Epitalon 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 2026-03-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published 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.
| 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 |
Aldehyde tags were first inserted into the modified sulfatase motif peptide for proteins of interest in 2007. Since then, similar usage of aldehydes and ketones as chemical reporters in bioorthogonal applications has been demonstrated in self-assembly of cell-lysing drugs, the targeting of proteins, as well as glycans and the preparation of heterobifunctional fusion proteins.
The interaction between the chlorine substituent of the thiophene moiety and the aromatic ring of Tyr-228, which is located at the bottom of the S1, it is very important due to the fact that it obviates the need for strongly basic groups for high affinity for FXa. This enables rivaroxaban, which is non-basic, to achieve good oral bioavailability and potency.
== Ceramic materials == The isoelectric points (IEP) of metal oxide ceramics are used extensively in material science in various aqueous processing steps (synthesis, modification, etc.). In the absence of chemisorbed or physisorbed species particle surfaces in aqueous suspension are generally assumed to be covered with surface hydroxyl species, M-OH (where M is a metal such as Al, Si, etc.). At pH values above the IEP, the predominant surface species is M-O−, while at pH values below the IEP, M-OH2+ species predominate. Some approximate values of common ceramics are listed below:
pH A logarithmic scale used to specify the acidity or basicity of an aqueous solution. The pH scale approximates the negative of the base-10 logarithm of the molar concentration of hydrogen ions in a solution. At room temperature, pure water is neutral (pH = 7); solutions with a pH less than 7 are acidic and those with a pH greater than 7 are basic.
Sources: en.wikipedia.org
A significant controversy arose with elements 102 through 106 in the 1960s and 1970s, as competition arose between the LBNL team (now led by Albert Ghiorso) and a team of Soviet scientists at the Joint Institute for Nuclear Research (JINR) led by Georgy Flyorov. Each team claimed discovery, and in some cases each proposed their own name for the element, creating an element naming controversy that lasted decades. These elements were made by bombardment of actinides with light ions. IUPAC at first adopted a hands-off approach, preferring to wait and see if a consensus would be forthcoming. But as it was also the height of the Cold War, it became clear that this would not happen. As such, IUPAC and the International Union of Pure and Applied Physics (IUPAP) created a Transfermium Working Group (TWG, fermium being element 100) in 1985 to set out criteria for discovery, which were published in 1991. After some further controversy, these elements received their final names in 1997, including seaborgium (106) in honour of Seaborg.
White tried to use taking more pictures as an excuse to stay out longer, and McDivitt had to coax him in. He finally came back in after a total of approximately 23 minutes, almost 10 minutes later than was planned. He said: "It's the saddest moment of my life." By the time he got in, the spacecraft had entered darkness. The hatch proved to be as stubborn to relatch as it was to open. This would have been disastrous, resulting in both men's deaths on reentry. McDivitt was able to fix the mechanism once again, so White could close it, about 20 minutes after he got in. The mission plan called for opening the hatch again to throw out White's now-unnecessary EVA equipment, but McDivitt elected not to do this, instead keeping the unnecessary equipment on board for the rest of the flight. They powered down the spacecraft's maneuvering system, intending to drift for the next two-and-a-half days to conserve the remaining fuel. They also intended to sleep alternate four-hour periods, but this turned out to be extremely difficult with the constant radio communications and the small cabin, about the size of the front seats of a compact car. White's 20-minute space walk was the mission's highlight, with McDivitt's photographs being published worldwide. These also showed White wearing an Omega Speedmaster chronograph watch on his spacesuit sleeve, one of two makes which had been approved by NASA for space use following extensive tests. Omega were unaware of these tests or the fact that its product was going to be used in space, until the photos.
=== Insulin biosynthesis and transcription === Insulin biosynthesis is regulated by transcriptional and translational levels. The β-cells promote their protein transcription in response to nutrients. The exposure of rat Langerhans islets to glucose for 1 hour is able to remarkably induce the intracellular proinsulin levels. It was noted that the proinsulin mRNA remained stable. This suggests that the acute response to glucose of the insulin synthesis is independent of mRNA synthesis in the first 45 minutes because the blockage of the transcription decelerated the insulin accumulation during that time. PTBPs, also called polypyrimidine tract binding proteins, are proteins that regulate the translation of mRNA. They increase the viability of mRNA and provoke the initiation of the translation. PTBP1 enable the insulin gene-specific activation and insulin granule protein mRNA by glucose. Two aspects of the transduction pathway process are explained below: insulin secretion and insulin action on the cell.
=== Non-genomic pathways === Because non-genomic pathways include any mechanism that is not a genomic effect, there are various non-genomic pathways. However, all of these pathways are mediated by some type of steroid hormone receptor found at the plasma membrane. Ion channels, transporters, G-protein coupled receptors (GPCR), and membrane fluidity have all been shown to be affected by steroid hormones. Of these, GPCR linked proteins are the most common. For more information on these proteins and pathways, visit the steroid hormone receptor page.
=== Label-free drug screening === Thermofluor has been extensively used in drug screening campaigns. Because Thermofluor detects high affinity binding sites for small molecules on proteins, it can find hits that bind to active site subsites, cofactor sites, or allosteric binding sites with equal efficacy. The method typically requires the use of screening compound concentrations at >10x the desired binding threshold. Setting 5 μM as a reasonable hit threshold consequently requires a test ligand concentration of 50 to 100 μM in the sample well. For most drug compound libraries, where many compounds are not soluble beyond ~100 μM, screening multiple compounds is consequently not feasible owing to solubility issues. Thermofluor screens do not require the development of custom screening reagents (e.g. cleavable substrate analogs), do not require any radioactive reagents, and are generally less sensitive to the effects of compounds that are chemically reactive with protein active site residues, and that consequently show up as undesirable hits in enzyme activity screens.
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.
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.