This is a working overview of melanocortin signalling, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-02. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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。
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.
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.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Amane Waseda reported δD of oil samples in northeast Japan to increase from around −130‰ to around −110‰ with higher maturity. At low thermal maturity, dos Santos Neto and Hayes reported δD of saturate fraction of oil in Portiguar Basin derived from a lacustrine environment is -90‰, and from a marine-evaporitic environment is -120‰ to −135‰. Bulk analysis of oil, which yields a complex mixture of organic compounds, obscures much of the valuable information. Switching to compound-specific study greatly expanded our understanding of hydrogen isotopes of oil. Analyzing HIC at the compound level avoids problems from differences in exchange rates, simplifies sources and products relationships, and draws a much more detailed picture. δDs of n-alkanes are generally thought to be representative of oil as they are the major components. Schimmelmann et al. confirmed that alkane fractions have almost the same DHRs as whole oils. Depending on source material type and maturity, δD of n-alkanes can vary from −100‰ to −180‰. A common phenomenon of various oil and matured rock derived n-alkanes is a trend of increasing δD with chain length. For example, Li et al. analyzed oils from the Western Canada Sedimentary Basin and found δD increased between 20‰ and 40‰ from C13 to C27. This "isotope slope" is an artifact of kinetic fractionation associated with thermal cracking of carbon chains. This trend has been experimentally reproduced and theoretically modeled by Tang et al. N-alkanes are also known to preserve detailed information of source material. Li et al.
Ethanol (alcohol) is first converted into acetaldehyde, consuming NAD+ twice, before being converted into acetate. The acetate is then converted into acetyl-CoA. When alcohol is consumed in small quantities, the NADH/NAD+ ratio remains in balance enough for the acetyl-CoA to be used by the Krebs cycle for oxidative phosphorylation. However, even moderate amounts of alcohol (1-2 drinks) results in more NADH than NAD+, which inhibits oxidative phosphorylation. When the NADH/NAD+ ratio is disrupted (far more NADH than NAD+), this is called pseudohypoxia. The Krebs cycle needs NAD+ as well as oxygen, for oxidative phosphorylation. Without sufficient NAD+, the impaired aerobic metabolism mimics hypoxia (insufficient oxygen), resulting in excessive use of anaerobic glycolysis and a disrupted pyruvate/lactate ratio (low pyruvate, high lactate). The conversion of pyruvate into lactate produces NAD+, but only enough to maintain anaerobic glycolysis. In chronic excessive alcohol consumption (alcoholism), the microsomal ethanol oxidizing system (MEOS) is used in addition to alcohol dehydrogenase.
=== Growth === By 1970, Millipore had established subsidiaries in seven countries. The company opened manufacturing plants in Jaffrey, New Hampshire; Molsheim, France; County Cork, Ireland; and other locations. Millipore's 2006 acquisition of Serologicals Corporation provided entry to high-growth markets for drug discovery products and services, antibodies, cell biology reagents, and stem cell research. As of the late 2000s, Millipore was the only company providing both upstream cell culture and downstream separations offerings for biopharmaceutical production.
At the conclusion of the 2019 AFL season, Ryder requested a trade to St Kilda. The trade was finalised on 15 October and Ryder was traded to St Kilda along with Port Adelaide teammate Dougal Howard and pick 10 and a 2020 fourth-round selection, in return for the Saints' picks 12 and 18 and a 2020 third-round selection. Ryder nominated to join St Kilda ahead of his former club Essendon. He chose to leave Port Adelaide due to a perceived lack of opportunity in the ruck division at the Power. Of the move, Ryder stated that "I guess the way things have panned out at Port Adelaide over the past couple of years is Port Adelaide’s brought in Scotty Lycett, who's a terrific ruckman, and they've got a couple of young blokes on the list that probably need a bit more time to develop. And I guess being my age and stuff I’m taking away that opportunity for them, so I'm very understanding of the football club and respect their decision. But I feel like I've still got a lot more to give, so I'll be going down to Moorabbin." On choosing to join the Saints ahead of his former team, Ryder admitted that he was leaning towards rejoining the Bombers until he toured their facilities; "I just didn't get like a really, really good feeling from going back there", said Ryder in October 2019. "But then I went down to Moorabbin and it was a sense of like excitement and in the end thats what I ended up basing my decision on." Ryder played 14 of a possible 19 games for the Saints in the 2020 season.
