ACTH analog 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 2025-11-17. 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。
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。
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
| 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.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
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.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
It's a little sarcastic, but it's pretty much about dealing with your mortality and life. Everybody's going to die someday. Instead of being afraid of it, that's the way it is: so enjoy the time you've got. Live as much as you can, have as much fun as possible. Face your fear and live. I had family members die at a fairly early age; so I've always had kind of a phobia about it. Death freaks me out. I think it freaks a lot of people out. It's the end of life, depending on your views. It's a pretty scary thing. "Them Bones" is trying to put that thought to rest. Use what you have left, and use it well." Cantrell was inspired to write "Dam That River" after a fight he had with Sean Kinney, in which Kinney broke a coffee table over his head. The lyrics to "Rain When I Die" were written by Cantrell and Staley about their respective girlfriends. "Sickman" came together after Staley asked Cantrell to "write him the sickest tune, the sickest, darkest, most fucked up and heaviest thing [Cantrell] could write." "Rooster" was written by Cantrell for his father, Jerry Cantrell Sr., who served in the Vietnam War and his childhood nickname was "Rooster". Cantrell described the song as "the start of the healing process between my Dad and I from all that damage that Vietnam caused." Discussing the title track "Dirt", Cantrell stated that "the words Layne put to it were so heavy, I've never given him something and not thought it was gonna be the most bad-assed thing I was going to hear." Staley said he wrote the song "to a certain person who basically buried my ass".
Affimer molecules, also known as adhiron, are small proteins that bind to target proteins with affinity in the nanomolar range. These engineered non-antibody binding proteins are designed to mimic the molecular recognition characteristics of monoclonal antibodies in different applications. These affinity reagents have been optimized to increase their stability, make them tolerant to a range of temperatures and pH, reduce their size, and to increase their expression in E.coli and mammalian cells.
Works by Oscar Wilde at Project Gutenberg Works by Oscar Wilde at LibriVox (public domain audiobooks) The Oscar Wilde collection, hosted by University College Cork. The works of Oscar Wilde, hosted by The Oscar Wilde Collection. Oscar Wilde's essay Impressions of America (complete and corrected). Online Books by Oscar Wilde, hosted by the University of Pennsylvania Oscar Wilde Online, the Works and Life of Oscar Wilde. Profile of, writings adapted into films and films about Oscar Wilde at IMDb Complete Works of Oscar Wilde on BooksVooks
Sources: en.wikipedia.org
Second, Downstream-peptides are consistently positioned in a place that is consistent with a cis-regulatory role in regulating the downstream ORFs, although the biological role of the ORFs is unknown. Third, the pseudoknot structure has a moderate complexity that is typical of riboswitches. Finally, the observation of regulation of a downstream ORF by nitrogen availability also suggests a cis-regulatory role of the element. This hypothesis is supported by biochemical and genetic data. First, both Downstream-peptide RNAs and glnA RNAs selectively bind glutamine. Second, reporter gene analysis of the Downstream-peptide motif revealed that this RNA promotes reporter gene expression upon binding of glutamine and can therefore be considered an activating riboswitch. Possible candidates to be regulated by the Downstream-peptide motif are genes that frequently carry the Downstream-peptide motif in their 5′UTR and encode small, unknown proteins that contain DUF4278 and are putative regulators of glutamine synthetase. This hypothesis is supported by the finding that expression of the DUF4278-containing glutamine synthetase inhibitory factor IF17 encoding gene gifB was shown to be regulated by the structurally related glnA RNA motif. Downstream-peptide RNAs overlap a predicted non-coding RNA called yfr6 that is over 200 nucleotides in length, but it was proposed that only the upstream region (corresponding to the Downstream-peptide motif) functions as an RNA structure. A distinct predicted non-coding RNA called yfr14 overlaps both yfr6 and Downstream-peptide RNAs.
Mammals are a diverse class of animals, mostly terrestrial but some are aquatic and others have evolved flapping or gliding flight. They mostly have four limbs, but some aquatic mammals have no limbs or limbs modified into fins, and the forelimbs of bats are modified into wings. The legs of most mammals are situated below the trunk, which is held well clear of the ground. The bones of mammals are well ossified and their teeth, which are usually differentiated, are coated in a layer of prismatic enamel. The teeth are shed once (milk teeth) during the animal's lifetime or not at all, as is the case in cetaceans. Mammals have three bones in the middle ear and a cochlea in the inner ear. They are clothed in hair and their skin contains glands which secrete sweat. Some of these glands are specialized as mammary glands, producing milk to feed the young. Mammals breathe with lungs and have a muscular diaphragm separating the thorax from the abdomen which helps them draw air into the lungs. The mammalian heart has four chambers, and oxygenated and deoxygenated blood are kept entirely separate. Nitrogenous waste is excreted primarily as urea. Mammals are amniotes, and most are viviparous, giving birth to live young. Exceptions to this are the egg-laying monotremes, the platypus and the echidnas of Australia. Most other mammals have a placenta through which the developing foetus obtains nourishment, but in marsupials, the foetal stage is very short and the immature young is born and finds its way to its mother's pouch where it latches on to a teat and completes its development.
