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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Computed for the free acid of Ala-Glu-Asp-Gly |
| Molecular mass | About 390.35 g/mol | Free peptide; salt forms shift the value |
| Appearance | White to off-white solid | Typical of short peptides after freeze-drying |
| Solubility class | Freely soluble in water | Aqueous buffers are also commonly used |
| Common synonyms | Epitalon, epithalone, AEDG | AEDG is the single-letter sequence |
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.
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.
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.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
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.
=== Vacuum system === The specimen should be in a high-vacuum environment for optimal milling results. The vacuum makes sure that there are few air particles that could interfere with the ion beam. This way, all the energy in the energy beam can be transferred to the surface with much less energy loss.
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India, officially the Republic of India, is a country in South Asia. It is the world's seventh-largest country by area and its most populous. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the north, and Bangladesh and Myanmar to the east. In the Indian Ocean, India is near Sri Lanka and the Maldives. Modern humans arrived on the Indian subcontinent from Africa by 55,000 years ago. Settled life emerged in the western margins of the Indus river basin 9,000 years ago, evolving into the Indus Valley Civilisation of the third millennium BCE. By 1200 BCE, an archaic form of Sanskrit, an Indo-European language, diffused into India from the northwest, its earliest hymns containing elements of what would become Hinduism. The pre-existing Dravidian and other languages were gradually superseded in India's northern plains. Across the central stretch of these plains, rapid urbanisation took place, and after 500 BCE a caste-based, hereditary form of social stratification began to solidify as Hinduism took fuller shape. During this period, Buddhism and Jainism arose, proclaiming social orders unlinked to heredity. The subsequent emergence of the loose-knit Maurya and Gupta Empires gave rise to wide-ranging cultural and scientific creativity. However, these eras saw a steady decline in women's status, alongside the eventual institutionalisation of untouchability.
Researchers are investigating biomarkers to help diagnose MS, to inform prognoses, and track response to medication. Ideally, biomarker would be detectable in blood, as cerebrospinal fluid is more difficult to access. Three biomarkers are emerging as candidates for real-world applications: Neurofilament light chain (NfL), chitinase-3-like protein 1 (CHI3L1) and glial fibrillary acidic protein (GFAP). NfL levels are elevated years before people typically get an MS diagnosis, and is of interest as a potential screening tool. GFAP and CHI3L1 may be able to track progression independent if relapse activity, and be used as disease progress markers.
Sources: en.wikipedia.org
=== Analogues === Analogues of SR-17018, which is also known as 5,6-dichlorodesmethylchlorphine, include brorphine, chlorphine, SR-14968 (5,6-dichlorobrorphine), SR-14969, SR-15098, SR-15099, SR-16435, Muzepan1, and Muzepan2, among others.
Brazilian cuisine varies greatly by region, reflecting the country's varying mix of indigenous and immigrant populations. This has created a national cuisine marked by the preservation of regional differences. Some of the most well known Brazilian foods are the feijoada, considered the country's national dish; and churrasco, a kind of barbecue which is often served in rodízio style. Other regional foods include beijú, feijão tropeiro, vatapá, moqueca, polenta (from Italian cuisine) and acarajé (from African cuisine). The national beverage is coffee; cachaça is Brazil's native liquor. Cachaça is distilled from sugar cane and is the main ingredient in the national cocktail, Caipirinha. A typical meal consists mostly of rice and beans with beef, salad, french fries and a fried egg. Often, it is mixed with cassava flour (farofa). Fried potatoes, fried cassava, fried banana, fried meat and fried cheese are very often eaten in lunch and served in most typical restaurants. Popular snacks are pastel (a fried pastry); coxinha (a variation of chicken croquete); pão de queijo (cheese bread and cassava flour / tapioca); pamonha (corn and milk paste); esfirra (a variation of Lebanese pastry); kibbeh (from Arabic cuisine); and empada (pastry), little salt pies filled with shrimps or heart of palm. Brazil has a variety of desserts such as brigadeiros (chocolate fudge balls), bolo de rolo (roll cake with goiabada), cocada (a coconut sweet), beijinhos (coconut truffles and clove) and Romeu e Julieta (cheese with goiabada). Peanuts are used to make paçoca, rapadura and pé de moleque.
=== Non-demographic evidence === Evidence for maximum lifespan is also provided by the dynamics of physiological indices with age. For example, scientists have observed that a person's VO2max value (a measure of the volume of oxygen flow to the cardiac muscle) decreases as a function of age. Therefore, the maximum lifespan of a person could be determined by calculating when the person's VO2max value drops below the basal metabolic rate necessary to sustain life, which is approximately 3 ml per kg per minute. On the basis of this hypothesis, athletes with a VO2max value between 50 and 60 at age 20 would be expected "to live for 100 to 125 years, provided they maintained their physical activity so that their rate of decline in VO2max remained constant".
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Sources: en.wikipedia.org
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.
Epitalon and epithalon both circulate, and the difference reflects transliteration of a name coined in Russian-language publications. Reference to the extract it derives from, epithalamin, explains the shared stem. Databases and suppliers are inconsistent, so a search for one spelling alone may miss relevant entries.
No. Epithalamin is a multi-component preparation obtained from pineal tissue, and its exact composition is not fully characterised. Epitalon is a single defined tetrapeptide described as a short synthetic counterpart of that extract, so the two are related in origin but not interchangeable in identity.
It is a synthetic tetrapeptide built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.