research chemical 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 2025-08-30. 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.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
| 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 |
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 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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
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.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Injo-gogi-bap – a Korean steamed rice wrapped in leftover soybean paste and dressed with a chili sauce. Oncom – one of the traditional staple foods of West Java (Sundanese) cuisine of Indonesia, there are two types: red oncom and black oncom. Oncom is closely related to tempeh; both are foods fermented using mold. Koya dofu – a freeze-dried tofu that has a taste and texture similar to meat when prepared, common in Buddhist vegetarian cuisine
=== Eating Disorder === To address the underlying eating disorder psychosocial interventions such as cognitive behavioral therapy, motivational therapy, problem-solving therapy, coping skills training, and family behavior therapy have all been shown to improve treatment adherence and achieve good glycemic control. It has been observed that addressing psychological needs improves HbA1c by 0.5%–1% in adults with T2DM. Useful therapies may involve cognitive behavioral therapy. Cognitive behavioral therapy focuses on changing unhealthy thinking surrounding the use of insulin. Family involvement and family therapy is helpful for long-term maintenance of good behaviors with taking insulin. A positive mindset to recovery, and connection with others who have experienced diabulimia, increases the probability of successful recovery.
=== Reactions of strained alkenes === Strained alkenes also use strain-relief as a driving force that allows for their participation in click reactions. Trans-cycloalkenes (usually cyclooctenes) and other strained alkenes such as oxanorbornadiene react in click reactions with a number of partners including azides, tetrazines, and tetrazoles. These reaction partners may interact specifically with the strained alkene, staying bioorthogonal to endogenous alkenes found in lipids, fatty acids, cofactors, and other natural products.
1962 Waksman Merck postdoc fellowship, USA. 1967 Humboldt assistant professorship stipend at the Max-Planck Institute, Munich, Germany. 1970 visiting professorship at the Weizmann Institute of Science, Rehovot, Israel. 1973 guest professorship in Dallas, Texas, USA. 1978 guest professorship (Japan Society for the Promotion of Science) in Japan. 1982–1986 Full Professor (Ordinarius) in biotechnology at The Federal Institute of technology, ETH Zurich, Switzerland. 1993 honorary visiting professorship in biochemistry at the University of Bath, UK. 1995 honorary visiting professorship in biochemistry at the Université Catholique de Louvain, Louvain-la-Neuve, Belgium. During these stays he collaborated with Nobel Prize winners Lynen, Waksman as well as with Professors Estabrook and Srere, Katchalski-Katzir and Wilchek, Fukui, Chibata, Suzuki, Rees and Creighton respectively.
Sources: en.wikipedia.org
For a definitive diagnosis to be made, symptoms must occur within 6 hours of transfusion, hypoxemia must be present, there must be radiographic evidence of bilateral infiltrates and there must be no evidence of left atrial hypertension (fluid overload). It occurs in 15% of the transfused patient with mortality rate of 5 to 10%. Recipient risk factors includes: end-stage liver disease, sepsis, haematological malignancies, sepsis, and ventilated patients. Antibodies to human neutrophil antigens (HNA) and human leukocyte antigens (HLA) have been associated with this type of transfusion reaction. Donor's antibodies interacting with antigen positive recipient tissue result in release of inflammatory cytokines, resulting in pulmonary capillary leakage. The treatment is supportive. Transfusion associated circulatory overload (TACO) is a common, yet underdiagnosed, reaction to blood product transfusion consisting of the new onset or exacerbation of three of the following within 6 hours of cessation of transfusion: acute respiratory distress, elevated brain natriuretic peptide (BNP), elevated central venous pressure (CVP), evidence of left heart failure, evidence of positive fluid balance, and/or radiographic evidence of pulmonary vascular congestion. Patients with congestive heart failure or kidney disease are more susceptible to volume overload. For especially vulnerable patients, a standard RBC unit could be split by sterile technique in the blood bank and administered over 8 hours instead of the standard 4 hours.
