The short version of ACTH analog fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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。
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。
| 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. 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.
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.
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.
The subject of the elaborate tomb is being discussed in scientific literature as "the Ivory Lady" and she is considered as the most socially prominent person identified during archaeological research of the Copper Age cultures of the Iberian peninsula that are dated to 3200 to 2500 BC, approximately the time Ancient Egyptian and Mesopotamian cultures were emerging and flourishing. Other large tholoi with long entrance passages are the Dolmen de la Pastora and the Dolmen de Matarrubilla. Archaeological remains from 2500 BC indicate it was a major copper-smelting town.
=== Filming === For the scene where Baby Billy exposes himself naked to Jesse, Judy and Kelvin, Walton Goggins was offered the option of getting naked, but he declined. He said, "We've done lot of chaotic things over the course of our 12-year collaboration; I will follow Danny McBride anywhere — except there. That's one thing I won't do. Danny McBride commented, "The beautiful thing about Walton is that he's never shown his actual penis on the show. It's always a stunt double penis. Another fun fact: it's never the same penis. We've cast different elderly penises — or Peni — for all his scenes." Tim Baltz did his own stunts for his character's pole dancing, saying "I was excited, because it felt like an evolution of the character; I felt like each season there was something more ridiculous that BJ was getting into. It made perfect sense that this was the hobby, but I wasn't prepared for it, so I just started pounding creatine and training hard."
=== Hematologic involvement === Hematologic abnormalities are prevalent in MCTD. Mild lymphadenopathy affects 25–50% of patients, and it is frequently an early symptom of the disease. This usually subsides over time; however, it may reappear during flares. Between 50% and 75% of people with MCTD will experience anemia, lymphopenia, or leukopenia. Anemia of chronic disease is the most common type of anemia seen in MCTD. Thrombocytopenia can develop in MCTD but is less common than leukopenia or anemia.
Sources: en.wikipedia.org
== Career and research == After graduating, Hopkins then taught physiology and toxicology at Guy's Hospital from 1894 to 1898. In 1898, while attending a meeting of the Physiological Society, he was invited by Sir Michael Foster to join the Physiological Laboratory in Cambridge to investigate the chemical aspects of physiology. Biochemistry was not, at that time, recognised as a separate branch of science. He was a lecturer in chemical physiology at Emmanuel College, Cambridge in March 1900, when he received the academic rank Master of Arts (MA) honoris causa. He earned a doctorate in physiology (D.Sc.) from the University of London in July 1902, and at the same time was given a readership in biochemistry at Trinity College. While at Cambridge he was initiated into Freemasonry. In 1910 he became a Fellow of Trinity College, and an Honorary Fellow of Emmanuel College. In 1914 he was elected to the Chair of Biochemistry at Cambridge University, thus becoming the first Professor in that discipline at Cambridge. His Cambridge students included neurochemistry pioneer Judah Hirsch Quastel and pioneer embryologist Joseph Needham. Hopkins had for a long time studied how cells obtain energy via a complex metabolic process of oxidation and reduction reactions. His study in 1907 with Sir Walter Morley Fletcher of the connection between lactic acid and muscle contraction was one of the central achievements of his work on the biochemistry of the cell. He and Fletcher showed that oxygen depletion causes an accumulation of lactic acid in the muscle.
==== p53 regulation ==== Gene amplification often occur in various tumor cases, including of MDM2, a gene encodes for a RING E3 Ubiquitin ligase responsible for downregulation of p53 activity. MDM2 targets p53 for ubiquitylation and proteasomal degradation thus keeping its level appropriate for normal cell condition. Overexpression of MDM2 causes loss of p53 activity and therefore allowing cells to have a limitless replicative potential.
Bears living in areas near human settlements or around a considerable influx of recreational human activity often come to rely on foods inadvertently provided by humans, especially during summertime. These include refuse, birdseed, agricultural products and honey from apiaries. The majority of the animal portion of their diet consists of insects, such as bees, yellow jackets, ants, beetles and their larvae. American black bears are also fond of honey and will gnaw through trees if hives are too deeply set into the trunks for them to reach it with their paws. Once the hive is breached, the bears will scrape the honeycombs together with their paws and eat them, regardless of stings from the bees. Bears that live in northern coastal regions (especially the Pacific Coast) will fish for salmon during the night, as their black fur is easily spotted by salmon in the daytime. Other bears, such as the white-furred Kermode bears of the islands of western Canada, have a 30% greater success rate in catching salmon than their black-furred counterparts. Other fish, including suckers, trout and catfish, are readily caught whenever possible. Although American black bears do not often engage in active predation of other large animals for much of the year, the species will regularly prey on mule and white-tailed deer fawns in spring, given the opportunity. Bears may catch the scent of hiding fawns when foraging for something else and then sniff them out and pounce on them. As the fawns reach 10 days of age, they can outmaneuver the bears, and their scent is soon ignored until the next year.
Sources: en.wikipedia.org
Perfumes contain chemicals that vaporize at different temperatures and at different rate in scent accords, known as notes. Atmospheric water vapor is found near the earth's surface, and may condense into small liquid droplets and form meteorological phenomena, such as fog, mist, and haar. Mercury-vapor lamps and sodium vapor lamps produce light from atoms in excited states. Flammable liquids do not burn when ignited. It is the vapor cloud above the liquid that will burn if the vapor's concentration is between the lower flammable limit (LFL) and upper flammable limit (UFL), of the flammable liquid. E-cigarettes produce aerosols, not vapors.
4-Chloromethcathinone (also known as 4-CMC and clephedrone) is a stimulant drug of the cathinone class that has been sold online as a designer drug. 4-CMC produces similar effects to mephedrone, and has been sold as an alternative in countries where mephedrone was scheduled. 4-CMC produces similar side effects to mephedrone, including: increased blood pressure, tachycardia, hyperthermia, and anxiety. Its chemical structure closely resembles para-chloromethamphetamine, raising concerns about its potential to readily induce cell death of serotonergic neurons. However, no neurotoxicity of this kind has been found to occur, but studies involving mice do indicate that it is neurotoxic through other mechanisms, similarly to other cathinones. 4-CMC is cytotoxic and induces oxidative stress, more so than 4-MMC. Moreover, β-keto substitution is thought to change cathinone structure activity relationships (SAR) and metabolism compared to amphetamines, leading to differences in pharmacology.
It is unclear if phytoestrogens have any effect on the cause or prevention of cancer in women. Some epidemiological studies have suggested a protective effect against breast cancer. Additionally, other epidemiological studies found that consumption of soy estrogens is safe for patients with breast cancer, and that it may decrease mortality and recurrence rates. It remains unclear if phytoestrogens can minimize some of the deleterious effects of low estrogen levels (hypoestrogenism) resulting from oophorectomy, menopause, or other causes. A Cochrane review of the use of phytoestrogens to relieve the vasomotor symptoms of menopause (hot flashes) stated that there was no conclusive evidence to suggest any benefit to their use, although genistein effects should be further investigated. A 2024 evidence map separately identified 31 randomized controlled trials of 20 different phytoestrogen products tested for the genitourinary symptoms of menopause, though most used different formulations or doses, which prevented the results from being combined.
Although the 5f orbitals are unoccupied in an actinium atom, it can be used as a valence orbital in actinium complexes and hence it is generally considered the first 5f element by authors working on it. Ac3+ is the largest of all known tripositive ions and its first coordination sphere contains approximately 10.9 ± 0.5 water molecules.
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。
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。