If you have been reading about AEDG tetrapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-02-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
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.
| 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 |
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.
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.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
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 chain's image has also made it popular in some unusual ways. For example, In-N-Out is still considered acceptable in some areas with strong opposition to corporate food restaurants, such as McDonald's. Commercial leaders in San Francisco's Fisherman's Wharf district said they opposed every other fast-food chain except In-N-Out because they wanted to maintain the flavor of family-owned, decades-old businesses in the area, with one saying locals would ordinarily "be up in arms about a fast-food operation coming to Fisherman's Wharf," but "this is different." California native and Colorado Rockies player Jason Giambi would often visit In-N-Out Burger when on the West Coast with his former team, the New York Yankees. He said he tried to open an In-N-Out Burger restaurant in New York but was unsuccessful.The chain also has fans in a number of renowned chefs including Gordon Ramsay, Thomas Keller, Julia Child, Anthony Bourdain, Ina Garten, and Mario Batali. Famous London chef and restaurateur Ramsay ate In-N-Out for the first time when taping Hell's Kitchen in Los Angeles, and it soon became one of his favorite spots for take-out. Ramsay was quoted, saying about the experience: "In-N-Out burgers were extraordinary. I was so bad, I sat in the restaurant, had my double cheeseburger then minutes later I drove back round and got the same thing again to take away." Thomas Keller, a fan of In-N-Out, celebrated with In-N-Out burgers at the anniversary party of his restaurant, The French Laundry.
Proteasome inhibitors have effective anti-tumor activity in cell culture, inducing apoptosis by disrupting the regulated degradation of pro-growth cell cycle proteins. This approach of selectively inducing apoptosis in tumor cells has proven effective in animal models and human trials. Lactacystin, a natural product synthesized by Streptomyces bacteria, was the first non-peptidic proteasome inhibitor discovered and is widely used as a research tool in biochemistry and cell biology. Lactacystin was licensed to Myogenics/Proscript, which was acquired by Millennium Pharmaceuticals, now part of Takeda Pharmaceuticals. Lactacystin covalently modifies the amino-terminal threonine of catalytic β subunits of the proteasome, particularly the β5 subunit responsible for the proteasome's chymotrypsin-like activity. This discovery helped to establish the proteasome as a mechanistically novel class of protease: an amino-terminal threonine protease. Bortezomib (Boronated MG132), a molecule developed by Millennium Pharmaceuticals and marketed as Velcade, is the first proteasome inhibitor to reach clinical use as a chemotherapy agent. Bortezomib is used in the treatment of multiple myeloma. Notably, multiple myeloma has been observed to result in increased proteasome-derived peptide levels in blood serum that decrease to normal levels in response to successful chemotherapy. Studies in animals have indicated that bortezomib may also have clinically significant effects in pancreatic cancer.
=== Pathology === As a bioactive lipid, ceramide has been implicated in a variety of physiological functions including apoptosis, cell growth arrest, differentiation, cell senescence, cell migration and adhesion. Roles for ceramide and its downstream metabolites have also been suggested in a number of pathological states including cancer, neurodegeneration, diabetes, microbial pathogenesis, obesity, and inflammation. Several distinct ceramides potently predict major adverse cardiovascular events (MACE), namely C16:0, C18:0, and C24:1, although C24:0 has an inverse relationship. C16-C18 are harmful in the liver. Ceramide levels are positively correlated with inflammation and oxidative stress in the liver, and the onset and progression of non-alcoholic fatty liver disease (NAFLD) is associated with elevated ceramide in hepatocytes. Dietary intake of saturated fat has been shown to increase serum ceramide and increase insulin resistance. Although initial studies showed increased insulin resistance in muscle, subsequent studies also showed increased insulin resistance in liver and adipose tissue. Interventions that limit ceramide synthesis or increase ceramide degradation lead to improved health (reduced insulin resistance and reduced fatty liver disease, for example). Ceramides induce skeletal muscle insulin resistance when synthesized as a result of saturated fat activation of TLR4 receptors. Unsaturated fat does not have this effect. Ceramides induce insulin resistance in many tissues by inhibition of Akt/PKB signaling.
