This is a working overview of Tetrapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
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.
| 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 |
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Weapons supplied to SWALA between 1962 and 1966 included PPSh-41 submachine guns, SKS carbines, and TT-33 pistols, which were well-suited to the insurgents' unconventional warfare strategy. Despite its burgeoning relationship with SWAPO, the Soviet Union did not regard Southern Africa as a major strategic priority in the mid 1960s, due to its preoccupation elsewhere on the continent and in the Middle East. Nevertheless, the perception of South Africa as a regional Western ally and a bastion of neocolonialism helped fuel Soviet backing for the nationalist movement. Moscow also approved of SWAPO's decision to adopt guerrilla warfare because it was not optimistic about any solution to the South West Africa problem short of revolutionary struggle. This was in marked contrast to Western governments, which opposed the formation of SWALA and turned down the latter's requests for military aid.
microfilament A long, thin, flexible, rod-like structure composed of polymeric strands of proteins, usually actins, that occurs in abundance in the cytoplasm of eukaryotic cells, forming part of the cytoskeleton. Microfilaments comprise the cell's structural framework. They are modified by and interact with numerous other cytoplasmic proteins, playing important roles in cell stability, motility, contractility, and facilitating changes in cell shape, as well as in cytokinesis.
== Personal life == Best later claimed that the greatest moment of his life occurred when he met his future wife, Margaret Mahon (1900–1988) following his return. Best married Margaret Hooper Mahon in Toronto in 1924 and they had two sons. Best's eldest son was Charles Alexander Best, a Canadian politician and geneticist. Best is the grandfather of Susan MacTavish Best. His other son, Henry Best was a well-regarded historian who later became president of Laurentian University in Sudbury, Ontario. Best died on March 31, 1978, in Toronto. He is interred in Mount Pleasant Cemetery, Toronto, not far from Sir Frederick Banting.
== Prognosis == There are risks of long-term neurological effects from maple syrup urine disease. These may include ADHD, anxiety, depression, etc. The severity of these effects is dependent on the level of metabolic control. If left untreated, MSUD will lead to death due to central neurological function failure and respiratory failure. Early detection, protein-restricted diet low in branched-chain amino acids, close monitoring of blood chemistry, and aggressive treatment during a metabolic crisis can lead to a good prognosis with little or no abnormal developments. Early diagnosis can improve cognitive development, but the effects are largely dependent on the quality of healthcare systems and disease type. Cognitive development may be shown to be below that of the general population. The severity of the cognitive delay is related to the time the condition remained undiagnosed and the effectiveness of dietary control including during metabolic crises.
Sources: en.wikipedia.org
=== In sport === The WADA has prohibited the use of tramadol in competition since 1 January 2024. Misuse of painkillers is up to four times more common among athletes compared to the general population. From March 2019, the Union Cycliste Internationale (UCI) banned the drug, after riders were using the painkiller to improve their performance. No significant improvements in performance were found when compared to placebo. In 2026 the International Go Federation (IGF) revoked Korean player Sa Woo Kim’s third place in the 2025 World Amateur Go Championship in Vancouver, Canada because he had tested positive for tramadol. The IGF adopted the World Anti-Doping Code in October 2020.
The concept of in situ in contemporary art developed in the late 1960s and 1970s, referring to works created for a specific site. Such works incorporate the site's physical, historical, political, and sociological characteristics as integral elements of their composition. This approach contrasts with autonomous artistic production, where artworks are conceived independently of their display location. Theoretical discussions, particularly in the writings and practice of French conceptual artist and sculptor Daniel Buren, have addressed the dynamic relationship between artistic intervention and its surrounding environment. The site-specific installations of Christo and Jeanne-Claude exemplify the application of in situ principles in art. Their large-scale interventions such as The Pont Neuf Wrapped (1985) and Wrapped Reichstag (1995) involved the systematic wrapping of buildings and landscape elements in fabric, temporarily transforming familiar spaces and altering public perception. Another example is the land art movement, wherein artists such as Robert Smithson and Michael Heizer integrated their works directly into natural landscapes. In contemporary aesthetic discourse, in situ describes practices that reinforce the fundamental unity between an artwork and its site.
== Education == Synovec was born in 1959 to Eugene "Gene" Synovec and Joan Synovec. Synovec graduated with a BS in chemistry from Bethel College in 1981. He obtained his PhD from Iowa State in 1986 working under Edward Yeung where he developed detection and data analysis methods for liquid chromatography. He started at the University of Washington in 1986.
The Christian and Druze communities have a long history of interaction dating back roughly a millennium, particularly in Mount Lebanon. Over the centuries, they have peacefully interacted and lived together, sharing common social and cultural landscapes, although occasional exceptions have occurred. This interaction been marked by shared economic activities, cultural exchange, and even political alliances in some cases. The two communities lived among each other and interacted socially on an everyday basis. The close bonds between Christian and Druze neighbors led to Christian communities thriving in some Druze towns. According to some scholars, historically, Druze communities had better relationships with Christians than with Muslims. They also points out that Christians tended to show more tolerance towards the Druze community and their religion compared to Muslims. Traditionally, Druze settlements in the Levant often included Christian families and communities, while Muslim presence was rare.
Jung decided that his near-psychotic experiences were of value and, in private, he induced hallucinations or, in his words, a process of "active imagination". He recorded everything he experienced in small journals, which Jung referred to in the singular as his Black Book, considering it a "single integral whole", even though some of these original journals have a brown cover. Jung described his 1912 book as "an attempt, only partially successful, to create a wider setting for medical psychology and to bring the whole of the psychic phenomena within its purview". The book was later revised and retitled Symbols of Transformation in 1952. The material Jung wrote was subjected to several edits, hand-written and typed, including another, "second layer" of text, his continual psychological interpretations during the process of editing. Around 1915, Jung commissioned a large red leather-bound book, and began to transcribe his notes and paint, working intermittently for sixteen years. Jung left no posthumous instructions about the final disposition of what he called the Liber Novus or Red Book. Sonu Shamdasani, a historian of psychology from London, tried for three years to persuade Jung's resistant heirs to have it published. Ulrich Hoerni, Jung's grandson who manages the Jung archives, decided to publish it when the necessary additional funds were raised through the Philemon Foundation. Up to September 2008, fewer than about two dozen people had ever seen it. In 2007, two technicians for DigitalFusion, working with New York City publishers W. W.
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 peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.