Everything below concerns Pineal gland. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
== Contraindications == Sulfanilamide is contraindicated in those known to be hypersensitive to sulfonamides, in nursing mothers, during pregnancy near term, and in infants less than two months of age.
The bodies of unaffected XY individuals masculinize by, among other things, enlarging the genital tubercle into a penis, which in females becomes the clitoris, while what in females becomes the labia fuses to become the scrotum of males (where the testicles will later descend). XY individuals affected by CAIS develop a normal external female habitus, despite the presence of a Y chromosome, but internally, they will lack a uterus, and the vaginal cavity will be shallow, while the gonads, which differentiated into testes in the earlier separate process also triggered by their Y chromosome, will remain undescended in the place. This results not only in infertility in individuals with CAIS, but also presents a risk of gonadal cancer later on in life. CAIS is one of the three categories of androgen insensitivity syndrome (AIS) since AIS is differentiated according to the degree of genital masculinization: complete androgen insensitivity syndrome (CAIS) when the external genitalia is that of a typical female, mild androgen insensitivity syndrome (MAIS) when the external genitalia is that of a typical male, and partial androgen insensitivity syndrome (PAIS) when the external genitalia is partially, but not fully masculinized. Androgen insensitivity syndrome is the largest single entity that leads to 46, XY undermasculinization.
==== Hypoxia/anoxia tolerance ==== The naked mole rat (Heterocephalus glaber) is a hypoxia-tolerant species that sleeps in deep burrows and in large colonies. The depth of these burrows reduces access to oxygen, and sleeping in large groups will deplete the area of oxygen quicker than usual, leading to hypoxia. The naked mole rat has the unique ability to survive low oxygen conditions for no less than several hours, and zero oxygen conditions for 18 minutes. One of the ways of combatting hypoxia in the brain is decreasing the reliance on oxygen for ATP production, achieved by decreased respiration rates and proton leak.
Chancellor Hunt says that cuts in public spending will cost "a great deal less" than allowing Russia to win. 25 April Labour pledges to renationalise most rail services within five years if it wins the next general election. The SNP's power-sharing deal with the Scottish Greens collapses. Shoplifting is reported to have hit a record high in 2023, with more than 430,000 offences recorded. This figure is up by more than one-third compared to 2022, and likely represents a fraction of the true number of incidents. In the High Court, Laurence Fox is ordered to pay £180,000 in libel damages to former Stonewall trustee Simon Blake and drag artist Crystal. The Environment Minister, Robbie Moore says "Additional time will be needed to efficiently and effectively roll out the schemes across the UK," as the Cash for Bottle deposit scheme is delayed until October 2027. Moroccan asylum seeker Ahmed Alid is convicted of the murder of Terence Carney, who was stabbed multiple times in an attack at Hartlepool in October 2023. Gary Roden resigns as the general manager of Co-op Live following a series of problems and delays at the venue. 26 April A trial begins of the first personalised melanoma vaccine, based on mRNA, the same technology as current COVID vaccines. Buckingham Palace announces that King Charles will resume his public duties from the following week after making good progress with his cancer treatment. An inquest into the 2020 Reading stabbings concludes they could have been avoided but for problems with the sharing of intelligence between authorities.
Sources: en.wikipedia.org
Torsten Krude (Ed.); DNA Changing Science and Society (ISBN 0-521-82378-1) CUP 2003. (The Darwin Lectures for 2003, including one by Sir Aaron Klug on Rosalind Franklin's involvement in the determination of the structure of DNA). Robert Olby; The Path to The Double Helix: Discovery of DNA; first published in October 1974 by MacMillan, with foreword by Francis Crick; ISBN 0-486-68117-3; revised in 1994, with a 9-page postscript. Robert Olby; Oxford National Dictionary article: Crick, Francis Harry Compton (1916–2004). In: Oxford Dictionary of National Biography, Oxford University Press, January 2008. Anne Sayre. 1975. Rosalind Franklin and DNA. New York: W.W. Norton and Company. ISBN 0-393-32044-8. James D. Watson; The Double Helix: A Personal Account of the Discovery of the Structure of DNA, Atheneum, 1980, ISBN 0-689-70602-2 (first published in 1968) is a very readable firsthand account of the research by Crick and Watson. The book also formed the basis of the award-winning television dramatisation Life Story by BBC Horizon (also broadcast as Race for the Double Helix). [The Norton Critical Edition, which was published in 1980, edited by Gunther S. Stent: ISBN 0-393-01245-X] James D. Watson; Avoid Boring People and Other Lessons from a Life in Science, New York: Random House. ISBN 978-0-375-41284-4.
Valve is an American video game developer and publisher founded in 1996 by Gabe Newell and Mike Harrington. The company is based in Bellevue, Washington. Valve's first game was Half-Life, a first-person shooter released in 1998. It sold over nine million retail copies. Alongside Half-Life's launch, Valve released development tools to enable the player community to create content and mods. The company then proceeded to hire the creators of popular mods such as Counter-Strike. Valve continued their trend of developing predominantly first-person video games in the 2000s with a number of critically successful releases. In 2004, they released the highly anticipated sequel Half-Life 2 through their own digital distribution service Steam. The game sold over 10 million copies and was met with acclaim. Valve released two subsequent episodes for Half-Life 2 and later packaged those games together with the puzzle game Portal and the multiplayer shooter Team Fortress 2 in a collection known as The Orange Box. By the end of 2008, combined retail sales of the Half-Life series, Counter-Strike series and The Orange Box had surpassed 32 million units. Newell also projected that digital sales of Valve's games would eventually exceed retail sales as Steam continued to grow. In the late 2000s, Valve released two zombie-themed first-person shooters focusing on cooperative gameplay with the Left 4 Dead series. The company continued to release multiplayer games with the launches of Counter-Strike: Global Offensive and Dota 2, both of which have large esports communities fostered by Valve.
