epitalon raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-10-18 and is reviewed periodically as new material appears.
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.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
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.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
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.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
=== Microbead-based immobilization === Microbead-based immobilization is a modular technique in that it allows the investigator to decide whether they wish to fish for protein targets from the proteome or drug-like compounds from chemical libraries. The macroscopic properties of microbeads make them amenable to relatively low labor enrichment applications, since they are easily to visualize and their bulk mass is readily removable protein solutions. Microbeads were historically made of inert polymers, such as agarose and dextran, that are functionalized to attach a bait of choice. In the case of using proteins as bait, amine functional groups are common linkers to facilitate attachment. More modern approaches have benefitted from the popularization of dynabeads, a type of magnetic microbead, which enable magnetic separation of bead-immobilized analytes from treated samples. Magnetic beads exhibit superparamagnetic properties, which make them very easy to remove from solution using an external magnet. In a simplified workflow, magnetic beads are used to immobilize a protein target, then the beads are mixed with a chemical library to screen for potential ligands. High-affinity ligands bind to the immobilized target and resist removal by washing, so they are enriched in the sample. Conversely, a ligand of interest can be immobilized and screened against proteome proteins by incubation with a lysate.
== Publications == Ondetti M A, Sabo E F. Angiotensin-converting enzyme inhibitors from the venom of Bothrops jararaca. Isolation, elucidation of structure, and synthesis, Biochemistry 1971; 10 (22): 4033–4039. Ondetti M A, Rubin B, Cushman D W. Design of specific inhibitors of angiotensin-converting enzyme: new class of orally active antihypertensive agents, Science 1977; 196 (4288): 441–444.
Carfentanil or carfentanyl, formerly sold under the brand name Wildnil, is an extremely potent opioid analgesic formerly used in veterinary medicine to anesthetize large animals such as elephants and rhinoceroses. It is a structural analogue of the synthetic opioid analgesic fentanyl. It is typically administered in this context by tranquilizer dart. Carfentanil has also been used in humans to image opioid receptors. It has additionally been used as a recreational drug, typically by injection, insufflation, or inhalation. Deaths have been reported in association with carfentanil. Effects and side effects of carfentanil in humans are similar to those of other opioids and include euphoria, relaxation, pain relief, pupil constriction, drowsiness, sedation, slowed heart rate, low blood pressure, lowered body temperature, loss of consciousness, and suppression of breathing. The effects of carfentanil, including overdose, can be reversed by the opioid antagonists naloxone and naltrexone, though higher doses than usual may be necessary compared to other opioids. It acts as an ultrapotent and highly selective agonist of the μ-opioid receptor. Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceuticals which included Paul Janssen. It was introduced into veterinary medicine in 1986. Carfentanil is legally controlled in most jurisdictions.
Sources: en.wikipedia.org
Their feature documentary Kumu Hina, about transgender native Hawaiian teacher and cultural icon Hinaleimoana Wong-Kalu, was supported by ITVS, Pacific Islanders in Communications and the Ford Foundation and won the GLAAD Media Award for Outstanding Documentary and the Independent Lens Audience Award on PBS In 2017, Hamer and Wilson, with Hinaleimoana Wong-Kalu as producer, released Leitis in Waiting and Lady Eva, which documented the lives of transgender women in the conservative South Pacific Kingdom of Tonga. This was followed in 2019 by The Rogers, about transgender men in Samoa. These films became part of a campaign to decriminalize same-sex relationships across the Pacific. Hamer, Wilson and Wong-Kalu continued their collaboration in 2020 with the animated short film Kapaemahu, based on the hidden history of four stones on Waikiki Beach placed there as a tribute to four legendary mahu who first brought the healing arts from Tahiti to Hawaii. It premiered and won the Special Jury Prize at the Tribeca Film Festival and was shortlisted for an Oscar as Best Animated Short Film at the 93rd Academy Awards. The animated film was followed by a children's book published by Kokila, a PBS feature documentary, a multimedia exhibition at the Bishop Museum, permanent display at the Hawaiʻi Convention center, and inclusion in new interpretative signage at the Kapaemahu monument in Waikiki. The team's most recent film is Aikane, an animated short based on the Hawaiian term for intimate friends of the same sex.
The other main memorial is the SAS and Airborne Forces memorial in the cloisters at Westminster Abbey. The SAS Brigade Memorial at Sennecey-le-Grand in France commemorates the wartime dead of the Belgian, British and French SAS and recently a memorial plaque was added to the David Stirling Memorial in Scotland. There are other smaller memorials "scattered throughout Europe and in the Far East". The local church of St Martin's, Hereford has part of its graveyard set aside as an SAS memorial; over twenty SAS soldiers are buried there. There is also a wall of remembrance displaying memorial plaques to some who could not be buried, including the 18 SAS men who lost their lives in the Sea King helicopter crash during the Falklands Campaign on 19 May 1982 and a sculpture and stained glass window dedicated to the SAS. On 17 October 2017 Ascension, a new sculpture and window honouring the Special Air Service Regiment in Hereford Cathedral, was dedicated by the Bishop of Hereford at a service attended by Prince William.
==== Radial glial cells ==== The radial glial cells are disposed in planes perpendicular to the axes of ventricles. One of their processes abuts the pia mater, while the other is deeply buried in grey matter. Radial glia are mostly present during development, playing a role in neuron migration. Müller cells of the retina and Bergmann glia cells of the cerebellar cortex represent an exception, being present still during adulthood. When in proximity to the pia mater, all three forms of astrocytes send out processes to form the pia-glial membrane.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
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.