The short version of synthetic heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-18 and is reviewed periodically as new material appears.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead 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 | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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 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.
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.
== Clinical significance == Leukotrienes, which require the FLAP protein to be synthesized, have an established pathological role in allergic and respiratory diseases. Animal and human genetic evidence suggests they may also have an important role in atherosclerosis, myocardial infarction, and stroke. The structure of FLAP provides a tool for the development of novel therapies for respiratory and cardiovascular diseases and for the design of focused experiments to probe the cell biology of FLAP and its role in leukotriene biosynthesis.
On 10 January 1972, an ad hoc strike committee led by Johannes Nangutuuala, was formed to negotiate with the South African government; the strikers demanded an end to contract labour, freedom to apply for jobs according to skill and interest and to quit a job if so desired, freedom to have a worker bring his family with him from Ovamboland while taking a job elsewhere, and for equal pay with white workers. The strike was later brought to an end after the South African government agreed to several concessions which were endorsed by Nangutuuala, including the implementation of uniform working hours and allowing workers to change jobs. Responsibility for labour recruitment was also transferred to the tribal authorities in Ovamboland. Thousands of the sacked Ovambo workers remained dissatisfied with these terms and refused to return to work. They attacked tribal headmen, vandalised stock control posts and government offices, and tore down about a hundred kilometres of fencing along the border, which they claimed obstructed itinerant Ovambos from grazing their cattle freely. The unrest also fueled discontent among Kwanyama-speaking Ovambos in Angola, who destroyed cattle vaccination stations and schools and attacked four border posts, killing and injuring some SADF personnel as well as members of a Portuguese militia unit. South Africa responded by declaring a state of emergency in Ovamboland on 4 February.
=== Gardening === Nolina lindheimeriana, like other species of Nolina, are favored for their extreme drought resistance, deer resistance, and their rosettes' attractive grassy texture; rosettes may clump into groups. The plants can be quite attractive when in flower or fruit, with the inflorescences rising about three meters tall (10 feet). However, because of the cutting leaf margins, plants shouldn't be placed near walkways. It is reported as cold tolerant, not needing much watering, and preferring locations in full or partial sunlight. It grows in various kinds of limestone-based loam soils, including caliche type. Also, true to its desert origins, the species can be a bit slow growing.
=== Chinese majors === On 16 September, the AQSIQ released test of samples from 491 batches of products sold by all 109 companies producing baby formula. It said all 11 samples from Sanlu failed the melamine test. Sanlu, whose products sell at half the price of equivalents on the market, recorded the highest levels of contamination among all the samples tested, at 2,563 mg/kg or parts per million ("ppm"). Tainted samples were found among 21 other suppliers, where concentrations ranged from 0.09 to 619.00 ppm. There was melamine contamination in 10% of liquid milk samples from Mengniu and Yili, and 6% of those from Bright Dairy. On discovery of contamination, the three major producers were all stripped of their status as 'Chinese national brands'. Yili, Mengniu and Bright Dairy & Food Co. recalled tainted powdered milk and apologised in separate statements. Mengniu recalled all its baby formula, and trading in its shares on the Hong Kong Stock Exchange was suspended on 17 September. Shares in other dairy companies fell strongly the next day. Mengniu's CFO attempted to reassure consumers by offering a no-quibble refund on all products, and by drinking liquid milk in front of reporters in Hong Kong. He also said that its export products were less likely to be contaminated. On 30 September, the AQSIQ announced test results of a further 265 batches of powdered milk produced by 154 different companies prior to 14 September, where it found 31 batches produced by 20 domestic dairy companies were tainted with melamine.
Sources: en.wikipedia.org
== Lewis bases == A Lewis base or electron-pair donor is a molecule with one or more high-energy lone pairs of electrons which can be shared with a low-energy vacant orbital in an acceptor molecule to form an adduct. In addition to H+, possible electron-pair acceptors (Lewis acids) include neutral molecules such as BF3 and high oxidation state metal ions such as Ag2+, Fe3+ and Mn7+. Adducts involving metal ions are usually described as coordination complexes. According to the original formulation of Lewis, when a neutral base forms a bond with a neutral acid, a condition of electric stress occurs. The acid and the base share the electron pair that formerly belonged to the base. As a result, a high dipole moment is created, which can only be decreased to zero by rearranging the molecules.
==== Renovation ==== In 1983, in an attempt to draw crowds to the park and raise money for continued maintenance, the BPRC proposed leasing Bryant Park from the city, renovating it, and building a café in the park. The $18 million renovation was to be executed by an alliance between the BPRC, NYPL, and NYC Parks. Restaurateur Warner LeRoy was to operate the eatery, and he planned to build an 80-foot-tall (24 m), 10,500-square-foot (980 m2) glass café on the park's east side adjacent to the library. In addition, the park would include four smaller food kiosks, a reflecting pool and water fountain, and a dedicated security team.
