Everything below concerns RP-HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
== History == The practice of salting fish dates back to ancient times. In classical antiquity, the town of Magdala on the Sea of Galilee, located in present-day Israel, was also known by its Greek name, Taricheae, meaning "place of fish salting." The Greek geographer Strabo even praised the quality of its fish (Geographica 16.2.45).
1934 The first widely known scientific publication on the impact of dietary restriction on life expectancy, authored by Clive McCay. McCay's group carried out intensive research in this direction in 1930–43, soon other scientists began to do related research. The effect of increasing life expectancy by starvation is usually observed in rats and mice, whose development until puberty is very labile (growth retardation and puberty, decreased metabolism and body temperature). In larger animals, such as rabbits, dogs and monkeys, the effect is less pronounced. The impact of fasting on human life expectancy still remains a question where not everything is clear and is unambiguous. 1936 The first European (and Western) journal about aging and longevity. It was published in Kishinev by Dimu Kotsovsky. During the first year of existence it was called Monatsberichte, then got the name German: Altersprobleme: Zeitschrift für Internationale Altersforschung und Altersbekämpfung = "Problems of Aging: Journal for the International Study and Combat of Aging". The journal published materials mostly in the German language, less in French and English. 1937 A Ukrainian Soviet pathophysiologist Alexander Bogomolets created antireticular cytotoxic serum in the hope to extend life of people to 150 years. Although the drug did not achieve its main goal, it has become widely used for the treatment of a number of diseases, especially infectious diseases and fractures. The serum of Bogomolets was actively used in Soviet hospitals during WWII.
Otto later meets with Henry, who is being prosecuted for his role as CEO of the fraudulent fintech firm Tender, and asks Otto to make an official inquiry regarding the Russian government's involvement in the firm. Otto, however, talks Henry out of implicating Russia, citing the risk of assassination. Otto is later seen fishing with Norton and Henry, who serves house arrest at the Norton estate.
=== Variations and accessories === Bottles may be designed to attach directly to a breast pump for a complete "feeding system" that maximizes the reuse of the components. Such systems include a variety of drinking spouts for when the child is older. This converts the bottle into a sippy cup, a cup with lid and spout for toddlers, which is intermediate between a baby bottle and an open top cup. Bottles that are part of a feeding system may include handles that can be attached. The ring and teat may be replaced by a storage lid. Accessories for bottles include cleaning brushes, or bottle brushes, sterilizers, and drying racks. Brushes may be specially designed for a specific manufacturer's bottles and teats. Bottle sterilizers use different techniques for sterilization, including ultraviolet light, boiling water, and hot steam.
== Applications == Cyclic voltammetry (CV) has become an important and widely used electroanalytical technique in many areas of chemistry. It is often used to study a variety of redox processes, to determine the stability of reaction products, the presence of intermediates in redox reactions, electron transfer kinetics, and the reversibility of a reaction. It can be used for electrochemical deposition of thin films or for determining suitable reduction potential range of the ions present in electrolyte for electrochemical deposition. CV can also be used to determine the electron stoichiometry of a system, the diffusion coefficient of an analyte, and the formal reduction potential of an analyte, which can be used as an identification tool. In addition, because concentration is proportional to current in a reversible, Nernstian system, the concentration of an unknown solution can be determined by generating a calibration curve of current vs. concentration. In cellular biology, it is used to measure the concentrations of target molecules (such as specific proteins or DNA) or flow of conductive ions in living organisms. In organometallic chemistry, it is used to evaluate redox mechanisms.
Sources: en.wikipedia.org
=== Early years === Sidney Fox was the son of Jacob Fox, a wig-maker, and Louise Berman, a Ukrainian immigrant. Fox married Raia Joffe Fox and they had three sons: Lawrence, Ronald, and Thomas. All three of his sons became scientists. His family was Jewish. Fox obtained a Bachelor of Arts degree from University of California, Los Angeles in Chemistry. He went on to earn a Ph.D. from California Institute of Technology in 1940 and did his postdoctoral work at the Linus Pauling Laboratory where he grew close with Linus Pauling.
