The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-07. Anything still debated is marked as such rather than presented as settled.
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.
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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
| 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 |
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.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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.
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.
== Background == A glucose sensitive treatment method for diabetes has long been pursued by researchers since 1979. Such a platform is expected to solve the problem of fluctuations of blood sugar levels. For diabetic patients, skipping a single meal can lead to hypoglycemia, a common complication which can lead to loss of consciousness or seizures. There have been several attempts to create such a medicine, with various levels of success.
==== Forms ==== Two forms of colistin are available commercially: colistin sulfate and colistimethate sodium (colistin methanesulfonate sodium, colistin sulfomethate sodium). Colistin sulfate is cationic; colistimethate sodium is anionic. Colistin sulfate is stable, whereas colistimethate sodium is readily hydrolysed to a variety of methanesulfonated derivatives. Colistin sulfate and colistimethate sodium are eliminated from the body by different routes. With respect to Pseudomonas aeruginosa, colistimethate is the inactive prodrug of colistin. The two drugs are not interchangeable.
=== Position of Tantulocarida === According to Petrunina A.S. and Kolbasov G.A., the sixth subclass of Maxillopoda Tantulocarida may lie within Thecostraca, forming a clade with thecostracan infraclass Cirripedia (if so, Thecostraca excluding Tantulocarida is paraphyletic):
decay channel, which is more difficult to detect in water Cherenkov detectors because the antineutrino leaves the detector undisturbed and the kaon momentum is below the Cherenkov-light production threshold in water. The process can be identified by detecting the muons produced by kaon decays at rest, as well as the gamma rays emitted when a nucleon decays within the oxygen nucleus. The nucleus may remain in an excited state following this decay, from which it rapidly relaxes by emitting gamma rays. Other processes can enable experiments to test the baryon number conservation, such as neutron-antineutron oscillations and specific nucleon–antinucleon conversion processes, accessible through electron–deuteron scattering.
Corticotropin-releasing hormone receptor 2 (CRHR2) is a protein, also known by the IUPHAR-recommended name CRF2, that is encoded by the CRHR2 gene and occurs on the surfaces of some mammalian cells. CRF2 receptors are type 2 G protein-coupled receptors for corticotropin-releasing hormone (CRH) that are resident in the plasma membranes of hormone-sensitive cells. CRH, a peptide of 41 amino acids synthesized in the hypothalamus, is the principal neuroregulator of the hypothalamic-pituitary-adrenal axis, signaling via guanine nucleotide-binding proteins (G proteins) and downstream effectors such as adenylate cyclase. The CRF2 receptor is a multi-pass membrane protein with a transmembrane domain composed of seven helices arranged in a V-shape. CRF2 receptors are activated by two structurally similar peptides, urocortin II, and urocortin III, as well as CRH.
Sources: en.wikipedia.org
Including the continued aerial slaughter over Orote Field, Japanese losses exceeded 350 planes on the first day of battle. About 30 American planes were lost, and there was little damage to American ships; even the damaged South Dakota was able to remain in formation to continue her anti-aircraft duties.
The distinction is awarded by information and insights company Clarivate to researchers whose work has been deemed to be of "Nobel Class" as they are among the most highly cited and influential, even transformative, in their fields. Citation Laureate candidates are selected from authors of the 0.01 per cent of some 52 million articles and proceedings that have been cited 2,000 times or more. He was one of 16 scientists (one of three in Chemistry) around the world listed in the Hall of Citation Laureates for 2021.
From 13 to 15 May 2026, the president of the United States Donald Trump made a state visit to China. This visit was Trump's second state visit to China, and the first to occur during his second presidency. Trump's first state visit to China occurred in November 2017. This trip was also the first by a U.S. president since Trump's visit in 2017. During the visit, Trump was received by CCP general secretary Xi Jinping at the Great Hall of the People, where the two leaders held talks. Xi announced the two sides had agreed to establish a Constructive Strategic and Stable Relationship. Following the talks, Xi and Trump visited the Temple of Heaven, the second US president to visit the Temple while in office after President Gerald Ford in 1975. Later, Xi hosted Trump for a dinner banquet at the Golden Room of the Great Hall of the People. Trump invited Xi for a state visit to the United States on 24 September 2026. At the second day of the visit on 15 May, Trump visited the Chinese leadership compound Zhongnanhai. The visit was the first of the four summits between Xi and Trump in 2026. It was reciprocated by a state visit by Xi Jinping to the United States in September 2026. Additionally, Trump is scheduled travel to China for APEC 2026 in November while Xi is scheduled to visit the United States for 2026 G20 Miami summit in December.
== Early life and education == Rudolf Schoenheimer was born in Berlin, Germany on 10 May 1898. He was the son of Gertrude Edel and Hugo Schoenheimer, who was a physician. He was Jewish, however his family converted to Christianity. He attended local schools in Berlin before graduating from the Dorotheen-Stadtische Gymnasium in 1916. Following his graduation Schoenheimer was drafted into the German army. He served in the artillery on the western front for two years during world war 1. Following his service in the war, he began his study of medicine at the University of Berlin. In 1922 he received his M.D. His M.D dissertation was titled "Über die experimentelle Cholesterinkrankheit der Kaninchen" ("About the experimental cholesterol disease of rabbits"). He then spent a year working at the Moabit Hospital in Berlin as a pathologist. He continued his scientific research during this time and studied the production of atherosclerosis in animals through administering cholesterol. In 1924, Schoenheimer began his 3-year study at the University of Leipzig, in a program aimed at advancing his knowledge in chemistry. The program was aided by the Rockefeller Foundation and taught by Karl Thomas, professor of physiological chemistry at the University of Leipzig. During his time at Leipzig, Schoenheimer was able to develop a method of synthesising peptides.
