The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-24 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
== Occurrence == It arises via the action of urocanase on urocanic acid. Hydrolysis of the heterocycle to the glutamic acid derivative is catalyzed by imidazolonepropionate hydrolase. Microbial production of imidazol-4-one-5-propionic acid in the human gut has been shown to affect insulin signaling, which is relevant to type II diabetes. Imidazole propionate has been causally implicated in atherosclerosis and Parkinson’s disease, primarily by triggering inflammation. Streptococcus mutans, known for its role in dental caries, has been identified as a contributor to elevated ImP levels through the urdA gene, which is involved in the conversion of urocanate to ImP.
== South America == In June 2026, three Brazilian sisters with a combined age of 313, were recognized by Guinness as the oldest living trio of siblings in the world. The sisters, 103, 104 and 106 years old live, in Rio de Janeiro. They were discovered through a global organization that verifies longevity records, called LongeviQuest. Researchers are interested in not only the environmental, but also the genetic components that contribute to longevity. Ben Meyers, the CEO of LongeviQuest stated "When sisters reach that age, there is clearly a strong genetic component. But because they live near each other, they also have a support network, with family able to help when needed. There is definitely a community aspect as well."
Necrosis (from Ancient Greek νέκρωσις (nékrōsis) 'death') is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is often regarded as one of the founders of modern pathology. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates an inflammatory response in the surrounding tissue, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would create collateral damage to surrounding tissues. This excess collateral damage inhibits the healing process. Thus, untreated necrosis results in a build-up of decomposing dead tissue and cell debris at or near the site of the cell death. A classic example is gangrene. For this reason, it is often necessary to remove necrotic tissue surgically, a procedure known as debridement.
Apart from negative affectivity and disinhibition, research has found "substantial but mixed" associations with the other trait domains, indicating the heterogeneity of the diagnosis, which aligns with the view of BPD as an "index of global personality pathology and severity, which aligns with the original metaphorical use of the term 'borderline' or 'borderland'". It is suggested that it "therefore seems reasonable if the borderline pattern serves as a transitional specifier that eventually is phased out in the coming era".
Sources: en.wikipedia.org
Rubredoxin is an electron-carrier found in sulfur-metabolizing bacteria and archaea. The active site contains an iron ion coordinated by the sulfur atoms of four cysteine residues forming an almost regular tetrahedron. Rubredoxins perform one-electron transfer processes. The oxidation state of the iron atom changes between the +2 and +3 states. In both oxidation states the metal is high spin, which helps to minimize structural changes.
=== Kaku and the knowledge economy === In Physics of the Future (2011), American physicist Michio Kaku examines the conditions for humanity to converge on a Type I planetary civilization. This convergence is based primarily on the knowledge economy. Kaku uses the Kardashev scale, but develops it by adding an additional stage: a Type IV civilization would be able to draw the energy it needs from extragalactic radiation. By studying the evolution of technologies that have changed history (paper, the integrated circuit), Kaku believes that humanity is moving toward a civilization of planetary dimensions, the "starting point" of which is the Internet. A Type I civilization consumes power on the order of thousands to millions of times our current planetary output, about 100 trillion trillion watts. It would have enough energy to manipulate the occurrence of certain natural phenomena, such as earthquakes or volcanoes, and could build cities on the oceans. We can see the beginnings of a Type I civilization in the fact that a global language is developing (English), a global communication system is emerging (the Internet), a global economic system is in the making (the establishment of the European Union), and even a globalized culture is standardizing humanity (mass media, television, rock music, and Hollywood movies).
== Sources == Baikiain has been found in diverse natural sources including dates, African teak (Baikiaea plurijuga) wood, and the red algae Serraticardia maxima. Several laboratory syntheses of baikiain and its racemic form have been reported.
The brand name featured on the label is usually the same as the distillery name (for example, the Talisker distillery labels its whiskies with the Talisker name). Indeed, the SWR prohibits bottlers from using a distillery name when the whisky was not made there. A bottler's name may also be listed, sometimes independent of the distillery. In addition to requiring that Scotch whisky be distilled in Scotland, the SWR requires that it also be bottled and labelled in Scotland. Labels may also indicate the region of the distillery (for example, Islay or Speyside). Alcoholic strength is expressed on the label by Alcohol By Volume (ABV) or sometimes simply "Vol". Typically, bottled whisky is between 40% and 46% ABV. Whisky is considerably stronger when first emerging from the cask—normally 60–63% ABV. Water is then added to create the desired bottling strength. If the whisky is not diluted before bottling, it can be labelled as cask strength. A whisky's age may be listed on the bottle providing a guarantee of the youngest whisky used. An age statement on the bottle, in the form of a number, must reflect the age of the youngest whisky used to produce that product. A whisky with an age statement is known as guaranteed age whisky. Scotch whisky without an age statement may, by law, be as young as three years old. In the early 21st century, such "No age statement" whiskies have become more common, as distilleries respond to the depletion of aged stocks caused by improved sales. A label may carry a distillation date or a bottling date.
