Electrospray ionization is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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 |
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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
=== Natural occurrence === Earth has retained all of the noble gases that were present at its formation except helium. Krypton's concentration in the atmosphere is about 1 ppm. It can be extracted from liquid air by fractional distillation. The amount of krypton in space is uncertain, because measurement is derived from meteoric activity and solar winds. The first measurements suggest an abundance of krypton in space.
According to UN Human Rights Chief Volker Türk, the "reckless" war is disproportionately impacting civilians in the Middle East and beyond. 138,000 civilian sites in Iran were damaged during the conflict, with estimated time of reconstruction being 2-5 years. As the US and Israel executed joint strikes targeting Iranian military and institutional targets, Iran's capital reportedly became a ghost town, as civilians feared going outside or to their daily jobs. Reports have emerged that prisoners in Evin Prison have been receiving limited bread and water since the onset of the war. After the strikes, schools were ordered closed while banks and government offices remained in operation at reduced capacity. Local media reported that subway and bus services would remain operational. During the "near total" internet blackout in Iran, NetBlocks reported that internet connectivity dropped to 4% of ordinary levels. As the internet blackout exceeded 240 hours, making it the second longest ever, the government started handing out "white sim cards", which bypass filters, to government supporters, to allow them to promote its messaging. As news of Khamenei's death broke, security forces were deployed to prevent an uprising, with footage showing them opening fire on celebrants in the streets and shooting at people chanting behind the windows of their homes. During the first two weeks of March 2026, over 70,000 Afghan refugees returned to Afghanistan, frequently under forced circumstances, exacerbating the country's severe humanitarian crisis.
(2026) recover ancient DNA from mammoth ivory from the Hohle Fels cave (Germany), and report evidence of presence of mammoth specimens from multiple distinct lineages in the studied sample. Zanina et al. (2026) reconstruct the environment and diet of the woolly mammoth calf specimen "Yana" from the Batagay section (Sakha, Russia) on the basis of the study of contents of its gastrointestinal tract and the material found between its forelimbs. A new, nearly complete skeleton of a woolly mammoth, identified as a male aged approximately 30–40 years, is described from the latest Pleistocene strata from the Taymyr Peninsula (Russia) by Petrova et al. (2026). Moots et al. (2026) determine sex of 521 woolly mammoth specimens on the basis of the study of ancient DNA, reporting evidence indicating that mammoths from bone accumulation sites were predominantly female, while mammoths from other depositional settings were predominantly male, and interpret these findings as suggestive of anthropogenic origin of mammoth bone accumulations and of preferential targeting of mammoth females by humans. Hannold et al. (2026) reconstruct the diets of pygmy mammoths from Northern Channel Islands and Columbian mammoths from Rancho La Brea and coastal Santa Barbara in southern California on the basis of stable isotopes in tooth enamel. Evidence from the study of tooth enamel of Columbian mammoths from 14 sites in the Central Basin of Mexico, interpreted as indicative of a generalist diet with varying proportions of C3 and C4 plants, is presented by Rodríguez-Franco et al. (2026).
High oil prices also induced investment in oil production by non-OPEC countries, including Prudhoe Bay in Alaska, the North Sea offshore fields of the United Kingdom and Norway, the Cantarell offshore field of Mexico, and oil sands in Canada.
==== Commander of the Order of the British Empire (CBE) ==== Civil Division Ereman Kasese Ragi. For services to the savings and loan society. Chief Superintendent John Toguata, . For services to the Royal Papua New Guinea Constabulary.
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=== Filming === Scouting began in the beginning of July. The table read for the first episode was announced to occur on July 14, 2015, by Kerry Washington. The title of the season premiere, "Heavy is the Head" was revealed on August 8, 2015, by its director Tom Verica on Twitter. Filming for the season began on July 16, 2015. Several actors working on ShondaLand-produced shows directed an episode for the fifth season. Tony Goldwyn from Scandal directed the second and 17th episodes, making it the fourth and fifth episodes he has directed on the show. Chandra Wilson, who plays Dr. Miranda Bailey on Grey's Anatomy, directed her first Scandal episode, which was the sixth episode "Get Out of Jail, Free". Scott Foley from Scandal also directed his first Scandal episode, the 16th named "The Miseducation of Susan Ross". Foley's director-debut was announced on Twitter by Foley himself and executive producer Tom Verica.
