The short version of ACTH(4-10) fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-22. Anything still debated is marked as such rather than presented as settled.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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.
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.
After Ceaușescu left, the mood of the crowds in Palace Square grew celebratory, perhaps even more than in the other former Eastern Bloc countries because of the recent violence. People cried, shouted and gave each other gifts mainly because it was also close to Christmas Day, a long-suppressed holiday in Romania. The occupation of the Central Committee building continued. People threw Ceaușescu's writings, official portraits and propaganda books out the windows, intending to burn them. They also promptly ripped off the giant letters from the roof making up the word "comunist" ("communist") in the slogan: "Trăiască Partidul Comunist Român!" ("Long live the Communist Party of Romania!"). A young woman appeared on the rooftop and waved a flag with the coat of arms torn out. At that time, fierce fights were underway at Bucharest Otopeni International Airport between troops sent against each other with the claim that they were going to confront terrorists. Early in the morning, troops sent to reinforce the airport were fired upon. These troops were from the UM 0865 Câmpina military base, and were summoned there by General Ion Rus, commander of the Romanian Air Force. The confrontation resulted in the deaths of 40 soldiers, as well as eight civilians. The military trucks were allowed entrance into the airport's perimeter, passing several checkpoints. However, after passing the last checkpoint, they were fired upon from different directions. A civilian bus was also fired upon during the firefight.
== History == Glucose was first isolated from raisins in 1747 by the German chemist Andreas Marggraf. Glucose was discovered in grapes by another German chemist, Johann Tobias Lowitz, in 1792, and distinguished as being different from cane sugar (sucrose). Glucose is the term coined by Jean-Baptiste Dumas in 1838, which has prevailed in the chemical literature. Friedrich August Kekulé proposed the term dextrose (from the Latin dexter, meaning "right"), because in aqueous solutions of glucose, the plane of linearly polarized light is turned to the right. In contrast, l-fructose (usually referred to as l-fructose) (a ketohexose) and l-glucose (l-glucose) turn linearly polarized light to the left. The earlier notation according to the rotation of the plane of linearly polarized light (d and l-nomenclature) was later abandoned in favor of the d- and l-notation, which refers to the absolute configuration of the asymmetric center furthest from the carbonyl group, and in concordance with the configuration of d- or l-glyceraldehyde. Since glucose is a basic necessity of many organisms, a correct understanding of its chemical makeup and structure contributed greatly to a general advancement in organic chemistry. This understanding occurred largely as a result of the investigations of Hermann Emil Fischer, a German chemist who received the 1902 Nobel Prize in Chemistry for his findings.
Transdermal progesterone is usually supplied in the form of creams and water-based gels, and the studies in which very low levels of progesterone in circulation were observed with transdermal progesterone used these formulations. One study of 100 mg/day transdermal progesterone in the form of an alcohol-based gel found relatively high concentrations of progesterone in circulation that corresponded to luteal-phase levels. The peak levels of progesterone were 8 ng/mL and were theoretically sufficient to confer endometrial protection. These findings, although based on a single study, suggest that alcohol-based progesterone gels might yield relatively high levels of circulating progesterone. One possible explanation for the difference is that progesterone creams are more lipophilic and may have a preference for uptake into the fatty layer under the skin. Conversely, alcohol-based gels are more water-soluble and may rapidly distribute into the microcirculation of the skin and then into the general circulation. However, in another study that investigated the pharmacokinetics of transdermal progesterone using either a hydrophilic-, lipophilic-, or emulsion-type base, it was found that in all three cases that the time to peak concentrations was around 4 hours and the venous blood levels observed were very low.
=== Food Preparation === The cooking of protein sources, particularly animal protein, may significantly alter both the composition and digestibility of amino acids. Since this is not always reflected in nutritional data, changes during cooking may be factored into measurements of protein quality. For example, the browning of many meats causes the Maillard reaction, which may decrease the availability of lysine, the limiting amino acid for many foods. As a result, it is recommended to use lysine as the limiting amino acid for any food likely to have undergone the Maillard reaction.
