A practical reference on intranasal route: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-25 and is reviewed periodically as new material appears.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
| 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 |
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.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
The PAH world hypothesis is a speculative hypothesis that proposes that polycyclic aromatic hydrocarbons (PAHs), known to be abundant in the universe, including in comets, and assumed to be abundant in the primordial soup of the early Earth, played a major role in the origin of life by mediating the synthesis of RNA molecules, leading into the RNA world. However, as yet, the hypothesis is untested.
Three major forms of hCG are produced by humans, with each having distinct physiological roles. These include regular hCG, hyperglycosylated hCG, and the free beta-subunit of hCG. Degradation products of hCG have also been detected, including nicked hCG, hCG missing the C-terminal peptide from the beta-subunit, and free alpha-subunit, which has no known biological function. Some hCG is also made by the pituitary gland with a pattern of glycosylation that differs from placental forms of hCG. Regular hCG is the main form of hCG associated with the majority of pregnancy and in non-invasive molar pregnancies. This is produced in the trophoblast cells of the placental tissue. Hyperglycosylated hCG is the main form of hCG during the implantation phase of pregnancy, with invasive molar pregnancies, and with choriocarcinoma. Gonadotropin preparations of hCG can be produced for pharmaceutical use from animal or synthetic sources.
The clinical significance of bilirubin glucuronide is involved in many conditions. Drugs that inhibit the activities of the components involved in bilirubin metabolism can give rise to accumulation of bilirubin in the blood. In comparison, conjugation of some drugs is also usually impaired if the liver cannot normally metabolize indirect bilirubin. When excretion of bilirubin glucuronide by the kidney is detected in the urine through urine examination, meaning that a conspicuous amount of conjugated bilirubin is present and circulating in the blood. In Dubin–Johnson syndrome, impaired biliary excretion of bilirubin glucuronide is due to a mutation in the canalicular multiple drug-resistance protein 2 (MRP2). A darkly pigmented liver is due to polymerized epinephrine metabolites, not bilirubin.
Traditionally, Escherichia coli is the choice bacterium to express eukaryotic and recombinant genes. E. coli is well understood and has a successful track record producing insulin, the artemisinin precursor artemisinic acid, and filgrastim (Neupogen). However, use of E. coli has limitations including misfolding of eukaryotic proteins, insolubility issues, deposition in inclusion bodies, low secretion efficiency, secretion to periplasmic space. Streptomyces offers potential advantages including superior secretion mechanisms, higher yields, a simpler end-product purification process, making Streptomyces an attractive alternative to E. coli and Bacillus subtilis. Streptomyces coelicolor, Streptomyces avermitilis, Streptomyces griseus, and Saccharopolyspora erythraea, are capable of secondary metabolite production. Streptomyces coelicolor has shown useful for the heterologous expression of proteins. Methods like "ribosome engineering" have been used to achieve 180-fold higher yields with S. coelicolor.
Sources: en.wikipedia.org
62. Neuro Endocrinol Lett. 2001 Aug;22(4):251-4. Synthetic tetrapeptide epitalon restores disturbed neuroendocrine regulation in senescent monkeys. Khavinson V(1), Goncharova N, Lapin B. Author information: (1)St. Petersburg Institute of Bioregulation and Gerontology, 3 Dynamo Prospect, 197110 St. Petersburg, Russia. ibg@medport.ru The OBJECTIVE of this research was to investigate the regulatory effect of Epitalon on the production of melatonin and cortisol in senescent monkeys. MATERIAL AND METHODS: We investigated the character of melatonin and cortisol secretion by immunoferment assay in Epitalon-administered female Macaca mulatta in different age periods. RESULTS: Epitalon was proven to significantly stimulate melatonin synthesis in senescent monkeys in the evening, thereby normalising the circadian rhythm of cortisol secretion.
A distinctive feature of collagen is the regular arrangement of amino acids in each of the three chains of these collagen subunits. The sequence often follows the pattern Gly-Pro-X or Gly-X-Hyp, where X may be any of various other amino acid residues. Proline or hydroxyproline constitute about 1/6 of the total sequence. With glycine accounting for the 1/3 of the sequence, this means approximately half of the collagen sequence is not glycine, proline or hydroxyproline, a fact often missed due to the distraction of the unusual GX1X2 character of collagen alpha-peptides. The high glycine content of collagen is important with respect to stabilization of the collagen helix, as this allows the very close association of the collagen fibers within the molecule, facilitating hydrogen bonding and the formation of intermolecular cross-links. This kind of regular repetition and high glycine content is found in only a few other fibrous proteins, such as silk fibroin. Collagen is not only a structural protein. Due to its key role in the determination of cell phenotype, cell adhesion, tissue regulation, and infrastructure, many sections of its non-proline-rich regions have cell or matrix association/regulation roles. The relatively high content of proline and hydroxyproline rings, with their geometrically constrained carboxyl and (secondary) amino groups, along with the rich abundance of glycine, accounts for the tendency of the individual polypeptide strands to form left-handed helices spontaneously, without any intrachain hydrogen bonding.
