semax raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-09-29 and is reviewed periodically as new material appears.
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.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集,其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸,因此氧化风险相对突出。工作液一般主张现配现用,或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率,而关于最佳条件的公开数据并不统一。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
Dalton's law – Empirical law of partial pressures Charles's law – Relationship between volume and temperature of a gas at constant pressure Ideal gas law – Equation of the state of a hypothetical ideal gas
The 2022–23 FA Cup was the 142nd edition of the oldest football tournament in the world, the Football Association Challenge Cup. It is a one-legged competition whereby teams play each other once and the winner proceeds to the next round, in contrast to a two-legged competition in which teams play each other twice (home and away) to determine which team progresses to the next round. The FA Cup was sponsored by Emirates and known as the Emirates FA Cup for sponsorship purposes. Premier League team Liverpool were the defending champions, having defeated Chelsea to secure their eighth title in the previous year's final, but they were eliminated in the fourth round by Brighton & Hove Albion. Manchester City defeated city rivals Manchester United 2–1 in the final to win their seventh FA Cup title. As winners, they would have qualified for the 2023–24 UEFA Europa League group stage; however, as they had already qualified for European competition via the league standings, the spot was passed down to the sixth-placed Premier League team.
== Duration == Short-term PN may be used if a person's digestive system has shut down (for instance by peritonitis), and they are at a low enough weight to cause concerns about nutrition during an extended hospital stay. Long-term PN is occasionally used to treat people suffering the extended consequences of an accident, surgery, or digestive disorder. PN has extended the life of children born with nonexistent or severely deformed organs.
14 July Prime Minister Keir Starmer condemns the attempted assassination of Donald Trump at a rally in Pennsylvania, saying: "I am appalled by the shocking scenes at President Trump's rally and we send him and his family our best wishes. Political violence in any form has no place in our societies and my thoughts are with all the victims of this attack." 2024 Wimbledon Championships: Carlos Alcaraz wins the Men's singles final, defeating Novak Djokovic for the second consecutive year. The Met Office issues a yellow weather warning for heavy rain for parts of England and Wales for the following day. Euro 2024: England are beaten 2–1 against Spain in the final of the tournament. A peak TV audience of 23.8 million across the BBC and ITV is reported, the highest combined audience for any TV event broadcast this year so far. Buckingham Palace announces that King Charles III and Queen Camilla will visit Australia and Samoa in October. 15 July Disappearance of Jay Slater: Spanish police announce that search teams looking for Jay Slater in Tenerife have found a body. A 34-year-old man appears in court and is remanded in custody charged with the murders of Albert Alfonso and Paul Longworth, whose remains were found in suitcases at the Clifton Suspension Bridge. A new search begins for the body of Muriel McKay, who was kidnapped in December 1969 and held for ransom, then later killed. Figures show that 427 migrants crossed the English Channel in small boats, the highest daily number since Keir Starmer became the prime minister.
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== Products == Its primary products are based on Morpholino oligomers (PMOs), synthetic nucleic acid analogs that were conceived of by James Summerton and invented by Summerton with Dwight Weller, originally developed under the name NeuGene Antisense. Since morpholino oligomers can form sequence-specific double-stranded complexes with RNA they are suitable use in antisense therapy. In one application, translation blocking, a morpholino oligomer binds to messenger RNA produced by a known disease-causing gene to prevent it from being translated into protein. Morpholinos can also work as splice-switching oligos, targeting pre-mRNA to alter splicing and so causing changes in the structure of the mature mRNA (the mechanism of the approved drug eteplirsen). Morpholinos have been tested for a wide range of applications including prevention of cardiac restenosis after angioplasty, treatment of coronary artery bypass grafts, treatment of polycystic kidney disease, redirection of drug metabolism, treatment of some mutations causing Duchenne muscular dystrophy (DMD), and inhibition of infectious diseases. Their greatest clinical and commercial success thus far has been in the treatment of DMD. A new class of Morpholino oligos, the peptide-linked Morpholinos or PPMO, are linked to an arginine-rich cell-penetrating peptide to enhance their delivery into cells and have entered clinical trials.
== Vegetables == Apart from vegetables that can be commonly seen, some unique vegetables used in Chinese cuisine include baby corn, bok choy, snow peas, Chinese eggplant, Chinese broccoli, and straw mushrooms. Other vegetables, including bean sprouts, pea vine tips, watercress, lotus roots, chestnuts, water chestnuts, and bamboo shoots, are also used in different cuisines of China. Because of different climate and soil conditions, cultivars of green beans, peas, and mushrooms can be found in rich variety. A variety of dried or pickled vegetables are also processed, especially in drier or colder regions where fresh vegetables were hard to get out of season.
