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Epitalon Background And Identification — Reference Sheet

By Editorial Desk · published 2025-12-27 · last reviewed 2026-02-15 · News

epithalamin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-02-15. Anything still debated is marked as such rather than presented as settled.

Epitalon Background And Identification

Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.

Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.

Research Claims and Evidence Status

Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.

No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.

Epitalon at a glance

PropertyValueNotes
Chemical classSynthetic tetrapeptideFour amino acid residues
Residue sequenceAla-Glu-Asp-GlyAbbreviated AEDG
Approximate mass390.35 DaMonoisotopic, free base form
Parent preparationEpithalamin extractDerived from pineal tissue
Common spelling variantsEpithalon, epithalone, AEDGAffects literature retrieval

Chemical Identity and Research Background

In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.

Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.

The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.

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Stability Handling and Quality Control

Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.

Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.

Notes from published material

The PC version received "mixed or average reviews" according to the review aggregation website Metacritic. In a review for IGN, critic Tal Blevins noted that Blue Shift's gameplay "is pretty much what we've come to expect out of Half-Life" by blending action and puzzle solving, stating that the latter "were all logical and well done, although some of the jumping puzzles were frustrating". Though IGN praised the game for maintaining the "epic" feel of the original, Blevins was critical of the relatively short length of the game. GameSpot reviewer Greg Kasavin agreed with many of IGN's criticisms, stating that "it's not that the game is easy so much that it's extremely short" and that Blue Shift "doesn't amount to much on its own terms". In addition, Kasavin described the graphical enhancements brought about by the High Definition pack as "helpful", but noted that "they still don't make Half-Life look like a new game—nor are many of the changes themselves very noticeable". Other reviews echoed complaints about the similarity of Blue Shift to previous games. GameSpy reviewer Jamie Madigan stated that "what really pulls the game down is the 'more of the same' factor". Although writing that the game "feels like just a few more levels for the original game", he noted that this is what Blue Shift was designed to be, given its origins as an add-on for a Dreamcast version of Half-Life. Madigan described the single-player campaign as "decent" and commented that the new graphics made the game "worthy of consideration".

As f decreases progressively during condensation, the remaining vapor becomes more and more depleted of the heavy isotopes, and the depletion becomes larger as f approaches zero. Rayleigh distillation can explain some first-order spatial patterns observed in the isotopic composition of precipitation across the globe, including isotopic depletion from the tropics to the poles, isotopic depletion from coastal to inland regions, and isotopic depletion with elevation over a mountain range,[1] all of which are associated with progressive moisture loss during transport. The Rayleigh distillation model can also be used to explain the strong correlation between δD and δ18O in global precipitation, expressed as the global meteoric water line (GMWL): δD = 8δ18O+10 (later updated to δD = 8.17±0.07 δ18O+11.27±0.65) The slope of the GMWL reflects the relative magnitude of hydrogen and oxygen isotope fractionation during condensation. The intercept of GMWL is non-zero (called deuterium-excess, or d-excess), which means ocean water does fall on GMWL. This is associated with the KIE during evaporation when water vapor diffuses from the saturated boundary layer to the unsaturated transition zone, and cannot be explained by the Rayleigh model. Nevertheless, the robust pattern in GMWL strongly suggests a single dominant moisture source to the global atmosphere, which is the tropical West Pacific. It should also be pointed out that a local meteoric water line can have a different slope and intercept from the GMWL, due to differences in humidity and evaporation intensity at different places.

== External links == Eukaryotic Linear Motif resource motif class TRG_NLS_Bipartite_1 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoCore_2 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoExtC_3 Eukaryotic Linear Motif resource motif class TRG_NLS_MonoExtC_4

South Africa claimed 152 security-related incidents involving PLAN occurred in South West Africa that year, and acknowledged the combat deaths of 77 SADF and SWATF personnel. In July 1983 PLAN carried out its first major act of urban sabotage, detonating a bomb in the centre of Windhoek, which caused extensive property damage but no civilian injuries. Infiltration of Ovamboland and Kavangoland increased dramatically at around the same time, with 700 insurgents entering both regions. The SADF claimed to have killed or captured just under half the insurgents by May, but was unable to prevent the others from making their way further south. These developments indicated that PLAN had not lost its will to persevere despite the enormous materiel losses sustained during Protea, and the infiltration of men and supplies into South West Africa continued apace. Their confidence buoyed by the previous successful incursions into FAPLA-held territory, which had achieved marked success at only minimal cost in lives and materiel, Botha and his defence chiefs scheduled Operation Askari for December 1983. Like Protea, Askari was a major combined arms assault on PLAN base areas and supply lines in Angola; it also targeted nearby FAPLA air-defence installations and brigade headquarters. According to General Georg Meiring, commander of the SADF in South West Africa, Askari would serve the purpose of a preemptive strike aimed at eliminating the large numbers of PLAN insurgents and stockpiles of weapons being amassed for the annual rainy season infiltration.

