tetrapeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-11-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
Epitalon is a synthetic tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. Its design traces to epithalamin, a peptide fraction prepared from bovine pineal gland extracts that researchers in Saint Petersburg began investigating in the 1970s. The compound has a molecular formula of C14H22N4O9 and a nominal molecular mass near 390 daltons. It holds no approved drug status in the United States or the European Union, and material sold under this name is generally offered as a research chemical rather than a finished pharmaceutical product.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised and often hygroscopic |
| Solubility class | Freely soluble in water | Poor solubility in non-polar solvents |
| Typical storage temperature | -20 degrees Celsius or colder | Sealed, desiccated, protected from light |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Establishes purity and confirms mass |
| Common salt form | Trifluoroacetate or acetate | Counterion reported alongside purity values |
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
The World Health Organization (WHO) recommends that all donated blood be tested for transfusion-transmissible infections. These include HIV, hepatitis B, hepatitis C, Treponema pallidum (syphilis) and, where relevant, other infections that pose a risk to the safety of the blood supply, such as Trypanosoma cruzi (Chagas disease) and Plasmodium species (malaria). According to the WHO, 10 countries are not able to screen all donated blood for one or more of: HIV, hepatitis B, hepatitis C, or syphilis. One of the main reasons for this is that testing kits are not always available. However, the prevalence of transfusion-transmitted infections is much higher in low-income countries compared to middle and high-income countries. All donated blood should also be tested for the ABO blood group system and Rh blood group system to ensure that the patient is receiving compatible blood. In addition, in some countries, platelet products are also tested for bacterial infections due to their higher inclination for contamination due to storage at room temperature. Donors may be tested for cytomegalovirus (CMV) because of the risk of transmission to certain immunocompromised recipients, such as those with stem cell transplant or T cell diseases. However, testing is not universally mandated, because leukoreduced blood is generally considered safe from CMV transmission; also, most donors (and recipients) are seropositive for CMV, and are not actively viremic. CMV seropositive donors are still eligible to donate. Leukocyte reduction is the removal of white blood cells by filtration.
== See also == Charcot–Marie–Tooth disease classifications Christina's World – 1948 painting by Andrew Wyeth Hereditary motor and sensory neuropathies Hereditary motor neuropathies Low copy repeats Palmoplantar keratoderma and spastic paraplegia
42 BC to at least early 5th century, Mark Antony (emblem: capricorn) Legio V Macedonica (Macedonian): 43 BC – AD 637, Octavian (emblem: bull) Legio V Alaudae (Larks): 52 BC – AD 70 or 86 (destroyed either during the Batavian rebellion or by the Dacians in first Battle of Tapae), Julius Caesar (emblem: elephant) Legio VI Ferrata (Ironclad): 52 BC – after AD 250, Julius Caesar (emblem: bull, she-wolf and Romulus and Remus); twin legion of Legio VI Victrix Legio VI Victrix (Victorious): 41 BC – after AD 402, Octavian (emblem: bull) Legio VII Claudia Pia Fidelis (loyal and faithful to Claudius): before 58 BC – 44 BC, Julius Caesar; disbanded and re-formed by Octavian Legio VIII Augusta: 59 BC – 46 BC, Julius Caesar, originally named Gallica, disbanded and re-enlisted by Octavian as Legio VIII Augusta, 44 BC – AD 420 Legio IX Hispana (Hispanian): before 58 BC – AD 120-161 Legio X Equestris (Equestrian): before 58 BC – 45 BC, Julius Caesar's personal legion, later renamed as Legio X Gemina Legio X Fretensis (of the sea strait): levied by Octavian in 41/40 BC, recorded to have existed at least until the 410s Legio XI Claudia: 58 BC – 45 BC, Julius Caesar (emblem: Neptune), disbanded, reconstituted by Octavian Legio XII Fulminata (Thunderbolt): 57 BC – AD 45, Julius Caesar, first reconstituted by Lepidus in 43 BC, named by Mark Antony as Legio XII Antiqua (Ancient) Legio XIII Gemina (Twin): 57 BC – 45 BC: Julius Caesar, later (41 BC) reconstituted by Octavian. The legion that crossed the Rubicon with Caesar on his assault on Rome.
Sources: en.wikipedia.org
The liver plays the major role in producing proteins that are secreted into the blood, including major plasma proteins, factors in hemostasis and fibrinolysis, carrier proteins, hormones, prohormones and apolipoprotein:
Alan H. B. Wu is an American clinical chemist, toxicologist, professor, and author. He is known for his work in laboratory medicine, particularly in clinical chemistry, cardiac biomarkers, pharmacogenomics, and clinical toxicology. He is a professor of Laboratory Medicine at the University of California, San Francisco (UCSF), and Chief of Clinical Chemistry and Toxicology and Co-Core Lab Director at the Zuckerberg San Francisco General Hospital.
