The short version of ACTH analog fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-10 and is reviewed periodically as new material appears.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assay | RP-HPLC, UV 214 nm | Typical research grade 95 percent or higher |
| Mass confirmation | ESI-MS or MALDI-TOF | Compared with theoretical value |
| Main degradation route | Methionine oxidation | Sulfoxide formation in solution |
| Powder storage | -20 °C, desiccated | Amber vial, minimal headspace |
| Working solution | Sterile water or saline | Prepare fresh; avoid repeated thawing |
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
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.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
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.
The internal roof of the nose is composed by the horizontal, perforated cribriform plate (of the ethmoid bone) through which pass sensory filaments of the olfactory nerve (cranial nerve I); finally, below and behind (posteroinferior) the cribriform plate, sloping down at an angle, is the bony face of the sphenoid sinus.
=== Afrikaans === Afrikaans, as it is a daughter language of the Dutch language, is capable of forming compounds of potentially limitless length in the same way as in the Dutch language. According to the Total Book of South African Records, the longest word in the language is Tweedehandsemotorverkoopsmannevakbondstakingsvergaderingsameroeperstoespraakskrywerspersverklaringuitreikingsmediakonferensieaankondiging (136 letters), which means "issuable media conference's announcement at a press release regarding the convener's speech at a secondhand car dealership union's strike meeting". This word, however, is contrived to be long and does not occur in everyday speech or writing.
=== As an unsafe dietary ingredient === In the United States, DMHA is not eligible for use as a dietary ingredient, is not approved for use in manufactured foods or dietary supplements, and is not considered to be safe for human consumption (is not GRAS); in regarding DMHA as an unsafe food additive, the FDA has warned manufacturers that dietary supplements containing DMHA are adulterated and illegal for marketing.
==== Escherichia coli cells ==== Photo-methionine can be used to label recombinant proteins in Escherichia coli cells; though methionine in general is a rare amino acid so that means it could only give limited structural data. Nevertheless, photo-methionine was incorporated into Ca2+ regulating protein calmodulin (CaM that was 17-kDa) that has nine methionine's and studied via mass spectrometry (MS). What makes this method different is the use of mineral salts medium instead of DMEM (Dulbecco's Modified Eagle's Limiting Medium) or dialyzed fetal bovine serum for the incorporation into the cells. Using the mineral salt medium allowed the cells to be grown from the beginning in order to eliminate complicated steps with other protocols (incubating the cells in LB medium, followed by washing, and further incubating in the depleted medium), meaning that photo-methionine could be incorporated at the very beginning of the cell growth that had a high yield above 30%. Photo-methionine had shown no damage during the cell growth process and once photo-activated by UV-A light, CaM had nine distinct cross-link sites once MS had determined there was peaks of photo-methionine labeled CaM. Not only can photo-methionine be used for mapping 3D protein structure, studying protein-protein interactions, but now hydrophobic regions in the protein.
== Plot == After the alien invasion at the Black Mesa Research Facility, a multidimensional alien empire known as the Combine has conquered Earth. Approximately twenty years after being placed in stasis, Gordon Freeman is inserted into a train bound for City 17 by the G-Man (Michael Shapiro). Helped by the undercover Resistance member Barney Calhoun (Shapiro), Gordon attempts to reach the laboratory of Dr. Isaac Kleiner (Harry S. Robins) but is subdued by Combine officers. He is rescued by Alyx Vance (Merle Dandridge), who guides him to the laboratory. Kleiner's attempt to teleport Gordon to the Resistance base fails, and Gordon is momentarily teleported to the Citadel, the skyscraper headquarters of Dr. Wallace Breen (Robert Culp), the former Black Mesa administrator and the Combine's puppet ruler. Gordon uses an airboat to progress to the base via the city's canal system, eluding Combine forces. At the base, Gordon reunites with Alyx's father, Dr. Eli Vance (Robert Guillaume), and meets Dr. Judith Mossman (Michelle Forbes). Alyx introduces Gordon to her pet robot, Dog, and gives Gordon the gravity gun. Combine forces storm the base and capture Eli and Mossman. Gordon diverts through the zombie-infested town of Ravenholm, aided by its lone inhabitant, Father Grigori (Jim French), to a Resistance outpost whose occupants provide him with a dune buggy. He drives along the coastline of depleted water levels to reach the Combine prison of Nova Prospekt, where Eli and Mossman are being held. Gordon and Alyx reunite, locate Eli, and discover that Mossman is a Combine spy.