== Chemistry == Protriptyline is a tricyclic compound, specifically a dibenzocycloheptadiene, and possesses three rings fused together with a side chain attached in its chemical structure. Other dibenzocycloheptadiene TCAs include amitriptyline, nortriptyline, and butriptyline. Protriptyline is a secondary amine TCA, with its N-methylated analog N–methylprotriptyline being a tertiary amine, and a structural isomer of amitriptyline. The tertiary amine analog of protriptyline, N–methylprotriptyline, has not been marketed. Other secondary amine TCAs include desipramine and nortriptyline. The chemical name of protriptyline is 3-(5H-dibenzo[a,d][7]annulen-5-yl)-N-methylpropan-1-amine and its free base form has a chemical formula of C19H21N1 with a molecular weight of 263.377 g/mol. The drug is used commercially mostly as the hydrochloride salt; the free base form is not used. The CAS Registry Number of the free base is 438-60-8 and of the hydrochloride is 1225-55-4.
Sources: en.wikipedia.org
Aluminon, the triammonium salt of aurintricarboxylic acid, is a dye often used to detect the presence of the aluminium ion in an aqueous solution. Aluminon forms a red complex salt in combination with Al3+. In addition to its use in qualitative inorganic analysis, aluminon has applications in pigment production. It forms brilliantly colored lake pigments with many metals. The pigments are red in combination with Be2+ and Ga3+. The pigment is deep purple or reddish-brown in combination with Fe3+. Color of a particular pigment in acidic solutions may change: aluminon and Sc3+ form red pigments if the solution is acidic, but otherwise the solutions are colorless. Aluminon is prepared by reacting sodium nitrite with salicylic acid, adding formaldehyde, then treating with ammonia. Analytical chemistry Colorimetry
. The americium-241 and curium-242 isotopes also were produced by irradiating plutonium in a nuclear reactor. The latter element was named after Marie Curie and her husband Pierre who are noted for discovering radium and for their work in radioactivity. Bombarding curium-242 with α-particles resulted in an isotope of californium 245Cf in 1950, and a similar procedure yielded berkelium-243 from americium-241 in 1949. The new elements were named after Berkeley, California, by analogy with its lanthanide homologue terbium, which was named after the village of Ytterby in Sweden. In 1945, B. B. Cunningham obtained the first bulk chemical compound of a transplutonium element, namely americium hydroxide. Over the few years, milligram quantities of americium and microgram amounts of curium were accumulated that allowed production of isotopes of berkelium and californium. Sizeable amounts of these elements were produced in 1958, and the first californium compound (0.3 μg of CfOCl) was obtained in 1960 by B. B. Cunningham and J. C. Wallmann. Einsteinium and fermium were identified in 1952–1953 in the fallout from the "Ivy Mike" nuclear test (1 November 1952), the first successful test of a hydrogen bomb. Instantaneous exposure of uranium-238 to a large neutron flux resulting from the explosion produced heavy isotopes of uranium, which underwent a series of beta decays to nuclides such as einsteinium-253 and fermium-255.
== Adverse effects == Since acarbose prevents the degradation of complex carbohydrates into glucose, some carbohydrate will remain in the intestine and be delivered to the colon. In the colon, bacteria digest (ferment) the complex carbohydrates, causing gastrointestinal side-effects such as flatulence (78% of patients) and diarrhea (14% of patients). Since these effects are dose-related, in general it is advised to start with a low dose and gradually increase the dose to the desired amount. One study found that gastrointestinal side effects decreased significantly (from 50% to 15%) over 24 weeks, even on constant dosing. Sucrose is more likely to trigger GI side effects compared to starch. Acarbose is associated with very rare elevated transaminases (19 out of 500,000). Even rarer cases of hepatitis has been reported with acarbose use. It usually goes away when the medicine is stopped. Liver enzymes should be checked before and during use of this medicine as a precaution. A 2016 meta-analysis confirms that alpha-glucosidase inhibitors, including acarbose, have a statistically significant link to elevated transaminase levels.
In October 2008, Pierre-Emmanuel Thomann wrote in Défense nationale et sécurité: "This conflict is, above all, the multipolar world's first war. [...] The conflict between Russia and Georgia is larger than a local territorial affair and will have repercussions on a regional and worldwide scale. [...] Its presence in South Ossetia, close to the territorial heart of Georgia, enables Russia to reach the capital Tbilisi very rapidly, to cut the country's main east-west communications corridor, and to neutralise the Baku-Tbilisi-Ceyhan oil pipeline, which supplies the world markets and passes south of the Georgian capital. [...] Russia's priority to break its encirclement by the Atlantic Alliance has been achieved." On 11 November 2008, Melik Kaylan wrote in Forbes: "There is an additional misconception that [...] the Bush administration encouraged Saakashvili to confront the Russians or at least bolstered his sense of allied support. This is manifestly untrue. Tbilisi insiders told me that Georgia had been asking the Bushies for anti-aircraft missiles for some years.
Monocyte Monocytes are large cells with a curved or folded nucleus and finely granulated, grey-blue cytoplasm that often contains vacuoles. Monocytes are the third most common white blood cell after neutrophils and lymphocytes. Increased monocyte counts (monocytosis) are seen in chronic infection and inflammation. Extremely high monocyte counts, as well as immature forms of monocytes, occur in chronic myelomonocytic leukaemia and acute leukemias of monocytic origin. Monocyte counts may be decreased (monocytopenia) in individuals who are receiving chemotherapy as well as those with aplastic anemia, severe burns, and AIDS.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.