This is a working overview of Khavinson, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-03. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
（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.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
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 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.
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.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
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.
== Instruments and Technologies == The National Dope Testing Laboratory is equipped with state of the art technologies and the most modern equipment. The use of Gas Chromatography coupled with Mass Spectrometry (GC-MS) is the most common and the oldest technology being used worldwide for dope testing. Nowadays, the use of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has become quite widespread. This technique has helped detect the difficult drugs falling into various categories of banned substances and is becoming increasingly more important in the fight against doping. Apart from GC-MS and LC-MS/MS, the use of Gas Chromatography coupled with tandem Mass Spectrometry (GC-MS/MS) and Isotope-ratio mass spectrometry (IRMS) is also very prevalent in sports dope testing. Both GC-MS/MS and LC-MS/MS are used primarily to analyze urine samples. The analysis of the blood matrix requires a completely different type of equipment which is commonly used in hospital laboratories.
=== KdV-SIR equation === Based on the classical SIR model, a Korteweg-de Vries (KdV)–SIR equation and its analytical solution have been proposed to illustrate the fundamental dynamics of an epidemic wave, the dependence of solutions on parameters, and the dependence of predictability horizons on various types of solutions. The KdV-SIR equation is written as follows:
=== Early career === In 1966, Jim and Tammy Faye Bakker began working at Pat Robertson's Christian Broadcasting Network (CBN) in Portsmouth, Virginia, which had an audience in the low thousands at the time. The Bakkers contributed to the network's growth, hosting a children's variety show called Come On Over that employed comic routines with puppets. Due to the success of Come On Over, Robertson made Bakker the host of a new prime-time talk show, The 700 Club, which gradually became CBN's flagship program. The Bakkers left CBN in 1973 and, soon after, joined with Paul and Jan Crouch to help co-found the Trinity Broadcasting Network (TBN) in California. However, this partnership lasted only eight months until a falling-out between Jim Bakker and Paul Crouch caused the Bakkers to eventually leave the new network.
== Orthodox accounts == The first school of interpretation to emerge in the United States was "orthodox". For more than a decade after the end of the World War II, few American historians challenged the official American interpretation of the beginnings of the Cold War. The "orthodox" school places the responsibility for the Cold War on the Soviet Union and its expansion into Eastern Europe. For example, Thomas A. Bailey argued in his 1950 America Faces Russia that the breakdown of postwar peace was the result of Soviet expansionism in the immediate years following World War II. Bailey argued Joseph Stalin violated promises he had made at the Yalta Conference, imposed Soviet-dominated regimes on unwilling Eastern European populations and conspired to spread communism throughout the world. From that view, American officials were forced to respond to Soviet aggression with the Truman Doctrine, plans to contain communist subversion around the world and the Marshall Plan. Another prominent "orthodox" historian was Herbert Feis, who in his works like Churchill, Roosevelt, Stalin and From Trust to Terror: The Onset of the Cold War stated similar views. According to him, Soviet aggression in Eastern Europe in the postwar period was responsible for starting of the Cold War. Apart from this, he also argued that Franklin D. Roosevelt's policies towards Stalin and his "surrender" to Stalin's demands in the Yalta Conference paved the way for Soviet aggression and destabilized balance of power in Europe in Soviet favor.
=== Biosynthesis === Ricin is synthesized in the endosperm of castor oil plant seeds. The ricin precursor protein is 576 amino acid residues in length and contains a signal peptide (residues 1–35), the ricin A chain (36–302), a linker peptide (303–314), and the ricin B chain (315–576). The N-terminal signal sequence delivers the prepropolypeptide to the endoplasmic reticulum (ER) and then the signal peptide is cleaved off. Within the lumen of the ER the propolypeptide is glycosylated and a protein disulfide isomerase catalyzes disulfide bond formation between cysteines 294 and 318. The propolypeptide is further glycosylated within the Golgi apparatus and transported to protein storage bodies. The propolypeptide is cleaved within protein bodies by an endopeptidase to produce the mature ricin protein that is composed of a 267 residue A chain and a 262 residue B chain that are covalently linked by a single disulfide bond.
Sources: en.wikipedia.org
Christine Helen Foyer (born 3 October 1952) is professor of plant science at the University of Birmingham, Birmingham, UK. She is President Elect of the Association of Applied Biologists, the General Secretary of the Federation of European Societies of Plant Biologists, an elected Board Member of the American Society of Plant Biologists and a Member of the French Academy of Agriculture. She has published and co-authored many papers on related subjects. Foyer's name is included in the "Foyer–Halliwell–Asada" pathway, a cellular process of hydrogen peroxide metabolism in plants and animals and named for the three principal discoverers.