Sources: en.wikipedia.org

Background from the literature

Polyphenols are natural products with "several hydroxyl groups on aromatic rings", including four principal classes: phenolic acids, flavonoids, stilbenes, and lignans. Flavonoids can be grouped as flavones, flavonols, flavanols, flavanones, isoflavones, proanthocyanidins, and anthocyanins. Particularly abundant flavanoids in foods are catechin (tea, fruits), hesperetin (citrus fruits), cyanidin (red fruits and berries), daidzein (soybean), proanthocyanidins (apple, grape, cocoa), and quercetin (onion, tea, apples). Polyphenols also include phenolic acids, such as caffeic acid, and lignans, which are derived from phenylalanine present in flax seed and other cereals.

Fibrinogen gamma chain, also known as the fibrinogen gamma gene (FGG), is a human gene found on chromosome 3. The protein encoded by this gene is the gamma component of fibrinogen, a blood-borne glycoprotein composed of three pairs of nonidentical polypeptide chains. Following vascular injury, fibrinogen is cleaved by thrombin to form fibrin which is the most abundant component of blood clots. In addition, various cleavage products of fibrinogen and fibrin regulate cell adhesion and spreading, display vasoconstrictor and chemotactic activities, and are mitogens for several cell types. Mutations in this gene lead to several disorders, including dysfibrinogenemia, hypofibrinogenemia and thrombophilia. Alternative splicing of the mRNA chain results in two transcript variants; the common γA chain and the alternatively spliced γ' chain. Approximately 10% of the total plasma fibrinogen consists of γA/γ' fibrinogen, with <1% consisting of γ'/γ' fibrinogen. Increased and decreased levels of γA/γ' fibrinogen have been associated with coronary artery disease and deep vein thrombosis respectively. In the lung parenchyma of smokers, upregulation of FGG transcript levels has been reported.

In 1984, the state passed legislation to allow the BPRC to lease space for such an eatery. The City Planning Commission also approved the structure the following year. However, the proposed café was met with opposition from the public, as it would obscure the library's rear facade. Several park advocates who opposed it argued that the proposed eatery would turn over part of a public park to a private entity. LeRoy withdrew from the project in 1986 due to this opposition, saying that he feared that the constant reviews of the plan would bring the proposed structure to "mediocrity". The renovation was approved by the City Art Commission in January 1987, though the restaurant plan had not yet been approved. Following LeRoy's withdrawal from the proposed Bryant Park café, the BPRC created a new plan with multiple smaller restaurant spaces. The spaces would be composed of two smaller pavilions, each 20 feet (6.1 m) tall with an area of 5,250 square feet (488 m2), flanking the Bryant memorial next to the library. In September 1987, the plans went to another vote before the City Art Commission, with the New York City Landmarks Preservation Commission taking an advisory role. The redesigned restaurant spaces were also approved by the City Art Commission that December, though the New York City Landmarks Preservation Commission registered no official position on the matter. A concessionaire for one of the spaces was found in 1988, and the same year, the city turned over duties of Bryant Park's land to BPRC. Subsequently, the park redesign was drafted by Hanna/Olin Ltd.

Hemoglobinopathy is the medical term for a group of inherited blood disorders involving the hemoglobin, the major protein of red blood cells. They are generally single-gene disorders and, in most cases, they are inherited as autosomal recessive traits. There are two main groups: abnormal structural hemoglobin variants caused by mutations in the hemoglobin genes, and the thalassemias, which are caused by an underproduction of otherwise normal hemoglobin molecules. The main structural hemoglobin variants are HbS, HbE and HbC. The main types of thalassemia are alpha-thalassemia and beta thalassemia.

Magistrate Judge Sarah Netburn by questioning her about the sexual harassment that resulted from her decision to allow an inmate who claimed to be transgender to transfer to a women's prison. Kennedy's derailment of Netburn's nomination was the first time the Democratic-led Senate Judiciary Committee rejected one of President Biden's nominees. Kennedy introduced a bill to extend the statute of limitations for victims of sexual harassment who worked for the FDIC after an independent investigation found that the agency had a culture where harassment was commonplace. As a member of the Senate Appropriations Committee, Kennedy has secured millions in federal funding for Louisiana, including several million-dollar FEMA grants to fund hurricane recovery efforts after Hurricane Laura in 2020. In the 2024 appropriations package, Kennedy also secured millions to improve the Boggs Lock and Dam on the J. Bennett Johnston Waterway. On September 17, 2024, in a hearing on rising racially motivated hate crimes in the United States, Kennedy claimed that pro-Palestinian figures promoted antisemitism. He asked Maya Berry, the incumbent executive director of the Arab American Institute, about her stance on Hamas, Hezbollah, and the Iranian regime. He also asked Berry whether she still supported the UNWRA amid claims that the organization "participated" in the October 7 massacres. Berry said: "I think it's exceptionally disappointing you're looking at an Arab American witness before you and saying you support Hamas.

