The short version of ACTH fragment fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-27. Anything still debated is marked as such rather than presented as settled.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Numerous other total syntheses utilize the Stille reaction, including those of oxazolomycin, lankacidin C, onamide A, calyculin A, lepicidin A, ripostatin A, and lucilactaene. The image below displays the final natural product, the organohalide (blue), the organostannane (red), and the bond being formed (green and circled). From these examples, it is clear that the Stille reaction can be used both at the early stages of the synthesis (oxazolomycin and calyculin A), at the end of a convergent route (onamide A, lankacidin C, ripostatin A), or in the middle (lepicidin A and lucilactaene). The synthesis of ripostatin A features two concurrent Stille couplings followed by a ring-closing metathesis. The synthesis of lucilactaene features a middle subunit, having a borane on one side and a stannane on the other, allowing for a Stille reaction followed by a subsequent Suzuki coupling.
Swift noted that any similarities to psychological situations in the Milgram experiment or 2001: A Space Odyssey are entirely coincidental. The portal gun's full name, Aperture Science Handheld Portal Device, can be abbreviated as ASHPD, which resembles a shortening of the name Adrian Shephard, the protagonist of Half-Life: Opposing Force. Fans noticed this similarity before Portal's release; as a result, the team placed a red herring by having the letters of Adrian Shephard highlighted on keyboards found within the game. According to Swift, the cake is a Black Forest cake that she thought looked the best at the nearby Regent Bakery and Cafe in Redmond, Washington, and, as an Easter egg, its recipe is scattered among various screens showing lines of binary code. The Regent Bakery has stated that since the release of Portal, its Black Forest cake has been one of its more popular items.
Ethylene oxide causes acute poisoning, accompanied by a variety of symptoms. Central nervous system effects are frequently associated with human exposure to ethylene oxide in occupational settings. Headache, nausea, and vomiting have been reported. Peripheral neuropathy, impaired hand-eye coordination and memory loss have been reported in more recent case studies of chronically-exposed workers at estimated average exposure levels as low as 3 ppm (with possible short-term peaks as high as 700 ppm). The metabolism of ethylene oxide is not completely known. Data from animal studies indicate two possible pathways for the metabolism of ethylene oxide: hydrolysis to ethylene glycol and glutathione conjugation to form mercapturic acid and meththio-metabolites. Ethylene oxide easily penetrates through ordinary clothing and footwear, causing skin irritation and dermatitis with the formation of blisters, fever, and leukocytosis. Toxicity data for ethylene oxide are as follows:
George Mikes, Hungarian-born comic writer Ralph Miliband (born Adolphe Miliband; 7 January 1924 – 21 May 1994) sociologist and Marxist author of Polish Jewish ancestry; father of Ed Miliband and David Miliband, described as "one of the best known academic Marxists of his generation", on a par with E. P. Thompson, Eric Hobsbawm and Perry Anderson. Beth Miller, novelist and nonfiction writer. Her first two novels were When We Were Sisters (Ebury, 2014) and The Good Neighbour (Ebury, 2015). The Two Hearts of Eliza Bloom (Bookouture, 2019), tells the story of Eliza, an Orthodox Jewish girl who runs away on the day of her arranged marriage; and The Missing Letters of Mrs Bright (Bookouture, 2020), Yvonne Mitchell (born Yvonne Frances Joseph; 7 July 1915) actress, playwright, biographer, novelist and author; acting roles include Julia in the 1954 BBC adaptation of George Orwell's novel Nineteen Eighty-Four; also an established author, writing several books for children and adults as well as winning awards for playwriting. Her plays include The Same Sky. She wrote an acclaimed biography of the French writer Colette, and her own autobiography was published in 1957.