Sources: en.wikipedia.org
== Safety == The acute toxicity of TMU is moderate. However, it is embryotoxic and teratogenic towards several animal species. TMU has been demonstrated to exhibit dermal and eye irritation. The sensitization potential of TMU was shown to be low compared (non-sensitizing at 1% in LLNA testing according to OECD 429).
=== Adhesion to zirconia === Tensile bond strength to zirconia of ethanol solutions that contains MDP were measured. MDP showed high bond strengths to zirconia. Tensile bond strengths of MDP containing resin composites to zirconia ceramic were statistically significantly higher when compared with the bond strength of the conventional Bis-GMA resin composite which contains no adhesive monomer. The mechanisms of coordination between MDP and zirconium oxide were demonstrated by using 1H and 31P magic angle spinning nuclear magnetic resonance (NMR) and two dimensional 1H → 31P heteronuclear correlation NMR. The spectra indicated three possible models as mechanisms of interaction of MDP with zirconia.
=== Federal government initiative === A 2026 executive order directed US agencies to accelerate research, regulatory review, and potential patient access pathways for psychedelic drugs, including ibogaine, for serious mental illness.
=== Asylum fees and immigration === The law establishes a $100 annual fee to apply for asylum, down from $1,000 in the House bill, a $550 fee to apply for employment authorization for asylum seekers and migrants on humanitarian parole or temporary protected status, and a $500 fee to apply for temporary protected status. It also increases the fees for non-immigrant visas to $250.
==== Data Protection Commission (Europe) ==== In September 2021, the Ireland Data Protection Commission (DPC) launched investigations into TikTok concerning the protection of minors' data and transfers of personal data to China. The Irish DPC became the lead agency to handle such matters after TikTok established an office in the country, taking over investigations started by Dutch and Italian authorities. In September 2023, the DPC fined TikTok €345 million for violations of the General Data Protection Regulation (GDPR) vis-à-vis the mishandling of children data. In April 2025, the Ireland DPC fined TikTok over €500 million for illegally sending European user data to China. In July 2025, the DPC opened a new investigation into TikTok for unauthorized transfers of user data to China.
Sources: en.wikipedia.org
Jonathan Rhoads, was the first to successfully nourish initially Beagle puppies and subsequently newborn babies with catastrophic gastrointestinal malignancies. Dudrick collaborated with Dr. Willmore and Dr. Vars to complete the work necessary to make this nutritional technique safe and successful. He showed that a central venous catheter could be used to administer the infusion fluid intravenously. Presented with Judy Ellis Taylor in September 1970 who had all her bowels surgically removed due to gangrene, gastroenterologist and University of Toronto clinical researcher Dr. Khursheed Nowrojee Jeejeebhoy, who'd been working with short-term hyperalimentation (as TPN was then called) at Toronto General Hospital, determined to create complete nutrition and send her home to live on it. Taylor was the first person in the world to live without eating, receiving no calories or nutrition by mouth, unlike previous patients, and to live at home and care for her family. As a result, Jeejeebhoy was able to demonstrate a person could live at home with good quality of life on TPN, that fatty liver develops as a result of carbohydrates not fat, discover that chromium is involved in the development of diabetes, investigate the role of zinc, and study the effect of intravenous Vitamin D on the development of osteomalacia and parenteral nutrition-induced metabolic bone disease, among other discoveries. Prof. Wretlind called him, "the father of complete long-term parenteral nutrition in man." And in the 2009 biography in the journal Gastroenterology, the author Myron Lewis dubbed him, "Mr.
=== Second World War === The Special Air Service was a unit of the British Army during the Second World War that was formed in July 1941 by David Stirling and originally called "L" Detachment, Special Air Service Brigade – the "L" designation and Air Service name being a tie-in to a British disinformation campaign, trying to deceive the Axis into thinking there was a paratrooper regiment with numerous units operating in the area (the real SAS would "prove" to the Axis that the fake one existed). It was conceived as a commando force to operate behind enemy lines in the North African Campaign and initially consisted of five officers and 60 other ranks. Its first mission, in November 1941, was a parachute drop in support of the Operation Crusader offensive, codenamed Operation Squatter. Due to German resistance and adverse weather conditions, the mission was a disaster, with only 22 men, a third of the unit, making it back to base. The rest were either killed or captured. Its second mission was a major success. Transported by the Long Range Desert Group, it attacked three airfields in Libya, destroying 60 aircraft without loss. In September 1942, it was renamed 1st SAS, consisting at that time of four British squadrons, one Free French, one Greek, and the Folboat Section.