Sources: en.wikipedia.org

Further detail

These initially involved groups of soldiers that were inserted by helicopter, and were later expanded with paratroopers. The Rhodesian Light Infantry often provided the soldiers for fireforce teams. A key element of the Selous Scouts' methods was 'turning' captured insurgents to join the Rhodesian security forces. This was normally attempted shortly after insurgents were captured, with them being both threatened and offered incentives. The captured insurgent was usually approached by a former insurgent. In the resulting conversation, the former insurgent emphasised the hardships insurgents were experiencing and that those who were captured faced the death penalty under the Law and Order (Maintenance) Act. This legislation imposed severe penalties for people found to be members of subversive organisations, including the death penalty or long prison terms. The captured insurgent was also offered a lump sum payment as well as a soldier's salary if they agreed to fight for the Rhodesian government. If an insurgent agreed to be 'turned' and passed further vetting, they were assigned to a Selous Scout team and operated in regions in which they would not be recognised. Where possible, their family was housed on a Selous Scouts base. Only a small number of 'turned' insurgents ever deserted or betrayed the unit. Some of the prisoners captured by the Selous Scouts who refused to be 'turned' were killed. One of the tactics used by the Selous Scouts was to violate local customs while posing as insurgents with the goal of reducing support for the actual insurgents.

=== Glass production === The largest commercial use of selenium, accounting for about 50% of consumption, is for the production of glass. Selenium compounds confer a red color to glass. This color cancels out the green or yellow tints that arise from iron impurities typical for most glass. For this purpose, various selenite and selenate salts are added. For other applications, a red color may be desired, produced by mixtures of CdSe and CdS.

==== United States ==== As of 2023, 38 states, four territories, and the District of Columbia allow medical use of cannabis (in which THC is the primary psychoactive component), with the exception of Georgia, Idaho, Indiana, Iowa, Kansas, Nebraska, North Carolina, South Carolina, Tennessee, Texas, Wisconsin, and Wyoming. As of 2022, the federal government maintains cannabis as a schedule I controlled substance, while dronabinol is classified as Schedule III in capsule form (Marinol) and Schedule II in liquid oral form (Syndros). On 18 December 2025, President Donald Trump issued an Executive Order titled "Increasing Medical Marijuana and Cannabidiol Research", directing the DEA and FDA to reclassify medical marijuana. To that end, on 23 April 2026, the Department of Justice issued an order to immediately reclassify medical cannabis as a Schedule III controlled substance when dispensed by state-licensed cannabis dispensaries to individuals with a state issued medical marijuana card. The DEA is in the process of conducting expedited public hearings to address the broader rescheduling of all cannabis from Schedule I to Schedule III, with the hearings scheduled to begin 29 June 2026. This rescheduling makes medical marijuana legal for medicinal use when obtained from licensed dispensaries, and once the broader rescheduling is complete, should allow it to be prescribed by licensed physicians who are also licensed by the DEA to prescribed controlled substances. However, as it is still a controlled substance, diversion for recreational use will still be illegal under federal law.

During this period, the average EBITDA/sales and EBIT/sales ratios of representative companies were 15% and 71⁄2%, respectively; during the boom, they were 20% and 10–13% respectively and, during the bust, they were 10% and 5% respectively. The differences within these ranges reflects the volatility of the industry's profitability. All in all, the average Western fine-chemical firms have been making a return below the cost of capital — they are not reinvestment grade.

=== Pharmacodynamics === Similarly to ketamine, norketamine acts as a noncompetitive NMDA receptor antagonist (Ki = 1.7 μM and 13 μM for (S)-(+)-norketamine and (R)-(–)-norketamine, respectively). Also, similarly again to ketamine, norketamine binds to the μ- and κ-opioid receptors. Relative to ketamine, norketamine is much more potent as an antagonist of the α7-nicotinic acetylcholine receptor, and produces rapid antidepressant effects in animal models which have been reported to correlate with its activity at this receptor. However, norketamine is about 1/5 as potent as ketamine as an antidepressant in mice as per the forced swim test, and this seems also to be in accordance with its 3–5-fold reduced comparative potency in vivo as an NMDA receptor antagonist. Norketamine's metabolites, dehydronorketamine (DHNK) and hydroxynorketamine (HNK), are far less or negligibly active as NMDA receptor antagonists in comparison, but retain activity as potent antagonists of the α7-nicotinic acetylcholine receptor. In 2024, norketamine was discovered to act as a highly potent positive allosteric modulator of the opioid receptors, including of the μ-opioid receptor (MOR). It shares this action with ketamine and hydroxynorketamine (HNK). They are all active in this action at very low concentrations, for instance 1 nM. Ketamine, norketamine, and HNK can potentiate the effects of endogenous opioids like met-enkephalin and exogenous opioids like morphine.

Sources: en.wikipedia.org

Frequently asked questions

What is epitalon derived from?

It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.

Is epitalon identical to epithalamin?

No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.

Why are human studies so limited?

Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.

Has epitalon been studied in people?

Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.

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