If you have been reading about Epitalon and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-22. Numbers and descriptions here follow the published literature rather than marketing material.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
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.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
However, against this tradition, and international standards, the High Court in ZG Operations Australia Pty Ltd v Jamsek overturned the Federal Court to find that drivers who were made to buy their own vehicles were not employees, despite them bearing the employer's trade marks, working only for the company, and doing so for decades. The drivers were originally contracted as employees, but then their contracts were unilaterally altered in 1985–86 to deem them self-employed. Yet in the court's opinion, "the exercise of superior bargaining power... has no bearing on the meaning and effect of the bargains that were struck" and claims against resulting injustice "cannot be made by stealth under the obscurantist guise of a search for the "reality" of the situation". This opinion, meeting with widespread derision, was reversed by the Fair Work Act 2009 section 15AA(1) which states that an employee "is to be determined by ascertaining the real substance, practical reality and true nature of the relationship between the individual and the person" and (2) "regard must be had not only to the terms of the contract governing the relationship, but also to other factors relating to the totality of the relationship including, but not limited to, how the contract is performed in practice." By comparison, wealthier jurisdictions determine employee status and rights based on reality, bargaining power, and the purpose of the law, and disregard inconsistent contract terms.
Which they called a rapid and simple method for testing blood compatibility, sodium citrate was used to dilute the blood samples, and after mixing the recipient's and donor's blood in 9:1 and 1:1 parts, blood would either clump or remain watery after 15 minutes. According to their advice, blood without clumping "should always be chosen if possible." Canadian doctor and Lieutenant Lawrence Bruce Robertson became instrumental in persuading the Royal Army Medical Corps to adopt the use of blood transfusion at the Casualty Clearing Stations for the wounded. In October 1915, Robertson performed his first wartime transfusion with a syringe to a patient who had multiple shrapnel wounds. He followed this up with four subsequent transfusions in the following months, and his success was reported to Sir Walter Morley Fletcher, director of the Medical Research Committee.
Acetoacetyl CoA is the precursor of HMG-CoA in the mevalonate pathway, which is essential for cholesterol biosynthesis. It also takes a similar role in the ketone bodies synthesis (ketogenesis) pathway of the liver. In the ketone bodies digestion pathway (in the tissue), it is no longer associated with having HMG-CoA as a product or as a reactant. It is created from acetyl-CoA, a thioester, which reacts with the enolate of a second molecule of acetyl-CoA in a Claisen condensation reaction, and it is acted upon by HMG-CoA synthase to form HMG-CoA. During the metabolism of leucine, this last reaction is reversed. Some individuals may experience Acetoacetyl-CoA deficiency. This deficiency is classified as a disorder ketone body and isoleucine metabolism that can be inherited. Additional mutations include those with the enzymes within pathways related to Acetoacetyl CoA, including Beta-Ketothiolase deficiency and Mitochondrial 3-hydroxy-3-methylglutaryl-CoA Synthase mutation.
==== 1800–1899 ==== Double Taxation Relief (Taxes on Income) (Ghana) Order 1993 (S.I. 1993/1800) Double Taxation Relief (Taxes on Income) (India) Order 1993 (S.I. 1993/1801) Double Taxation Relief (Taxes on Income) (Uganda) Order 1993 (S.I. 1993/1802) Double Taxation Relief (Taxes on Income) (Ukraine) Order 1993 (S.I. 1993/1803) Army, Air Force and Naval Discipline Acts (Continuation) Order 1993 (S.I. 1993/1804) Films Co-Production Agreements (Amendment) Order 1993 (S.I. 1993/1805) Confiscation of the Proceeds of Drug Trafficking (Designated Countries and Territories) (Scotland) Amendment Order 1993 (S.I. 1993/1806) Criminal Justice (International Co-operation) Act 1990 (Enforcement of Overseas Forfeiture Orders) (Scotland) Amendment Order 1993 (S.I. 1993/1807) Development Board for Rural Wales (Transfer of Housing Stock) Regulations 1993 (S.I. 1993/1808) Civil Courts (Amendment) Order 1993 (S.I. 1993/1809) Local Government Superannuation (National Rivers Authority) Regulations 1993 (S.I. 1993/1810) Cardiothoracic Centre–Liverpool National Health Service Trust (Establishment) Amendment Order 1993 (S.I. 1993/1811) Civil Defence (General Local Authority Functions) Regulations 1993 (S.I. 1993/1812) Channel Tunnel (International Arrangements) Order 1993 (S.I. 1993/1813) Local Government Superannuation (Part-time Employees) Regulations 1993 (S.I. 1993/1814) Disclosure of Interests in Shares (Amendment) Regulations 1993 (S.I. 1993/1819) Partnerships and Unlimited Companies (Accounts) Regulations 1993 (S.I. 1993/1820) Income Tax (Interest Relief) (Qualifying Lenders) (No.
