synthetic heptapeptide 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.
Last reviewed on 2025-11-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
| 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 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.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
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.
=== End of the party === The passing of the Enabling Act did not, as Kaas had suggested, prevent the Centre Party's demise. As promised during the negotiations, a working committee chaired by Hitler and Kaas was supposed to inform about further legislative measures. However, it met only three times (31 March, 2 and 7 April) without any major impact. At that time, the Centre Party was weakened by massive defections by party members. Loyal party members, in particular civil servants, and other Catholic organisations were subject to increasing reprisals, despite Hitler's previous guarantees. The party was also hurt by a declaration of the German bishops that, while maintaining their opposition to Nazi ideology, modified the ban on cooperation with the new authorities. The issue of the concordat prolonged Kaas's stay in Rome, leaving the party without an effective chairman: On 5 May Kaas finally resigned from his post and the party now elected Brüning as his successor. The party adopted a tempered version of the leadership principle; pro-Centre papers now declared that the party's members, or "retinue", would fully submit itself to Brüning. It was not enough, however, to relieve the growing pressure that it and other parties faced in the wake of the process of Gleichschaltung. Prominent members were frequently arrested and beaten, and pro-Centre civil servants were fired. As the summer of 1933 wore on, several government officials—including Papen—demanded that the Centre either dissolve or be closed down by the government.
==== Carbon-oxygen ==== Glucose oxidase (GOX) catalyzes the oxidation of β-D-glucose to D-glucono-δ-lactone with the simultaneous reduction of enzyme-bound flavin. GOX exists as a homodimer, with each subunit binding one FAD molecule. Crystal structures show that FAD binds in a deep pocket of the enzyme near the dimer interface. Studies showed that upon replacement of FAD with 8-hydroxy-5-carba-5-deaza FAD, the stereochemistry of the reaction was determined by reacting with the re face of the flavin. During turnover, the neutral and anionic semiquinones are observed which indicates a radical mechanism.
An amphetamine overdose can result in a stimulant psychosis that may involve a variety of symptoms, such as delusions and paranoia. A Cochrane review on treatment for amphetamine, dextroamphetamine, and methamphetamine psychosis states that about 5–15% of users fail to recover completely. According to the same review, there is at least one trial that shows antipsychotic medications effectively resolve the symptoms of acute amphetamine psychosis. Psychosis rarely arises from therapeutic use.
Sources: en.wikipedia.org
=== Insomnia === Doxepin is used in the treatment of insomnia. In 2016, the American College of Physicians advised that insomnia be treated first by treating comorbid conditions, then with cognitive behavioral therapy and behavioral changes, and then with drugs; doxepin was among those recommended for short-term help maintaining sleep, on the basis of weak evidence. The 2017 American Academy of Sleep Medicine recommendations focused on treatment with drugs were similar. A 2015 Agency for Healthcare Research and Quality review of treatments for insomnia had similar findings. A major systematic review and network meta-analysis of medications for the treatment of insomnia published in 2022 found that doxepin had an effect size (standardized mean difference (SMD)) against placebo for treatment of insomnia at 4 weeks of 0.30 (95% CITooltip confidence interval –0.05 to 0.64). The certainty of evidence was rated as very low, and no data were available for longer-term treatment (3 months). For comparison, the other sedating antihistamines assessed, trimipramine and doxylamine, had effect sizes (SMD) at 4 weeks of 0.55 (95% CI –0.11 to 1.21) (very low certainty evidence) and 0.47 (95% CI 0.06 to 0.89) (moderate certainty evidence), respectively. Benzodiazepines and Z-drugs generally showed larger effect sizes (e.g., SMDs of 0.45 to 0.83) than doxepin, whereas the effect sizes of orexin receptor antagonists, such as suvorexant, were more similar (SMDs of 0.23 to 0.44).
MPs' basic salary is set to rise by 2.8% to £93,904 from April. Darren Millar tells the Senedd he was in the "right place at the right time" as he defends his decision to attend the National Prayer Breakfast in the United States and miss a vote on the Welsh Government's budget. Millar also says he was promoting Welsh interests while in the US. Simon Case, the former Cabinet Secretary, is appointed as the chair of the Team Barrow Delivery Board, a board that will oversee a £200m project to redevelop Barrow-in-Furness, Cumbria. 11 February – Labour suspends 11 councillors in Greater Manchester as part of its investigation into a WhatsApp group in which offensive messages were exchanged. James Garnor resigns as a member of Whittlebury Parish Council after a video was share that appeared to show an explosive device being triggered by a cat. 12 February – A review into the events leading up to the murder of David Amess finds that his killer, Ali Harbi Ali, was exited from the government's Prevent anti-terror programme "too quickly" and that its handling of him was "sub-optimal". 13 February – A BBC News investigation discovers Chancellor Rachel Reeves was the subject of an expenses investigation while she was a senior manager at Halifax Bank of Scotland in the late 2000s. Her online CV is also reported to have exaggerated the length of time she was employed by the Bank of England. In response, Reeves says that no concerns were raised with her at the time of the investigation.
The exhibition was sponsored by the General Agent and Sole Distribution of medicine in Egypt and Sudan, Syria and Lebanon. Later on, Teva exported its products to the US, Soviet Union (USSR), health institutes in Denmark, Czechoslovakia, Persia and Burma.
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。
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.