He wrote in McClure's in 1908 that the claims were based on self-diagnosis or secondhand reports from doctors, and attributed them to the placebo effect. In 1900 medical lecturer William Purrington called the beneficiaries "hysterical patients ... the victims of obscure nervous ailments." Rodney Stark writes that a key to Christian Science's appeal at the time was that its success rate compared favorably with that of physicians, particularly when it came to women's health. Most doctors had not been to medical school, there were no antibiotics, and surgical practices were poor. By comparison the placebo effect (being treated at all, no matter what the treatment was) worked well. Stark argues that the "very elaborate and intensely psychological Christian Science 'treatments' maximize such effects, while having the advantage of not causing further harm."
The highest approval rating for the government was in the Northeast (65%), among people with up to a completed elementary education (60%), those earning two minimum wages (59%), and among women (59%). In a survey conducted by PoderData between 24 and 26 September with 2,500 people, a margin of error of 2 percentage points, and a confidence level of 95%, the government obtained 48% approval and 45% disapproval. The regions that most approve of the Lula government are the Southeast and the Northeast, and his government is more approved among younger and older poor and middle-class women. Lula as a person received 36% of mentions as excellent or good, 25% as regular, and 35% as bad or terrible. The survey also asked whether respondents liked Lula's administration more than Bolsonaro's. Forty-eight percent agreed with the statement, 40% disagreed, and 9% said there was no difference. Among evangelicals, government approval fell by two percentage points to 32%, and rejection rose to 64%. Among Catholics, approval fell by 3 percentage points to 57%, and disapproval rose to 36%. In a survey released by Paraná Pesquisas on 13 January 2025, it was revealed that the negative evaluation of President Luiz Inácio Lula da Silva's government exceeded the positive one. According to the survey data, 11.1% of Brazilians considered the government excellent and 22.7% classified it as good, totaling 33.8% positive evaluation. On the other hand, 42.6% of respondents evaluated the government as bad (8.4%) or terrible (34.2%).
The study reported functional KNa1.1 conductance in prenatal and neonatal human brain tissue, gain-of-function potassium currents in patient-derived excitatory and inhibitory neurons, and that ASO-mediated knockdown altered firing in mid-gestation primary human neurons, supporting the hypothesis that KCNT1-targeted ASO therapy may act on disease-relevant neuronal physiology during early human brain development.
Sources: en.wikipedia.org
April 9: Law establishing the postal savings bank: regardless of her marital status, a wife does not need her husband's permission to open a postal savings account or withdraw money from it—unless the husband expressly objects. June 16: Law establishing free primary education in public schools: these also include girls' schools in communes with more than 400 inhabitants. August 2: Decree organizing nursery schools—coeducational, they accept children aged 2 to 7; all directors and workers are women; female general and departmental inspectors are assigned to their oversight. Girls are granted access to secondary education, with specific provisions and a diploma different from the baccalaureate (which boys may obtain). March 28, 1882: Law on mandatory primary education for both boys and girls between the ages of 6 and 13; school curricula differ only in that girls learn needlework and boys take military exercises. July 27, 1884: Law reinstating divorce. 1885
== Calculation of CAL == CAL is measured in mm as the distance from the CEJ to the gingival margin (GM), using a periodontal probe. This provides an estimate of the true periodontal support and is used for monitoring changes in periodontal support over time. CAL is easily measured when CEJ is exposed / visible. CAL can also be calculated following the formula CAL (mm) = PPD (mm) + GR (mm) Calculation of CAL can be categorized into different clinical situations, depending on the position and level of the gingival margin.
==== Vaso-occlusive crisis ==== Also termed "sickle cell crisis" or "sickling crisis", the vaso-occlusive crisis (VOC) manifests principally as extreme pain, most often affecting the chest, back, legs, and/or arms. The underlying cause is sickle-shaped red blood cells that obstruct capillaries and restrict blood flow to an organ, resulting in ischaemia, pain, necrosis, and often organ damage. The frequency, severity, and duration of these crises vary considerably. Milder crises can be managed with nonsteroidal anti-inflammatory drugs. For more severe crises, patients may require inpatient management for intravenous opioids. Vaso-occlusive crisis involving organs such as the lungs or the penis are considered an emergency and treated with red blood cell transfusions. A VOC can be triggered by anything which causes blood vessels to constrict; this includes physical or mental stress, cold, and dehydration. "After Haemoglobin S (HbS) deoxygenates in the capillaries, it takes some time (seconds) for HbS polymerization and the subsequent flexible-to-rigid transformation. If the transit time of RBC through the microvasculature is longer than the polymerization time, sickled RBC will lodge in the microvasculature."
In vertebrates, the nervous system consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The primary effect of leptins is in the hypothalamus, a part of the central nervous system. Leptin receptors are expressed not only in the hypothalamus but also in other brain regions, particularly in the hippocampus. Thus some leptin receptors in the brain are classified as central (hypothalamic) and some as peripheral (non-hypothalamic). As scientifically known so far, the general effects of leptin in the central nervous system are:
This function shares the same values for its term in common with the Kármán–Prandtl resistance equation, plus one parameter 0.305 or 0.34 to fit the asymptotic behavior for R∗ → ∞ along with one further parameter, 26, to govern the transition from smooth to rough flow.
Sources: en.wikipedia.org
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.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
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.