A coalition of forces opposing Iraq's aggression was formed, consisting of forces from 42 countries: Argentina, Australia, Bahrain, Bangladesh, Belgium, Canada, Czechoslovakia, Denmark, Egypt, France, Germany, Greece, Honduras, Hungary, Italy, Japan, Kuwait, Luxembourg, Morocco, the Netherlands, New Zealand, Niger, Norway, Oman, Pakistan, the Philippines, Poland, Portugal, Qatar, Romania, Saudi Arabia, Senegal, Sierra Leone, Singapore, South Korea, Spain, Sweden, Syria, Turkey, the United Arab Emirates, the UK and US. It was the largest coalition since World War II. A group of Afghan mujahideen soldiers also reportedly joined towards the end of the war. Although they did not contribute forces, Japan and Germany made financial contributions totaling $10 billion and $6.6 billion respectively. Luxembourg provided financial support. US troops represented 73% of the coalition's 956,600 troops in Iraq. A pact between the Indian government and the US also allowed US C-141 aircraft flying in materials from the Philippines to stop in Mumbai to refuel, which led to disquiet within most of the nation's formerly pro-Iraqi stance. US Army General Norman Schwarzkopf, Jr. was designated to be the commander of the coalition forces. The Soviet Union condemned Baghdad's aggression against Kuwait, but did not support the US and allied intervention in Iraq and tried to avert it. Many of the coalition countries were reluctant to commit military forces. Some felt that the war was an internal Arab affair or did not want to increase US influence in the Middle East.
Sources: en.wikipedia.org
The quantitative "reading" is usually based on detection of intensity of transmitted light by spectrophotometry, which involves quantitation of transmission of some specific wavelength of light through the liquid (as well as the transparent bottom of the well in the multiple-well plate format). The sensitivity of detection depends on amplification of the signal during the analytic reactions. Since enzyme reactions are very well known amplification processes, the signal is generated by enzymes which are linked to the detection reagents in fixed proportions to allow accurate quantification, and thus the name "enzyme-linked". The analyte is also called the ligand because it will specifically bind or ligate to a detection reagent, thus ELISA falls under the bigger category of ligand binding assays. The ligand-specific binding reagent is "immobilized", i.e., usually coated and dried onto the transparent bottom and sometimes also side wall of a well (the stationary "solid phase"/"solid substrate" here as opposed to solid microparticle/beads that can be washed away), which is usually constructed as a multiple-well plate known as the "ELISA plate". Conventionally, like other forms of immunoassays, the specificity of antigen-antibody type reaction is used because it is easy to raise an antibody specifically against an antigen in bulk as a reagent. Alternatively, if the analyte itself is an antibody, its target antigen can be used as the binding reagent.
Haloxazolam (marketed in Japan under the brand name Somelin), is a drug which is a benzodiazepine derivative. It has similar hypnotic properties as the benzodiazepine drugs triazolam, temazepam, and flunitrazepam and as such is indicated for the treatment of insomnia. A study in cats comparing estazolam and haloxazolam found that haloxazolam only affects gamma motor neurons, whereas estazolam affects both alpha and gamma motor neurons. Chemically, it is an oxazolobenzodiazepine.
Directed by Bob Bee, produced by Michael Wills, made by Juniper Productions 5 September Fatal Protein, looking at the cause of CJD in humans, BSE in cattle, and scrapie in sheep; BSE was killing 1,000 British cattle a week; a brain disorders conference in Jamaica; in Papua New Guinea, the disease was called kuru or 'the laughing death', first found in the Okapa District in early 1950s by Carlton Gadjusek; Australian Michael Alpers took an interest in 1960s, at the Institute of Medical Research; epidemiologist Paul Brown of the National Institutes of Health; chimpanzees were tested on, and one suffered from ataxia; GSS, discovered in Austria, was similar, and found in Indiana; Martin Farlow, of the Indiana University Medical Center; most research was carried out on mice and hamsters; Stanley B.
==== NMR spectroscopy ==== The proton resonances of alkanes are usually found at δH = 0.5–1.5. The carbon-13 resonances depend on the number of hydrogen atoms attached to the carbon: δC = 8–30 (primary, methyl, –CH3), 15–55 (secondary, methylene, –CH2–), 20–60 (tertiary, methyne, C–H) and quaternary. The carbon-13 resonance of quaternary carbon atoms is characteristically weak, due to the lack of nuclear Overhauser effect and the long relaxation time, and can be missed in weak samples, or samples that have not been run for a sufficiently long time.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.