=== Pretreatments === If the raw material used in the production of the gelatin is derived from bones, dilute acid solutions are used to remove calcium and other salts. Hot water or several solvents may be used to reduce the fat content, which should not exceed 1% before the main extraction step. If the raw material consists of hides and skin, then size reduction, washing, hair removal, and degreasing are necessary to prepare the materials for the hydrolysis step.
==== Ultrastructure and collagen synthesis ==== Collagen fibres coalesce into macroaggregates. After secretion from the cell, cleaved by procollagen N- and C-proteases, the tropocollagen molecules spontaneously assemble into insoluble fibrils. A collagen molecule is about 300 nm long and 1–2 nm wide, and the diameter of the fibrils that are formed can range from 50–500 nm. In tendons, the fibrils then assemble further to form fascicles, which are about 10 mm in length with a diameter of 50–300 μm, and finally into a tendon fibre with a diameter of 100–500 μm. The collagen in tendons are held together with proteoglycan (a compound consisting of a protein bonded to glycosaminoglycan groups, present especially in connective tissue) components including decorin and, in compressed regions of tendon, aggrecan, which are capable of binding to the collagen fibrils at specific locations. The proteoglycans are interwoven with the collagen fibrils – their glycosaminoglycan (GAG) side chains have multiple interactions with the surface of the fibrils – showing that the proteoglycans are important structurally in the interconnection of the fibrils. The major GAG components of the tendon are dermatan sulfate and chondroitin sulfate, which associate with collagen and are involved in the fibril assembly process during tendon development. Dermatan sulfate is thought to be responsible for forming associations between fibrils, while chondroitin sulfate is thought to be more involved with occupying volume between the fibrils to keep them separated and help withstand deformation.
Radioluminescence (or scintillation) is the phenomenon by which light is produced in a material by bombardment with ionizing radiation such as alpha particles, beta particles, or gamma rays. Radioluminescence is used as a low level light source for night illumination of instruments or signage. Radioluminescent paint is occasionally used for clock hands and instrument dials, enabling them to be read in the dark. Radioluminescence is also sometimes seen around high-power radiation sources, such as nuclear reactors and radioisotopes.
Sources: pubmed.ncbi.nlm.nih.gov
Production process – it can be derived from biotechnology or from other technologies. It may be prepared using more conventional techniques as is the case for blood or plasma-derived products and a number of vaccines. Active substance – consisting of entire microorganisms, mammalian cells, nucleic acids, proteinaceous, or polysaccharide components originating from a microbial, animal, human, or plant source. Mode of action – therapeutic and immunological medicinal products, gene transfer materials, or cell therapy materials.
==== Orinoco River exploration ==== Humboldt’s expedition to the Upper Orinoco and the Casiquiare canal began at 4 a.m. on March 30, 1800, departing from San Fernando de Apure. The transition from the dry Llanos to the river marked a significant environmental change. The team, which included Don Nicolas Sotto, four Native rowers, and a pilot, traveled in a large sailing canoe outfitted with a cabin made of leaves and ox-hide benches. The river’s dense forests replaced the open horizons of the plains, and travel became more constrained. Wildlife was abundant, with numerous birds, capybaras, river dolphins, tapirs, peccaries, and alligators observed along the riverbanks, as well as piranhas and stingrays in the water. Humboldt noted the intensity of insect life, particularly at midday.
== Risk factors == Identified risk factors for plantar fasciitis include excessive running, prolonged standing on hard surfaces, high arches, leg length inequality, and flat feet. The tendency of flat feet to excessively roll inward, or supinate, during walking or running makes them more susceptible. Obesity is seen in 70% of individuals who present with plantar fasciitis and is an independent risk factor. Plantar fasciitis is commonly a result of some biomechanical imbalance that causes increased tension along the fascia. Achilles tendon tightness and inappropriate footwear are significant risk factors.
=== Synthesis === Early and seemingly inefficient syntheses of synephrine were discussed by Priestley and Moness, writing in 1940. These chemists optimized a route beginning with the O-benzoylation of p-hydroxy-phenacyl chloride, followed by reaction of the resulting O-protected chloride with N-methyl-benzylamine to give an amino-ketone. This intermediate was then hydrolyzed with HCl/alcohol to the p-hydroxy-aminoketone, and the product then reduced catalytically to give (racemic) synephrine. A later synthesis, due to Bergmann and Sulzbacher, began with the O-benzylation of p-hydroxy-benzaldehyde, followed by a Reformatskii reaction of the protected aldehyde with ethyl bromoacetate/Zn to give the expected β-hydroxy ester. This intermediate was converted to the corresponding acylhydrazide with hydrazine, then the acylhydrazide reacted with HNO2, ultimately yielding the p-benzyloxy-phenyloxazolidone. This was N-methylated using dimethyl sulfate, then hydrolyzed and O-debenzylated by heating with HCl, to give racemic synephrine.
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.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.