counter-ion comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
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.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
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.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
Nevertheless, without clear biosynthetic pathways (not yet found in animals, but shown for bacteria), it remains uncertain whether it is simply via bacteria that each animal accumulates TTX; the question remains as to whether the quantities can be sufficiently explained by ingestion, ingestion plus colonization, or some other mechanism.
Once a nucleic acid sequence has been obtained from an organism, it is stored in silico in digital format. Digital genetic sequences may be stored in sequence databases, be analyzed (see Sequence analysis below), be digitally altered and be used as templates for creating new actual DNA using artificial gene synthesis.
A New York Times article in 1995 referred to the park as the "Town Square of Midtown" and an "office oasis" frequented by midtown office workers. Further improvements included the installation of two newsstands in 1992, one each at Fifth and Sixth Avenues. Open-air concerts in the summers, which drew thousands of people, were commenced. To lessen infestations of pigeons eating the plants, the BPC started scattering corn kernels that contained the drug azacosterol, which resulted in many pigeons becoming infertile without any other side effects. Meanwhile, financing for a restaurant in Bryant Park next to the library was finally secured in 1993. The restaurant, Bryant Park Grill, opened in 1995.
2020, I. S. Pires, D. A. Belcher, R. Hickey, C. Miller, A. K. Badu-Tawiah, J. H. Baek, P. W. Buehler, A. F. Palmer, “Novel manufacturing method for producing apohemoglobin and its biophysical properties,” Biotechnology and Bioengineering Jan;117(1):125-145. 2020, I. S. Pires, A. F. Palmer, “Tangential flow filtration of haptoglobin,” Biotechnology Progress Sep;36(5):e3010. 2020, C. J. Munoz, I. S. Pires, J. H. Baek, P. W. Buehler, A. F. Palmer, P. Cabrales, “A novel apo-hemoglobin-haptoglobin complex attenuates the pathobiology of circulating acellular hemoglobin and heme,” American Journal of Physiology Heart and Circulatory Physiology May 1;318(5):H1296-H1307.
More recent publications have defined the usually recommended doses as 50 mg DMT and 100 mg harmaline orally. Besides DMT with harmaline, the properties and effects of oral DMT in combination with harmine have also been studied by Jonathan Ott. He found that the threshold dose was 20 or 30 mg DMT and 120 mg harmine orally. Shulgin also reported in TiHKAL that 35 to 40 mg DMT and 140 to 190 mg harmine were unmistakably active, whereas smaller doses of 30 mg DMT and 120 to 140 mg harmine orally were inactive. In notable contrast to harmaline, harmine does not have its own psychoactive effects when used at doses of up to at least 300 mg orally. In pharmahuasca, the harmala alkaloid is usually taken first and then DMT is taken 15 to 20 minutes later, although a shorter or longer interval may also be employed. The onset of oral DMT with an MAOI is within 1 hour and its duration is 4 to 6 hours.
Sources: en.wikipedia.org
== Classification == Argiotoxin can be classified, according to the 1980s classification of spider venoms, as a toxin of the acylpolyamines family, which contains more than 100 different chemical structures of closely related toxins. Acylpolyamines are neurotoxic compounds that are found only in the venom glands of spiders at a picomolar level. Argiotoxins are classified into three different categories according to its chromophore's nature: the argiopine type, the argiopinine type and the pseudoargiopinine type.
== Structure == Each nerve is covered on the outside by a dense sheath of connective tissue, the epineurium. Beneath this is a layer of fat cells, the perineurium, which forms a complete sleeve around a bundle of axons. Perineurial septa extend into the nerve and subdivide it into several bundles of fibres. Surrounding each such fibre is the endoneurium. This forms an unbroken tube from the surface of the spinal cord to the level where the axon synapses with its muscle fibres, or ends in sensory receptors. The endoneurium consists of an inner sleeve of material called the glycocalyx and an outer delicate meshwork of collagen fibres. Nerves are bundled and often travel along with blood vessels, since the neurons of a nerve have fairly high energy requirements. Within the endoneurium, the individual nerve fibres are surrounded by a low-protein liquid called endoneurial fluid. This acts in a similar way to the cerebrospinal fluid in the central nervous system and constitutes a blood-nerve barrier similar to the blood–brain barrier. Molecules are thereby prevented from crossing the blood into the endoneurial fluid. During the development of nerve edema from nerve irritation (or injury), the amount of endoneurial fluid may increase at the site of irritation. This increase in fluid can be visualized using magnetic resonance (MR) neurography, and thus MR neurography can identify nerve irritation and/or injury.