=== M–Mey === Ida Maclean (1877–1944). British biochemist at the Lister Institute of Preventive Medicine, known work on fatty acids in animals and fat synthesis. John Macleod FRS (1876–1935). British biochemist and physiologist at the University of Toronto, discoverer of insulin. Nobel Prize in Physiology or Medicine (1923). Thaddeus Mann FRS (1908–1993). Ukrainian-British biochemist at the University of Cambridge, who worked on reproductive biology. Bengt Mannervik (b. 1943). Swedish biochemist at Stockholm University known for work on enzymes related to glutathione metabolism. Emanuel Margoliash (1920–2008). Israeli-American biochemist at Northwestern University, known for research on cytochrome c sequences, which formed the starting point for studies of protein evolution. Member Natl. Acad. Sci. USA. Vincent Massey FRS (1926–2002). Australian biochemist and enzymologist at the University of Michigan, best known for studies of flavoenzymes. Member Natl. Acad. Sci. USA. Elmer Verner McCollum (1879–1967). American biochemist at Johns Hopkins University, who discovered Vitamins A and D, and their benefits. Member Natl. Acad. Sci. USA. Harden M. McConnell (1927–2014). American biochemist at Stanford known for the technique of spin-labels, whereby electron and nuclear magnetic resonance can be used to study the structure and kinetics of proteins. Member Natl. Acad. Sci. USA. William D. McElroy (1917–1999). American biochemist and science administrator at University of California San Diego. Member Natl. Acad. Sci. USA. Enrique Meléndez-Hevia (born 1946).
== Chemistry == Ampicillin sodium is derived from the basic penicillin nucleus, 6-aminopenicillanic acid. Its chemical name is monosodium (2S, 5R, 6R)-6-[(R)-2-amino-2-phenylacetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate. It has a molecular weight of 371.39 grams and its chemical formula is C16H18N3NaO4S. Sulbactam sodium is also a derivative of 6-aminopenicillanic acid. Chemically, it is known as either sodium penicillinate sulfone or sodium (2S, 5R)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate 4,4-dioxide. It has a molecular weight of 255.22 grams and its chemical formula is C8H10NNaO5S.
=== Communities === Scabies is endemic in many developing countries, and it tends to be particularly prevalent in rural and remote areas. In such settings, community-wide control strategies are required to reduce the rate of disease, as treatment of only individuals is ineffective due to the high rate of reinfection. Large-scale mass drug administration strategies may be required where coordinated interventions aim to treat whole communities in one concerted effort. Although such strategies have shown to be able to reduce the burden of scabies in these kinds of communities, debate remains about the best strategy to adopt, including the choice of drug. The resources required to implement such large-scale interventions in a cost-effective and sustainable way are significant. Furthermore, since endemic scabies is largely restricted to poor and remote areas, it is a public health issue that has not attracted much attention from policymakers and international donors.
Sources: en.wikipedia.org
Secondary radionuclides in a decay chain will occur in proportion to their half-lives, so short-lived ones will be very rare. For example, polonium can be found in uranium ores at a concentration about 1 part 1010 of uranium (0.1 mg per metric ton) by calculating the ratio of half-lives of polonium-210 to uranium-238, its ultimate parent.
==== Combination with other medications ==== When used for type 2 diabetes, metformin is often prescribed in combination with other medications. Several medications are available as fixed-dose combinations, with the potential to reduce pill burden, decrease cost, and simplify administration.
== Structure == Most sv-LAAOs are reported as being homodimers with multiple subunits that have molecular weights around 50–70 kDa and the interaction between the subunits occurs via non-covalent interactions. Sv-LAAOs are present in the acidic, basic, and neutral forms of the protein. Studies that look at x-ray crystal structures have confirmed that sv-LAAOs are often found as functional dimers, with each dimer having three domains. The three domains are the substrate-binding site, FAD-binding site, and a helical domain. The substrate-binding site lies at the bottom of a funnel-shaped cavity approximately 25 Å deep, enabling substrate specificity among sv-LAAOs. Structural differences in active site topology likely account for species-dependent substrate preferences. Additionally, LAAOs are thermolabile, with cold inactivation and heat reactivation properties, necessitating specific storage and pre-activation conditions to preserve enzymatic activity. It has also been determined that the FAD prosthetic group becomes deeply entrenched in the enzyme structure, which allows for pervasive interactions with both neighboring atoms and conserved water molecules. Additionally, this flavin-containing prosthetic group has been classified as providing snake venom with its quintessential dark yellow coloration, which is shown in Figure 2. One unusual characteristic reported for sv-LAAOs regards the cold inactivation and heat reactivation properties of the protein. Thereby, most sv-LAAOs are considered to be thermolabile enzymes.
Recent estimates have found ~135,000 validated nonsynonymous cSNPs currently housed within SwissProt. In dbSNP, there are 4.7 million candidate cSNPs, yet only ~670,000 cSNPs have been validated in the 1,000-genomes set as nonsynonymous cSNPs that change the identity of an amino acid in a protein. Dark proteome. The term dark proteome coined by Perdigão and colleagues, defines regions of proteins that have no detectable sequence homology to other proteins of known three-dimensional structure and therefore cannot be modeled by homology. For 546,000 Swiss-Prot proteins, 44–54% of the proteome in eukaryotes and viruses was found to be "dark", compared with only ~14% in archaea and bacteria. Human proteome. Currently, several projects aim to map the human proteome, including the Human Proteome Map Archived 2020-08-06 at the Wayback Machine, ProteomicsDB, isoform.io, and The Human Proteome Project (HPP). Much like the Human Genome Project, these projects seek to find and collect evidence for all predicted protein coding genes in the human genome. The Human Proteome Map currently (October 2020) claims 17,294 proteins and ProteomicsDB 15,479, using different criteria. On October 16, 2020, the HPP published a high-stringency blueprint covering more than 90% of the predicted protein coding genes. Proteins are identified from a wide range of fetal and adult tissues and cell types, including hematopoietic cells.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
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.