Epithalamin 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.
Updated 2026-05-23. Numbers and descriptions here follow the published literature rather than marketing material.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
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.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Synthetic tetrapeptide, four residues |
| Nominal mass | Approximately 390 Da | Free peptide; salt forms differ |
| Appearance | White to off-white powder | Commonly supplied lyophilised |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffer |
| Typical storage | −20 °C, desiccated | Cold packs used during transport |
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
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.
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.
== The conserved gene and its alleles == Thy-1 has been conserved throughout vertebrate evolution and even in some invertebrates, with homologs described in many species like squid, frogs, chickens, mice, rats, dogs, and humans. The Thy-1 gene is located at human chromosome 11q22.3 (mouse chromosome 9qA5.1). In AceView, it covers 6.82 kb, from 119294854 to 119288036 (NCBI 37, August 2010), on the reverse strand. This locus is very close to CD3 & CD56/NCAM genes. Some believe that there may be a functional significance of both this gene and CD3 delta subunit (T3D) mapping to chromosome 11q in man and chromosome 9 in mouse, though there is no homology (in fact this speculation led to its localization in chromosome 11q - the human chromosome region syntenic to mouse chromosome 9 which harbored T3D). In mice, there are two alleles: Thy-1.1 (Thy-1a, CD90.1) and Thy-1.2 (Thy-1b, CD90.2). They differ by only one amino acid at position 108; an arginine in Thy-1.1 and a glutamine in Thy-1.2. Thy-1.2 is expressed by most strains of mice, whereas Thy-1.1 is expressed by others such as AKR/J and PL mouse strains.
Np(V) will also react efficiently in pH levels greater than 5.5 if there are no carbonates present and in these conditions it has also been observed to readily bond with quartz. It has also been observed to bond well with goethite, ferric oxide colloids, and several clays including kaolinite and smectite. Np(V) does not bond as readily to soil particles in mildly acidic conditions as its fellow actinides americium and curium by nearly an order of magnitude. This behavior enables it to migrate rapidly through the soil while in solution without becoming fixed in place, contributing further to its mobility. Np(V) is also readily absorbed by concrete, which because of the element's radioactivity is a consideration that must be addressed when building nuclear waste storage facilities. When absorbed in concrete, it is reduced to Np(IV) in a relatively short period of time. Np(V) is also reduced by humic acids if they are present on the surface of goethite, hematite, and magnetite. Np(IV) is less mobile and efficiently adsorbed by tuff, granodiorite, and bentonite; although uptake by the latter is most pronounced in mildly acidic conditions. It also exhibits a strong tendency to bind to colloidal particulates, an effect that is enhanced when in surface soil with high clay content. The behavior provides an additional aid in the element's observed high mobility.
==== United States ==== The price of insulin in the United States dramatically increased from 1991 to 2019, prompting state governments to sue pharmaceutical companies over alleged price fixing. In 2019, the House Committee on Energy and Commerce questioned how the annual cost of insulin for treating Type 1 diabetes rose to $5,705 by 2019 ($7,184 in 2025), which was up to six times higher than prices in other countries. In 2020, President Donald Trump established the Part D Senior Savings Model for some Medicare Part D plans to offer insulin at $35 or less per month. In 2022, President Joe Biden signed the Inflation Reduction Act, requiring all Part D plans to adopt this price ceiling and cost sharing under Medicare Part B to follow the same threshold. In 2022, California allocated $100 million for the state to create its own insulin at a close-to-cost price.
Log-odds matrices based on the Dayhoff PAM model were commonly used to assess the significance of homology search results, although the BLOSUM matrices have superseded the PAM log-odds matrices in this context because the BLOSUM matrices appear to be more sensitive across a variety of evolutionary distances, unlike the PAM log-odds matrices. The Dayhoff PAM matrix was the source of the exchangeability parameters used in one of the first maximum-likelihood analyses of phylogeny that used protein data and the PAM model (or an improved version of the PAM model called DCMut) continues to be used in phylogenetics. However, the limited number of alignments used to generate the PAM model (reflecting the limited amount of sequence data available in the 1970s) almost certainly inflated the variance of some rate matrix parameters (alternatively, the proteins used to generate the PAM model could have been a non-representative set). Regardless, it is clear that the PAM model seldom has as good of a fit to most datasets as more modern empirical models (Keane et al. 2006 tested thousands of vertebrate, bacterial, and archaeal proteins and they found that the Dayhoff PAM model had the best-fit to at most <4% of the proteins). Starting in the 1990s, the rapid expansion of sequence databases due to improved sequencing technologies led to the estimation of many new empirical matrices (see for a complete list).