=== Pharmacokinetics === After application to the skin, miconazole can be measured in the skin for up to four days, but less than 1% is absorbed into the bloodstream. When applied to the oral mucosa (and possibly also for vaginal use), it is significantly absorbed. In the bloodstream, 88.2% are bound to plasma proteins and 10.6% to blood cells. The substance is partly metabolized via the liver enzyme CYP3A4 and mainly eliminated via the faeces.
In the United States, all fifty states, along with the District of Columbia, Puerto Rico, and the U.S. Virgin Islands, have laws that allow a mother to breastfeed a baby in any public or private location. In that country, the Friendly Airports for Mothers (FAM) Act was signed into law in 2019, and the requirements went into effect in 2021. This law requires that all large and medium hub airports in the U.S. provide a private, non-bathroom lactation space in each terminal building. Some commercial establishments in the U.S. provide breastfeeding rooms, although laws generally specify that mothers may breastfeed anywhere without requiring a special area. Despite these laws, many women in the United States continue to be publicly shamed or asked to refrain from breastfeeding in public. In the United Kingdom, the Equality Act 2010 makes the prevention of breastfeeding in any public place discrimination under the law. In Scotland, it is a criminal offense for one to attempt to prevent another from feeding a child under 24 months in public. While laws in the U.S. were passed in 2010 which required that nursing mothers who had returned to work be given a non-bathroom space to express milk and a reasonable break time to do so, as of 2016 the majority of American women still did not have access to both accommodations. In 2014, newly elected Pope Francis drew worldwide commentary when he encouraged mothers to breastfeed babies in church. During a papal baptism, he said that mothers "should not stand on ceremony" if their children were hungry.
Sources: en.wikipedia.org
== Preparation, occurrence, and applications == Phenyl groups are usually introduced using reagents that behave as sources of the phenyl anion or the phenyl cation. Representative reagents include phenyllithium (C6H5Li) and phenylmagnesium bromide (C6H5MgBr). Electrophiles are attacked by benzene to give phenyl derivatives:
=== PTEN hamartoma syndrome === PTEN hamartoma syndrome encompasses hamartomatous disorders characterized by genetic mutations in the PTEN tumor suppressor gene, including Cowden syndrome, Bannayan–Riley–Ruvalcaba syndrome, Proteus syndrome and Proteus-like syndrome. Absent or dysfunctional PTEN protein allows cells to over-proliferate, causing hamartomas. Cowden syndrome is an autosomal dominant genetic disorder characterized by multiple benign hamartomas (trichilemmomas and mucocutaneous papillomatous papules) as well as a predisposition for cancers of multiple organs including the breast and thyroid. Bannayan–Riley–Ruvalcaba syndrome is a congenital disorder characterized by hamartomatous intestinal polyposis, macrocephaly, lipomatosis, hemangiomatosis and glans penis macules. Proteus syndrome is characterized by nevi, asymmetric overgrowth of various body parts, adipose tissue dysregulation, cystadenomas, adenomas, vascular malformation.
ATSDR - Toxicity of Polycyclic Aromatic Hydrocarbons (PAHs) Archived 30 May 2020 at the Wayback Machine U.S. Department of Health and Human Services Fused Ring and Bridged Fused Ring Nomenclature Database of PAH structures Cagliari PAH Theoretical Database NASA Ames PAH IR Spectroscopic Database National Pollutant Inventory: Polycyclic Aromatic Hydrocarbon Fact Sheet Understanding Polycyclic Aromatic Hydrocarbons NASA Spitzer Space Telescope "The Aromatic World: An Interview with Professor Pascale Ehrenfreund" from Astrobiology Magazine Oregon State University Superfund Research Center focused on new technologies and emerging health risks of Polycyclic Aromatic Hydrocarbons (PAHs) Polycyclic Aromatic Hydrocarbons (PAHs)--EPA Fact Sheet. U.S. Environmental Protection Agency, Office of Solid Waste, January 2008.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
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.