Charcot–Marie–Tooth (CMT) disease is an inherited neurological disorder primarily caused by genetic mutations that disrupt critical proteins within peripheral nerves. These mutations predominantly affect proteins essential for the structure and function of the myelin sheath, including peripheral myelin protein 22 (PMP22), myelin protein zero (P0/MPZ), connexin32 (Cx32/GJB1), and periaxin (PRX), leading to demyelination. Additionally, mutations in proteins involved in axonal integrity, such as neurofilament light chain (NF-L), dynamin 2 (DNM2), ganglioside-induced differentiation-associated protein 1 (GDAP1), and mitofusin 2 (MFN2), can cause axonal forms of CMT. Due to the close interaction between Schwann cells (which produce myelin) and axons, mutations affecting Schwann cells often result in secondary axonal degeneration, further complicating disease progression. Ultimately, the pathogenesis of CMT involves the disruption of essential cellular processes, including protein synthesis, sorting, intracellular transport, protein degradation, and mitochondrial function, highlighting the complex molecular mechanisms underlying this disorder.
Four dead bodies were also recovered from Bannu whereas two people were injured in a drone and a bridge was destroyed by insurgentsin Miryan Tehsil of Bannu. An MBIED attack took place in Quetta with no casualties. TTP killed an FC soldier in Wara Mamund while another soldier was killed and several injured in a TTP attack on a military camp in Shakai area of South Waziristan. An insurgent vehicle was destroyed by a drone strike in Wana Tehsil. TTP issued warnings to the public, Police and tribal elders in Tank District in a video message warning against participation in military operations and also destroyed the Outar police checkpost there with explosives. On 18 July, a premature IED detonation led to the death of five TTP militants in the Nakhtar area of Wara Mamund Tehsil while another was killed in Wana Tehsil in a foiled VBIED attack. A TTP attack on Khazina Banda post in Hangu District wounded an Elite Force Personnel. CTD conducted an operation in Koraai area of Dera Ismail Khan District killing a TTP militant. On 19 July, heavy skirmishes took place between Afghan and Pakistani forces in Kurram District following an attack on Pakistani positions by the Taliban, Pakistani forces then launched a counteroffensive forcing Taliban to abandon multiple posts at the border. An FC soldier was killed in an IMP sniper attack on Tor Chapar post in Tirah while several civilians were injured in a drone strike in Dabori Ganda Mela area of Tirah.
Glycocyamine kinase (EC 2.7.3.1), which catalyses the transfer of phosphate from ATP to guanidoacetate. Arginine kinase (EC 2.7.3.3), which catalyses the transfer of phosphate from ATP to arginine. Taurocyamine kinase (EC 2.7.3.4), an annelid-specific enzyme that catalyses the transfer of phosphate from ATP to taurocyamine. Lombricine kinase (EC 2.7.3.5), an annelid-specific enzyme that catalyses the transfer of phosphate from ATP to lombricine. Smc74, a cercaria-specific enzyme from Schistosoma mansoni. Creatine kinase (EC 2.7.3.2) (CK), which catalyses the reversible transfer of high energy phosphate from ATP to creatine, generating phosphocreatine and ADP. Creatine kinase plays an important role in energy metabolism of vertebrates. There are at least four different, but very closely related, forms of CK. Two isozymes, M (muscle) and B (brain), are cytosolic, while the other two are mitochondrial. In sea urchins there is a flagellar isozyme, which consists of the triplication of a CK-domain. A cysteine residue is implicated in the catalytic activity of these enzymes and the region around this active site residue is highly conserved. ATP:guanido phosphotransferases contain a C-terminal catalytic domain which consists of a duplication where the common core consists of two beta-alpha-beta2-alpha repeats. The substrate binding site is located in the cleft between N and C-terminal domains, but most of the catalytic residues are found in the larger C-terminal domain.
