If you have been reading about 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four-residue sequence |
| Molar mass | About 390.35 g/mol | Free peptide, counter-ion not included |
| Appearance | White to off-white powder | Lyophilised solid from aqueous solution |
| Water solubility | Freely soluble | Short, polar peptide chain |
| Common synonyms | AEDG; epithalone | Catalogues use the names interchangeably |
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.
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.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
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.
Bacteria can also eventually become resistant, through systems like CRISPR/Cas9 system. Many clinical trials have been promising though, showing that it could potentially help with the antimicrobial resistance problem. It can also be used in conjunction with antibiotics for a cumulative effect. Medical microbiology is not only about diagnosing and treating disease, it also involves the study of beneficial microbes. Microbes have been shown to be helpful in combating infectious disease and promoting health. Treatments can be developed from microbes, as demonstrated by Alexander Fleming's discovery of penicillin as well as the development of new antibiotics from the bacterial genus Streptomyces among many others. Not only are microorganisms a source of antibiotics but some may also act as probiotics to provide health benefits to the host, such as providing better gastrointestinal health or inhibiting pathogens.
Deramciclane (developmental code names EGIS-3886, EXV-801) is an experimental drug which was studied for the treatment of anxiety disorders but was never marketed. It has since been repurposed for the treatment of agitation, both alone (as EXV-801) and in combination with dextromethorphan (DXM) (as EXV-802). The drug acts as a serotonin 5-HT2A receptor antagonist, serotonin 5-HT2C receptor inverse agonist, GABA reuptake inhibitor, and weak CYP2D6 inhibitor.
=== Health effects === Research starting in 1975 showed substantially increased risk of endometrial cancer. Since 1976, the drug has carried a label warning about the risk. As part of the Women's Health Initiative sponsored by the National Institutes of Health, a large-scale clinical trial of menopausal HRT showed that long-term use of estrogen and a progestin may increase the risk of strokes, heart attacks, blood clots, and breast cancer. Following these results, Wyeth experienced a significant decline in its sales of Premarin, Prempro (CEEs and medroxyprogesterone acetate), and related products, from over $2 billion in 2002 to just over $1 billion in 2006.
Sources: en.wikipedia.org
=== Interpretation === The ability to quantitate the βhCG level is useful in monitoring germ cell and trophoblastic tumors, follow-up care after miscarriage, and diagnosis of and follow-up care after treatment of ectopic pregnancy. The lack of a visible fetus on vaginal ultrasound after βhCG levels reach 1500 mIU/mL is strongly indicative of an ectopic pregnancy. Still, even an hCG over 2000 IU/L does not necessarily exclude the presence of a viable intrauterine pregnancy in such cases. As pregnancy tests, quantitative blood tests and the most sensitive urine tests usually detect hCG between 6 and 12 days after ovulation. It must be taken into account, however, that total hCG levels may vary in a very wide range within the first 4 weeks of gestation, leading to false results during this period. A rise of 35% over 48 hours is proposed as the minimal rise consistent with a viable intrauterine pregnancy.
Several methods for predicting drug metabolism have also been proposed in the scientific literature. Due to the large number of drug properties that must be simultaneously optimized during the design process, multi-objective optimization techniques are sometimes employed. Finally because of the limitations in the current methods for prediction of activity, drug design is still very much reliant on serendipity and bounded rationality.
== Measurement techniques == The choice of various conventional or in-situ analysis techniques affects the resolution, precision, detection limits and cost of monazite geochronology. The recent analytical progress in U-Th-Pb system in natural monazite has been mainly achieved by (1) Isotope Dilution Thermal Ionization Mass Spectrometry (ID-TIMS), (2) Secondary Ion Mass Spectrometry (SIMS), (3) Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and (4) Electronic Microprobe Analyses (EMPA).
Sources: en.wikipedia.org
=== Normal-phase === Normal phase elution is achieved by pumping the non-aqueous or phase of a biphasic solvent system through the column as the mobile phase, with a more polar stationary phase being retained in the column. The cause of original nomenclature of is relevant. As original stationary phases of paper chromatography were superseded by more efficient materials such as diatomaceous earths (natural micro-porous silica) and followed by modern silica gel, the thin-layer chromatography stationary phase was polar (hydroxy groups attached to silica) and maximum retention was achieved with non-polar solvents such as n-hexane. Progressively more polar eluents were then used to move polar compounds up the plate. Various alkane bonded phases were tried with C18 becoming the most popular. Alkane chains were chemically bonded to the silica, and a reversal of the elution trend occurred. Thus a polar stationary became "normal" phase chromatography, and the non-polar stationary phase chromatography became "reversed" phase chromatography.