=== Pregnancy and breastfeeding === Currently, melarsoprol is not recommended for use in pregnant women. The World Health Organization suggests that treatment be deferred until immediately after delivery since the effects of the medication on the developing fetus have not yet been established. Lactation guidelines associated with melarsoprol have not yet been established.
Sources: en.wikipedia.org
== Clinical relevance == Interference with aminoacylation may be useful as an approach to treating some diseases: cancerous cells may be relatively vulnerable to disturbed aminoacylation compared to healthy cells. The protein synthesis associated with cancer and viral biology is often very dependent on specific tRNA molecules. For instance, for liver cancer charging tRNA-Lys-CUU with lysine sustains liver cancer cell growth and metastasis, whereas healthy cells have a much lower dependence on this tRNA to support cellular physiology. Similarly, hepatitis E virus requires a tRNA landscape that substantially differs from that associated with uninfected cells. Hence, inhibition of aminoacylation of specific tRNA species is considered a promising novel avenue for the rational treatment of a plethora of diseases.
An old qualitative test for the presence of the alkene functional group is that alkenes turn brown aqueous bromine solutions colourless, forming a bromohydrin with some of the dibromoalkane also produced. The reaction passes through a short-lived strongly electrophilic bromonium intermediate. This is an example of a halogen addition reaction.
== Medical uses == Gepirone is indicated for the treatment of major depressive disorder (MDD) in adults. Of 15 clinical trials of gepirone for major depressive disorder submitted to the U.S. Food and Drug Administration (FDA), three were excluded for methodological reasons, three were deemed "failed" and "uninformative", seven were deemed negative and did not demonstrate effectiveness, and two were deemed positive and did show effectiveness. Two positive trials are needed for FDA drug approval, with this being the case regardless of the number of negative trials. In the two positive trials of gepirone for depression, the drug significantly outperformed placebo in terms of depressive symptom reduction and showed effect sizes similar to those of other approved antidepressants. In both trials, gepirone reduced depressive symptoms by about 2.5 points more than placebo on the 52-point Hamilton Depression Rating Scale (17-item version or HAMD-17). The baseline depression scores in the trials ranged from 22.7 to 24.2 in the different patient groups.
==== Nitrogen ==== The nitrogen stable isotope system is based on the relative enrichment/depletion of 15N in comparison to 14N in δ15N. Carbon and nitrogen stable isotope analyses are complementary in paleodiet studies. Nitrogen isotopes in bone collagen are ultimately derived from dietary protein, while carbon can be contributed by protein, carbohydrate, or fat. δ13C values help distinguish between dietary protein and plant sources while systematic increases in δ15N values as you move up in trophic level helps determine the position of protein sources in the food web. 15N increases 3-4% with each trophic step upward. It has been suggested that the relative difference between human δ15N values and animal protein values scales with the proportion of that animal protein in the diet, though this interpretation has been questioned due to contradictory views on the impact of nitrogen intake through protein consumption and nitrogen loss through waste release on 15N enrichment in the body. Variations in nitrogen values within the same trophic level are also considered. Nitrogen variations in plants, for example, can be caused by plant-specific reliance on nitrogen gas which causes the plant to mirror atmospheric values. Enriched or higher δ15N values can be achieved in plants that grew in soil fertilized by animal waste. Nitrogen isotopes have been used to estimate the relative contributions of legumes verses nonlegumes, as well as terrestrial versus marine resources.