On the other hand, it has been suggested by some authors that the high levels of estrone and/or estrone conjugates with oral estradiol may result in excessive estradiol levels in certain tissues such as the breasts and endometrium, due to high expression in these tissues of the requisite enzymes (17β-HSDs and STS) necessary to transform these metabolites back into estradiol. In accordance, circulating levels of estrone sulfate have been found to be positively associated with breast density in postmenopausal women treated with oral estradiol, with 1.3% higher breast density observed for every 1 ng/mL greater level of estrone sulfate. Similarly, levels of estradiol, estrone, and estrone sulfate are all strongly associated with the risk of breast cancer in women. Preclinical studies have shown that estrone sulfate, via local transformation into estradiol, stimulates the growth of mammary cancer cells. Due to the first pass through the liver, disproportionate and supraphysiological levels of estrogens occur locally in the liver with oral estradiol. These levels are approximately 4- to 5-fold higher than in the circulation, based on differences in hepatic estrogenic potency for oral estradiol relative to transdermal estradiol. As a result, there is abnormally high estrogenic signaling in the liver with oral estradiol, and a variety of unphysiological effects on liver protein synthesis result.
There are no FDA-approved Health Claims or Qualified Health Claims for vitamin B6. Structure/Function Claims can be made without FDA review or approval as long as there is some credible supporting science. Examples for this vitamin are "Helps support nervous system function" and "Supports healthy homocysteine metabolism."
Mark Salisbury of Time Out wrote of the lead acting to be "excellent" and the crowd scenes "astonishing", while equally observing how the climax was "truly nerve-wracking". He called it "an implacable work of authority and compassion, Cry Freedom is political cinema at its best." James Sanford, however, writing for the Kalamazoo Gazette, did not appreciate the film's qualities, calling it "a Hollywood whitewashing of a potentially explosive story." Rating the film with 3 Stars, critic Leonard Maltin wrote that the film was a "sweeping and compassionate film". He did, however, note that the film "loses momentum as it spends too much time on Kline and his family's escape from South Africa". But in positive followup, he pointed out that it "cannily injects flashbacks of Biko to steer it back on course." John Simon of the National Review called Cry Freedom "grandiosely inept". In 2013, the movie was one of several discussed by David Sirota in Salon in an article concerning white saviour narratives in film.
Sources: en.wikipedia.org
==== MeSH D12.125.837 – serine ==== MeSH D12.125.837.075 – azaserine MeSH D12.125.837.150 – cycloserine MeSH D12.125.837.225 – droxidopa MeSH D12.125.837.300 – enterobactin MeSH D12.125.837.800 – phosphoserine
Fosdagrocorat (developmental code names PF-04171327 and PF-4171327; also known as dagrocorat 2-(dihydrogen phosphate)) is a nonsteroidal but steroid-like selective glucocorticoid receptor modulator (SGRM) which was under development for the treatment of rheumatoid arthritis but was never marketed. It is the C2 dihydrogen phosphate ester of dagrocorat, and acts as a prodrug of dagrocorat with improved pharmacokinetics. The drug reached phase II clinical trials prior to the discontinuation of its development.
=== RNAi therapeutics === Just after Fire and Mello's ground-breaking discovery, Elbashir et al. discovered, by using synthetically made siRNA, it was possible to target the silencing of specific sequences in a gene, rather than silencing the entire gene. Only a year later, McCaffrey and colleagues demonstrated that this sequence-specific silencing had therapeutic applications by targeting a sequence from the Hepatitis C virus in transgenic mice. Since then, multiple researchers have been attempting to expand the therapeutic applications of RNAi, specifically looking to target genes that cause various types of cancer. By 2006, the first applications to reach clinical trials were in the treatment of macular degeneration and respiratory syncytial virus. Four years later the first-in-human Phase I clinical trial was started, using a nanoparticle delivery system to target solid tumors. The FDA approved the first siRNA-based drug (patisiran) in 2018. Givosiran and lumasiran later won FDA approval for the treatment of AHP and PH1 in 2019 and 2020, respectively. Inclisiran received EMA approval in 2020 for the treatment of high cholesterol and is currently under review by the FDA.
=== Pregnancy === Valproate is a teratogen. Teratogens can cause birth defects. Valproate is restricted for all women under age 55 in the United Kingdom and European Union. It has a black box warning for pregnancy in the United States. There are also restrictions for men. Children fathered by men taking valproate have a higher risk of neurodevelopmental disorders. Valproate is restricted for men under age 55 in the United Kingdom and European Union. The restrictions require two specialists to agree that there is no other effective or tolerated treatment for the patient.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
The dry powder is typically held at -20 degrees Celsius or lower, protected from light and moisture. Allowing a sealed vial to reach room temperature before opening reduces condensation on its contents. Conditions stated on a supplier certificate of analysis take precedence over general guidance.