A practical reference on ACTH fragment: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-07 and is reviewed periodically as new material appears.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
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。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
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.
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.
== Types of comparisons == Because protein structures are composed of amino acids whose side chains are linked by a common protein backbone, a number of different possible subsets of the atoms that make up a protein macromolecule can be used in producing a structural alignment and calculating the corresponding RMSD values. When aligning structures with very different sequences, the side chain atoms generally are not taken into account because their identities differ between many aligned residues. For this reason it is common for structural alignment methods to use by default only the backbone atoms included in the peptide bond. For simplicity and efficiency, often only the alpha carbon positions are considered, since the peptide bond has a minimally variant planar conformation. Only when the structures to be aligned are highly similar or even identical is it meaningful to align side-chain atom positions, in which case the RMSD reflects not only the conformation of the protein backbone but also the rotameric states of the side chains. Other comparison criteria that reduce noise and bolster positive matches include secondary structure assignment, native contact maps or residue interaction patterns, measures of side chain packing, and measures of hydrogen bond retention.
== History == The first on-line coupling of gas chromatography to a mass spectrometer was reported in the late 1950s. An interest in coupling the methods had been suggested as early as December 1954, but conventional recording techniques had too poor temporal resolution. Fortunately, time-of-flight mass spectrometry developed around the same time allowed to measure spectra thousands times a second. The development of affordable and miniaturized computers has helped in the simplification of the use of this instrument, as well as allowed great improvements in the amount of time it takes to analyze a sample. In 1964, Electronic Associates, Inc. (EAI), a leading U.S. supplier of analog computers, began development of a computer controlled quadrupole mass spectrometer under the direction of Robert E. Finnigan. By 1966 Finnigan and collaborator Mike Uthe's EAI division had sold over 500 quadrupole residual gas-analyzer instruments. In 1967, Finnigan left EAI to form the Finnigan Instrument Corporation along with Roger Sant, T. Z. Chou, Michael Story, Lloyd Friedman, and William Fies. In early 1968, they delivered the first prototype quadrupole GC/MS instruments to Stanford and Purdue University. When Finnigan Instrument Corporation was acquired by Thermo Instrument Systems (later Thermo Fisher Scientific) in 1990, it was considered "the world's leading manufacturer of mass spectrometers".
A migraine trigger is anything that increases the sensitivity of the brain to migraines. The activity of nerve cells and chemical signals in the brain is affected by genetic, environmental, and neurological factors which interact. Once physical and chemical stimuli exceed an individual's sensitivity threshold, further neurological changes can lead to increased activity in the pain pathway of the brain, with heightened blood flow and transmission of pain signals. Categories of potential migraine triggers include emotions, nutrition, sleep, hormones, weather, environmental factors (noise, smells, lights), and strenuous movement. Internal migraine triggers such as hormones, stress, disturbed sleep, and fasting affect the body's ability to maintain a stable state. External migraine triggers such as temperature, noises, and odors can change how the body reacts to sensory information. Air pollution, in particular nitrous oxide, carbon monoxide, and particulate matter, appears to increase migraine risk. Determining when something truly acts as a causal trigger, as opposed to being a symptom of already occurring changes in the brain, is an ongoing area of research. In some cases, factors reported as triggers, such as sensory sensitivities, food cravings, and mood changes, may instead be symptoms in the early (prodromal) phase of migraine. Relationships between triggers are complex and may be bidirectional.
Emu leather has a distinctive patterned surface, due to a raised area around the feather follicles in the skin; the leather is used in such items as wallets, handbags, shoes and clothes, often in combination with other leathers. The feathers and eggs are used in decorative arts and crafts. In particular, emptied emu eggs have been engraved with portraits, similar to cameos, and scenes of Australian native animals. Mounted Emu eggs and emu-egg containers in the form of hundreds of goblets, inkstands and vases were produced in the second half of the nineteenth century, all richly embellished with images of Australian flora, fauna and indigenous people by travelling silversmiths, founders of a 'new Australian grammar of ornament'. They continued longstanding traditions that can be traced back to the European mounted ostrich eggs of the thirteenth century and Christian symbolism and notions of virginity, fertility, faith and strength. For a society of proud settlers who sought to bring culture and civilisation to their new world, the traditional ostrich-egg goblet, freed from its roots in a society dominated by court culture, was creatively made novel in the Australian colonies as forms and functions were invented to make the objects attractive to a new, broader audience.
Sources: en.wikipedia.org
=== Domain insertion === This technique involves the fusion of consecutive protein domains by encoding desired structures into a single polypeptide chain, but sometimes may require insertion of a domain within another domain. This technique is typically regarding as more difficult to carry out than tandem fusion, due to difficulty finding an appropriate ligation site in the gene of interest.
Casuarinas are flowering plants with fruit and leaves resembling the leaves and cones of the gymnosperm pines Some dicots (Anemone) and monocots (Trillium) in inhospitable environments are able to form underground organs such as corms, bulbs and rhizomes for reserving of nutrition and water until the conditions become better. Carnivorous plants: nitrogen-deficient plants have in at least seven distinct times become carnivorous, like: flypaper traps such as sundews and butterworts, spring traps-Venus fly trap, and pitcher traps in order to capture and digest insects to obtain scarce nitrogen. Pitcher plants: the pitcher trap evolved independently in three eudicot lineages and one monocot lineage. Similar-looking rosette succulents have arisen separately among plants in the families Asphodelaceae (formerly Liliaceae) and Crassulaceae. The orchids, the birthwort family and Stylidiaceae have evolved independently the specific organ known as gynostemium, more popular as column. The Euphorbia of deserts in Africa and southern Asia, and the Cactaceae of the New World deserts have similar modifications (see picture below for one of many possible examples). Sunflower: some types of sunflower and Pericallis are due to convergent evolution. Crassulacean acid metabolism (CAM), a carbon fixation pathway that evolved in multiple plants as an adaptation to arid conditions. C4 photosynthesis is estimated to have evolved over 60 times within plants, via multiple different sequences of evolutionary events.
Brown (1912–2004), American chemist known for work on organoboranes, 1979 Nobel Prize in Chemistry Jeannette Brown (born 1934), American organic medicinal chemist, historian, and author, known for research on drug development targeting tuberculosis and coccidiosis Jeanette Grasselli Brown (1928–2025), American analytical chemist and spectroscopist Rachel Fuller Brown (1898–1980), American chemist who co-developed the first useful antifungal antibiotic, nystatin
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。