A practical reference on peptide synthesis: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-01 and is reviewed periodically as new material appears.
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.
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.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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。
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.
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.
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.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
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.
Muhammad, Naseem; Tsai, Peter S.; Lauback, Ronald G. (1982). "High-Pressure Liquid Chromatography Assay for Dane Salt Potassium (-)-N-(1-Methoxycarbonylpropene-2yl)-p-hydroxyphenylglycine". Journal of Liquid Chromatography. 5 (7): 1349–1355. doi:10.1080/01483918208067593. Lauback, Ronald (1984). "Specific High-Performance Liquid Chromatographic Determination of Ampicillin in Bulks, Injectables, Capsules, and Oral Suspensions by Reverse-Phase Ion-Pair Chromatography". Journal of Liquid Chromatography. 7 (6): 1243–1265. doi:10.1080/01483918408074041. Ron Lauback retired in July 2014 from Hanford Pharmaceuticals, based out of Syracuse, New York. He was Vice President of Science from 2007 to 2014.
== Treatment == Although the origin of the disease is unknown, there is speculation that it is an aggressive healing response to small tears in the plantar fascia, almost as if the fascia over-repairs itself following an injury. There is also some evidence that it might be genetic. In the early stages, when the nodule is single and/or smaller, it is recommended to avoid direct pressure to the nodule(s). Soft inner soles on footwear and padding may be helpful. MRI and sonogram (diagnostic ultrasound) are effective in showing the extent of the lesion, but cannot reveal the tissue composition. Even then, recognition of the imaging characteristics of plantar fibromatoses can help in the clinical diagnosis. Surgery of Ledderhose's disease is difficult because tendons, nerves, and muscles are located very closely to each other. Additionally, feet have to carry heavy load, and surgery might have unpleasant side effects. If surgery is performed, the biopsy is predominantly cellular and frequently misdiagnosed as fibrosarcoma. Since the diseased area (lesion) is not encapsulated, clinical margins are difficult to define. As such, portions of the diseased tissue may be left in the foot after surgery. Inadequate excision is the leading cause of recurrence. Radiotherapy has been shown to reduce the size of the nodules and reduce the pain associated with them. It is approximately 80% effective, with minimal side effects. Post-surgical radiation treatment may decrease recurrence. There has also been variable success in preventing recurrence by administering gadolinium.
=== Byproduct === The production of polonium-210 is a downside to reactors cooled with lead-bismuth eutectic rather than pure lead. However, given the eutectic properties of this alloy, some proposed Generation IV reactor designs still rely on lead-bismuth.
==== Snuff ==== Snuff is a type of smokeless tobacco product made from finely ground or pulverized tobacco leaves. It is snorted or "sniffed" (alternatively sometimes written as "snuffed") into the nasal cavity, delivering nicotine and a flavored scent to the user (especially if flavoring has been blended with the tobacco). Traditionally, it is sniffed or inhaled lightly after a pinch of snuff is either placed onto the back surface of the hand, held pinched between thumb and index finger, or held by a specially made "snuffing" device.
The Port of Holyhead is a busy ferry port. Stena Line, Northern Europe's biggest ferry company, operates from the port, as do Irish Ferries. Ferries sail to Dublin. Holyhead railway station is the terminus of the North Wales Coast Line and is currently served by Avanti West Coast and Transport for Wales services. Avanti West Coast runs direct trains to London Euston via Crewe and Transport for Wales operate direct trains to Cardiff and Birmingham International, via Wrexham and Shrewsbury; they also operate on the route to Manchester Piccadilly, via Warrington.
Sources: en.wikipedia.org
=== Immunomodulatory treatments === In PBC, the liver is filled with T cells and B cells that contribute to a worsening condition. Therefore, some treatments are looking into targeting the antigens of these immune cells. The monoclonal antibody rituximab targets the CD20 antigen on the B cells, and is already used in a wide array of other rheumatologic diseases. In an open-label study, six patients that were unresponsive to UDCA had improvement in ALP levels after rituximab infusions. However, the efficacy of rituximab is still uncertain, and awaits further studies and trials. PBC can also lead to higher levels of interleukin 12 and interleukin 23. This was what motivated researches to look at the viability of ustekinumab, a monoclonal antibody targeted against interleukin 12 and 23. An experiment found though it did not significantly improve serum ALP levels. The researchers were further even criticized for placing patients at risk by allowing them to move to advanced disease stages where immunomodulatory therapies may not even be an option.
The TV show Inside Amy Schumer premiered on Comedy Central on April 30, 2013. Inside Amy Schumer was picked up for a second season that began in 2014. A behind-the-scenes miniseries entitled Behind Amy Schumer premiered in 2012. The third season premiered on April 21, 2015, with a fourth season ordered the same day. In 2014, Schumer embarked on her Back Door Tour to promote the second season of her show. The show was closed by Bridget Everett, whom Schumer cites as her favorite live performer. She also appeared as a guest on an episode of comedian Jerry Seinfeld's Internet series Comedians in Cars Getting Coffee in 2014. She hosted the 2015 MTV Movie Awards, which took place on April 11. Schumer wrote and played her first leading film role in Trainwreck, co-starring Bill Hader, which was released on July 17, 2015. In August 2015, Jennifer Lawrence said she and Schumer planned to co-star in a film for which they and Schumer's sister Kim were co-writing a screenplay. However, Schumer later revealed the project was on the "back burner". Schumer performed as opening act for Madonna on three New York City dates of the singer's Rebel Heart Tour in September 2015. On October 17, 2015, Schumer's comedy special Amy Schumer: Live at the Apollo premiered on HBO. In 2016, it was nominated for three Primetime Emmy Awards for Outstanding Variety Special, Writing, and Directing. It also garnered her a nomination for the Grammy Award for Best Comedy Album. Schumer started her first world tour on August 26 in Dublin.
