A practical reference on ACTH(4–10): what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-23. Anything still debated is marked as such rather than presented as settled.
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.
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。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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。
| 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 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.
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.
== History and name == The name leukotriene, introduced by Swedish biochemist Bengt Samuelsson in 1979, comes from the words leukocyte and triene (indicating the compound's three conjugated double bonds). What would be later named leukotriene C, "slow reaction smooth muscle-stimulating substance" (SRS) was originally described between 1938 and 1940 by Feldberg and Kellaway. The researchers isolated SRS from lung tissue after a prolonged period following exposure to snake venom and histamine.
Biosynthesis is chemical synthesis occurring in biological contexts. It most often refers to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex products. Examples of biosynthetic pathways include those for the production of amino acids, lipid membrane components, and nucleotides, but also for the production of all classes of biological macromolecules, and of acetyl-coenzyme A, adenosine triphosphate, nicotinamide adenine dinucleotide and other key intermediate and transactional molecules needed for metabolism. Thus, in biosynthesis, any of an array of compounds, from simple to complex, are converted into other compounds, and so it includes both the anabolism and catabolism (building up and breaking down) of complex molecules (including macromolecules). Biosynthetic processes are often represented via charts of metabolic pathways. A particular biosynthetic pathway may be located within a single cellular organelle (e.g., mitochondrial fatty acid synthesis pathways), while others involve enzymes that are located across an array of cellular organelles and structures (e.g., the biosynthesis of glycosylated cell surface proteins).
Octopuses mainly move about by relatively slow crawling with some swimming in a head-first position. Jet propulsion or backward swimming, is their fastest means of locomotion, while crawling is slowest. While crawling, the suckers adhere and detach from the substrate as the animal hauls itself forward with its powerful arm muscles. In 2005, Adopus aculeatus and veined octopus (Amphioctopus marginatus) were found to walk on two arms, while at the same time mimicking plant matter. This form of locomotion allows these octopuses to move quickly away from a potential predator without being recognised. Some species of octopus can crawl out of the water briefly, which they may do between tide pools. "Stilt walking" is used by the veined octopus when carrying stacked coconut shells. The octopus carries the shells underneath it with two arms, and progresses with an awkward gait supported by its remaining arms, which are stiffened.
==== Absorption ==== The absolute bioavailability of gepirone is 14 to 17%. The time to peak concentrations of gepirone with the extended-release formulation is 6 hours. When taken with a high-fat meal, the time to peak levels decreases to 3 hours. A high-fat meal increases exposure to gepirone, with the effect increasing dependent on the amount of fat in the meal. Peak concentrations were increased by 27% with a low-fat meal, 55% with a medium-fat meal, and 62% with a high-fat meal, while area-under-the-curve levels of gepirone were increased by 14% with a low-fat meal, 22% with a medium-fat meal, and 32 to 37% with a high-fat meal. The effect was similar for the metabolites of gepirone, 1-PP and 3'-hydroxygepirone (3'-OH-gepirone).
== Further reading == Epstein, Noah; Chandran, Sheena; Chou, Loretta (2012). "Current Concepts Review: Intra-Articular Fractures of the Calcaneus". Foot & Ankle International. 33 (1): 79–86. doi:10.3113/FAI.2012.0079. ISSN 1071-1007. McKinley, Todd O; Borrelli, Joseph; D'Lima, Darryl D; Furman, Bridgette D; Giannoudis, Peter V (2010). "Basic Science of Intra-articular Fractures and Posttraumatic Osteoarthritis". Journal of Orthopaedic Trauma. 24 (9). Ovid Technologies (Wolters Kluwer Health): 567–570. doi:10.1097/bot.0b013e3181ed298d. ISSN 0890-5339. PMC 3662545.
Sources: en.wikipedia.org
=== Diabetes === Januvia (sitagliptin) ($1.3 billion in 2024 revenues) is a dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes. In 2013, Januvia was the second largest selling diabetes drug worldwide. It has been popular due in part because unlike many other diabetes drugs, it causes little or no weight gain and is not associated with hypoglycemic episodes. There has been some concern that treatment with Januvia and other DPP-IV inhibitors may be associated with a modestly increased risk of pancreatitis. Janumet ($1.0 billion in 2024 revenues) is a single pill combination drug containing both Januvia and metformin.
== Genes == Most research that has been conducted on CLE peptide signaling has been conducted with Arabidopsis, since this genome contains 32 members of the CLE gene family. CLV3, which belongs to the CLE family of genes, is found within one or more tissues of Arabidopsis. All 32 members of the CLE family share two characteristics that include: encoding of a small protein with a putative secretion signal at their N- termini and contain a conserved CLE motif at or near their C-termini. The 32 members of the CLE gene family originated from mutations of the original gene.
== History == Caleb Hillier Parry first made the association between the goiter and eye protrusion in 1786; however, he did not publish his findings until 1825. In 1835, Irish doctor Robert James Graves discovered a link between the protrusion of the eyes and goiter, giving his name to the autoimmune disease now known as Graves' Disease.
Malic acid is typically associated with the taste of green apples, while lactic acid is richer and more buttery tasting. Grapes produced in cool regions tend to be high in acidity, much of which comes from the contribution of malic acid. Malolactic fermentation generally enhances the body and flavor persistence of wine, producing wines of greater palate softness. Many winemakers also feel that better integration of fruit and oak character can be achieved if malolactic fermentation occurs during the time the wine is in barrel. A wine undergoing malolactic conversion will be cloudy because of the presence of bacteria, and may have the smell of buttered popcorn, the result of the production of diacetyl. The onset of malolactic fermentation in the bottle is usually considered a wine fault, as the wine will appear to the consumer to still be fermenting (as a result of CO2 being produced). However, for early Vinho Verde production, this slight effervesce was considered a distinguishing trait, though Portuguese wine producers had to market the wine in opaque bottles because of the increase in turbidity and sediment that the "in-bottle MLF" produced. Today, most Vinho Verde producers no longer follow this practice and instead complete malolactic fermentation prior to bottling with the slight sparkle being added by artificial carbonation.
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.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。