If you have been reading about semax and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-02-14. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉，避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
Relatives of highly placed Chinese officials, including seven current and former members of the Politburo, have been named in the Panama Papers, including Deng Jiagui, Xi's brother-in-law. Deng had two shell companies in the British Virgin Islands while Xi was a member of the Politburo Standing Committee, which became dormant by the time Xi became CCP general secretary in 2012. According to The New York Times in 2012, after coming to power, Xi told his family to get out of their investments and that Qi Qiaoqiao and Deng Jiagui had divested their investments in at least 10 companies. In 2015, Wang Jianlin, the leader of the company Dalian Wanda, defended Qi and Deng, saying that they sold their shares in the company two months before the IPO in October 2014. The New York Times commented that this information is conflicted with official documents, which state that Qi and Deng transferred the ownership of the holding company to one of their employees in October 2013.
It also requires secondary dressing because wounds can quickly dry up with alginate dressing. Hydrofiber dressing: Made up of sodium carboxymethyl cellulose, hydrofibers can absorb high amounts of wound discharge, forming a gel and preventing skin maceration.
==== Prize ==== The French government had offered over 320,000 Francs as a reward to whoever could discover a cure for the blight. Having reportedly been the first to suggest the possibility of using the resistant American rootstock, Leo Laliman tried to claim the money, but the French government refused to award it, with the rationale that he had not cured the blight, but rather stopped it from occurring. However, there may have been other reasons for the government denying Laliman the prize: he was mistrusted by several notable parties, and he was thought by many to have originally introduced the pest.
Police Scotland arrest Scotland's former First Minister, Nicola Sturgeon, as part of their ongoing investigation into the SNP's finances. She is subsequently released without charge. 12 June Following a period of hot weather, thunderstorms and torrential rain bring flash flooding to parts of the UK. A mother-of-three is sentenced to 28 months in prison for inducing an abortion at home during 2020 with medication while she was 32–34 weeks pregnant. The medication was obtained following a remote consultation at which the woman misled doctors over the advancement of her pregnancy. 13 June 2023 Nottingham attacks: A major incident is declared in Nottingham, with much of the city centre cordoned off, following a vehicle-ramming and knife attack. A 31-year-old man is arrested on suspicion of multiple murders, following the deaths of three people including two university students, while three others are hospitalised. The first day of a public inquiry into the COVID-19 pandemic begins in central London. The inquiry's lead lawyer says "very little thought" was given about the impact of a national lockdown and that Brexit planning may have occupied too much of the government's time and resources, while a counsel for the Covid-19 Bereaved Families for Justice accuses the authorities of being "complacent". A heatwave is declared in several parts of the UK as temperatures reach 30 °C, and after exceeding 25 °C for three consecutive days; the UK's heat-health alert is also extended.
Sources: en.wikipedia.org
Prolyl endopeptidase is a large cytosolic enzyme that belongs to a distinct class of serine peptidases. It was first described in the cytosol of rabbit brain as an oligopeptidase, which degrades the nonapeptide bradykinin at the Pro-Phe bond. The enzyme is involved in the maturation and degradation of peptide hormones and neuropeptides such as alpha-melanocyte-stimulating hormone, luteinizing hormone-releasing hormone (LH-RH), thyrotropin-releasing hormone, angiotensin, neurotensin, oxytocin, substance P and vasopressin. PREP cleaves peptide bonds at the C-terminal side of proline residues. Its activity is confined to action on oligopeptides of less than 10 kD and it has an absolute requirement for the trans-configuration of the peptide bond preceding proline. Prolyl endopeptidases are involved in the maturation and degradation of peptide hormones and neuropeptides.
{\displaystyle {\begin{aligned}u_{x}&={\frac {4{\sqrt {2}}}{3{\sqrt {3}}}}\,U_{0}\left[\,\sin \left(kx-{\frac {\pi }{3}}\right)\cos \left(ky+{\frac {\pi }{3}}\right)\sin \left(kz+{\frac {\pi }{2}}\right)-\cos \left(kz-{\frac {\pi }{3}}\right)\sin \left(kx+{\frac {\pi }{3}}\right)\sin \left(ky+{\frac {\pi }{2}}\right)\,\right]e^{-3\nu k^{2}t}\\u_{y}&={\frac {4{\sqrt {2}}}{3{\sqrt {3}}}}\,U_{0}\left[\,\sin \left(ky-{\frac {\pi }{3}}\right)\cos \left(kz+{\frac {\pi }{3}}\right)\sin \left(kx+{\frac {\pi }{2}}\right)-\cos \left(kx-{\frac {\pi }{3}}\right)\sin \left(ky+{\frac {\pi }{3}}\right)\sin \left(kz+{\frac {\pi }{2}}\right)\,\right]e^{-3\nu k^{2}t}\\u_{z}&={\frac {4{\sqrt {2}}}{3{\sqrt {3}}}}\,U_{0}\left[\,\sin \left(kz-{\frac {\pi }{3}}\right)\cos \left(kx+{\frac {\pi }{3}}\right)\sin \left(ky+{\frac {\pi }{2}}\right)-\cos \left(ky-{\frac {\pi }{3}}\right)\sin \left(kz+{\frac {\pi }{3}}\right)\sin \left(kx+{\frac {\pi }{2}}\right)\,\right]e^{-3\nu k^{2}t}\end{aligned}}}
The Maduro regime has violated all such principles in every respect. We stand for further developments in accordance with the principles of international law, prioritising democracy, human rights, and the interests of Venezuelans." Ukrainian President Volodymyr Zelenskyy reacted with a pointed remark to the United States' capture of Nicolás Maduro, suggesting the U.S. now "knows what to do next" when dealing with dictators. United Kingdom: Prime Minister Keir Starmer stated "The UK has long supported a transition of power in Venezuela. We regarded Maduro as an illegitimate President and we shed no tears about the end of his regime", adding "I always say and believe we should all uphold international law." He also clarified that the United Kingdom was not involved in the strikes. The Foreign Office advised against all travel to Venezuela for British citizens. South Ossetia: South Ossetia condemned the US attacks.
