合成七肽 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
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。
Diagnosis is made with reasonable certainty based on history and clinical examination. X-rays may confirm the diagnosis. The typical changes seen on X-ray include: joint space narrowing, subchondral sclerosis (increased bone formation around the joint), subchondral cyst formation, and osteophytes. The combination of knee pain and osteophytes on x-ray or hip pain and osteophytes on x-ray, has good sensitivity and specificity for the diagnosis of osteoarthritis of those joints. X-rays may not correlate with the findings on physical examination or with the degree of pain, especially in the early course of osteoarthritis, where imaging findings may be relatively normal. In 1990, the American College of Rheumatology, using data from a multi-center study, developed a set of criteria for the diagnosis of hand osteoarthritis based on hard tissue enlargement and swelling of certain joints. These criteria were found to be 92% sensitive and 98% specific for hand osteoarthritis versus other entities such as rheumatoid arthritis and spondyloarthropathies.
The complete laboratory synthesis of B12 was achieved by Robert Burns Woodward and Albert Eschenmoser in 1972. The work required the effort of 91 postdoctoral fellows (mostly at Harvard) and 12 PhD students (at ETH Zurich) from 19 nations. The synthesis constitutes a formal total synthesis, since the research groups only prepared the known intermediate cobyric acid, whose chemical conversion to vitamin B12 was previously reported. This synthesis of vitamin B12 is of no practical consequence due to its length, taking 72 chemical steps and giving an overall chemical yield well under 0.01%. Although there have been sporadic synthetic efforts since 1972, the Eschenmoser–Woodward synthesis remains the only completed (formal) total synthesis.
=== Railways === Caledonian Railway (Scotland) Commonwealth Railways (Australia) Central Railway (India) Chiltern Railways (England) China Railway, or China Railway Corporation, a national corporation in the People's Republic of China Consolidated Rail Corporation (Conrail), US Copper Range Railroad
In March 2009, the Obama administration cleared the US$2.1 billion sale of eight P-8 Poseidons to India. This deal, and the $5 billion agreement to provide Boeing C-17 military transport aircraft and General Electric F414 engines announced during Obama's November 2010 visit, made the US one of the top three military suppliers to India (after Israel and Russia). US Chairman of the Joint Chiefs of Staff Mike Mullen encouraged stronger military ties between the two nations, and said that "India has emerged as an increasingly important strategic partner [of the US]". US Undersecretary of State William J. Burns also said, "Never has there been a moment when India and America mattered more to each other." The Deputy Secretary of Defense, Ashton Carter, during his address to the Asia Society in New York City on August 1, 2012, said that India–US relationship has a global scope, in terms of the reach and influence of both countries. He also said that both countries are strengthening the relations between their defense and research organizations.
Sources: en.wikipedia.org
Large gatherings of vapers, called vape meets, take place around the US. They focus on e-cigarette devices, accessories, and the lifestyle that accompanies them. Vapefest, which started in 2010, is an annual show hosted by different cities. People attending these meetings are usually enthusiasts that use specialized, community-made products not found in convenience stores or gas stations. These products are mostly available online or in dedicated "vape" storefronts where mainstream e-cigarettes brands from the tobacco industry and larger e-cig manufacturers are not as popular. Some vape shops have a vape bar where patrons can test out different e-liquids and socialize. The Electronic Cigarette Convention in North America which started in 2013, is an annual show where companies and consumers meet up. A subclass of vapers configure their atomizers to produce large amounts of vapor by using low-resistance heating coils. This practice is called "cloud-chasing". By using a coil with very low resistance, the batteries are stressed to a potentially unsafe extent. This could present a risk of dangerous battery failures. As vaping comes under increased scrutiny, some members of the vaping community have voiced their concerns about cloud-chasing, stating the practice gives vapers a bad reputation when doing it in public. The Oxford Dictionaries' word of the year for 2014 was "vape".
Nanoparticles, tiny carriers engineered at a molecular level, can protect drugs from being broken down too quickly in the body, improve how well they're absorbed, and deliver them directly to the tissues where they're needed. This targeted delivery not only reduces side effects but also helps patients stay on track with their treatments. These advances in nanotechnology are transforming the landscape of drug delivery and are emphasizing the importance of developing the next generation of CR systems.
Department of Defense in 2012, when the devices were not yet commercially available and therefore did not require FDA approval. FDA inspection reports from 2014 and 2015 stated that its containers for blood collection were "not validated under actual or simulated use conditions" and "were not reviewed and not approved by designated individual(s) prior to issuance". In 2015, an FDA inspection resulted in multiple observed violations of FDA Title 21 Regulations. It was eventually revealed that the FDA had classified Theranos's device, called a nanotainer, as a Class II medical device, meaning that Theranos would need to use special labels, meet certain performance standards and perform post-market surveillance of the device. Theranos asserted that the nanotainer was a Class I medical device and therefore not subject to any regulatory requirements. After the 2015 inspection, Theranos announced that it would voluntarily suspend its tests apart from the FDA-approved herpes simplex virus (HSV-1) test. The Arizona Department of Health Services reported issues with the company's Scottsdale lab meeting regulations in September 2015. The reports were revealed in the Arizona Republic in November 2015. In January 2016, the Centers for Medicare and Medicaid Services (CMS) sent a letter to Theranos based on a 2015 inspection of its Newark, California lab, reporting that the facility caused "immediate jeopardy to patient health and safety" due to a test to determine the correct dose of the blood-thinning drug warfarin.
=== Kinases === Posttranslational modification of proteins with phosphate groups by kinases is a key regulatory step throughout all biological systems. Phosphorylation events, either phosphorylation by protein kinases or dephosphorylation by phosphatases, result in protein activation or deactivation. These events have an impact on the regulation of physiological pathways, which makes the ability to dissect and study these pathways integral to understanding the details of cellular processes. There exist a number of challenges—namely the sheer size of the phosphoproteome, the fleeting nature of phosphorylation events and related physical limitations of classical biological and biochemical techniques—that have limited the advancement of knowledge in this area. Through the use of small molecule modulators of protein kinases, chemical biologists have gained a better understanding of the effects of protein phosphorylation. For example, nonselective and selective kinase inhibitors, such as a class of pyridinylimidazole compounds are potent inhibitors useful in the dissection of MAP kinase signaling pathways. These pyridinylimidazole compounds function by targeting the ATP binding pocket. Although this approach, as well as related approaches, with slight modifications, has proven effective in a number of cases, these compounds lack adequate specificity for more general applications. Another class of compounds, mechanism-based inhibitors, combines knowledge of the kinase enzymology with previously utilized inhibition motifs.
=== Hollow microneedles === Hollow MNs are designed with a hole at the tip and a hollow capacity that store drugs. Upon MNs insertion, the stored drug is directly injected into the dermis and this effectively facilitates the absorption of either large-molecular or large-dosage drug. Yet, a portion of the drug can leaked or become clogged, and may hinder the overall drug administration. Since the delivery of the drug depends on the flow rate of the microneedle, this type of array could become clogged by excessive swelling or flawed design. This design also increases the likelihood of buckling under the pressure and therefore failing to deliver any drugs.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。