Semax 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 2025-10-20. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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 is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
| 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 |
are calculated for a short time frame, and the matrices for longer periods of time are calculated by assuming mutations follow a Markov chain model. The base unit of time for the PAM matrices is the time required for 1 mutation to occur per 100 amino acids, sometimes called 'a PAM unit' or 'a PAM' of time. This is precisely the duration of mutation assumed by the PAM1 matrix. The constant
In 2001, the entire line was facelifted with new styling, a revised suspension, and a new audio system. For North America, ES models received rear disc brakes and a stiffer suspension. The 1.8 L engine was increased to 2.0 L for the ES models, and was optional on the LX model, becoming the 2.0LX. The standard 2001 Protegé LX engine was the carryover 1.6 L ZM-DE. A 2.0-litre, petrol engine appeared in 2001 on the Japanese market Sport 20. In 1999, Ford of Japan ceased to market Mazda-based models, and the Ford Laser, along with the Ixion, Telstar, and Festiva, was discontinued.
== Protein properties == There are two keyhole limpet hemocyanin genes, termed KLH1 and KLH2 which share around 60% identity at the protein level. Both encode large glycosylated proteins consisting of around 3400 amino acids and a molecular weight of around 390,000 daltons, excluding the glycosylation. The protein oligomerises to form a barrel shaped didecameric complex which is composed of 20 monomers. Each domain of a KLH subunit contains two copper atoms that together bind a single oxygen molecule (O2). When oxygen is bound to hemocyanin, the molecule takes on a distinctive transparent, opalescent blue color, due to the Cu2+ state of the copper. In the absence of oxygen, the bound copper is found as Cu1+ and hemocyanin is colorless. The KLH protein is potently immunogenic, but does not cause an adverse immune response in humans. It is therefore highly prized as a vaccine carrier protein. Because of its size and glycosylation, KLH protein cannot be reproduced synthetically; it is available only as a purified biological product from the keyhole limpet Megathura crenulata.
Sources: en.wikipedia.org
==== Management of future flooding ==== The floodings from earlier in the year became an issue during the course of his reelection campaign in 2024. After he was questioned about the subject, Melo mentioned that "it will continue to flood". According to him, the situation would depend on drainage systems, but the budget did not cover projects to protect against flooding, and the new investment of $4.5 billion real would depend on the creation of a partnership with the Municipal Department of Water and Sewage (DMAE). During the same time period, strong rains affected the city, leaving the city without lights and transport, also affecting the swearing in of municipal secretaries, which had to be cancelled after the rain took out the lights. Former minister of president Lula da Silva, Paulo Pimenta, criticized Melo for his stance on the issue, claiming that he was responsible for the new bouts of flooding in Porto Alegre.
Probenecid, also sold under the brand name Probalan, is a medication that increases uric acid excretion in the urine. It is primarily used in treating gout and hyperuricemia. Probenecid was developed as an alternative to caronamide to competitively inhibit renal excretion of some drugs, thereby increasing their plasma concentration and prolonging their effects.
=== Second formation === The division was reconstituted starting in March 1945 and placed under the operational control of the 2nd Army (Army Group Vistula) in West Prussia. On 10 March 1945, the division was reformed near Schwedt with only two regiments. The "Shadow Division Hannover" was utilized for this purpose. Grenadier Regiment 1093 was not re-established, and the artillery regiment consisted of only a single battalion. Subsequently, the division was assigned to the 3rd Panzer Army and deployed on the Oder front against the Red Army. In May 1945, the 547th Volksgrenadier Division surrendered to US forces near Schwerin in Mecklenburg.
Sources: en.wikipedia.org
==== The Scout Association (United Kingdom) ==== The Scout Association refers to WOSM's emblem as its "Membership Award" and uses it as its joining badge for its Beavers, Cubs, Scouts, Explorer Scouts and Scout Network, with progressing requirements intended to help the member understand their commitment.
=== Salinization/acidification of soils === Sediment from abandoned aquaculture farms can remain hypersaline, acidic and eroded. This material can remain unusable for aquaculture purposes for long periods thereafter. Various chemical treatments, such as adding lime, can aggravate the problem by modifying the physicochemical characteristics of the sediment.
== Definition == The name amyloid comes from the early mistaken identification by Rudolf Virchow of the substance as starch (amylum in Latin, from Ancient Greek: ἄμυλον, romanized: amylon), based on crude iodine-staining techniques. For a period, the scientific community debated whether or not amyloid deposits are fatty deposits or carbohydrate deposits until it was finally found (in 1859) that they are, in fact, deposits of albumin-like proteinaceous material.
== Committees and governance == IUPAC is governed by several committees that all have different responsibilities. The committees are as follows: Bureau, CHEMRAWN (Chem Research Applied to World Needs) Committee, Committee on Chemistry Education, Committee on Chemistry and Industry, Committee on Printed and Electronic Publications, Evaluation Committee, Executive Committee, Finance Committee, Interdivisional Committee on Terminology, Nomenclature and Symbols, Project Committee, and Pure and Applied Chemistry Editorial Advisory Board. Each committee is made up of members of different National Adhering Organizations from different countries. The steering committee hierarchy for IUPAC is as follows:
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。
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.