If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-06. 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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
| 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 |
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
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.
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.
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.
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.
== External links == Overview of all the structural information available in the PDB for UniProt: Q04760 (Human Lactoylglutathione lyase) at the PDBe-KB. Overview of all the structural information available in the PDB for UniProt: Q9CPU0 (Mouse Lactoylglutathione lyase) at the PDBe-KB.
The general molecular structure of the ribosome has been known since the early 1970s. In the early 2000s, the structure has been achieved at high resolutions, of the order of a few ångströms. The first papers giving the structure of the ribosome at atomic resolution were published almost simultaneously in late 2000. The 50S (large prokaryotic) subunit was determined from the archaeon Haloarcula marismortui and the bacterium Deinococcus radiodurans, and the structure of the 30S subunit was determined from the bacterium Thermus thermophilus. These structural studies were awarded the Nobel Prize in Chemistry in 2009. In May 2001 these coordinates were used to reconstruct the entire T. thermophilus 70S particle at 5.5 Å resolution. Two papers were published in November 2005 with structures of the Escherichia coli 70S ribosome. The structures of a vacant ribosome were determined at 3.5 Å resolution using X-ray crystallography. Then, two weeks later, a structure based on cryo-electron microscopy was published, which depicts the ribosome at 11–15 Å resolution in the act of passing a newly synthesized protein strand into the protein-conducting channel. The first atomic structures of the ribosome complexed with tRNA and mRNA molecules were solved by using X-ray crystallography by two groups independently, at 2.8 Å and at 3.7 Å. These structures allow one to see the details of interactions of the Thermus thermophilus ribosome with mRNA and with tRNAs bound at classical ribosomal sites.
In 2011, Talarico joined Teach For America, teaching sixth-grade English language arts at Rhodes Middle School on the west side of San Antonio. After two years of teaching, he became Central Texas executive director for Reasoning Mind, a nonprofit that implements computer-based math lessons in classrooms.
=== Protein Nanocages === Protein nanocages are natural nanocarriers composed of protein subunits with a porous structure. They benefit from monodispersity, intrinsic high stability for protection of internalized drugs from enzymatic degradation and controllable assembly for cargo loading and release. However, their application might be blocked by immunogenicity, broad biodistribution and significant function and property variations. The incorporation of polymer chains by performing in situ ATRP on the outer surface of or inside the protein nanocages can be an effective way to mitigate those drawbacks. For example, increased loading density of cargo molecules and enhanced stability of the cage assembly can be obtained via internal ATRP inside the cavity of the virus capsid. Beyond virus type particles, large multimeric proteins such as the iron storage protein ferritin have emerged as attractive tools to be used as well-defined nano-containers. Using a grafting from strategy, polymers can be introduced to ferritin in a highly regular fashion for precise spatial control. These polymer–ferritin constructs exhibited protease resistance, enabling longer retention time within the bloodstream while reducing possible antibody interactions.
The relationship between SHBG and insulin resistance has been known for some time; decades prior, ratios of SHBG and adiponectin were used before glucose to predict insulin resistance. Patients with Laron syndrome, with resultant deficient IGF, demonstrate varying degrees of alopecia and structural defects in hair follicles when examined microscopically. Because of its association with metabolic syndrome and altered glucose metabolism, anyone with early androgenic hair loss should be screened for impaired glucose tolerance and diabetes mellitus II. Measurement of subcutaneous and visceral adipose stores by MRI, demonstrated inverse association between visceral adipose tissue and testosterone/DHT, while subcutaneous adipose correlated negatively with SHBG and positively with estrogen. SHBG association with fasting blood glucose is most dependent on intrahepatic fat, which can be measured by MRI in and out of phase imaging sequences. Serum indices of hepatic function and surrogate markers for diabetes, previously used, show less correlation with SHBG by comparison. Female patients with mineralocorticoid resistance present with androgenic alopecia. IGF levels are lower in those with metabolic syndrome. Circulating serum levels of IGF-1 are increased with vertex balding, although this study did not look at mRNA expression at the follicle itself. Locally, IGF is mitogenic at the dermal papillae and promotes elongation of hair follicles. The major site of production of IGF is the liver, although local mRNA expression at hair follicles correlates with an increase in hair growth.