Sources: en.wikipedia.org
The advanced reprocessing of spent nuclear fuel is a potential key to achieve a sustainable nuclear fuel cycle and to tackle the heavy burden of nuclear waste management. In particular, the development of such advanced reprocessing systems may save natural resources, reduce waste inventory and enhance the public acceptance of nuclear energy. This strategy relies on the recycling of major actinides (Uranium and Plutonium, and also Thorium in the breeder fuel cycle) and the transmutation of minor actinides (Neptunium, Americium and Curium) in appropriate reactors. In order to fulfill this objective, selective extracting agents need to be designed and developed by investigating their complexation mechanism.
=== Reassigned Codon Behavior === When codon reassignment occurs, it is usually due to a change in tRNAs. A tRNA can be assigned to a new codon or the tRNA can be altered to pick up a different amino acid. For the protein, this means either swapping one amino acid for another, or in the case of a stop codon, adding an amino acid where there was none before. Since the primary structure determines the functionality of a protein, changing even one amino acid in this way can drastically impact what the final protein is able to do.
Most of the insurgents apparently concealed their arms and vanished into the local population. This proved less successful in Zambia, where the civilians in Sesheke District were irritated by the constant presence of South African patrols and reconnaissance aircraft; they demanded their government remove the remaining PLAN fighters. President Kaunda subsequently bowed to pressure and ordered PLAN to close its rear base facilities in Zambia, resulting in the collapse of its Caprivi insurgency. On 16 March, Angola lodged a formal complaint with the UN Security Council concerning the violation of its borders and airspace as a result of Operation Rekstok. United Nations Security Council Resolution 447 was passed in response. The resolution "condemned strongly the racist regime of South Africa for its premeditated, persistent, and sustained armed invasions of the People's Republic of Angola, which constitute a flagrant violation of the sovereignty and territorial integrity of the country as well as a serious threat to international peace and security". A UN commission of inquiry logged 415 border violations by the SADF in 1979, an increase of 419% since the previous year. It also made note of 89 other incidents, which were mostly airspace violations or artillery bombardments that struck targets on Angolan soil.
The degree of its adherence to feng shui is believed to determine a business's success. Bagua mirrors are regularly used to deflect evil spirits, and buildings often lack floor numbers with a 4; the number has a similar sound to the word for "die" in Cantonese.
== Side effects == Common adverse reactions include nausea, headache, fatigue, vomiting, diarrhea, Anorexia (symptom) (loss of appetite), and insomnia (trouble sleeping). Rare but serious side effects include hypersensitivity reaction such as rash, elevated AST and ALT, depression, anxiety, fever/chills, URI, lactic acidosis, hypertriglyceridemia, and lipodystrophy.
Sources: en.wikipedia.org
Valve has released two versions of a game controller aimed to be used for Steam games, the Steam Controller. The first model was released in November 2015, alongside the original Steam Machine concept, while the second was released in May 2026 ahead of Valve's dedciated Steam Machine model and Steam Frame. Among other features, both generations of the controller use two small trackpads with haptic feedback which can be used either as traditional controller actions like a joystick, but also like a computer mouse input to control many personal computer games that lack traditional controller support.
Dylan Marlais Thomas (27 October 1914 – 9 November 1953) was a Welsh poet and writer, whose works include the poems "Do not go gentle into that good night" and "And death shall have no dominion", as well as the "play for voices" Under Milk Wood. He also wrote stories and radio broadcasts such as A Child's Christmas in Wales and Portrait of the Artist as a Young Dog. He became widely popular in his lifetime, and remained so after his death at the age of 39 in New York City. By then, he had acquired a reputation, which he had encouraged, as a "roistering, drunken and doomed poet". Dylan Thomas was born in Swansea in 1914, leaving school in 1932 to become a reporter for the South Wales Daily Post. A number of the some 200 poems he produced between 1931 and 1935 appeared in print while he was still a teenager, including one of his best known, And Death Shall Have No Dominion, the first he had published, in May 1933, in a national journal. While living in London, Thomas met Caitlin Macnamara; they married in 1937 and had three children: Llewelyn, Aeronwy, and Colm. He came to be appreciated as a popular poet during his lifetime, though he found earning a living as a writer difficult. He began augmenting his income with reading tours and radio broadcasts. His radio recordings for the BBC during the late 1940s brought him to a wider public's attention, and he was frequently featured by the BBC as an accessible voice of the literary scene.
