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.
Last reviewed on 2026-05-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
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 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.
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.
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.
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.
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.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
=== Fertilizer === Hydrolyzing a protein improves the digestibility not only for animals, but also for soil microbes. As a result, it becomes useful as a fertilizer providing nitrogen and potentially also sulfur. Hydrolyzed keratin from chicken feather is the most common type, though other kinds of waste proteins (e.g. waste wool, waste fish) are also re-used this way. Hydrolyzed protein fertilizer is considered an organic fertilizer. It contains a high amount of available nitrogen, and unlike unhydrolyzed feather meal, tends to release the nitrogen quickly. It helps the growth of soil microbes and improves soil quality.
==== Stress and addiction ==== Stress contributes to both the development and the persistence of addiction, affecting neurophysiological pathways, decision-making and relapse risk. Acute and chronic stress activate the hypothalamic–pituitary–adrenal axis, raising levels of cortisol and corticotropin-releasing hormone; these changes alter reward processing and increase the motivational pull of substances, particularly those that temporarily relieve negative mood. In animal studies, repeated stress exposure increases dopamine release in the nucleus accumbens and sensitizes the mesolimbic reward system, making drugs more reinforcing. Chronic stress also disturbs glutamatergic signaling in the prefrontal cortex, impairing inhibitory control and self-regulation, which increases susceptibility to compulsive drug seeking and reduces the ability to disregard drug-associated cues. Stress is among the more reliable predictors of relapse. In human neuroimaging studies, stress-induced activation of the amygdala together with reduced prefrontal regulation is associated with self-reported craving and with subsequent return to use. People with a history of trauma, or of chronic social stress such as discrimination, poverty or housing insecurity, are at increased risk of substance use disorders. Because stress interacts with reward circuitry and decision-making systems, many treatment approaches incorporate stress-reduction strategies, including cognitive behavioral therapy, mindfulness-based interventions and medications acting on stress-related neurochemistry.
=== Reduction === Alloxan may be reduced to dialuric acid, which has a reductone structure, similar to ascorbic acid (Vitamin C). However, unlike ascorbic acid, alloxan and dialuric acid have strong pro-oxidant physiological effects. A dimeric derivative alloxantin can be prepared by partial reduction of alloxan with hydrogen sulfide.
=== Structural superposition === The most basic possible comparison between protein structures makes no attempt to align the input structures and requires a precalculated alignment as input to determine which of the residues in the sequence are intended to be considered in the RMSD calculation. Structural superposition is commonly used to compare multiple conformations of the same protein (in which case no alignment is necessary, since the sequences are the same) and to evaluate the quality of alignments produced using only sequence information between two or more sequences whose structures are known. This method traditionally uses a simple least-squares fitting algorithm, in which the optimal rotations and translations are found by minimizing the sum of the squared distances among all structures in the superposition. More recently, maximum likelihood and Bayesian methods have greatly increased the accuracy of the estimated rotations, translations, and covariance matrices for the superposition. Algorithms based on multidimensional rotations and modified quaternions have been developed to identify topological relationships between protein structures without the need for a predetermined alignment. Such algorithms have successfully identified canonical folds such as the four-helix bundle. The SuperPose Archived 2015-10-31 at the Wayback Machine method is sufficiently extensible to correct for relative domain rotations and other structural pitfalls.
Sources: en.wikipedia.org
For example, people with migraine are more likely to become anxious and depressed, but people with anxiety and depression also have a higher risk of becoming affected by migraine. The most frequently reported migraine trigger for women is hormonal variation, followed by stress for both women and men. Disrupted sleep, fasting, missing meals, dehydration, and sensory overstimulation are also commonly reported triggers. There is strong evidence that hormonal changes, stress, quality of sleep, and fasting are causally related to migraine attacks. These "catalyst triggers" may increase activity in the hypothalamus or trigeminal system of the brain until it exceeds the brain's migraine threshold. From puberty onwards, women experience migraine attacks more frequently and with greater severity than men, particularly for migraine without aura. The incidence of attacks of migraine without aura is strongly related to hormonal fluctuations in estrogen, both monthly and across a woman's lifespan. Keeping the body's internal environment stable and consistent appears to protect the brain's migraine sensitivity threshold, while disruption and stresses may make it more likely for the brain to go past its sensitivity threshold. Lifestyle changes that support stability, such as regular sleep, regular meals, and stress management, can help to prevent migraines. Whether a possible trigger is an actual cause or an early symptom, it may be possible to reduce discomfort by managing exposure to sensory stimuli such as smells, lights, sound, or touch.
Experimental gene therapy exists to treat hereditary spherocytosis in lab mice; however, this treatment has not yet been tried on humans due to all of the risks involved in human gene therapy. Bone marrow transplant. Paradoxical endurance-based athleticism associated with hereditary spherocytosis. Evolution of spherocytic erythrocyte adaptation in those of Northern European and Japanese descent. Increased ability to defend against viral infections in hereditary spherocytosis patients.
