The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-30. Anything still debated is marked as such rather than presented as settled.
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 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.
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.
| 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. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Slaves are often identified or marked via mutilation or tattooing. A widespread practice was branding, either to explicitly mark slaves as property or as punishment. Some slaves are forced to wear shackles that cannot be removed such as cuffs, legcuffs, collars, chains, or anklets.
Independent Order of Sons of Abraham - Founded in 1892 by a group of Jewish men who were already members of the Masons, Sons of Benjamin, and the Order of B'rith Abraham. Membership in 1899 almost exclusively in New York and Brooklyn, numbered about 2,400 divided equally between men and women. Independent Order of Sons of Benjamin - Founded in 1877 in New York by a group of men who were already members of the Brith Abraham. By 1899 it had spread to the "principal cities of the United States and the Dominion of Canada." It authorized the creation of female lodges, of which there were about 20 in 1899. In 1899 there were about 18,000 male members and 2,500 women. In 1918 it had 800 members in 25 lodges, of which 450 were located in New York City with 18 lodges. Its headquarters in 1918 were at 953 Third Avenue. Offered the "usual secret society forms, and privileges". The emblem was a triangle between the letters F and P with an L under it. Offered insurance against death under the Metropolitan Life Insurance Company. Independent Western Star Order - Founded in 1894. The Eastern Division was headquartered at 40 Rivington Street. Had 21,000 members in 1918, with 2000 members in 24 lodges in New York City. Offered accident, death, and burial insurance May or may not be related to an order of the same name operating out of Chicago. Independent Workmens Circle - Founded in 1906 in Boston. Open to working men and women and "those in sympathy with the cause of labor". In 1923 had 77 lodges with 5,726 benefit members. Headquarters 86 Leverett Street, Boston.
Photograph 1. – Open rhinoplasty: The incisions are endonasal (in the nose), and thus are hidden. The skin-incision to the columella aids the plastic surgeon in precisely suturing to hide the scar—except for the columellar incision (red-dot guideline) across the nasal base. The columellar incision allows the surgeon to view the size, shape, and condition of the nasal cartilages and bones to be corrected. Photograph 2. – Open rhinoplasty: The nasal interior. The scissors indicate the lower lateral cartilage (blue), which is one of the wing-shaped cartilages that conform the tip of the nose. The jagged red delineation indicates the locale of the columellar incision. Once the skin has been lifted from the bone-and-cartilage framework, the surgeon performs the nasal correction tasks. Photograph 3. – Open rhinoplasty: To narrow the tip of a too-wide nose, the surgeon first determines the cause of the excess nasal width. The suture being emplaced will narrow the tip of the nose. The red delineation indicates the edge of the nose-tip cartilage, which is narrowed when the surgeon tightens the folded cartilage apex. The suture (light blue) ends in the needle (white); tweezers (green) hold the nasal cartilage in place for the suturing. Photograph 4. – Nasal hump excision: The black delineation indicates the desired nose-reduction outcome: a straight nose. The nasal hump is bone (red) above the scalloped grey line, and cartilage (blue) below the scalloped grey line.
Sources: en.wikipedia.org
=== Solvation === Many liquids are used as solvents, to dissolve other liquids or solids. Solutions are found in a wide variety of applications, including paints, sealants, and adhesives. Naphtha and acetone are used frequently in industry to clean oil, grease, and tar from parts and machinery. Body fluids are water-based solutions. Surfactants are commonly found in soaps and detergents. Solvents like alcohol are often used as antimicrobials. They are found in cosmetics, inks, and liquid dye lasers. They are used in the food industry, in processes such as the extraction of vegetable oil.
==== United States plan announcement ==== On 3 January 2026, Trump stated: "We are going to run the country until such time as we can do a safe, proper and judicious transition". He indicated that the US might send troops to Venezuela as part of this. Trump also said that Rubio had made contact with Rodríguez and that she allegedly told Rubio, "We'll do whatever you need", and that she was gracious but "really doesn't have a choice"; Trump further opined that Rodríguez was "essentially willing to do what we think is necessary" to revive Venezuela, marking a shift in the administration's stance compared to months prior, when the US excluded any settlement with Rodríguez. Media outlets noted Rodríguez's statements contradicted Trump's.