Sources: en.wikipedia.org
=== Greg Grayson === Greg Grayson (Ben Lloyd-Hughes) is a VP on Pierpoint's CPS desk. He is initially romantically interested in Harper; she rejects his advances, but the two remain friends afterwards. Greg copes with Pierpoint's ruthless culture using drugs, and also explores writing in his spare time, which Eric publicly mocks him for. During an office Christmas party, Harper tells Robert to look after Greg and make sure he stays sober, but Robert and Greg end up indulging in heavy drug use with a client, culminating in Greg running headfirst into a window and injuring himself. Greg leaves Pierpoint after the incident. In series 2 it is revealed that Greg has had a book published. Greg briefly reappears at the end of series 3, now working as a venture capital investor in California. He listens to a sales pitch from Robert for Little Labs, a startup producing medicinal psilocybin.
=== Use in poultry industries === Broiler chickens are yellow when they are fed with carotenoid-containing feed, as these carotenoids accumulate in the skin and subcutaneous fat of the animal. Carotenoid deposition is also the cause of the yellow colour of egg yolk. For this reason, poultry producers add carotenoids (typically lutein, zeaxanthin, canthaxanthin, and β-apo-8´-apocarotenal) to the feed to increase the attractiveness of the final product for the consumer, but also to support animal health. It is believed that lutein and zeaxanthin act synergistically to increase the yellow hue, whereas zeaxanthin is more powerful than lutein due to its larger chromophore. Therefore, several companies use marigold extract where a percentage of lutein has been converted into meso-zeaxanthin in order to supplement broilers and hens with both carotenoids. The isomer of zeaxanthin obtained from lutein is meso-zeaxanthin due to the nature of the technique used (see below).
== Treatment == For newborn infants starved of oxygen during birth, there is now evidence that hypothermia therapy for neonatal encephalopathy applied within 6 hours of cerebral hypoxia effectively improves survival and neurological outcome. In adults, however, the evidence is less convincing and the first goal of treatment is to restore oxygen to the brain. The method of restoration depends on the cause of the hypoxia. For mild-to-moderate cases of hypoxia, removal of the cause of hypoxia may be sufficient. Inhaled oxygen may also be provided. In severe cases, treatment may also involve life support and damage control measures. A deep coma will interfere with the body's breathing reflexes even after the initial cause of hypoxia has been dealt with; mechanical ventilation may be required. Additionally, severe cerebral hypoxia causes an elevated heart rate, and in extreme cases the heart may tire and stop pumping. CPR, defibrilation, epinephrine, and atropine may all be tried in an effort to get the heart to resume pumping. Severe cerebral hypoxia can also cause seizures, which put the patient at risk of self-injury, and various anti-convulsant drugs may need to be administered before treatment.
The CC1 fold is the most common, and includes tyrosine-specific (PTP), dual-specific (DSP) and even lipid-specific (PTEN) families. The major serine/threonine-specific folds are PPM (PP2C) and PPPL (PPP). The only known histidine phosphatases is in the PHP fold. Other folds encode phosphatases that act on various combination of pSer, pThr, pTyr, and non-protein substrates (CC2, CC3, HAD, HP, AP, RTR1).