The left corridor had a beautiful mural showing a monk transmitting the teachings of the Buddha to a kneeling royal family, whether the mural in front of it on the external wall was entirely gone. Similarities have been noted between the paintings of the Cave of the Painters and those of Dilberjin Tepe and Penjikent of the 5th–6th centuries.
Sources: en.wikipedia.org
Newly formed astatine-211 is the subject of ongoing research in nuclear medicine. It must be used quickly as it decays with a half-life of 7.2 hours; this is long enough to permit multistep labeling strategies. Astatine-211 has potential for targeted alpha-particle therapy, since it decays either via emission of an alpha particle (to bismuth-207), or via electron capture (to an extremely short-lived nuclide, polonium-211, which undergoes further alpha decay), very quickly reaching its stable granddaughter lead-207. Polonium X-rays emitted as a result of the electron capture branch, in the range of 77–92 keV, enable the tracking of astatine in animals and patients. Although astatine-210 has a slightly longer half-life, it is wholly unsuitable because it usually undergoes beta plus decay to the extremely toxic polonium-210. The principal medicinal difference between astatine-211 and iodine-131 (a radioactive iodine isotope also used in medicine) is that iodine-131 emits high-energy beta particles, and astatine does not. Beta particles have much greater penetrating power through tissues than do the much heavier alpha particles. An average alpha particle released by astatine-211 can travel up to 70 μm through surrounding tissues; an average-energy beta particle emitted by iodine-131 can travel nearly 30 times as far, to about 2 mm.
=== Correlates === A variety of studies have examined the relationship between health behaviors and health outcomes (e.g., Blaxter 1990) and have demonstrated their role in both morbidity and mortality. These studies have identified seven features of lifestyle which were associated with lower morbidity and higher subsequent long-term survival (Belloc and Breslow 1972):
The two substrates of this enzyme are 5,10-methylenetetrahydrofolate and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are 5,10-methenyltetrahydrofolate, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 5,10-methylenetetrahydrofolate:NAD+ oxidoreductase. This enzyme is also called methylenetetrahydrofolate dehydrogenase (NAD+). This enzyme participates in one carbon pool by folate.
=== Positive staining === Unlike negative staining, positive staining uses basic dyes to color the specimen against a bright background. While chromophore is used for both negative and positive staining alike, the type of chromophore used in this technique is a positively charged ion instead of a negative one. The negatively charged cell wall of many microorganisms attracts the positively charged chromophore which causes the specimen to absorb the stain giving it the color of the stain being used. Positive staining is more commonly used than negative staining in microbiology. The different types of positive staining are listed below.
Dexamethasone is recommended by the National Health Service in the UK and the National Institutes of Health (NIH) in the US for people with COVID-19 who need either mechanical ventilation or supplemental oxygen (without ventilation). The Infectious Diseases Society of America (IDSA) guideline panel suggests the use of glucocorticoids for people with severe COVID-19, defined as people with SpO2 ≤94% on room air, and those who require supplemental oxygen, mechanical ventilation, or extracorporeal membrane oxygenation (ECMO). The IDSA recommends against the use of glucocorticoids for those with COVID-19 without hypoxemia requiring supplemental oxygen. The World Health Organization (WHO) recommends systemic corticosteroids rather than no systemic corticosteroids for the treatment of people with COVID-19 (strong recommendation, based on moderate certainty evidence). The WHO suggests not to use corticosteroids in the treatment of people with non-severe COVID-19 (conditional recommendation, based on low certainty evidence). The Oxford University RECOVERY Trial issued a press release announcing preliminary results that the drug could reduce deaths by about a third in participants on ventilators and by about a fifth in participants on oxygen; it did not benefit people who did not require respiratory support. A meta-analysis of seven clinical trials of critically ill COVID-19 participants, each treated with one of three different corticosteroids found a statistically significant reduction in death. The largest reduction was obtained with dexamethasone (36% compared to placebo).
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.
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.