== Role in protection against oxidative stress == Aerobic bacteria inevitably are prone to the formation of reactive oxygen species due to the nature of their respiration processes. Under normal conditions these ROS strive to maintain a dynamic balance; however, this balance can often be disrupted by biotic or abiotic stressors such as superoxide radicals, endogenous lipids, DNA hydroperoxides, hydrogen peroxide, hydroxyl radicals, and hydroxy alkenals. Therefore, these susceptible organisms have intrinsic mechanisms to protect from oxidative damage; glutathione plays a key role in most of these antioxidant mechanisms. Once reduced, glutathione interacts with these reactive oxygen and nitrogen species. This interaction is catalyzed by GSTs and their involvement is vital for successful oxidation of glutathione. GSTs bind the ROS substrate at its hydrophobic alpha-helical C-terminal domain, as well as reduced glutathione to its glutathione-binding site on the N-terminal domain. These two domains are adjacent to each other on the enzyme, and together form the active site of the GST where the redox reaction occurs. Once both substrates are bound at the enzyme's active site, the monomeric GST interacts with another substrate-bound GST monomer and catalyzes a disulphide bridge between the two glutathione molecules. This yields the active dimeric enzyme structure. The reactive oxygen species then donates one electron to a glutathione molecule, completing the oxidation-reduction reaction and rendering it unable to perform oxidative damage to the cell.
== History == April 2016: initiation of Phase 2b trial December 2017: initiation of JADE Mono-1 Phase 3 trial May 2018: Results of Phase 2b trial posted October 2019: Results of Phase 3 trial presented June 2020: Results of second Phase 3 trial published The US Food and Drug Administration (FDA) approved abrocitinib based on evidence from three controlled clinical trials enrolling a total of 1615 participants supporting efficacy and safety. Two of the trials enrolled participants twelve years of age and older with moderate-to-severe atopic dermatitis and one trial enrolled adults with moderate-to-severe atopic dermatitis. The trials were conducted at multiple sites in 18 countries (i.e., United States, Canada, Australia, Mexico, Chile, Great Britain, Poland, Germany, Bulgaria, Hungary, Czech Republic, Latvia, Slovakia, Spain, Italy, Japan, Korea, Taiwan). In addition, safety analyses were performed on the combined results of these 3 controlled clinical trials and one additional controlled study in a total of 1,540 participants. All three trials evaluated two doses of abrocitinib: 100 mg and 200 mg. The monotherapy trials were identically designed, 16-week, randomized, multicenter, double-blind, placebo-controlled, parallel group, phase 3 trials. Trial-AD-3 with concomitant background therapy was a 24-week, multicenter, randomized, double-blind, active-comparator (dupilumab) and placebo-controlled, phase 3 trial.
Operating a CH station was a manpower-intensive situation, with an operator in the transmitter hut, an operator and assistant in the receiver hut, and as many as six assistants in the receiver hut operating the plotters, calculators and telephone systems. In order to provide 24-hour service, multiple crews were needed, along with a number of service and support personnel. This was then multiplied by the reporting hierarchy, which required similar numbers of WAAFs at each level of the Dowding system hierarchy. Plotting the angle of the target was a simple process of taking the gonio reading and setting a rotating straightedge to that value. The problem was determining where along that straightedge the target lay; the radar measured the slant range straight-line distance to the target, not the distance over the ground. That distance was affected by the target's altitude, which had to be determined by taking the somewhat time-consuming altitude measurements. Additionally, that altitude was affected by the range, due to the curvature of the Earth, as well as any imperfections in the local environment, which caused the lobes to have different measurements depending on the target angle. As no small part of the manpower required was dedicated to calculation and plotting, a great reduction could be made by using as much automation as possible. This started with the use of various mechanical aids; these were eventually replaced by the fruit machine, an electromechanical analogue computer of some complexity. It replicated all of these devices and tables in electrical form.
Sources: en.wikipedia.org
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.
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.