Brazzein is a sweet-tasting protein that occurs naturally in oubli (Pentadiplandra brazzeana), a fruit native to the Atlantic coastal areas of Central Africa. Brazzein was named in 1994 by scientists at the University of Wisconsin–Madison. It is roughly 500 to 2000 times sweeter than sucrose. Brazzein is found in the extracellular region of oubli fruit, in the pulp tissue surrounding the seeds. It was first discovered and isolated in 1989 by Wel et al. under the name of pentadin. The corresponding author of both these publications has later opined that pentadin and brazzein are two different names for the same protein. Even though pentadin is the earlier proposed name, brazzein is the more commonly used name after more extensive characterisation of the sweet protein. Like other sweet proteins discovered in plants, such as monellin and thaumatin, brazzein is extremely sweet compared to commonly used sweeteners. The fruit tastes sweet to humans, monkeys, and bonobos, but gorillas have mutations in their sweetness receptors so that they do not find brazzein sweet, and they are not known to eat the fruit.
=== Anxiety disorders === Pregabalin is effective for treatment of generalized anxiety disorder. It is also effective for short- and long-term treatment of social anxiety disorder and in reducing preoperational anxiety. However, there is concern regarding pregabalin's off-label use due to the lack of strong scientific evidence for its efficacy in multiple conditions and its proven side effects. The World Federation of Biological Psychiatry recommends pregabalin as one of several first line agents for the treatment of generalized anxiety disorder, but recommends other agents such as those of the selective serotonin reuptake inhibitor (SSRI) class as first-line treatment for obsessive–compulsive disorder (OCD) and post-traumatic stress disorder (PTSD). For PTSD, pregabalin as complementary treatment seems to be effective.
== Chemical properties == Temozolomide is an imidazotetrazine derivative. It is slightly soluble in water and aqueous acids, and decomposes at 212 °C (414 °F). It was discovered in 2021 that temozolomide is an explosive, tentatively assigned as UN Class 1. Temozolomide has also been reported to be a comparatively safe and stable in situ source of diazomethane in organic synthesis. In particular, use as a methylating and cyclopropanating reagent has been demonstrated.
Sources: en.wikipedia.org
=== Tray drying === A tray dryer is similar to a convection drier, which is placed in enclosed, insulated chambers and trays on top of each other in the tray. Input materials are batch-fed, placed in trays, and loaded into ovens for drying. Dryers are used in processing where drying and heating are important parts of the industrial manufacturing process, like dried fruits. Tray drying means dehydrating small pieces of fruit from a source of hot, dry air or the sun until they are dry enough to store at ambient temperature with minimal spoilage. Despite its poor re-hydration properties and shrunken appearance, this process requires a short period of time along with controlled humidity and heated air.
Scanners are used to monitor emergency police, fire, and ambulance frequencies, as well as other two way radio frequencies such as citizens band. Scanning capabilities have also become a standard feature in communications receivers, walkie-talkies, and other two-way radios. Communications receiver or shortwave receiver - a general purpose audio receiver covering the LF, MF, shortwave (HF), and VHF bands. Used mostly with a separate shortwave transmitter for two-way voice communication in communication stations, amateur radio stations, and for shortwave listening.
Alvin America "Eric" Tao (Ken Leung) is a MD on Pierpoint’s CPS desk and one of the series’ protagonists. A longtime Pierpoint executive, Eric is brilliant, volatile, and ruthlessly pragmatic, frequently crossing ethical lines in pursuit of power. He takes Harper Stern on as a protégé, recognizing her ambition as a reflection of his own. Eric rose through the firm’s New York headquarters under the late MD Newman, remaining conflicted between admiration for Newman and the racism Newman directed at him. Eric is longtime friends with global head of FICC Bill Adler, whom he once hired and who later surpassed him in rank. He is married to Candice Allbright with two daughters, Lily and Lara. In series 1, Eric salvages a disastrous trade Harper executes and admits he knows she never graduated from college but does not care. His relationship with key client Felim Bichan collapses after Eric makes offensive remarks in front of Felim’s wife. When Harper fails to recover the account, Eric traps and berates her in a conference room, prompting Daria Greenock to push Harper to report him, leading to Eric’s firing. On reduction-in-force day, Adler convinces Harper to retract her complaint to reinstate Eric, resulting in Daria’s dismissal. In series 2, Eric briefly regains Felim as client, only to lose him permanently after Harper goes behind Eric's back to sell a controlling stake in healthcare startup Rican to Jesse Bloom, which Eric had promised to Felim. Adler confronts Eric over sustained underperformance, sidelines him from the trading floor, and relegates him to a marginal role.
Stachys affinis, commonly called crosne, Chinese artichoke, Japanese artichoke, knotroot, or artichoke betony, is a perennial herbaceous plant of the family Lamiaceae, originating from China. Its rhizome is a root vegetable that can be eaten raw, pickled, dried or cooked.
affected relative pair Any pair of organisms which are related genetically and both affected by the same trait. For example, two cousins who both have blue eyes are an affected relative pair since they are both affected by the allele that codes for blue eyes.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.