Taghi allegedly wanted to kill Nabil B. as a punishment for being involved in killing the wrong person, which eventually led to Nabil B. collaborating with the Dutch authorities instead. As a result of this, Taghi ordered to kill Nabil B.'s innocent brother, who was a non-criminal, respected business owner in Amsterdam-Noord. Also Nabil B.'s lawyer Derk Wiersum was assassinated on the orders of Taghi, which eventually shocked the Netherlands. The Dutch parliament considered this as an attack on the Dutch legal system and the Dutch state, and a manhunt on Taghi by the Dutch authorities was eventually launched. In August 2020, six prominent lawyers in the Netherlands were accused of having delivered information to Ridouan Taghi's organisation in exchange for high sums of money. Their names were also added to the Marengo trials. T. Youssef one of Taghi's lawyers, and also his cousin, had been arrested on 8 October 2021, after being suspected of planning a jailbreak and smuggling messages out of prison to Taghi's organisation. In July 2021, the most prominent Dutch crime journalist Peter R. de Vries was assassinated after he left the studio of RTL Boulevard in Amsterdam, right after he appeared on a popular TV show. This assassination deeply shocked the Netherlands, with many politicians and celebrities sharing their condolences and speaking out on the increase of violence in the Netherlands. According to the Dutch authorities, all tracks lead to the already imprisoned Taghi.
== Achievements == George Kenner contributed to many areas of organic chemistry. In the 1960s, George Kenner, R.A. Gregory and Hilda Tracy were involved in the seminal discovery and synthesis of the peptide hormone gastrin at the University of Liverpool. Gastrin is involved in secretion of gastric acid (HCl) in the stomach. The first chemical synthesis of a lysozyme-like enzyme of 129 amino acids using the classical approach was attempted by Kenner and his group at the University of Liverpool in the 1970s. This would have been the largest protein molecule synthesised in a laboratory using classical peptide synthesis up to that time. He carefully planned a convergent synthesis of this lysozyme analogue, containing 129 amino acid residues joined in a rigorously defined order. The efforts of Kenner and his group led to the synthesis of the 129 amino acid peptide chain in protected form. But the dream of making a wholly synthetic lysozyme enzyme was only achieved 30 years later, in 2007. This synthesis of functionally active lysozyme was achieved by a single individual, Thomas Durek, working in Steve B. Kent's group at the University of Chicago. The value of George Kenner's contributions to the methodology of peptide chemistry had profound influence on developments in many biomedicine fields. For example it led to the synthesis of antigens of defined geometry for immunological studies.
Not only paints and inks, but other industries such as pharmaceutical, construction, and cosmetics, especially hair styling aids and facial detoxifying masks increasingly favor bentonite and attapulgite clays over other rheology modifiers, dispersion aids, opacifying fillers, antifoam, and numerous niche uses which exploit the numerous inherent qualities which have drawn artisans to this material. Clays are sustainably sourced and do not involve any egregious environmental damage, which were among the cheapest bulk materials until recently, when the pricing went up steadily, following the upsurge in its use pattern. Cellulosics - CMC, HMC, HPMC, and others, are chemically substituted cellulose macromolecules. The hydroxyl groups are substituted by other functional groups, such as methyl or propyl. The amount of substitution and molecular weight determine viscosity of the solution, assuming concentration stays the same; adding more also increases viscosity. Sulfonates - Sodium or calcium salts, good water retention, versatile, and highly efficient. Gums - guar, xanthan, cellulose, locust bean, and acacia are the main ones. Saccharides - carrageenan, pullulan, konjac, and alginate, sometimes called hydrocolloids, these thickeners are extremely versatile and specific in function—each has a series of grades or types which behave differently, for example kappa carrageenan will form strong gels (potassium activated) but iota carrageenan will not form gels and only thickens. Proteins - Casein, collagen, and sometimes albumin.
Sources: en.wikipedia.org
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.
The name derives from epithalamin, a pineal gland extract studied in the former Soviet Union. Researchers proposed that short fragments of that extract carried the biological activity of interest.
No major regulatory agency has approved it as a medicine. It is handled as a research chemical, and products sold under this name are not standardised drugs with defined clinical labelling.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.