Sources: en.wikipedia.org
== History == The first intein was discovered in 1988 through sequence comparison between the Neurospora crassa and carrot vacuolar ATPase (without intein) and the homologous gene in yeast (with intein) that was first described as a putative calcium ion transporter. In 1990 Hirata et al. demonstrated that the extra sequence in the yeast gene was transcribed into mRNA and removed itself from the host protein only after translation. Since then, inteins have been found in all three domains of life (eukaryotes, bacteria, and archaea) and in viruses. Protein splicing was unanticipated and its mechanisms were discovered by two groups (Anraku and Stevens) in 1990. They both discovered a Saccharomyces cerevisiae VMA1 in a precursor of a vacuolar H+-ATPase enzyme. The amino acid sequence of the N- and C-termini corresponded to 70% DNA sequence of that of a vacuolar H+-ATPase from other organisms, while the amino acid sequence of the central position corresponded to 30% of the total DNA sequence of the yeast HO nuclease. Many genes have unrelated intein-coding segments inserted at different positions. For these and other reasons, inteins (or more properly, the gene segments coding for inteins) are sometimes called selfish genetic elements, but it may be more accurate to call them parasitic.
=== Religious beliefs === De Duve was brought up as a Roman Catholic. In his later years he tended towards agnosticism, if not strict atheism. However, de Duve believed that "Most biologists, today, tend to see life and mind as cosmic imperatives, written into the very fabric of the universe, rather than as extraordinarily improbable products of chance." "It would be an exaggeration to say I'm not afraid of death", he explicitly said to a Belgian newspaper Le Soir just a month before his death, "but I'm not afraid of what comes after, because I'm not a believer." He strongly supported biological evolution as a fact, and dismissive of creation science and intelligent design, as explicitly stated in one of his last books, Genetics of Original Sin: The Impact of Natural Selection on the Future of Humanity (French original 2009). He was among the seventy-eight Nobel laureates in science to endorse the effort to repeal the Louisiana Science Education Act of 2008.
Additionally, the relative (and quantitative) success of the shock therapies, despite the considerable risks they posed to patients, also helped to inspire doctors in the field to pioneer ever more drastic forms of medical interventions, including lobotomies. The clinician-historian Joel Braslow argues that from malarial therapy onward to lobotomy, physical psychiatric therapies "spiral closer and closer to the interior of the brain", with this organ increasingly taking "center stage as a source of disease and site of cure". For medical historian Roy Porter, the often violent and invasive psychiatric interventions developed during the 1930s and 1940s are indicative of both the well-intentioned desire of psychiatrists to find some medical means of alleviating the suffering of the vast number of patients then in psychiatric hospitals and also the relative lack of social power of those same patients to resist the increasingly radical and even reckless interventions of asylum doctors. Many doctors, patients, and family members of the period believed that, despite potentially catastrophic consequences, the results of lobotomy were seemingly positive in many instances or were at least deemed as such when measured next to the apparent alternative of long-term institutionalisation. Lobotomy has always been controversial, but for a period of the medical mainstream, it was regarded as a legitimate last-resort remedy for categories of patients who were otherwise regarded as hopeless.
=== Transmasculine individuals === Numerous studies have recorded the proliferation of prostate tissue in transmasculine individuals undergoing testosterone therapy. A 2022 study concluded that "one hundred percent of vaginal specimens obtained from transmasculine individuals on testosterone therapy (21/21 cases) demonstrated prostatic metaplasia" and notes, congruously with similar studies, that further research in this area is warranted so as to contribute to higher standards of care for transgender patients, and so that the presence of this tissue does not register to healthcare providers as an abnormality.
Sources: en.wikipedia.org
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。
公开资料对此没有统一答案。普遍建议现配现用，或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化，放置时间越长风险越高。
反相高效液相色谱是最常用的手段，配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.