Sources: en.wikipedia.org
=== Sponges (Porifera) === Sponges are some of Earth’s oldest and most ubiquitous animals. The appearance of sponge spicule fossils date back to the Precambrian Era around 580 million years ago. An assemblage of these fossils were found in the Doushanto formation in Southern China. Some circular impressions from the Ediacaran Hills in Southern Australia are also reported to be sponges. They are one of the only lineages of metazoans from this era that continue to survive, and remain relatively unchanged. Sponges are such successful organisms due to their simple, yet effective morphology. They do not possess mouths or any digestive, nervous or circulatory systems. Instead they are filter feeders, which means that they obtain food through nutrients in the water. They have pores, called ostia, that water travels through to a chamber called the spongocoel, and exits through a chamber called the osculum. Through this water filtration system, they obtain nutrients that are needed for their survival. Specifically, they intracellularly digest bacteria, micro-algae or colloids. Sponge skeletons consist of either spongin or calcareous and siliceous spicules with some collagen molecules interspersed. The collagen holds the sponge cells together. Different lineages of sponges are distinguished based on the composition of their skeletons. The three main classes of sponges are Demospongiae, Hexactinellid, and Calcareous. Demonsponges are the most well-known type of sponge since they are used by humans.
IgA vasculitis (Henoch-Schönlein purpura) Acute hemorrhagic edema of infancy Urticarial vasculitis Cryoglobulinemic vasculitis Erythema elevatum diutinum Granuloma faciale ANCA-associated vasculitis Arthropod bites Platelet dysfunction or deficiency Cholesterol emboli Septic emboli Livedoid vasculopathy
Kinases are part of the larger family of phosphotransferases. Kinases should not be confused with phosphorylases, which catalyze the addition of inorganic phosphate groups to an acceptor, nor with phosphatases, which remove phosphate groups (dephosphorylation). The phosphorylation state of a molecule, whether it be a protein, lipid or carbohydrate, can affect its activity, reactivity and its ability to bind other molecules. Therefore, kinases are critical in metabolism, cell signalling, protein regulation, cellular transport, secretory processes and many other cellular pathways, which makes them very important to physiology.
The formation of an astatine compound with hydrogen—usually referred to as hydrogen astatide—was noted by the pioneers of astatine chemistry. As mentioned, there are grounds for instead referring to this compound as astatine hydride. It is easily oxidized; acidification by dilute nitric acid gives the At0 or At+ forms, and the subsequent addition of silver(I) may only partially, at best, precipitate astatine as silver(I) astatide (AgAt). Iodine, in contrast, is not oxidized, and precipitates readily as silver(I) iodide. Astatine is known to bind to boron, carbon, and nitrogen. Various boron cage compounds have been prepared with At–B bonds, these being more stable than At–C bonds. Astatine can replace a hydrogen atom in benzene to form astatobenzene C6H5At; this may be oxidized to C6H5AtCl2 by chlorine. By treating this compound with an alkaline solution of hypochlorite, C6H5AtO2 can be produced. The dipyridine-astatine(I) cation, [At(C5H5N)2]+, forms ionic compounds with perchlorate (a non-coordinating anion) and with nitrate, [At(C5H5N)2]NO3. This cation exists as a coordination complex in which two dative covalent bonds separately link the astatine(I) centre with each of the pyridine rings via their nitrogen atoms. With oxygen, there is evidence of the species AtO− and AtO+ in aqueous solution, formed by the reaction of astatine with an oxidant such as elemental bromine or (in the last case) by sodium persulfate in a solution of perchloric acid.