The Kingdom of Hanover (German: Königreich Hannover) was established in October 1814 by the Congress of Vienna, with the restoration of George III to his Hanoverian territories after the Napoleonic era. Its capital was Hanover and it also ruled Gottingen and Osnabruck. It had access to the North Sea, and bordered on the Netherlands and the free German cities of Hamburg and Bremen. It succeeded the former Electorate of Hanover, and joined 38 other sovereign states in the German Confederation in June 1815. The kingdom was ruled by the House of Hanover, a cadet branch of the House of Welf, in personal union with Great Britain between 1714 and 1837. Since its monarch resided in London, a viceroy, usually a younger member of the British royal family, handled the administration of the Kingdom of Hanover. The personal union with the United Kingdom ended in 1837 upon the accession of Queen Victoria because semi-Salic law prevented females from inheriting the Hanoverian throne while a dynastic male was still alive. Her uncle Ernest Augustus thus became the ruler of Hanover. His only son succeeded him to the throne as George V. As he backed the losing side in the Austro-Prussian War, his kingdom was conquered by Prussia in 1866 and ceased to exist as an independent kingdom, becoming the Prussian Province of Hanover. In January 1871, along with the rest of Prussia, Hanover became part of the German Empire upon the unification of Germany.
CD33 has now emerged as the primary target for novel drug discovery programs aimed at curbing neuroinflammation, at over a dozen pharmaceutical and biotech companies. Other AD genes Tanzi has discovered include ADAM10, UBQLN1, IDE, A2M, ITGB3, and ATXN1. In 2020, he used multiple whole genome sequencing datasets for the first time to identify sex-specific genetic risk factors for AD (ZBTB7C, GRID1, RIOK3, MCPH1) as well as several novel Alzheimer's disease-associated rare variants in loci related to synaptic function and neuronal development (FNBP1L, SEL1L, LINC00298, PRKCH, C15ORF41, C2CD3, KIF2A, APC, LHX9, NALCN, CTNNA2, SYTL3, CLSTN2, DTNB, DLG2). In 2022, Tanzi and colleagues whole-genome sequencing to discover two new genes associated with Alzheimer's disease: DTNB and DLG2. Over the past three decades, Tanzi has also contributed to the development of novel therapeutics for AD. In 2000, Tanzi and the late Dr. Steven Wagner discovered a class of Alzheimer’s drugs that they termed "gamma secretase modulators (GSM)". GSM's reverse the Abeta42:Abeta40 ratio and thereby prevent amyloid plaques. Notably, they do not inhibit gamma-secretase. Tanzi and Wagner have published several papers on these compounds. Their GSM is now slated for AD clinical trials in 2026 with Acta Pharmaceuticals. In 2014, Tanzi, and his ex-trainees, Doo Yeon Kim and Se Hoon Choi, were the first to use human stem cells to create three-dimensional cell culture organoids of AD, dubbed by The New York Times as “Alzheimer's-in-a-Dish”.
Several months after qualifying as a lecturer in philosophy, Adorno delivered an inaugural lecture at the Institute for Social Research, an independent organization that had recently appointed Horkheimer as its director and, with the arrival of the literary scholar Leo Löwenthal, social psychologist Erich Fromm, and philosopher Herbert Marcuse, sought to exploit recent theoretical and methodological advances in the social sciences. His lecture "The Actuality of Philosophy" created a scandal.
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== Monitoring glutathione reductase activity == The activity of glutathione reductase is used as indicator for oxidative stress. The activity can be monitored by the NADPH consumption, with absorbance at 340 nm, or the formed GSH can be visualized by Ellman's reagent. Alternatively the activity can be measured using roGFP (redox-sensitive Green Fluorescent Protein).
Camptotheca (Camptothecin · Topotecan · Irinotecan · Rubitecan · Belotecan); 2. Podophyllum (Etoposide · Teniposide); 3a. Anthracyclines (Aclarubicin · Daunorubicin · Doxorubicin · Epirubicin · Idarubicin · Amrubicin · Pirarubicin · Valrubicin · Zorubicin); 3b. Anthracenediones (Mitoxantrone · Pixantrone). The second main approach involves ethnobotany, the study of the general use of plants in society, and ethnopharmacology, an area inside ethnobotany, which is focused specifically on medicinal uses. Artemisinin, an antimalarial agent from sweet wormtree Artemisia annua, used in Chinese medicine since 200BC is one drug used as part of combination therapy for multiresistant Plasmodium falciparum.
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=== Developments in production === Until the end of the 19th century, vaccination was performed either directly with vaccine produced on the skin of calves or, particularly in England, with vaccine obtained from the calf but then maintained by arm-to-arm transfer; initially in both cases vaccine could be dried on ivory points for short-term storage or transport but increasing use was made of glass capillary tubes for this purpose towards the end of the century. During this period there were no adequate methods for assessing the safety of the vaccine and there were instances of contaminated vaccine transmitting infections such as erysipelas, tetanus, septicaemia and tuberculosis. In the case of arm-to-arm transfer there was also the risk of transmitting syphilis. Although this did occur occasionally, estimated as 750 cases in 100 million vaccinations, some critics of vaccination e.g. Charles Creighton believed that uncontaminated vaccine itself was a cause of syphilis. Smallpox vaccine was the only vaccine available during this period, and so the determined opposition to it initiated a number of vaccine controversies that spread to other vaccines and into the 21st century. Sydney Arthur Monckton Copeman, an English Government bacteriologist interested in smallpox vaccine, investigated the effects on the bacteria in it of various treatments, including glycerine. Glycerine was sometimes used simply as a diluent by some continental vaccine producers.
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It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受,但会加快降解风险。