A practical reference on ACTH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-10 and is reviewed periodically as new material appears.
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。
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 |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
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.
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。
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
that GABAA receptors containing the δ-subunit are sensitive to ethanol modulation, depending on subunit combinations receptors could be more or less sensitive to ethanol. It has been shown that GABAA receptors that contain both δ and β3-subunits display increased sensitivity to ethanol. One such receptor that exhibits ethanol insensitivity is α3-β6-δ GABAA. It has also been shown that subunit combination is not the only thing that contributes to ethanol sensitivity. Location of GABAA receptors within the synapse may also contribute to ethanol sensitivity. Ro15-4513, a close analogue of the benzodiazepine antagonist flumazenil (Ro15-1788), has been found to bind to the same site as ethanol and to competitively displace it in a saturable manner. In addition, Ro15-4513 blocked the enhancement of δ subunit-containing GABAA receptor currents by ethanol in vitro. In accordance, the drug has been found to reverse many of the behavioral effects of low-to-moderate doses of ethanol in rodents, including its effects on anxiety, memory, motor behavior, and self-administration. Taken together, these findings suggest a binding site for ethanol on subpopulations of the GABAA receptor with specific subunit compositions via which it interacts with and potentiates the receptor.
== N-terminal modifications == Protein N-termini can be modified co - or post-translationally. Modifications include the removal of initiator methionine (iMet) by aminopeptidases, attachment of small chemical groups such as acetyl, propionyl and methyl, and the addition of membrane anchors, such as palmitoyl and myristoyl groups
==== Pit closures ==== Heseltine's responsibilities also included Energy, as the separate Energy ministry was abolished. Electricity companies now decided on their own contracts, rather than being obliged by the government to choose British coal. With plans being made for the privatisation of British Coal, on 13 October 1992 Heseltine and British Coal both separately announced that 31 of British Coal's 50 pits were to close, with the loss of 30,000 jobs. Most of the detailed work had been done by the minister of state Tim Eggar. Many of the mines in Nottinghamshire that had continued working during the 1984–1985 strike were to close. Although this policy was seen by the Nottinghamshire miners as a betrayal, there was hardly any organised resistance to the programme. The government stated that since the pits were losing money they could be sustained only through unjustifiable government subsidies. Mine supporters pointed to the mines' high productivity rates and to the fact that their monetary losses were due to the large subsidies that other European nations were giving to their coal industries. An early leak had seen little reaction but Heseltine was taken aback by the public anger. Over 100 pits had closed since the 1984–1985 strike. The closures were to be rushed because the Treasury, under pressure from Major, had agreed to make money for generous redundancy settlements available only in the 1992–1993 fiscal year.
Sources: en.wikipedia.org
=== Clinical trials === In 2020, there were 197 clinical trials related to varied therapies and biomarkers for HD listed as either underway, recruiting or newly completed. Compounds trialed that have failed to prevent or slow the progression of HD include remacemide, coenzyme Q10, riluzole, creatine, minocycline, ethyl-EPA, phenylbutyrate and dimebon.
Spontaneous and unpredictable pain at any time, and specific causal factors cannot be identified Patient may complain of sharp lingering pains that last longer than 30 seconds, even after removal of stimulus Possible referred pain Pain may increase with changes of posture, e.g. from lying down to standing. Analgesics tend to be ineffective. No pain on percussion because the bacteria are not present in the peri-apical region. Key characteristics of asymptomatic irreversible pulpitis include:
=== Requirements for boron delivery agents === A BNCT therapeutic candidate must selectively accumulate the boron-10 in target tissue without significant uptake in normal tissue. If selectivity is low and boron accumulates in both, irradiation with thermal neutrons will cause significant damage to healthy tissue; if boron accumulates in neither, the treatment will be ineffective. Selectivity is quantified by the tumor⁄normal tissue boron ratio, which compares the concentration of boron atoms in tumor cells with that in the patient's healthy cells. A large tumor⁄normal tissue ratio (~3 or greater) is necessary. In addition, boron must remain in target tissue at significant concentrations (~20 μg/g) for long enough that concentration in the blood drops to low levels (generally several hours). Boron delivery agents should have high solubility to be efficiently circulated and effectively penetrate tumor tissues. These candidates must also minimize toxicity to and have rapid clearance from healthy tissues.
Sources: en.wikipedia.org
== Uses == Sulfuryl chloride is used as a source of Cl2. Because it is a pourable liquid, it is considered more convenient than Cl2 to dispense. Sulfuryl chloride is used in the conversion of C−H to C−Cl adjacent to activating substituents such as carbonyls and sulfoxides:
Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this functional group. Organic compounds, which are often poorly soluble in water, become water-soluble when they contain two or more hydroxyl groups, as illustrated by sugars and amino acid.
== Limitations == One major limitation of PCR is that prior information about the target sequence is necessary in order to generate the primers that will allow its selective amplification. This means that, typically, PCR users must know the precise sequence(s) upstream of the target region on each of the two single-stranded templates in order to ensure that the DNA polymerase properly binds to the primer-template hybrids and subsequently generates the entire target region during DNA synthesis. The limitation is offset when using arbitrarily amplified DNA techniques such as DNA amplification fingerprinting (DAF) or randomly amplification of polymorphic DNA (RAPD). These DNA profiling methods use arbitrary primers in PCR reactions that do not require sequence knowledge. Like all enzymes, DNA polymerases are also prone to error, which in turn causes mutations in the PCR fragments that are generated. Another limitation of PCR is that even the smallest amount of contaminating DNA can be amplified, resulting in misleading or ambiguous results. To minimize the chance of contamination, investigators should reserve separate rooms for reagent preparation, the PCR, and analysis of product. Reagents should be dispensed into single-use aliquots. Pipettors with disposable plungers and extra-long pipette tips should be routinely used. It is moreover recommended to ensure that the lab set-up follows a unidirectional workflow. No materials or reagents used in the PCR and analysis rooms should ever be taken into the PCR preparation room without thorough decontamination.
At the end of the 1950s, the USSR constructed the first satellite—Sputnik 1, which marked the beginning of the Space Race—a competition to achieve superior spaceflight capability with the United States. This was followed by other successful satellites, most notably Sputnik 5, where test dogs were sent to space. On 12 April 1961, the USSR launched Vostok 1, which carried Yuri Gagarin, making him the first human to ever be launched into space and complete a space journey. The first plans for space shuttles and orbital stations were drawn up in Soviet design offices, but personal disputes between designers and management prevented their development. In terms of the Luna program, the USSR only had automated spacecraft launches with no crewed spacecraft. The N1—a Super heavy-lift launch vehicle intended to match the American Saturn V for a Soviet crewed moon landing—failed all four of its test launches, and the 'Moon' part of Space Race was won by the Americans. The Soviet public's reaction to the American moon-landing was mixed. The Soviet government limited the release of information about it, which affected the reaction. A portion of the populace did not give it attention, and another portion was angered. In the 1970s, specific proposals for the design of a space shuttle emerged, but shortcomings, especially in the electronics industry (rapid overheating of electronics), postponed it till the end of the 1980s. The first shuttle, the Buran, flew in 1988, but without a human crew. Another, Ptichka, endured prolonged construction and was canceled in 1991.
Sources: en.wikipedia.org
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
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.