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semax-notes.peptides5388.com › Guide › Semax �š„分子背景与结构 — Research Overview

Semax �š„分子背景与结构 — Research Overview

By Editorial Desk · published 2025-10-23 · last reviewed 2025-12-15 · Guide

A practical reference on ACTH(4-10): what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.

Reviewed 2025-12-15. Anything still debated is marked as such rather than presented as settled.

Semax 的分子背景与结构

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。

化学性质与分析表征

从分子层面看,Semax 是线性七肽,没有二硫键、糖基或脂链修饰,N 端为游离氨基,C 端为游离羧基。分子含组氨酸与谷氨酸侧链,因此在水和甲醇等极性溶剂中溶解良好,在非极性溶剂中溶解有限。计算分子量约为 814 Da,与其质子化离子的质荷比吻合,可用于质谱确认。

稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定,遇到强碱或长时间高温则明显断裂;甲硫氨酸侧链容易被氧化成亚砜,使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间,配制后的水溶液通常需要冷藏并尽快用完。

纯度评估以反相高效液相色谱为主,通过主峰面积百分比给出粗略结果,再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例,手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告,独立第三方检测常被用来核实标称值。

Semax at a glance

PropertyValueNotes
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 Background and Molecular Structure

Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.

The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.

Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.

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Mechanism and Research Context

Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.

Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.

Semax Background and Chemistry

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.

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.

Background from the literature

The degradation of glycerol by some strains of LAB can yield the compound acrolein. Glycerol is a sweet-tasting polyol present in all wines, but at higher levels in wines that have been infected with Botrytis cinerea. An "active-aldehyde", acrolein can interact with some phenolic compounds in wine to create highly bitter-tasting wines, described as amertume by Pasteur. While at least one strain of O. oeni has been shown to produce acrolein, it is more commonly found in wines that have been infected by strains of Lactobacillus and Pediococcus species such as L. brevis, L. buchneri, and P. parvulus. Acrolein taint has also shown to be more common in wines that have been fermented at high temperatures and/or made from grapes that have been harvested at high Brix levels. Heterofermenting species from the genus Lactobacillus, as well as some wild strains of O. oeni, have the potential to metabolize fructose (one of the main sugars in wine) into the sugar alcohols mannitol and (less commonly) erythritol. These are sweet-tasting compounds can add sweetness to a wine where it is not desired (such as Cabernet Sauvignon). Mannitol taint, described as mannite by Pasteur, in wines is often accompanied by other wine faults, including the presence of excessive levels of acetic acid, diacetyl, lactic acid, and 2-butanol, which can contribute to a "vinegary-estery" aroma. The wine may also have a slimy sheen on the surface.

Those with tree nut allergies may be allergic to one or many tree nuts, including pecans, pistachios, and walnuts. In addition, seeds, including sesame seeds and poppy seeds, contain oils in which protein is present, which may elicit an allergic reaction. Allergens can be transferred from one food to another through genetic engineering; however, genetic modification can also remove allergens. Little research has been done on the natural variation of allergen concentrations in unmodified crops.

32S + n → 32P + p It decays by beta decay with a half-life of 14.29 days. It is commonly used to study protein phosphorylation by kinases in biochemistry. 33P is made in relatively low yield by neutron bombardment of 31P. It is also a beta-emitter, with a half-life of 25.4 days. Though more expensive than 32P, the emitted electrons are less energetic, permitting better resolution in, for example, DNA sequencing. Both isotopes are useful for labeling nucleotides and other species that contain a phosphate group.

Sources: en.wikipedia.org

Reference notes

=== Biodegradation === In industrial wastewater treatment plants, EDTA can be degraded at about 80% using microorganisms. Resulting byproducts are ethylenediaminetriacetic acid and iminodiacetic acid (IDA) – suggesting that both the backbone and acetyl groups were attacked. Some microorganisms have even been discovered to form nitrates out of EDTA, but they function optimally at moderately alkaline conditions of pH 9.0–9.5. Several bacterial strains isolated from sewage treatment plants efficiently degrade EDTA. Specific strains include Agrobacterium radiobacter ATCC 55002 and the sub-branches of Pseudomonadota like BNC1, BNC2, and strain DSM 9103. The three strains share similar properties of aerobic respiration and are classified as gram-negative bacteria. Unlike photolysis, the chelated species is not exclusive to iron(III) in order to be degraded. Rather, each strain uniquely consumes varying metal–EDTA complexes through several enzymatic pathways. Agrobacterium radiobacter only degrades Fe(III) EDTA while BNC1 and DSM 9103 are not capable of degrading iron(III) EDTA and are more suited for calcium, barium, magnesium and manganese(II) complexes. EDTA complexes require dissociation before degradation.

A study conducted at Hokkaido University found that a compound in wakame known as fucoxanthin may help burn fatty tissue in mice and rats. Studies in mice have shown that fucoxanthin induces expression of the fat-burning protein UCP1 that accumulates in fat tissue around the internal organs. Expression of UCP1 protein was significantly increased in mice fed fucoxanthin. Wakame is also used in topical beauty treatments. See also Fucoidan. Wakame is a rich source of eicosapentaenoic acid, an omega-3 fatty acid. At over 400 mg/(100 kcal) or almost 1 mg/kJ, it has one of the higher nutrient-to-energy ratios for this nutrient, and among the very highest for a vegetarian source. Wakame is a low calorie food. A typical 10–20 g (1–2 tablespoon) serving of wakame contains roughly 16 to 31 kJ (3.75 to 7.5 kcal) and provides 15–30 mg of omega-3 fatty acids. Wakame also has high levels of sodium, calcium, iodine, thiamine and niacin. In Oriental medicine it has been used for blood purification, intestinal strength, skin, hair, reproductive organs and menstrual regularity. In Korea, miyeok-guk soup is popularly consumed by women after giving birth as sea mustard (miyeok) contains a high content of calcium and iodine, nutrients that are important for new nursing mothers. Many women consume it during the pregnancy phase as well. It is also traditionally eaten on birthdays for this reason, a reminder of the first food that the mother has eaten and passed on to her newborn through her milk.