Sources: en.wikipedia.org
While Navi Pillay, the UN High Commissioner for Human Rights, said that both sides in the conflict appeared to have committed war crimes in 2012, United Nations' Independent International Commission of Inquiry on Syria also blamed the vast majority of atrocities on the Assad government forces. Baathist forces were responsible for vast majority of the killings during the war, far outstripping casualties inflicted by groups like IS. Over 21,000 deaths occurred in 2015 alone, with more than 75% of them (over 15,700) being perpetrated by Syrian regime forces. Regime attacks also resulted in more than 12,000 civilian deaths, with around 38% of the victims being women and children. On 2 March 2018, UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein said, "Syria must be referred to the International Criminal Court. Attempts to thwart justice, and shield these criminals, are disgraceful." Commission for International Justice and Accountability (CIJA), an independent war-crimes documentation agency has been conducting investigations on the crimes and atrocities committed during the Syrian war, with the organization employing around a hundred Syrians and Iraqis in the country, some of them insiders within the state bureaucratic apparatus.
== Honors and awards == Diamandis is a member of the Academy of Athens and the Royal Society of Canada. He is also a fellow of the American Association for the Advancement of Science, the Canadian Academy of Health Sciences, and the Royal College of Physicians and Surgeons of Canada. From the American Association for Clinical Chemistry, he has received the Morton K. Schwartz Award for Significant Contributions in Cancer Research Diagnostics, among other awards; he is also a member of the Association's Hall of Fame.
== Chemistry == Tiagabine, also known as (–)-(R)-1-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]nipecotic acid, is a GABA analogue and a derivative of nipecotic acid. Being a nipecotic acid derivative, introduction of 4,4-diphenylbut-3-enyl and 4,4-bis(3-methylthiophene-1-yl)but-3-enyl side chain increased lipophilicity compared to the parent compound, allowing blood–brain barrier permeability and GABA transporter 1 (GAT-1) selectivity. The experimental log P of tiagabine is 2.6. Analogues of tiagabine include CI-966, NNC-711, and SKF-89976A, among others.
== Use and effects == Isoergine occurs naturally in morning glory species, including Ipomoea tricolor (tlitliltzin), Ipomoea corymbosa (ololiuhqui), and Argyreia nervosa (Hawaiian baby woodrose). It has been found to constitute 8 to 35% of total alkaloid content relative to 5 to 58% for ergine. Albert Hofmann, the discoverer of LSD's psychedelic effects, tried 2 mg isoergine orally and experienced feelings of unreality, detachment from the outside world, feelings of mental emptiness, tiredness, and apathy, though no specific sensory distortions were mentioned. He described its effects as similar to those of ergine, which he had tested at doses of up to 2 mg. Subsequently Heim and colleagues assessed ergine at higher doses of 3 to 6 mg orally and observed toxic-like effects, while isoergine at 2 to 5 mg orally produced notable hallucinogenic effects. The psychedelic effects of isoergine observed in this study included some euphoria, synaesthesia, and altered time perception. However, although hallucinogenic, isoergine's effects have been described as not LSD-like. The presence of hallucinogenic effects of isoergine has been described as quite unusual for an isolysergamide derivative. It is thought that ergine and isoergine together may account for most or all of the effects of morning glory seeds, with ergine producing intoxication, sedation, and autonomic side effects and isoergine producing hallucinogenic effects. Conversely, other notable constituents, including elymoclavine, lysergol, and chanoclavine, produced no psychoactive or hallucinogenic effects in humans.
Cadmium is a chemical element; it has symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate. Cadmium occurs as a minor component in most zinc ores and is a byproduct of zinc production. It was used for a long time in the 1900s as a corrosion-resistant plating on steel, and cadmium compounds are used as red, orange, and yellow pigments, to color glass, and to stabilize plastic. Cadmium's use is generally decreasing because it is toxic, and nickel–cadmium batteries have been replaced with nickel–metal hydride and lithium-ion batteries. Because it is a neutron poison, cadmium is also used as a component of control rods in nuclear fission reactors. One of its few new uses is in cadmium telluride solar panels. Although cadmium has no known biological function in most organisms, a cadmium-dependent carbonic anhydrase has been found in certain diatoms.
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.
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.