Apart from a few notable by-election victories, its fortunes did not improve significantly until it formed the SDP–Liberal Alliance with the newly formed Social Democratic Party (SDP) in 1981. At the 1983 general election, the Alliance won over a quarter of the vote, but won only 23 of the 633 seats it contested. At the 1987 general election, its share of the vote fell below 23%. Further, the Liberals and the SDP merged in 1988 to form the Social and Liberal Democrats (SLD), who the following year were renamed the Liberal Democrats. A splinter group reconstituted the Liberal Party in 1989. The Liberals were a coalition with diverse positions on major issues and no unified national policy. This made them repeatedly liable to deep splits, such as that of the Liberal Unionists in 1886 (they eventually joined the Conservative Party); the faction of labour union members that joined the new Labour Party; the split between factions led by Asquith and that led by Lloyd George in 1918–1922; and a three-way split in 1931. Many prominent intellectuals were active in the party, including philosopher John Stuart Mill, economist John Maynard Keynes, and social planner William Beveridge. Winston Churchill during his years as a Liberal (1904–1924) authored Liberalism and the Social Problem (1909).
Sources: en.wikipedia.org
Paralytic peptides are a family of short (23 amino acids) insect peptides that halt metamorphosis of insects from larvae to pupae. These peptides contain one disulphide bridge. The family includes growth-blocking peptide (GBP) of Mythimna separata (Oriental armyworm) and the paralytic peptides from Manduca sexta (tobacco hawkmoth), Heliothis virescens (noctuid moth), and Spodoptera exigua (beet armyworm) as well as plasmatocyte-spreading peptide (PSP1).
Not long after assuming office, Mahathir visited Singapore in December 1981 as part of a delegation to meet with Prime Minister Lee Kuan Yew. Among various bilateral discussions, the two leaders agreed to implement a coordinated time adjustment. This led to the passing of the Malaysian Standard Time Act (1981), initiated by Mahathir. Later, Lee paid a return visit to Malaysia in August 1982. In the early days of his tenure, Mahathir improved relations with Singapore, not only strengthening bilateral ties but also gaining the support of the Malaysian Chinese community. During his time, Singapore's requests to Malaysia to move its railway immigration checkpoint away from Tanjong Pagar and disputes over water payments were major disagreements between the two countries. The Points of Agreement of 1990 set out the terms for developing land for a Rapid Transit System, although disputes still continued throughout the following decade. Mahathir and Singaporean counterparts also oversaw a dispute over the ownership of Pedra Branca, several islets between the two countries, with an agreed exchange of documents to settle ownership of the islets in 1981 being delayed until at least 1992. The 1997 Asian financial crisis further escalated tensions, with Singapore offering high interest rates for ringgit deposits leading to cash flow issues in Malaysia. However, Lee remarked that he had made more progress resolving bilateral issues with Mahathir between 1981 and 1990 than during the previous 12 years under Mahathir's two predecessors.
== Refusal == In the United States federal criminal system, refusing to take a drug test triggers an automatic revocation of probation or supervised release. In Victoria, Australia the driver of the car has the option to refuse the drug test. Refusing to undergo a drug test or refusing to undergo a secondary drug test after the first one, triggers an automatic suspension and disqualification for a period of two years and a fine of AUD$1000. The second refusal triggers an automatic suspension and disqualification for a period of four years and an even larger fine.
== Use == While originally invented as a tool to help university librarians to decide which journals to purchase, the impact factor soon became used as a measure for judging academic success. This use of impact factors was summarised by Hoeffel in 1998:
The bioavailability of estradiol and estradiol esters given by intramuscular injection is said to be essentially complete. For comparison, the bioavailability of oral estradiol is around 5%. The estradiol levels that result with typical clinical doses of estradiol and estradiol esters by intramuscular injection tend to be high compared to the typical estradiol levels that occur with other clinically used routes and forms of estradiol.
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 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.