The short version of semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
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.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
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.
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
=== Regioselectivity === Although the reaction produces a regioisomeric mixture of triazoles, the lack of regioselectivity in the reaction is not a major concern for most current applications. More regiospecific and less bioorthogonal requirements are best served by copper-catalyzed Huisgen cycloaddition, especially given the synthetic difficulty (compared to the addition of a terminal alkyne) of synthesizing a strained cyclooctyne.
== Treatment == There is currently no cure for leptomeningeal disease as the tumor is hard to eradicate. Current treatments for leptomeningeal tumors are palliative. The goals for treatment include prolonging survival and stabilizing neurological symptoms.
Milos Vratislav Novotny (born 19 April 1942) is an American chemist, currently the Distinguished Professor Emeritus and Director of the Novotny Glycoscience Laboratory and the Institute for Pheromone Research at Indiana University, and also a published author. Milos Novotny received his Bachelor of Science from the University of Brno, Czechoslovakia in 1962. In 1965, Novotny received his Ph.D. at the University of Brno. Novotny also holds honorary doctorates from Uppsala University, Masaryk University and Charles University, and he has been a major figure in analytical separation methods. Novotny was recognized for the development of PAGE Polyacrylamide Gel-filled Capillaries for Capillary Electrophoresis in 1993. In his years of work dedicated to analytical chemistry he has earned a reputation for being especially innovative in the field and has contributed a great deal to several analytical separation methods. Most notably, Milos has worked a great deal with microcolumn separation techniques of liquid chromatography, supercritical fluid chromatography, and capillary electrophoresis. Additionally, he is known for his research in proteomics and glycoanalysis and for identifying the first mammalian pheromones.
=== Ultraviolet (UV) inactivation === UV rays can damage the DNA of living organisms by creating nucleic acid dimers. However, the damages are usually not important due to low penetration of UVs through living tissues. UV rays can be used, however, to inactivate viruses since virus particules are small and the UV rays can reach the genetic material, inducing the dimerisation of nucleic acids. Once the DNA dimerised, the virus particules cannot replicate their genetic material which prevent them from spreading. UV light in combination with riboflavin has been shown to be effective in reducing pathogens in blood transfusion products. Riboflavin and UV light damages the nucleic acids in viruses, bacteria, parasites, and donor white blood cells rendering them unable to replicate and cause disease.
Lawrence Livermore National Laboratory (LLNL) is a federally funded research and development center in Livermore, California, United States. Established in 1952, the laboratory is sponsored by the United States Department of Energy and administered privately by Lawrence Livermore National Security, LLC. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response to the detonation of the Soviet Union's first atomic bomb during the Cold War. It later became autonomous in 1971 and was designated a national laboratory in 1981. Lawrence Livermore Lab is primarily funded by the United States Congress and it is managed privately and operated by Lawrence Livermore National Security, LLC (a partnership of the University of California, Bechtel, BWX Technologies, Amentum, and Battelle Memorial Institute in affiliation with the Texas A&M University System). In 2012, the synthetic chemical element livermorium (element 116) first made in year 2000, was named after the laboratory. The Livermore facility was co-founded by Edward Teller and Ernest Lawrence, then director of the Radiation Laboratory at Berkeley.
Sources: en.wikipedia.org
Secobarbital/brallobarbital/hydroxyzine was a combination tablet containing 50 mg brallobarbital, 150 mg secobarbital and 50 mg hydroxyzine that was used as a sedative. It was sold under the brand name Vesparax. This drug has been withdrawn from the market in most countries. Hydroxyzine and secobarbital lengthen the half-life of brallobarbital. Because of this long half-life, it has symptoms resembling a hangover on the next day. Jimi Hendrix was under the influence of Vesparax when he died of asphyxia due to aspiration of vomit on 18 September 1970.
==== Post-treatment isolation ==== Ablation doses are usually administered on an inpatient basis, and IAEA International Basic Safety Standards recommend that patients are not discharged until the activity falls below 1100 MBq. ICRP advice states that "comforters and carers" of patients undergoing radionuclide therapy should be treated as members of the public for dose constraint purposes and any restrictions on the patient should be designed based on this principle. Patients receiving I-131 radioiodine treatment may be warned not to have sexual intercourse for one month (or shorter, depending on dose given), and women told not to become pregnant for six months afterwards. "This is because a theoretical risk to a developing fetus exists, even though the amount of radioactivity retained may be small and there is no medical proof of an actual risk from radioiodine treatment. Such a precaution would essentially eliminate direct fetal exposure to radioactivity and markedly reduce the possibility of conception with sperm that might theoretically have been damaged by exposure to radioiodine." These guidelines vary from hospital to hospital and will depend on national legislation and guidance, as well as the dose of radiation given. Some also advise not to hug or hold children when the radiation is still high, and a one- or two- metre distance to others may be recommended. I-131 will be eliminated from the body over the next several weeks after it is given.
== Detroit Lions == It has been said that Detroit Lions' announcer Van Patrick applied the nickname "Fearsome Foursome" to the Lions front four as early as 1960, when the Lion defensive line consisted of ends Bill Glass and Darris McCord, and tackles Alex Karras and Roger Brown. Other reports state that sportswriter Bruno Kerns of the Pontiac Press first used the Fearsome Four nickname for the Lions' defensive line in 1960. The Fearsome Foursome name for the Lions' defensive line continued after Sam Williams replaced Glass in 1962; Glass being traded to the Cleveland Browns for quarterback Milt Plum after the 1961 season. Other than 1963, McCord, Karras, Brown and Williams started together from 1962 through 1965; until Williams was taken by the Atlanta Falcons in the 1966 expansion draft. Karras missed the 1963 season as he was suspended in connection with alleged gambling. Their most well-known game was the 1962 "Thanksgiving Day Massacre" game against the Green Bay Packers, where they sacked Bart Starr 11 times (seven by Brown) and broke the Packers 12-game winning streak. The group's early defensive coordinator was future Pro Football Hall of Fame head coach Don Shula. Karras is in the Pro Football Hall of Fame. The 6 ft 5 in (1.96 m) 300 pound (136 kg) Brown, was one of the first NFL lineman to play at 300 pounds or more, with the speed and agility to make him highly effective at that weight. Brown was named to the Pro Bowl as a Lion from 1962 through 1966 and first-team All-Pro twice (1962-63).
