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.
Last reviewed on 2025-08-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
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.
| 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 |
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.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
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.
== June 20, 1915 (Sunday) == The town of South Omaha, Nebraska was annexed by the larger city of Omaha, adding 40,000 residents to the city's population. Born: Terence Young, British film director, directed the James Bond films Dr. No, From Russia with Love and Thunderball; as Stewart Terence Herbert Young, in Shanghai International Settlement, Republic of China (present-day Shanghai, China) (d. 1994)
start codon The first codon translated by a ribosome from a mature messenger RNA transcript, used as a signal to initiate peptide synthesis. In the standard genetic code, the start codon always codes for the same amino acid, methionine, in eukaryotes and for a modified methionine in prokaryotes. The most common start codon is the triplet AUG. Contrast stop codon.
=== 2021: Olympic gold, second ATP Finals title === Zverev began his season in February with the ATP Cup, where he represented Germany with Jan-Lennard Struff, Kevin Krawietz and Andreas Mies to reach the semi-finals. In his first Grand Slam tournament appearance at the 2021 Australian Open, he defeated Marcos Giron, Maxime Cressy, Adrian Mannarino and Dušan Lajović. His run ended in the quarterfinals, where he lost to the eventual champion and world No. 1 Novak Djokovic. In March his first tournament was in Rotterdam, where he lost in the first round to Kazakh Alexander Bublik. He continued his performances in Acapulco, where he won his 14th ATP title by defeating Stefanos Tsitsipas in the final. At the tournament in Miami, he lost in the second round to Finland's Emil Ruusuvuori. At his first tournament in 2021 on clay in Monte Carlo, Zverev finished in the third round, losing to David Goffin. In Munich, he reached the quarterfinals, losing to the 107th ranked tennis player in the world, Ilya Ivashka. At the Madrid Open, Zverev defeated Rafael Nadal, Dominic Thiem, and Matteo Berrettini en route to his fourth Masters 1000 title and 15th career title. At the same tournament, he also reached his first semifinal in doubles at a Masters 1000, partnering with compatriot Tim Pütz, but withdrew from the match. He reached the quarterfinals of the Masters 1000 in Rome, losing to eventual tournament winner Rafael Nadal. In his second Grand Slam tournament of the year – in Paris, where he was seeded No.
Sources: en.wikipedia.org
If it's a legitimate rape, the female body has ways to try to shut the whole thing down." In 2017, Shaw had a supporting role as Gail Hurley in the feature film Stronger, which was directed by David Gordon Green, and starred Jake Gyllenhaal as 2013 Boston Marathon bombing survivor Jeff Bauman. In 2019, it was reported that Shaw is attached to direct an adaption of the Katherine Faw Morris novel Ultraluminous, produced by Steven Soderbergh. In 2020, numerous announcements were made regarding projects Shaw is attached to: she is reported to be writer and executive producer of an HBO series adapting the 1978 Judy Blume novel Wifey, and will direct the first episode; she is reportedly to star in Kill Switch, a film to be directed by Soderbergh; and she is attached to direct an adaption of T Kira Madden's memoir Long Live the Tribe of Fatherless Girls. She is also set to direct a film adaptation of the comic 4 Kids Walk Into a Bank.
The heavy isotope plutonium-244 has a half-life long enough that extreme trace quantities should have survived primordially (from the Earth's formation) to the present, but so far experiments have not yet been sensitive enough to detect it. Both plutonium-239 and plutonium-241 are fissile, meaning they can sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors. Plutonium-240 has a high rate of spontaneous fission, raising the neutron flux of any sample containing it. The presence of plutonium-240 limits a plutonium sample's usability for weapons or its quality as reactor fuel, and the percentage of plutonium-240 determines its grade (weapons-grade, fuel-grade, or reactor-grade). Plutonium-238 has a half-life of 87.7 years and emits alpha particles. It is a heat source in radioisotope thermoelectric generators, which are used to power some spacecraft. Plutonium isotopes are expensive and inconvenient to separate, so particular isotopes are usually manufactured in specialized reactors. Producing plutonium in useful quantities for the first time was a major part of the Manhattan Project during World War II that developed the first atomic bombs. The Fat Man bombs used in the Trinity nuclear test in July 1945, and in the bombing of Nagasaki in August 1945, had plutonium cores. Human radiation experiments studying plutonium were conducted without informed consent, and several criticality accidents, some lethal, occurred after the war.