The novel centers on a poor boy named Charlie Bucket who takes a tour through the greatest chocolate factory in the world, owned by the eccentric Willy Wonka. Two film adaptations of the novel were produced: Willy Wonka & the Chocolate Factory (1971) and Charlie and the Chocolate Factory (2005). A third adaptation, an origin prequel film titled Wonka, was released in 2023. Chocolat, a 1999 novel by Joanne Harris, was adapted for film in Chocolat which was released a year later. Some artists have utilized chocolate in their art; Dieter Roth was influential in this beginning with his works in the 1960s casting human and animal figures in chocolate, which used the chocolate's inevitable decay to comment on contemporary attitudes towards the permanence of museum displays. Other works have played on the audience's ability to consume displayed chocolate, encouraged in Sonja Alhäuser's Exhibition Basics (2001) and painfully disallowed in Edward Ruscha's Chocolate Room (1970). In the 1980s and 90s, performance artists Karen Finley and Janine Antoni used chocolate's cultural popular associations of excrement and consumption, and desirability respectively to comment on the status of women in society.
Sources: en.wikipedia.org
The actions undertaken in Canada to support incoming aircraft and their occupants were collectively titled Operation Yellow Ribbon. That evening, the Central Intelligence Agency informed President George W. Bush that its Counterterrorism Center had identified the attacks as having been the work of al-Qaeda under Osama bin Laden. The United States responded by invading Afghanistan and launching its Global War on Terror, with the stated goal of eliminating hostile groups it deemed terrorist organizations and the governments the United States identified as supporting them. NATO's invocation of Article 5 of the North Atlantic Treaty—its only usage to date—called upon allies to fight al-Qaeda as well. As U.S. and allied invasion forces swept through Afghanistan, bin Laden eluded them. He denied any involvement until 2004, when excerpts of a taped statement in which he accepted responsibility for the attacks were released. Al-Qaeda's cited motivations included U.S. support of Israel, the presence of U.S. military bases in Saudi Arabia, and sanctions against Iraq. The nearly decade-long manhunt for bin Laden concluded in May 2011, when he was killed during a U.S. military raid in Abbottabad, Pakistan. The war in Afghanistan continued for another decade. The attacks killed 2,977 people, injured thousands more, and gave rise to long-term health consequences while causing at least US$10 billion in infrastructure and property damage.
A DNA vaccine is a type of vaccine that transfects a specific antigen-coding DNA sequence into the cells of an organism as a mechanism to induce an immune response. DNA vaccines work by injecting genetically engineered plasmid containing the DNA sequence encoding the antigen(s) against which an immune response is sought, so the cells directly produce the antigen, thus causing a protective immunological response. DNA vaccines have theoretical advantages over conventional vaccines, including the "ability to induce a wider range of types of immune response". Several DNA vaccines have been tested for veterinary use. In some cases, protection from disease in animals has been obtained, in others not. Research is ongoing over the approach for viral, bacterial and parasitic diseases in humans, as well as for cancers. In August 2021, Indian authorities gave emergency approval to ZyCoV-D. Developed by Cadila Healthcare, it is the first DNA vaccine approved for humans.
The risk of experiencing severe withdrawal symptoms is high if a patient has become physically or mentally dependent and discontinues tapentadol abruptly. These symptoms can range from mild discomfort to more serious health issues, making abrupt cessation dangerous. When a person has been using tapentadol regularly for an extended period of time, tapering off the drug gradually is generally recommended. This approach allows the body to adjust to lower doses over time, minimizing the risk of withdrawal symptoms and ensuring a safer transition away from tapentadol. Gradual withdrawal helps to avoid the shock to the system that comes with abrupt discontinuation, ultimately making the process more manageable for a person who has developed a dependence. The symptoms of tapentadol withdrawal are typical of other opioids and can include anxiety, restlessness, fever or chills, joint pain, nausea or vomiting, loss of appetite, runny nose, stomach cramps, sweating, tremor, or insomnia. However, tapentadol withdrawal symptoms may be more intense and prolonged when compared with more typical opioids such as codeine or oxycodone, in some respects, due to the fact that tapentadol acts also as norepinephrine reuptake inhibitor (NRI). People withdrawing from a tapentadol dependency may experience both typical opioid withdrawal symptoms, such as fever or nausea, along with symptoms associated more commonly with the discontinuation of drugs which block the reuptake of norepinephrine.
"I poured the wine into the chalice our church had given me. In the one-sixth gravity of the moon, the wine curled slowly and gracefully up the side of the cup. It was interesting to think that the very first liquid ever poured on the moon, and the first food eaten there, were communion elements." —Buzz Aldrin Aldrin received the Eucharist in the same hour that his local church did on that Sunday Sabbath and he later stated that "I sensed especially strongly my unity with our church back home, and with the Church everywhere".
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。
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.