Former CIA director John O. Brennan called it "outrageous that we are threatening Denmark" and that there is a "sense of shame" among Americans over Trump's international behaviour. US Republican senator Thom Tillis and Democratic senator Jeanne Shaheen, co-chairs of the Senate NATO Observer Group, said that "the United States must honor its treaty obligations and respect Greenland and Denmark's sovereignty and territorial integrity". Republican senator Roger Wicker, the Senate Armed Services chair, said Trump's threats to seize Greenland was "a topic that should be dropped" and cautioned Trump against spending time "antagonizing allies". After meeting Danish officials, Wicker said it was clear that there was no room for negotiation and that Trump's attempt to obtain Greenland was not realistic.
==== Snake ==== Snakes are one of the few vertebrates in which the skin alone is sufficient for locomotion. During Rectilinear locomotion, the skeleton remains fixed, while the skin is alternately lifted and pulled forward, and then allowed to contact the ground and pulled backwards, propelling the body forward. One of the interesting aspects of snakeskin are folds of intersquamous skin between longitudinally oriented scale rows. The function of these folds is to permit the circumference of the snake to increase, allowing prey to pass into the stomach during feeling. Snakes differ from eels in the direction in which the skin is stiffer, the dorsal scale rows are more flexible in snake than in eels because the dorsal scale row associated with stretching. Differences in the local dermal structures, such as variations in the diameters and orientation of collagen fibers within the intersquamous skin create local differences in the mechanical properties of the snake skin, thus allowing it to adapt to the stresses and strains during the feeding process.
=== Properties === In terms of molecular structure, synephrine has a phenethylamine skeleton, with a phenolic hydroxy- group, an alcoholic hydroxy- group, and an N-methylated amino-group. Alternatively, synephrine might be described as a phenylethanolamine with an N-methyl and p-hydroxy substituent. The amino-group confers basic properties on the molecule, whereas the phenolic –OH group is weakly acidic: the apparent (see original article for discussion) pKas for protonated synephrine are 9.55 (phenolic H) and 9.79 (ammonium H). Common salts of racemic synephrine are its hydrochloride, C9H13NO2.HCl, m.p. 150–152°, the oxalate (C9H13NO2)2.C2H2O4, m.p. 221–222 °C, and the tartrate (Sympatol), (C9H13NO2)2.C4H6O6, m.p. 188–190 °C. The presence of the hydroxy-group on the benzylic C of the synephrine molecule creates a chiral center, so the compound exists in the form of two enantiomers, d- and l- synephrine, or as the racemic mixture, d,l- synephrine. The dextrorotatory d-isomer corresponds to the (S)-configuration, and the levorotatory l-isomer to the (R)-configuration. Racemic synephrine has been resolved using ammonium 3-bromo-camphor-8-sulfonate. The enantiomers were not characterized as their free bases, but converted to the hydrochloride salts, with the following properties: (S)-(+)-C9H13NO2.HCl: m.p. 178 °C; [α] = +42.0°, c 0.1 (H2O); (R)-(−)-C9H13NO2.HCl: m.p. 176 °C; [α] = −39.0°, c 0.2 (H2O) (−)-Synephrine, as the free base isolated from a Citrus source, has m.p. 162–164 °C (with decomposition). The X-ray structure for synephrine has been determined.
Sources: en.wikipedia.org
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.
The main chemical risks are methionine oxidation and backbone hydrolysis in solution. Moisture and repeated temperature cycling accelerate both processes. Dry powder held cold and desiccated is considerably more stable than any reconstituted preparation.
It holds a medicine registration in Russia, where it has been used clinically for decades. In most other countries it is treated as a research chemical. That split explains the uneven distribution of clinical literature.
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.