RYB (an abbreviation of red–yellow–blue) is a subtractive color model used in art and applied design in which red, yellow, and blue pigments are considered primary colors. Under traditional color theory, this set of primary colors was advocated by Moses Harris, Michel Eugène Chevreul, Johannes Itten and Josef Albers, and applied by countless artists and designers. The RYB color model underpinned the color curriculum of the Bauhaus, Ulm School of Design and numerous art and design schools that were influenced by the Bauhaus, including the IIT Institute of Design (founded as the New Bauhaus), Black Mountain College, Design Department Yale University, the Shillito Design School, Sydney, and Parsons School of Design, New York. In this context, the term primary color refers to three exemplar colors (red, yellow, and blue) as opposed to specific pigments. As illustrated, in the RYB color model, red, yellow, and blue are intermixed to create secondary color segments of orange, green, and purple. This set of primary colors emerged at a time when access to a large range of pigments was limited by availability and cost, and it encouraged artists and designers to explore the many diverse colors through mixing and intermixing a limited range of pigment colors. In art and design education, gray, red, yellow, and blue pigments were usually augmented with white and black pigments, enabling the creation of a larger gamut of colors and details including tints and shades.

Sources: en.wikipedia.org

Reference notes

=== Behavioral evidence === Fossils of the troodonts Mei and Sinornithoides demonstrate that some dinosaurs slept with their heads tucked under their arms. This behavior, which may have helped to keep the head warm, is also characteristic of modern birds. Several deinonychosaur and oviraptorosaur specimens have also been found preserved on top of their nests, likely brooding in a bird-like manner. The ratio between egg volume and body mass of adults among these dinosaurs suggest that the eggs were primarily brooded by the male and that the young were highly precocial, similar to many modern ground-dwelling birds. Some dinosaurs are known to have used gizzard stones like modern birds. These stones are swallowed by animals to aid digestion and break down food and hard fibers once they enter the stomach. When found in association with fossils, gizzard stones are called gastroliths.

== History == SCIEX was founded in 1974 by Canadian scientists Barry French, Neil Reid, Adele Buckley, and businessman William Breukelman, to develop a mass spectrometer system based on atmospheric pressure ionisation and direct air sampling. In 1981, SCIEX was acquired by MDS Inc., a Canadian medical services and equipment company. A joint venture was formed with PerkinElmer for sales and marketing of the inductively coupled plasma mass spectrometry (ICPMS) product line. In 1986, the joint venture was extended to include the liquid chromatography–mass spectrometry (LC/MS) business, managed through the Applied Biosystems division of Perkin Elmer. In 2008, Applied Biosystems merged with Invitrogen to form Life Technologies. In 2009, Danaher Corporation paid approximately $1.1 billion to buy SCIEX from MDS and the Applied Biosystems/MDS SCIEX joint venture business from Life Technologies. The business unit now operates as SCIEX within the Life Sciences Division of Danaher and is one of the major players in the global mass spectrometry market estimated (in 2018) at $5.5 billion worldwide.

The Jordanian Druze people are estimated to number at least 20,000, as of 2005. The main areas where they live are Amman, Azraq, Zarqa, Russiefa, Umm Al-Quttein, Aqaba and Mafraq. Druze settlement in Jordan began in 1918, when 22 Druze families left Jabal al-Druze for al-Azraq following the withdrawal of the Turks from the region. Jordan contains one of the oldest Christian communities in the world, their presence dating back to the crucifixion of Jesus Christ early in the 1st century AD. Christians today make up about 3% of the population. Jordanian Christians in a country of almost 10 million are thought to number 250,000–400,000, down from 20% in 1930, but their absolute numbers have increased. This is due to high immigration rate of Muslims into Jordan, higher emigration rates of Christians and higher birth rates for Muslims. Jordan's Arab Christians are exceptionally well integrated in the Jordanian society and enjoy a high level of freedom. Christians are allotted a minimum of 7% of the seats in the Jordanian parliament (9 out of 130 seats), significantly greater than their percentage of the total Jordanian population. They form a significant part of the kingdom's political and economic elite. In Amman, Zarqa, Russiefa, Umm Al-Quttein, Aqaba, and Mafraq there are Christian and Druze communities coexisting with the Sunni Muslim majority. Many Druze and Muslims attend Christian schools in these areas, where students from Christian, Druze, and Muslim backgrounds study and socialize together.

Bantu tribes were observed to be upholding what was described as Jewish law, including circumcision, in the 16th century. Circumcision and elements of Jewish dietary restrictions are still found among Bantu tribes.

Sources: en.wikipedia.org

Frequently asked questions

Semax 是天然存在的物质吗?

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 与 ACTH 是什么关系?

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。

为什么 Semax 的序列需要在羧基端延长?

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。

用什么方法确认分子量?

电喷雾或基质辅助激光解吸电离质谱是常用手段,测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内,才支持结构一致的判断。

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