Underarm bowling incident of 1981 - Australia's Trevor Chappell became very infamous when Australia played New Zealand at the MCG on February 1, 1981, Australian captain Greg Chappell instructed the bowler (and younger brother Trevor) to bowl the last ball underarm to New Zealand batsmen Brian McKechnie to prevent him from hitting a six. After the bowl, McKechnie threw his bat onto the ground in disgust and Australia won the match. Negative post reactions then occurred after the match. Trevor Chappell was best remembered for the incident. John the bookmaker controversy – a scandal in which Australia's Mark Waugh and Shane Warne were paid in 1994–95 to provide information on pitch and weather conditions to an Indian bookmaker. The scandal came to light in 1998. South Africa cricket match fixing in 2000 which resulted in the banning from cricket of Hansie Cronje Ball tampering controversy in August 2006 - On August 20, 2006, when Pakistan toured England in the fourth test, the umpires Darrell Hair and Billy Doctrove ruled that the Pakistani team had been ball tampering and gave five penalty runs to England then offered them a new ball. After the tea break, Pakistan refused to take the field in protest at the decision. Thus, England won the match by forfeit. After the incident, the whole Pakistan team were busted of the scandal and umpire Darrell Hair was banned from umpiring in cricket.
==== Police helicopter downed on Morro dos Macacos ==== The Morro dos Macacos is one of the most violent favelas in Rio de Janeiro, the community was invaded by CV on 17 October 2009, while it was still under the control of ADA, who clashed with Comando Vermelho members to contend for territory, 5 gang members were killed in the clashes from 11 to 17 October. In order to stop the clashes between the two groups, about 150 assault troops of the Special Operations Department of the Polícia Militar were dispatched for security purposes. In an attempt to prevent the intervention of the police in the ongoing feud, criminals built makeshift barricades at several key points and subsequently set them on fire. On 17 October, in the morning, the rear propeller of a Fenix helicopter patrolling above the community was shot and severely damaged by drug traffickers of Amigos dos Amigos. According to some sources, the weapons used in the attack were a bazooka and several machine guns. The helicopter crashed, killing 2 soldiers on impact, with another soldier later dying of his wounds. This attack sparked widespread retaliations by police and militias against drug cartels and civilians in the region, with massacres occurring from 17 to 25 October 2009, resulting in at least 45 deaths.
Sources: en.wikipedia.org
If there have not been out of tolerance temperatures for critical times, continue to use the shipment, without special inspection If potentially damaging temperature hazards have occurred, thoroughly inspect the shipment for damage or degradation. Possibly accelerate sale and use because of reduced shelf life. The consignee may negotiate with the carrier or shipper or even choose to reject a shipment where sensors indicate severe temperature history The time of the temperature extreme, or GPS tracking, may be able to determine the location of the infraction to direct appropriate corrective action. Multiple replicate shipments of data loggers are also used to compare modes of shipment (routes, vendors) and to develop composite data to be used in package testing protocols. There are many brands and models of data loggers. Most are a connectable device that must be plugged into a computer to extract the data that the logger has logged.
=== September === September 15, 2011 Canada The St. Thomas Assembly plant was closed permanently after decades of providing employing to the region of St. Thomas, Ontario; resulting in the loss of roughly 1,400 good-paying jobs.
== RM-ODP and UML == Currently there is growing interest in the use of UML for system modelling. However, there is no widely agreed approach to the structuring of such specifications. This adds to the cost of adopting the use of UML for system specification, hampers communication between system developers and makes it difficult to relate or merge system specifications where there is a need to integrate IT systems. Although the ODP reference model provides abstract languages for the relevant concepts, it does not prescribe particular notations to be used in the individual viewpoints. The viewpoint languages defined in the reference model are abstract languages in the sense that they define what concepts should be used, not how they should be represented. This lack of precise notations for expressing the different models involved in a multi-viewpoint specification of a system is a common feature for most enterprise architectural approaches, including the Zachman Framework, the "4+1" model, or the RM-ODP. These approaches were consciously defined in a notation- and representation-neutral manner to increase their use and flexibility. However, this makes more difficult, among other things, the development of industrial tools for modeling the viewpoint specifications, the formal analysis of the specifications produced, and the possible derivation of implementations from the system specifications. In order to address these issues, ISO/IEC and the ITU-T started a joint project in 2004: "ITU-T Rec.
Sources: en.wikipedia.org
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase HPLC establishes purity and separation from related peptides, and mass spectrometry confirms the molecular mass. Amino acid analysis can verify residue composition. No single method proves identity on its own, so the results are read together.
Yes. Residual trifluoroacetate or acetate from purification adds mass and can shift the value obtained by certain assays. Purity figures are therefore meaningful only when the counterion form is stated. Reporting both peptide content and salt form gives a clearer picture.
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.