The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-10-14 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 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。
Octadecyltrichlorosilane (ODTS or n-octadecyltrichlorosilane) is an organosilicon compound with the formula CH3(CH2)17SiCl3. A colorless liquid, it is used as a silanization agent to prepare hydrophobic stationary phase, for reversed-phase chromatography. It is also evaluated for forming self-assembled monolayers on silicon dioxide substrates. Its structural chemical formula is CH3(CH2)17SiCl3. It is flammable and hydrolyzes readily with release of hydrogen chloride. Dodecyltrichlorosilane, an ODTS analog with shorter alkyl chain, is used for the same purpose. ODTS-PVP films are used in organic-substrate LCD displays.
The citric acid cycle is a metabolic pathway that connects carbohydrate, fat, and protein metabolism. The reactions of the cycle are carried out by eight enzymes that completely oxidize acetate (a two carbon molecule), in the form of acetyl-CoA, into two molecules each of carbon dioxide. Through catabolism of sugars, fats, and proteins, the two-carbon organic product acetyl-CoA is produced which enters the citric acid cycle. The reactions of the cycle also convert three equivalents of nicotinamide adenine dinucleotide (NAD+) into three equivalents of reduced NAD (NADH), one equivalent of flavin adenine dinucleotide (FAD) into one equivalent of FADH2, and one equivalent each of guanosine diphosphate (GDP) and inorganic phosphate (Pi) into one equivalent of guanosine triphosphate (GTP). The NADH and FADH2 generated by the citric acid cycle are, in turn, used by the oxidative phosphorylation pathway to generate energy-rich ATP. One of the primary sources of acetyl-CoA is from the breakdown of sugars by glycolysis which yield pyruvate that in turn is decarboxylated by the pyruvate dehydrogenase complex generating acetyl-CoA according to the following reaction scheme:
=== Travelling wave === Though drift electric fields are normally uniform, non-uniform drift fields can also be used. One example is the travelling wave IMS, which is a low pressure drift tube IMS where the electric field is only applied in a small region of the drift tube. This region then moves along the drift tube, creating a wave pushing the ions towards the detector, removing the need for a high total drift voltage. A direct determination of collision cross sections (CCS) is not possible, using TWIMS. Calibrants can help circumvent this major drawback, however, these should be matched for size, charge and chemical class of the given analyte. An especially noteworthy variant is the "SUPER" IMS, which combines ion trapping by the so-called structures for lossless ion manipulations (SLIM) with several passes through the same drift region to achieve extremely high resolving powers.
Sources: en.wikipedia.org
The most common fault associated with malolactic fermentation is its occurrence when it is not desired. This could be for a wine that is meant to be acidic and fruity (such as Riesling) or it could be a wine that was previously thought to have gone through MLF and bottled only to have malolactic fermentation commence in the bottle. The outcome of this "in-bottle" fermentation is often gassy, hazy wine that can be unpalatable to consumers. Improvement in sanitation and control of lactic acid bacteria in the winery can limit the occurrence of these faults. For early Vinho Verde producers, the slight effervesce that came from in-bottle malolactic fermentation was considered a distinguishing trait that consumers enjoyed in the wine. However, wineries had to market the wine in opaque bottles to mask the turbidity and sediment that the "in-bottle MLF" produced. Today, most Vinho Verde producers no longer follow this practice and instead complete malolactic fermentation prior to bottle with the slight sparkle being added by artificial carbonation. While not necessarily a fault, malolactic fermentation does have the potential of making a wine "protein unstable" due to the resulting change in pH which affects the solubility of proteins in wine. For this reason, protein fining and heat stability tests on wine usually take place after malolactic fermentation has run to completion.
These inhibitors were followed by the next group of hydroxamate-based inhibitors, which focus on the suppression of metabolism, minimization of MMP-1 inhibitory activity and the control of subtype selectivity, by structure-based design. The tetrahydropyran in RS-130830 introduces a steric block that suppresses metabolism, which would fix the problem that the previous generation of inhibitors showed. The outcome of its clinical evaluation has not yet been disclosed. 239796-97-5 has improved ADME and MMP-1 selectivity properties and has shown excellent oral efficacy in an animal model of osteoarthritis. Although, the therapeutic objectives for these inhibitors is not cancer, like it has been for most of the MMP inhibitors.
Joan later has dinner with Vera, who confronts Joan about the riot incident and how it led Vera to being infected hepatitis C from a dirty syringe that was held to her neck. Joan turns Will and Franky against each other by sending Will the recording of Franky's confession on his wife's murder. Joan watches Will attack Franky but is enraged when he doesn't kill Franky so that Franky makes parole. Joan then plants drugs in toys that Nash Taylor bring forJoshua in revenge for Doreen making fun of her and to further turn Bea's friends against her. When Joan believes Vera tried using Jianna as an excuse to unsettle her, she violently slaps Vera and their friendship ends. She reveals Vera's Hep C to all the staff and removes her from deputy governorship. Joan realizes that Fletch witnessed her "talking to air" in a hallucination she was having about her father. She asks Nils to kill Fletch to stop him from revealing her previous murder attempt on him. In the third-season finale, Joan finds the walls closing in on her. She plants a recording device in the secure spot where Kaz Proctor tells Bea the name of Joan's henchman, Nils Jesper. She calls Nils who is waiting to murder Matthew Fletcher on Joan's command. Joan then listens in to a recording as she notices Bea turning her back on Kaz. Joan is later seen smiling as a news report states that due to an anonymous tip from the prison, Kaz Proctor has been incarcerated at Wentworth. Vera comes in and reveals that she's put in a complaint to the board against Joan.
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.