The Telecom Regulatory Authority of India (TRAI) regulates all major aspects pertaining to media and telecommunications in Jammu and Kashmir. In addition, the Jammu and Kashmir administration released their media policy in 2020 which enabled government officers to sanction journalists and media organisations for disseminating "fake news", and is valid for the next five years. The policy attracted criticism for allegedly reducing people to "passive recipients of the information the government intends to disseminate." The Press Council of India (PCI) expressed concern over the provisions of fake news in the policy, as it "interferes with the free functioning of the press." Major periodicals in Jammu and Kashmir include Greater Kashmir, Rising Kashmir, Kashmir Times, Daily Excelsior, Elite Kashmir and Kashmir Monitor. DD Kashir is the state-owned television broadcaster. Popular private television channels are ETV Urdu and Gulistan News. In association with All India Radio, DD Kashir has established high power transmitters along the India–Pakistan border. Radio Sharda, a worldwide community radio service for Kashmiri Pandits, was started by Ramesh Hangloo. FM Tadka 95.0, BIG FM 92.7, Radio Mirchi and Red FM 93.5 are private FM radio stations. Internet shutdowns are frequent in Jammu and Kashmir. As of February 2021, the region had 300 internet shutdowns since 2012. In 2020 alone, this number was 115, the highest of any year.
== Uses == Industrially, anthranilic acid is an intermediate in the production of azo dyes (c.f. methyl red) and saccharin. It and its esters are used in preparing perfumes to mimic jasmine and orange, pharmaceuticals (loop diuretics, such as furosemide) and UV-absorber as well as corrosion inhibitors for metals and mold inhibitors in soy sauce. Anthranilate-based insect repellents have been proposed as replacements for DEET. Fenamic acid is a derivative of anthranilic acid, which in turn is a nitrogen isostere of salicylic acid, which is the active metabolite of aspirin. Several non-steroidal anti-inflammatory drugs, including mefenamic acid, tolfenamic acid, flufenamic acid, and meclofenamic acid are derived from fenamic acid or anthranilic acid and are called "anthranilic acid derivatives" or "fenamates". Anthranilic acid [118-92-3] was demonstrated to have utility in the synthesis of the following list of substances: clozapine, quetiapine, thiosalicylic acid, ofornine, strinoline, ciliobrevin A, bentazon, quinezamide, nifurquinazol, nitromethaqualone, & YT-1 (1-azaflavone) [14802-18-7], atolide (actually isatoic anhydride), melicopicine. & tranilast. U-17660 [13450-72-1] & THA-Q [4425-23-4].
Precursor compounds: these compounds are the starting molecules or substrates in a reaction. These may also be viewed as the reactants in a given chemical process. Chemical energy: chemical energy can be found in the form of high energy molecules. These molecules are required for energetically unfavourable reactions. Furthermore, the hydrolysis of these compounds drives a reaction forward. High energy molecules, such as ATP, have three phosphates. Often, the terminal phosphate is split off during hydrolysis and transferred to another molecule. Catalysts: these may be for example metal ions or coenzymes and they catalyze a reaction by increasing the rate of the reaction and lowering the activation energy. In the simplest sense, the reactions that occur in biosynthesis have the following format:
Sources: en.wikipedia.org
=== Polymer shell protein core === A polymer shell is formed by conjugation of multiple molecules of polymers onto the protein core. The polymer shell can either protect the protein core from unwanted degradation or create desired interactive sites for guest molecules. The first generation of polymer shell protein core structures mainly used of Polyethylene glycol (PEG) chains to increase the hydrodynamic radius and reduce immune response to proteins. However, the PEG shell can reduce protein activity in the inner core. More advanced designs use biodegradable linkers to achieve programmed release of the protein core in specific tissues. Several therapeutic designs with biodegradable PEG shells are already being developed in vivo. Direct conjugation of polymers ("grafting to" strategy) can efficiently construct a polymer shell with diverse polymer types, however, it has low polymer density, especially with large polymers. In contrast, "grafting from" strategy allows the formation of a dense and uniform polymer shell. The protein core can also function as a carrier for other therapeutic molecules, such as plasmid DNA. Dendrite polymer shells have a high volume to molecular weight ratio compared with traditional polymer shells. Using branched carbohydrates can give unique biological properties while maintaining molecular definition.
Thermoresponsive polymer chains in solution adopt an expanded coil conformation. At the phase separation temperature they collapse to form compact globuli. This process can be observed directly by methods of static and dynamic light scattering. The drop in viscosity can be indirectly observed. When mechanisms which reduce surface tension are absent, the globules aggregate, subsequently causing turbidity and the formation of visible particles.
Bacterial infections may be treated with antibiotics, which are classified as bacteriocidal if they kill bacteria or bacteriostatic if they just prevent bacterial growth. There are many types of antibiotics and each class inhibits a process that is different in the pathogen from that found in the host. For example, the antibiotics chloramphenicol and tetracyclin inhibit the bacterial ribosome but not the structurally different eukaryotic ribosome, so they exhibit selective toxicity. Antibiotics are used both in treating human disease and in intensive farming to promote animal growth. Both uses may be contributing to the rapid development of antibiotic resistance in bacterial populations. Phage therapy, using bacteriophages can also be used to treat certain bacterial infections.
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.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.