。
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.