Sources: en.wikipedia.org
=== Fungal attack === The primary risk factor for fungal attack is incomplete drying of specimens, caused either during the specimen preparation process or afterwards, or in collections that become wet later through flood, other water damage or improper storage conditions, especially in the tropics. Properly dried plant specimens will not suffer from fungal attack if stored in the correct conditions. During the drying process specimens are particularly at risk if they dry slowly. This happens through poor drying conditions or specimens being wet before being pressed or having water-retaining or succulent parts. Specimens with sugary exudations or large quantities of nectar are also particularly attractive to fungi and need special care during drying to ensure that they dry fast enough to prevent mold growth. If fungal growth occurs on specimens, it can be brushed with 95% ethanol or methylated spirits (denatured alcohol). However, this may alter the specimen for chemical and other investigative research and only kills the fungus present on the specimen, not preventing further problems of fungal growth.
The formation of GPR43-GPR41 heterodimers has not been evaluated in most studies and may explain otherwise conflicting results on the roles of FFAR3 and FFAR2 in cell function. Furthermore, SC-FAs can alter the function of cells independently of FFAR3 and FFAR2 by altering the activity of cellular histone deacetylases which regulate the transcription of various genes or by altering metabolic pathways which alter cell functions. Given these alternate ways for SC-FAs to activate cells as well as the ability of SC-FAs to activate FFAR2 or, in the case of butyric acid, hydroxycarboxylic acid receptor 2, the studies reported here focus on those showing that the examined action(s) of an SC-FA is absent or reduced in cells, tissues, or animals that have no or reduced FFAR3 activity due respectively to knockout (i.e., removal or inactivation) or knockdown (i.e., reduction) of the FFAR3 protein gene, i.e., the Ffar3 gene in animals or FFAR3 gene in humans.
=== Systems biology === Advances in quantitative proteomics would clearly enable more in-depth analysis of cellular systems. Another research frontier is the analysis of single cells, and protein covariation across single cells which reflects biological processes such as protein complex formation, immune functions, as well as cell cycle and priming of cancer cells for drug resistance Biological systems are subject to a variety of perturbations (cell cycle, cellular differentiation, carcinogenesis, environment (biophysical), etc.). Transcriptional and translational responses to these perturbations results in functional changes to the proteome implicated in response to the stimulus. Therefore, describing and quantifying proteome-wide changes in protein abundance is crucial towards understanding biological phenomenon more holistically, on the level of the entire system. In this way, proteomics can be seen as complementary to genomics, transcriptomics, epigenomics, metabolomics, and other -omics approaches in integrative analyses attempting to define biological phenotypes more comprehensively. As an example, The Cancer Proteome Atlas provides quantitative protein expression data for ~200 proteins in over 4,000 tumor samples with matched transcriptomic and genomic data from The Cancer Genome Atlas. Similar datasets in other cell types, tissue types, and species, particularly using deep shotgun mass spectrometry, will be an immensely important resource for research in fields like cancer biology, developmental and stem cell biology, medicine, and evolutionary biology.
the person responsible under § 115 StrlSchG (in German) paragraph 2 or § 153 StrlSchG (in German) paragraph 1. The SSR numbers must then be available for further use as part of normal communication with monitoring stations or radiation pass authorities. The SSR number is derived from the social security number and personal data using non-traceable encryption. The transmission takes place online. Approximately 420,00 persons are monitored for radiation protection in Germany (as of 2019). Emergency responders (including volunteers) who are not occupationally exposed persons within the meaning of the Radiation Protection Act also require an SSR number retrospectively, i.e. after an operation in which they were exposed to radiation above the limits specified in the Radiation Protection Ordinance, as all relevant exposures must be recorded in the Radiation Protection Register.
Cracking breaks larger molecules into smaller ones. This reaction requires heat and catalysts. The thermal cracking process follows a homolytic mechanism with formation of free radicals. The catalytic cracking process involves the presence of acid catalysts (usually solid acids such as silica-alumina and zeolites), which promote a heterolytic (asymmetric) breakage of bonds yielding pairs of ions of opposite charges, usually a carbocation. Carbon-localized free radicals and cations are both highly unstable and undergo processes of chain rearrangement, C–C scission in position beta (i.e., cracking) and intra- and intermolecular hydrogen transfer or hydride transfer. In both types of processes, the corresponding reactive intermediates (radicals, ions) are permanently regenerated, and thus they proceed by a self-propagating chain mechanism. The chain of reactions is eventually terminated by radical or ion recombination.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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.