A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-22 and is reviewed periodically as new material appears.
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.
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.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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.
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.
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.
The Collaborative for academic, social, emotional learning (CASEL) addresses five broad and interrelated areas of competence and highlights examples for each: self-awareness, self-management, social awareness, relationship skills, and responsible decision-making. A meta-analysis was done by Alexendru Boncu, Iuliana Costeau, & Mihaela Minulescu (2017) looking at social-emotional learning (SEL) studies and the effects on emotional and behavior outcomes. They found a small but significant effect size (across the studies looked into) for externalized problems and social-emotional skills. Holistic approaches to education also emphasize social-emotional development as a key pillar of personal growth.
The regulation of drugs varies by jurisdiction. In some countries, such as the United States, they are regulated at the national level by a single agency. In other jurisdictions, they are regulated at the state level, or at both state and national levels by various bodies, as is the case in Australia. The role of therapeutic goods regulation is designed mainly to protect the health and safety of the population. Regulation is aimed at ensuring the safety, quality, and efficacy of the therapeutic goods which are covered under the scope of the regulation. In most jurisdictions, therapeutic goods must be registered before they are allowed to be marketed. There is usually some degree of restriction on the availability of certain therapeutic goods depending on their risk to consumers. Depending upon the jurisdiction, drugs may be divided into over-the-counter drugs (OTC) which may be available without special restrictions, and prescription drugs, which must be prescribed by a licensed medical practitioner in accordance with medical guidelines due to the risk of adverse effects and contraindications. The precise distinction between OTC and prescription depends on the legal jurisdiction. A third category, "behind-the-counter" drugs, is implemented in some jurisdictions. These do not require a prescription, but must be kept in the dispensary, not visible to the public, and be sold only by a pharmacist or pharmacy technician. Doctors may also prescribe prescription drugs for off-label use – purposes which the drugs were not originally approved for by the regulatory agency.
where subscripts p and n stand for the proton and neutron, and g(l)n = 0. By using the same identities as here and using the value g(l)p = 1, one gets the following result, in units of the nuclear magneton μN
Sources: en.wikipedia.org
Since about 1990, there has been a resurgence of the promotion of colloidal silver as a dietary supplement or used otherwise internally, marketed with claims of its being an essential mineral supplement, or that it can prevent or treat numerous diseases, such as cancer, diabetes, arthritis, HIV/AIDS, herpes, and tuberculosis. No medical evidence supports the effectiveness of colloidal silver for any of these claimed indications. Silver is not an essential mineral in humans; there is no dietary requirement for silver, and hence, no such thing as a silver "deficiency". There is no evidence that colloidal silver treats or prevents any medical condition, and it can cause serious and potentially irreversible side effects, such as argyria.
Each of the United States armed services had its own ICBM development program. The Air Force began ICBM research in 1945 with the MX-774. In 1950, von Braun began testing the Air Force PGM-11 Redstone rocket family at Cape Canaveral. By 1957, a descendant of the Air Force MX-774 received top-priority funding. and evolved into the Atlas-A, the first successful American ICBM. The Atlas made use of a thin stainless steel fuel tank which relied on the internal pressure of the tank for structural integrity, this allowed an overall lighter weight design. WD-40 was developed to prevent rust on the Atlas rockets so that rust protecting paint could be avoided, to further reduce weight. A later variant of the Atlas, the Atlas-D, served as a nuclear ICBM and as the orbital launch vehicle for Project Mercury and the remote-controlled Agena Target Vehicle used in Project Gemini.
Boli or bole is the term used for roasted plantain in Nigeria. The plantain is usually grilled and served with roasted fish, ground peanuts and a hot palm oil sauce. It is a dish native to the Yoruba people of Western Nigeria. It is popular among the working class as an inexpensive midday meal. Plantain is popular in West and Central Africa, especially Cameroon, Democratic Republic of Congo, Bénin, Ghana and Nigeria; when ripe plantain is fried, it is generally called dodo ("dough-dough"). The ripe plantain is usually sliced diagonally for a large oval shape, then fried in oil to a golden brown color. The diagonal slice maximizes the surface area, allowing the plantain to cook evenly. Fried plantain can be eaten as such, or served with stew or sauce. In Ikire, a town in Osun State in southwestern Nigeria, there is a special way of preparing fried plantain known as Dodo Ikire. This variation of Dodo (Fried Plantain) is made from overripe plantain, chopped into small pieces, sprinkled with chili pepper and then fried in boiling point palm oil until the pieces turn blackish. The fried plantains are then stuffed carefully into a plastic funnel and then pressed using a wooden pestle to compress and acquire a conical shape when removed. In Ghana, the dish is called kelewele and can be found as a snack sold by street vendors. Though sweeter and spicier variations exist, kelewele is often flavored with nutmeg, chili powder, ginger and salt.
Sources: en.wikipedia.org
An electron-dense granule defined by the presence of Toll-like receptor 9 (TLR9) and protein disulfide isomerase (PDI), termed the T granule, has also been described, although its existence remains controversial. PDI and other platelet-borne thiol isomerases have been reported to be packaged within a non-granular compartment derived from the megakaryocyte endoplasmic reticulum (ER), which may be associated with the dense tubular system.
Liberal Democrat History Group. Catalogue of the Liberal Party papers (mostly dating from after 1945) at LSE Archives. The Liberal Magazine Volume 2 1895. Liberal Magazine A Periodical for the Use of Liberal Speakers, Writers and Canvassers Volume 1 1893. Facts for Liberal Politicians By John Noble 1879. Proceedings in Connection with the Annual Meeting of the National Liberal Federation with the Annual Report By National Liberal Federation, 1881. Election Address and Speeches By Samuel Smith, 1882. Annual Report Presented at a Meeting of the Council By National Liberal Federation, 1887. Proceedings of the Annual Meeting of the Council By National Liberal Federation, 1895. Five Years of Liberal Policy and Conservative Opposition By George Charles Brodrick, 1874. Leaflets By National Liberal Federation, 1898. Pamphlets and Leaflets of the Liberal Publication Dept By Liberal Publication Department (Great Britain), 1900. The Liberal Magazine Volume 7, Publisher: Liberal Publication Department, 1900. Leaflets published by the Liberal Publication Department for the General Election of 1906, 1906. The Liberal year book for 1908. The Government's record, 1906–1913 : seven years of Liberal legislation and administration By Liberal Publication Dept. (Great Britain). The Yale Review Volume 4 1895. The Age of Lloyd George The Liberal Party and British Politics, 1890–1929 By Kenneth O. Morgan, 2021.
=== EC 2.4: glycosyl, hexosyl, and pentosyl transferases === EC 2.4 includes enzymes that transfer glycosyl groups, as well as those that transfer hexose and pentose. Glycosyltransferase is a subcategory of EC 2.4 transferases that is involved in biosynthesis of disaccharides and polysaccharides through transfer of monosaccharides to other molecules. An example of a prominent glycosyltransferase is lactose synthase which is a dimer possessing two protein subunits. Its primary action is to produce lactose from glucose and UDP-galactose. This occurs via the following pathway: UDP-β-D-galactose + D-glucose
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.