=== Discovery === The word "benzene" derives from "gum benzoin" (benzoin resin), an aromatic resin known since ancient times in Southeast Asia, and later to European pharmacists and perfumers in the 16th century via trade routes. An acidic material was derived from benzoin by sublimation, and named "flowers of benzoin", or benzoic acid. The hydrocarbon derived from benzoic acid thus acquired the names benzin, benzol, and benzene. Michael Faraday first isolated and identified benzene in 1825 from the oily residue derived from the production of illuminating gas, giving it the name bicarburet of hydrogen. In 1833, Eilhard Mitscherlich produced it by distilling benzoic acid (from gum benzoin) and lime. He gave the compound the name benzin. In 1836, the French chemist Auguste Laurent named the substance "phène"; this word has become the root of the English word "phenol", which is hydroxylated benzene, and "phenyl", the radical formed by abstraction of a hydrogen atom from benzene. In 1845, Charles Blachford Mansfield, working under August Wilhelm von Hofmann, isolated benzene from coal tar. Four years later, Mansfield began the first industrial-scale production of benzene, based on the coal-tar method. Gradually, the sense developed among chemists that a number of substances were chemically related to benzene, comprising a diverse chemical family. In 1855, Hofmann was the first to apply the word "aromatic" to designate this family relationship, after a characteristic property of many of its members. In 1997, benzene was detected in deep space.
== Safety designations == In 2016, the U.S. Food and Drug Administration (FDA) accepted nicotinamide riboside chloride (NRC, Niagen) as Generally recognized as safe (GRAS) as described in the dossier prepared by ChromaDex, Inc. The above regulatory acceptances were all in relation to the safety and manufacturing information provided by ChromaDex, Inc. for Niagen. It was designated a new dietary ingredient (NDI) for use in dietary supplements by the U.S. Food and Drug Administration in 2015 and 2017. It was listed in Health Canada's Licensed Natural Health Products Database (LNHPD) in 2018. The European Union has granted NRC a "New dietary ingredient" designation as a novel food pursuant to Regulation (EU) 2015/2283, as of 2019. It was authorized for use in food supplements by the EU in 2020. The EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) considered it as safe as pure nicotinamide for use in food for special medical purposes (FSMP) and total diet replacement for weight control (TDRWC) in adults as of 2021 but noted that further investigation would be required to establish safety for some other types of use. The Australian government has given nicotinamide riboside chloride a positive listing under the compositional guidelines of its Therapeutic Goods Administration (TGA).
Sources: en.wikipedia.org
==== Predicting molecular fingerprints ==== CSI:FingerID predicts a probabilistic fingerprint with a variety of molecular properties from several fingerprint types. The fingerprint is predicted from the given spectrum and its corresponding fragmentation tree using deep kernel learning, which is a combination of kernel methods and deep neural networks. Not only the top scoring molecular formula but multiple high-scoring molecular formula candidates are considered.
Centre of Policy and Legal Reform (CPLR), a non-governmental think tank founded in 1996. Center for Policy Studies in Ukraine, a non-governmental think tank founded in 1994. International Centre for Policy Studies, a non-governmental think tank founded in 1994. Razumkov Centre, a non-governmental think tank founded in 1994. It carries out research of public policy in the following spheres: domestic policy; state administration; economic policy; energy; land relations; foreign policy; social policy; international and regional security; national security and defense. Transatlantic Dialogue Center, a non-governmental think tank founded in 2021.
=== Cellulose nanofibers === Cellulose nanofibers (CNF), also called nanofibrillated cellulose (NFC), are nanosized cellulose fibrils with a high aspect ratio (length to width ratio). Typical fibril widths are 5–20 nanometers with a wide range of lengths, typically several micrometers. The fibrils can be isolated from natural cellulose, generally wood pulp, produced by mechanical fibrillation of cellulose fibres through high-pressure, high temperature and high velocity impact homogenization, grinding or microfluidization (see manufacture).
As the father of classical utilitarianism, Jeremy Bentham (1748–1832) proposed the felicific calculus as a method to measure, compare, and aggregate degrees of pleasure and pain, considering factors such as their intensity and duration. He also suggested a direct link between well-being and right action, arguing that individuals and governments should promote "the greatest happiness of the greatest number". His student John Stuart Mill (1806–1873) modified Bentham's idea, proposing that the contribution to well-being depends on the quality of the pleasure. He held that higher pleasures of the mind are more valuable than lower pleasures of the body, even if they have the same intensity and duration. Thomas Carlyle (1795–1881) rejected the utilitarian pursuit of happiness and the individualist market economy associated with Adam Smith, arguing instead that a sense of community and meaningful work are essential to well-being. The emergence of psychology as an empirical science prompted research into the internal factors of well-being, such as William James's (1842–1910) introspective research into the connection between happiness and religious experience. The psychoanalytic theory of Sigmund Freud (1856–1939) characterized the pursuit of pleasure and the reduction of tension as central aims of life. His early collaborator Carl Jung (1875–1961) explored how well-being depends on individuation as a form of psychological growth in which conscious and unconscious aspects are integrated.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
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。