The European Renaissance brought expanded interest in both empirical natural history and physiology. In 1543, Andreas Vesalius inaugurated the modern era of Western medicine with his seminal human anatomy treatise De humani corporis fabrica, which was based on dissection of corpses. Vesalius was the first in a series of anatomists who gradually replaced scholasticism with empiricism in physiology and medicine, relying on first-hand experience rather than authority and abstract reasoning. Via herbalism, medicine was also indirectly the source of renewed empiricism in the study of plants. Otto Brunfels, Hieronymus Bock and Leonhart Fuchs wrote extensively on wild plants, the beginning of a nature-based approach to the full range of plant life. Bestiaries—a genre that combines both the natural and figurative knowledge of animals—also became more sophisticated, especially with the work of William Turner, Pierre Belon, Guillaume Rondelet, Conrad Gessner, and Ulisse Aldrovandi. Artists such as Albrecht Dürer and Leonardo da Vinci, often working with naturalists, were also interested in the bodies of animals and humans, studying physiology in detail and contributing to the growth of anatomical knowledge. The traditions of alchemy and natural magic, especially in the work of Paracelsus, also laid claim to knowledge of the living world. Alchemists subjected organic matter to chemical analysis and experimented liberally with both biological and mineral pharmacology.
Sources: en.wikipedia.org
A vacuum (pl.: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective vacuus (neuter vacuum) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term in vacuo is used to describe an object that is surrounded by a vacuum. The process in which a mechanical device removes matter from a closed (such as a vacuum chamber) or open (such as a vacuum hose) system in an effort to create a vacuum is called evacuation. Evacuated substances captured, removed from the flowstream in another location, and held under vacuum are sometimes said to be collected by the vacuum system. The mechanical force the atmosphere exerts on air and material obstructing the flow of air into a vacuum is referred to as suction. The quality of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things being equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. But higher-quality vacuums are possible.
The inquiry will have two areas of focus – a review of the "placement and categorisation" of all inmates at Wandsworth, and an investigation of all people in custody currently charged with terror offences. The UK's first EV-only manufacturing plant begins production at Ellesmere Port, Cheshire. The UK experiences a fourth day of temperatures exceeding 30 °C (86 °F), the highest consecutive number on record for the month of September, with hot weather expected to continue until the weekend. 8 September – The first anniversary of the death of Elizabeth II is marked by gun salutes at Hyde Park and the Tower of London, as well as the release of a short message from Charles III along with a previously unreleased portrait of the Queen taken in 1968. 9 September – Following a four-day manhunt, Daniel Khalife is arrested by the Metropolitan Police in Chiswick, London. 10 September The Sunday Times reports that two men have been arrested under the Official Secrets Act, including a researcher in the UK Parliament accused of spying for China. Mo Farah, considered one of the greatest British athletes of all time, takes part in the final race of his career at age 40, finishing fourth in the Great North Run. The Metropolitan Police confirm that Daniel Khalife has been charged with escaping from Wandsworth Prison. He appears before Westminster Magistrates Court the following day, where he is remanded in custody until 29 September. 11 September The GMB Union confirms that the UK's 400 Wilko stores will close by early October after a bid to rescue the retailer fell through.
Copper(II) sulfate remains "the most effective algicidal treatment". A related traditional use is the Bordeaux mixture, used to control fungus on fruits. Hydrated lime, as a biocide, is allowed in the production of organic foods.
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 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.