=== Structural classification === Beyond chemical composition, cages are also classified based on their structural characteristics. Shape-persistent cages maintain fixed conformations due to their rigid building blocks and strong covalent bonds, providing stable and predictable cavity environments. In contrast, flexible cages exhibit dynamic structures that can adapt to guest molecules through conformational changes, allowing for responsive host-guest interactions. This flexibility can be advantageous in applications requiring adaptive binding, such as selective molecular capture under varying conditions. Some systems even form hierarchical assemblies, creating cage-of-cage structures with complex internal architectures that can provide multiple distinct environments for guest molecules or cascade reactions.
Sources: en.wikipedia.org
== Hazards == Silica gel is non-toxic, and non-reactive and stable with ordinary usage. It will react with hydrogen fluoride, fluorine, oxygen difluoride, chlorine trifluoride, strong acids, strong bases, and oxidizers. Silica gel is irritating to the respiratory tract and may cause irritation of the digestive tract. Dust from the beads may cause irritation to the skin and eyes, so precautions should be taken. Crystalline silica dust can cause silicosis, but synthetic amorphous silica gel is indurated, so it does not cause silicosis. Additional hazards may occur when doped with a humidity indicator.
==== Wismut AG ==== The approximately 200,000 uranium miners employed by Wismut AG in the former Soviet occupation zone of East Germany were exposed to very high levels of radiation, particularly between 1946 and 1955, but also in later years. This exposure was caused by the inhalation of radon and its radioactive by-products, which were deposited to a considerable extent in the inhaled dust. Radiation exposure was expressed in the historical unit of working level month (WLM). This unit of measurement was introduced in the 1950s specifically for occupational safety in uranium mines in the U.S. to record radiation exposure resulting from radioactive exposure to radon and its decay products in the air we breathe. Approximately 9000 workers at Wismut AG have been diagnosed with lung cancer.
Forskolin Interleukin-6 Pituitary adenylate cyclase-activating peptide (PACAP) Stress or trauma Circadian rhythms Forskolin and PACAP regulate the synthesis of CRH in the hypothalamus by binding to G protein-coupled receptors and stimulating and increase in cAMP within the cells via the action of adenylate cyclase. This activates the protein kinase A pathway, which results in the binding of cAMP response element binding protein (CREB) onto the CRH promoter region and induces transcription of CRH. This process is repressed by glucocorticoids; this inhibitory feedback helps maintain homeostasis of the stress response. Once released by the hypothalamus, CRH travels through the hypophyseal portal system to the anterior pituitary, where it binds to G protein-coupled receptors on the corticotropic cell membrane and stimulates cAMP production. The effects of CRH on pituitary corticotropes are potentiated by vasopressin (AVP); AVP is a weak inducer of ACTH production on its own, but has a strong synergistic effect on ACTH production when CRH is also bound to the receptor. These signaling hormones act via signal transduction, causing the synthesis of POMC and eventual cleavage to ACTH and β-lipotropin. These peptide hormones are then released into the bloodstream, where they circulate and act on target tissues.
=== Addiction and withdrawal === Aticaprant was well-tolerated in cocaine use disorder (CUD) patients. A positron emission tomography (PET) study in CUD patients utilizing a KOR selective agonist [11C]GR-103545 radioligand showed CUD individuals with higher KOR availability were more prone to stress-induced relapse. A subsequent PET scan following a three-day cocaine binge showed a decrease in KOR availability, interpreted as increased endogenous dynorphin competing with the radioligand at the KOR binding sites. These findings are in support of the negative affect state and further implicate the KOR/dynorphin system clinically and therapeutically relevant in humans with CUD. Taken together, in drug addiction the KOR system is implicated as a homeostatic mechanism to counteract the acute effects of drugs of abuse. Chronic drug use and stress up-regulate the system in turn leading to a dysregulated state which induces negative affective states and stress reactivity. KOR agonists have also been investigated for their therapeutic potential in the treatment of addiction, particularly substance use disorders. Ibogaine, atypical KOR agonist with G-protein-biased signaling and complex pharmacodynamics involving multiple neurotransmitter systems. Ibogaine's primary active metabolite, noribogaine, acts as a moderate KOR agonist selective for G protein and a potent serotonin reuptake inhibitor. This mechanism, combined with activity at 5-HT2A, 5-HT2C, σ2, and NMDA receptors, likely leads its anti-addictive effects.
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 is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.