The collision/reaction cell is used to remove interfering ions through ion/neutral reactions. Collision/reaction cells are known under several names. The dynamic reaction cell is located before the quadrupole in the ICP-MS device. The chamber has a quadrupole and can be filled with reaction (or collision) gases (ammonia, methane, oxygen or hydrogen), with one gas type at a time or a mixture of two of them, which reacts with the introduced sample, eliminating some of the interference. The integrated Collisional Reaction Cell (iCRC) used by Analytik Jena ICP-MS is a mini-collision cell installed in front of the parabolic ion mirror optics that removes interfering ions by injecting a collisional gas (He), or a reactive gas (H2), or a mixture of the two, directly into the plasma as it flows through the skimmer cone and/or the sampler cone. The iCRC removed interfering ions using a collisional kinetic energy discrimination (KED) phenomenon and chemical reactions with interfering ions similarly to traditionally used larger collision cells.
is not the same as the one mentioned before where it refers to the width of the spectrum. The shift is usually very small (3×10−5 cm−1 ms−1 for near-IR diode laser) and the shift-to-width ratio is of the order of 10−4.
=== Venom extraction syringes === Venom extraction syringes are different from standard syringes, because they usually do not puncture the wound. The most common types have a plastic nozzle which is placed over the affected area, and then the syringe piston is pulled back, creating a vacuum that allegedly sucks out the venom. Attempts to treat snakebites in this way are specifically advised against, as they are ineffective and can cause additional injury. Syringes of this type are sometimes used for extracting human botfly larvae from the skin.
Sources: en.wikipedia.org
In the continental European countries occupied by the Axis powers, the native communist party usually led the armed resistance (guerrilla warfare and urban guerrilla warfare) against fascist military occupation. In Mediterranean Europe, the communist Yugoslav Partisans led by Josip Broz Tito effectively resisted the German Nazi and Italian Fascist occupation. In the 1943–1944 period, the Yugoslav Partisans liberated territories with Red Army assistance and established the communist political authority that became the Socialist Federal Republic of Yugoslavia. To end the Japanese occupation of China in continental Asia, Stalin ordered Mao Zedong and the Chinese Communist Party to temporarily cease the Chinese Civil War (1927–1949) against Chiang Kai-shek and the anti-communist Kuomintang as the Second United Front in the Second Sino-Japanese War (1937–1945). In 1943, the Red Army began to repel the Nazi invasion of the Soviet Union, especially at the Battle of Stalingrad (23 August 1942 – 2 February 1943) and at the Battle of Kursk (5 July – 23 August 1943). The Red Army then repelled the Nazi and Fascist occupation armies from Eastern Europe until the Red Army decisively defeated Nazi Germany in the Berlin Strategic Offensive Operation (16 April–2 May 1945). On concluding the Great Patriotic War (1941–1945), the Soviet Union was a military superpower with a say in determining the geopolitical order of the world.
== Structure == AMH is a dimeric glycoprotein with a molar mass of 140 kDa. The molecule consists of two identical subunits linked by sulfide bridges, and characterized by the N-terminal dimer (pro-region) and C-terminal dimer. AMH binds to its Type 2 receptor AMHR2, which phosphorylates a type I receptor under the TGF beta signaling pathway.
=== Other FDA measures === One exception occurred during the 2010 Swine Flu Epidemic when the FDA authorized expired Tamiflu based on SLEP Data. The US FDA is able to extend the shelf life of drugs throughout national, state, local, tribal, and territorial stockpiles through two legal means: by issuing an Emergency Use Authorization on using a drug past its expiration date (which is legally an unapproved use of a drug), or by a "expiration dating extension authority" established by the Pandemic and All-Hazards Preparedness Reauthorization Act of 2013 (PAHPRA). The PAHPRA authority only applies to so-called medical countermeasures (MCMs), which are drugs and other tools used to counter CBRN emergencies. Furthermore, FDA can choose to not take enforcement action against use of a drug past its expiration date using its enforcement discretion, but this kind of discretion is not covered by Public Readiness and Emergency Preparedness Act liability protections. The FDA has, using these three measures, provided shelf life extensions on Covid-19 vaccines, Covid-19 antibody therapeutics, Covid-19 in vitro diagnostics, flu antivirals (Tamiflu, Relenza), doxycycline, the Jynneos Mpox vaccine (one single lot), nerve agent autoinjectors, and potassium iodide.
The university's mascots are a pair of anthropomorphized wildcats named Wilbur and Wilma. The human figures behind Wilbur and Wilma are kept secret through the year as the mascots appear only in costume. In 1986, Wilbur married his longtime wildcat girlfriend, Wilma. Together, Wilbur and Wilma appear along with the cheerleading squad at most Wildcat sporting events. Arizona's first mascot was a real desert bobcat named "Rufus Arizona", introduced in 1915.
=== Other uses in science === Electron transport chain, a sequence of chemical reactions yielding the transport of an electron through a membrane Food chain, a hierarchical or recursive list of predators and prey
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.