April 1 Trump says US military action in Iran could end in "two to three weeks", and that the US will "leave whether we have a deal or not" once he's certain Iran cannot build a nuclear weapon "for years". NASA launches the Artemis II lunar flyby mission from the Kennedy Space Center in Florida, the first crewed flight beyond low Earth orbit since Apollo 17 in 1972. With a crew of four astronauts – Reid Wiseman (commander) Victor Glover (pilot), Christina Koch (mission specialist), and Canadian astronaut Jeremy Hansen (mission specialist) – it also becomes the first time a person of color, a woman, and a non-United States citizen have left low Earth orbit. The Supreme Court hears oral arguments over the constitutionality of Trump's Executive Order 14160 ending birthright citizenship. Trump is in attendance, a first for a sitting president. The DOJ publishes an opinion that the Presidential Records Act is an unconstitutional overreach of congressional power, and advises Trump that he can refuse to hand over records to the National Archives and Records Administration at the end of his term. April 2 Trump fires Attorney General Pam Bondi, who is replaced by Todd Blanche in an acting capacity. Defense Secretary Hegseth fires three high-ranking U.S. Army generals: Chief Staff Randy George, Chief of Chaplins William Green Jr., and T2COM Commander David Hodne. The Pentagon did not provide a reason. The Colorado Court of Appeals vacates the nine-year sentence of 2020 election denier Tina Peters on First Amendment free speech grounds and remands the case for resentencing.
Sources: en.wikipedia.org
The society publishes three research journals and a review journal: the Journal of Pharmacology and Experimental Therapeutics, Drug Metabolism and Disposition, Molecular Pharmacology, and Pharmacological Reviews Starting in 2012 these publications are only offered online. The society copublishes a wholly open access journal with the British Pharmacological Society and Wiley entitled Pharmacology Research & Perspectives. ASPET also publishes a quarterly newsletter, The Pharmacologist, and, from 2001 to 2011, Molecular Interventions magazine. The society gives out several awards:
Matches in Team Fortress Classic typically feature two teams, one red and one blue, and nine playable character classes. Each character class has a set of weapons and abilities unique to that specific class. This differentiation between classes makes for rock-paper-scissors-esque gameplay that requires teammates to work together in order to effectively achieve the objective. The class-system also encourages players to vary their selection of classes and utilize certain classes in conjunction with one another to gain the advantage. In Team Fortress Classic, a server can hold up to 32 players simultaneously, and matches can be played in a number of game modes, each featuring different objectives.
HGEGTFTSDV SSYLEGQAAK EFIAWLVKGR HGEGTFTSDV SSYLEGQAAK EFIAWLVKGR (2 copies of modified GLP-1, modifications underlined) DAHKSEVAHR FKDLGEENFK ALVLIAFAQY LQQCPFEDHV KLVNEVTEFA KTCVADESAE (albumin starts at the beginning of this line) NCDKSLHTLF GDKLCTVATL RETYGEMADC CAKQEPERNE CFLQHKDDNP NLPRLVRPEV DVMCTAFHDN EETFLKKYLY EIARRHPYFY APELLFFAKR YKAAFTECCQ AADKAACLLP KLDELRDEGK ASSAKQRLKC ASLQKFGERA FKAWAVARLS QRFPKAEFAE VSKLVTDLTK VHTECCHGDL LECADDRADL AKYICENQDS ISSKLKECCE KPLLEKSHCI AEVENDEMPA DLPSLAADFV ESKDVCKNYA EAKDVFLGMF LYEYARRHPD YSVVLLLRLA KTYETTLEKC CAAADPHECY AKVFDEFKPL VEEPQNLIKQ NCELFEQLGE YKFQNALLVR YTKKVPQVST PTLVEVSRNL GKVGSKCCKH PEAKRMPCAE DYLSVVLNQL CVLHEKTPVS DRVTKCCTES LVNRRPCFSA LEVDETYVPK EFNAETFTFH ADICTLSEKE RQIKKQTALV ELVKHKPKAT KEQLKAVMDD FAAFVEKCCK ADDKETCFAE EGKKLVAASQ AALGL
=== Future technology and research === Gene therapy is being explored as a treatment for missense mutations. This involves inserting the correct sequence of DNA into an incorrect gene. Artificial Intelligence programs, such as AlphaFold, are also being developed to predict the effect of missense mutations. Identifying potential deleterious mutations can assist with disease diagnosis and treatment.
==== Vaal Civic Association ==== The organisation which spearheaded the 3 September march was the VCA, a residents' organisation partly modelled on the successful Soweto Civic Association. Launched on 9 October 1983, VCA was an affiliate of the UDF, and two senior officials in the UDF's Transvaal branch – Curtis Nkondo and Elliot Shabangu – were guest speakers at its launch in October 1983. Its inaugural chairman was Lord McCamel, a local priest with a parish in Evaton, and his deputy was Esau Ralitsela.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
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.