The cloning process can take up to 24 hours and creates larvae that are 2/3 their original length which can help conceal them from the predator. The larvae of these sand dollars clone themselves when they sense dissolved mucus from a predatory fish. The larvae exposed to this mucus from the predatory fish respond to the threat by cloning themselves. This process doubles their population and halves their size which allows them to better escape detection by the predatory fish but may make them more vulnerable to attacks from smaller predators like crustaceans. Sand dollars will also clone themselves during normal asexual reproduction. Larvae will undergo this process when food is plentiful or temperature conditions are optimal. Cloning may also occur to make use of the tissues that are normally lost during metamorphosis. The flattened test of the sand dollar allows it to burrow into the sand and remain hidden from sight from potential predators. Predators of the sand dollar are the fish species cod, flounder, sheepshead and haddock. These fish will prey on sand dollars even through their tough exterior. Sand dollars have spines on their bodies that help them to move around the ocean floor. When a sand dollar dies, it loses the spines and becomes smooth as the endoskeleton is then exposed. During the month of August, the sand dollar will have had its highest gonad index, and in November and December is the time when sand dollars will spawn. Broadcast spawning is how sand dollars reproduce.
Sources: en.wikipedia.org
== Ecology == Penicillium digitatum is found in the soil of areas cultivating citrus fruit, predominating in high temperature regions. In nature, it is often found alongside the fruits it infects, making species within the genus Citrus its main ecosystem. It is only within these species that P. digitatum can complete its life cycle as a necrotroph. However, P. digitatum has also been isolated from other food sources. These include hazelnuts, pistachio nuts, kola nuts, black olives, rice, maize, and meats. Low levels have also been noted in Southeast Asian peanuts, soybeans, and sorghum.
Since February 2026, Pakistan and Afghanistan have been engaged in the most sustained cross-border conflict between the two countries since the Taliban's 2021 return to power in Afghanistan. The conflict began with Pakistani airstrikes on alleged Pakistani Taliban (TTP) and Islamic State – Khorasan Province camps in eastern Afghanistan, and escalated within a week into what Pakistan's defence minister, Khawaja Asif, called an "open war" fought under the codename Operation Ghazab lil-Haq. The war has combined air and artillery exchanges along the Durand Line with a parallel insurgency inside Pakistan, as the TTP and allied groups intensified attacks in Khyber Pakhtunkhwa and Balochistan. Two ceasefire agreements for the Islamic holidays of Eid al-Fitr and Eid al-Adha briefly reduced hostilities but did not end them; fighting continued at lower intensity through the summer of 2026 and flared again in September following a mass-casualty attack in Kohat, Pakistan.
The RSP is also connected to the shaft via the pars intermedia (venous plexus of Kobelt). When engorged with blood, the bulbs cuff the vaginal opening and cause the vulva to expand outward. Although several texts state that they surround the vaginal opening, Ginger et al. state that this does not appear to be the case and tunica albuginea does not envelop the erectile tissue of the bulbs. In Yang et al.'s assessment of the bulbs' anatomy, they conclude that the bulbs "arch over the distal urethra, outlining what might be appropriately called the 'bulbar urethra' in women".
Burning solid fuels such as coal and biofuels in the home for cooking and heating is a dominant global source of PAH emissions that in developing countries leads to high levels of exposure to indoor particulate air pollution containing PAHs, particularly for women and children who spend more time in the home or cooking.
=== True protein === In at least one segment of the food industry, the dairy industry, some countries (at least the U.S., Australia, France and Hungary) have adopted "true protein" measurement, as opposed to crude protein measurement, as the standard for payment and testing: "True protein is a measure of only the proteins in milk, whereas crude protein is a measure of all sources of nitrogen and includes nonprotein nitrogen, such as urea, which has no food value to humans. ... Current milk-testing equipment measures peptide bonds, a direct measure of true protein." Measuring peptide bonds in grains has also been put into practice in several countries including Canada, the UK, Australia, Russia and Argentina where near-infrared reflectance (NIR) technology, a type of infrared spectroscopy is used. The more traditional approach to true protein analysis is amino acid analysis. Data from such analysis has additional nutritional meaning, as humans and other animals have specific requirements for essential amino acids. The Food and Agriculture Organization of the United Nations (FAO) recommends that only amino acid analysis be used to determine protein in, inter alia, foods used as the sole source of nourishment, such as infant formula, but also provides: "When data on amino acids analyses are not available, determination of protein based on total N content by Kjeldahl (AOAC, 2000) or similar method ...
Sources: en.wikipedia.org
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.
No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.
It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.
The powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.