Cipepofol (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name), also known as ciprofol or by its developmental code name HSK3486, sold under the brand name Cypsedo, is a general anesthetic related to propofol which is used for anesthesia and sedation. The drug is used by intravenous infusion. A short-acting and highly selective GABAA positive allosteric modulator, ciprofol is 4 to 6 times more potent than other phenol derivatives such as propofol or fospropofol. In May 2026, cipepofol was approved for medical use in the United States. Manufactured by Haisco Pharmaceutical Group, ciprofol underwent phase I and II trials in Australia and China.
== Silver nanoparticles in toothpaste == Silver nanoparticles are used for catalyzing chemical reactions, Raman imaging, and antimicrobial sterilization. Along with its antimicrobial properties, its low mammalian cell toxicity makes these particles a common addition to consumer products. Washing textiles embedded with silver nanoparticles results in the oxidation and transformation of metallic Ag into AgCl. Silver nanoparticles have different physicochemical characteristics from the free silver ion, Ag+ and possess increased optical, electromagnetic, and catalytic properties. Particles with one dimension of 100 nm or less can generate reactive oxygen species. Smaller particles less than 10 nm may pass through cellular membranes and accumulate within the cell. Silver nanoparticles were also found to attach to cellular membranes, eventually dissipating the proton motive force, leading to cell death. Silver nanoparticles that are larger than the openings of membrane channel proteins can easily clog channels, leading to the disruption of membrane permeability and transport. However, the antimicrobial effectiveness of silver nanoparticles has been shown to decrease when dissolved in liquid media. The free silver ion are potentially toxic to bacteria and planktonic species in the water. The positively charged silver ion can also attach to the negatively charged cell walls of bacteria, leading to deactivation of cellular enzymes, disruption of membrane permeability, and eventually, cell lysis and death.
Sources: en.wikipedia.org
The aerosol or spallation frangible powder produced by impact and combustion of depleted uranium munitions (or armour) can potentially contaminate wide areas around the impact sites, leading to possible inhalation by human beings. The actual level of acute and chronic toxicity of DU is also controversial. Several studies using cultured cells and laboratory rodents suggest the possibility of leukemogenic, genetic, reproductive, and neurological effects from chronic exposure. A 2005 epidemiology review concluded "In aggregate the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU." A 2021 study concluded that DU from exploding munitions did not lead to Gulf War illness in American veterans deployed in the Gulf War. A 2011 study found elevated levels of uranium in soil and hair samples from Fallujah, Iraq, but it was from slightly enriched uranium instead of DU.
=== Damaging and overloading === If a lithium-ion battery is damaged, crushed, or subjected to a higher electrical load without having overcharge protection, problems may arise. External short circuit can trigger a battery explosion. Such incidents can occur when lithium-ion batteries are not disposed of through the appropriate channels, but are thrown away with other waste. The way they are treated by recycling companies can damage them and cause fires, which in turn can lead to large-scale conflagrations. Twelve such fires were recorded in Swiss recycling facilities in 2023. If overheated or overcharged, Li-ion batteries may suffer thermal runaway and cell rupture. During thermal runaway, internal degradation and oxidization processes can keep cell temperatures above 500 °C, with the possibility of igniting secondary combustibles, as well as leading to leakage, explosion or fire in extreme cases. To reduce these risks, many lithium-ion cells (and battery packs) contain fail-safe circuitry that disconnects the battery when its voltage is outside the safe range of 3–4.2 V per cell, or when overcharged or discharged. Lithium battery packs, whether constructed by a vendor or the end-user, without effective battery management circuits are susceptible to these issues. Poorly designed or implemented battery management circuits also may cause problems; it is difficult to be certain that any particular battery management circuitry is properly implemented.
His resistance to reform caused military efficiency to lag well behind that of Britain's rivals, a problem that became obvious during the Second Boer War. The situation was only remedied in 1904, when the job of Commander-in-Chief was abolished, and replaced with that of the Chief of the General Staff, which was replaced by the job of Chief of the Imperial General Staff in 1908. An Army Council was created with a format similar to that of the Board of Admiralty, directed by the Secretary of State for War, and an Imperial General Staff was established to coordinate Army administration. The creation of the Army Council was recommended by the War Office (Reconstitution) Committee, and formally appointed by Letters Patent dated 8 February 1904, and by Royal Warrant dated 12 February 1904. The management of the War Office was hampered by persistent disputes between the civilian and military parts of the organisation. The government of H.H. Asquith attempted to resolve this during the First World War by appointing Lord Kitchener as Secretary for War. During his tenure, the Imperial General Staff was virtually dismantled. Its role was replaced effectively by the Committee of Imperial Defence, which debated broader military issues. The War Office decreased greatly in importance after the First World War, a fact illustrated by the drastic reductions of its staff numbers during the inter-war period. Its responsibilities and funding were also reduced. In 1936, the government of Stanley Baldwin appointed a Minister for Co-ordination of Defence, who was not part of the War Office.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.