Sources: en.wikipedia.org
The term diagenesis, literally meaning "across generation", is extensively used in geology. However, this term has filtered into the field of anthropology, archaeology and paleontology to describe the changes and alterations that take place on skeletal (biological) material. Specifically, diagenesis "is the cumulative physical, chemical, and biological environment; these processes will modify an organic object's original chemical and/or structural properties and will govern its ultimate fate, in terms of preservation or destruction". In order to assess the potential impact of diagenesis on archaeological or fossil bones, many factors need to be assessed, beginning with elemental and mineralogical composition of bone and enveloping soil, as well as the local burial environment (geology, climatology, groundwater). The composite nature of bone, comprising one-third organic (mainly protein collagen) and two thirds mineral (calcium phosphate mostly in the form of hydroxyapatite) renders its diagenesis more complex. Alteration occurs at all scales from molecular loss and substitution, through crystallite reorganization, porosity, and microstructural changes, and in many cases, to the disintegration of the complete unit. Three general pathways of the diagenesis of bone have been identified:
Thiols or mercaptans (so called because they capture mercury as chelators) are the sulfur analogs of alcohols; treatment of thiols with base gives thiolate ions. Thioethers are the sulfur analogs of ethers. Sulfonium ions have three groups attached to a cationic sulfur center. Dimethylsulfoniopropionate (DMSP) is one such compound, important in the marine organic sulfur cycle. Sulfoxides and sulfones are thioethers with one and two oxygen atoms attached to the sulfur atom, respectively. The simplest sulfoxide, dimethyl sulfoxide, is a common solvent; a common sulfone is sulfolane. Sulfonic acids are used in many detergents. Compounds with carbon–sulfur multiple bonds are uncommon, an exception being carbon disulfide, a volatile colorless liquid that is structurally similar to carbon dioxide. It is used as a reagent to make the polymer rayon and many organosulfur compounds. Unlike carbon monoxide, carbon monosulfide is stable only as an extremely dilute gas, found between solar systems. Organosulfur compounds are responsible for some of the unpleasant odors of decaying organic matter. They are widely known as the odorant in domestic natural gas, garlic odor, and skunk spray. Not all organic sulfur compounds smell unpleasant at all concentrations: the sulfur-containing monoterpenoid (grapefruit mercaptan) in small concentrations is the characteristic scent of grapefruit, but has a generic thiol odor at larger concentrations. Sulfur mustard, a potent vesicant, was used in World War I as a disabling agent.
The Germans pulled their remaining forces out of Calabria to send them to Salerno. Under the Allied occupation, some fascists waged a terrorist struggle on behalf of the Salo republic, although they tended to be concerned about social reforms that might weaken their power while a minority such as Prince Valerio Pignatelli were ideological Fascists. In June 1944, celebrations in Reggio Calabria over the liberation of Rome were disturbed by Fascists.
On 14 September 2025, the Wall Street Journal reported the US and China have reached the "framework of a deal" for the US operations of TikTok to be sold to a consortium of investors in the US including close Trump ally Larry Ellison of Oracle. The deal was completed by 22 January 2026, with a consortium of investors—including Oracle, Silver Lake, MGX, and others including the personal investment entity for Michael Dell—owning more than 80% of the new venture. ByteDance retained 19.9% ownership. Under the deal, the app would remain the same, and the algorithm would be adjusted over time to favor American topics for those users.
== Somatostatin receptor agonists versus antagonists in radiolabelling == Agonists of the somatostatin receptor had been long established as an imaging agent, with the first agonist Ga-DOTATOC coming out in 2001, which is based on a radiolabeled somatostatin receptor agonist drug octreotide, and further developments were based on its structure. Agonists share the characteristic of being uptaken into tumor cells, and degraded intracellularly. Antagonists, while not widely absorbed into the tumor cells, can bind to a wider range of receptors as they can bind to the receptors regardless if the receptors are activated or inactivated. They thus are more sensitive to neuroendocrine tumors. Another study noted the antagonists showed lowered internalization into tumors, cleared from the blood quickly, and had a higher binding to tumors, which were noted to be properties benefitting its use over agonists in detecting metastatic tumors. A head-to-head study of the gallium-containing compounds, where the Ga-NODAGA-JR11 antagonist and Ga-DOTATOC agonist are directly compared, showed that Ga-NODAGA-JR11 had higher hepatic metastatic tumor detection rate and lesion sensitivity than Ga-DOTATOC. Another head-to-head study of lutetium containing compound found the antagonist Lu-DOTA-JR11 bound with the receptors more quickly, had a longer retention time and unbound more slowly than the Lu-DOTA-TATE agonist.
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.
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.