This is a working overview of epithalamin, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-03 and is reviewed periodically as new material appears.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. The chromatogram shows the main peak and any truncated or oxidised by-products, while the mass spectrum confirms the expected 390 dalton mass. Amino acid analysis can corroborate composition when a sample's origin is uncertain. Counterion content, particularly residual trifluoroacetate from purification, is frequently reported alongside purity because it shifts the net mass of the solid.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised and often hygroscopic |
| Solubility class | Freely soluble in water | Poor solubility in non-polar solvents |
| Typical storage temperature | -20 degrees Celsius or colder | Sealed, desiccated, protected from light |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Establishes purity and confirms mass |
| Common salt form | Trifluoroacetate or acetate | Counterion reported alongside purity values |
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
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.
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.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
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.
Within the first two days after birth, kittens acquire passive immunity from their mother's milk. Milk within the first few days of parturition is called colostrum and contains high concentrations of immunoglobulins. These include immunoglobulin A and immunoglobulin G, which cross the neonatal intestinal barrier. The immunoglobulins and growth factors found in the colostrum begin to establish and strengthen the weak immune system of the offspring. Kittens are able to chew solid food around 5–6 weeks after birth, and it is recommended that 30% of their diet consist of solid food at this time. The kitten remains on the mother's milk until around eight weeks of age, when weaning is complete and solid food becomes the primary food source.
The project was suggested to and given the green light by Mazda's Senior Managing Director Keiji Asano while he was on a trip to Indonesia in 1986. Sold alongside the seventh generation 323, an MR90 cost less than half the price of the newer model, but still more expensive than Toyota Kijang and Suzuki Carry "minibuses" as the country imposed 30% tax for saloons. In the past hatchback and wagon were classified as sedan Indonesia, but then revised as "minibus" in early 2000s. This changes boosting the sales of hatchbacks and started the downfall of sedans popularity in Indonesia.
=== Nitrogen decompression === For nitrogen decompression, large quantities of nitrogen are first dissolved in the cell under high pressure within a suitable pressure vessel. Then, when the gas pressure is suddenly released, the nitrogen comes out of the solution as expanding bubbles that stretch the membranes of each cell until they rupture and release the contents of the cell. Nitrogen decompression is more protective of enzymes and organelles than ultrasonic and mechanical homogenizing methods and compares favorably to the controlled disruptive action obtained in a PTFE and glass mortar and pestle homogenizer. While other disruptive methods depend upon friction or a mechanical shearing action that generate heat, the nitrogen decompression procedure is accompanied by an adiabatic expansion that cools the sample instead of heating it. The blanket of inert nitrogen gas that saturates the cell suspension and the homogenate offers protection against oxidation of cell components. Although other gases: carbon dioxide, nitrous oxide, carbon monoxide and compressed air have been used in this technique, nitrogen is preferred because of its non-reactive nature and because it does not alter the pH of the suspending medium. In addition, nitrogen is preferred because it is generally available at low cost and at pressures suitable for this procedure. Once released, subcellular substances are not exposed to continued attrition that might denature the sample or produce unwanted damage. There is no need to watch for a peak between enzyme activity and percent disruption.
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The meta-analysis also noted that the mechanisms of acupuncture "are clinically relevant, but that an important part of these total effects is not due to issues considered to be crucial by most acupuncturists, such as the correct location of points and depth of needling" and that acupuncture may be "associated with more potent placebo or context effects" than other treatments. Commenting on these findings, both Edzard Ernst and David Colquhoun said the results were of negligible clinical significance. A 2011 overview of Cochrane reviews found evidence that suggests acupuncture is effective for some but not all kinds of pain. A 2010 systematic review found that there is evidence "that acupuncture provides a short-term clinically relevant effect when compared with a waiting list control or when acupuncture is added to another intervention" in the treatment of chronic low back pain. Two review articles discussing the effectiveness of acupuncture, from 2008 and 2009, have concluded that there is not enough evidence to conclude that it is effective beyond the placebo effect. Acupuncture is generally safe when administered using Clean Needle Technique (CNT). Although serious adverse effects are rare, acupuncture is not without risk. Severe adverse effects, including very rarely death (five case reports), have been reported.
Italian merchants, particularly the Venetians, Genoese, and Pisans, took control of international trade, thus reducing the influence of native merchants. The political system grew increasingly extractive and authoritarian, contributing to the empire's collapse in 1204. The fall of Constantinople during the Fourth Crusade in 1204 destroyed centuries of its wealth. Large landholdings were confiscated, and the empire fragmented into smaller rump states ruled by competing factions, making governance inefficient and increasing the costs of doing business. The state gradually lost control over trade practices, price regulations, the outflow of precious metals, and possibly even the minting of coins. Italian merchants further dominated trade as the events of 1204 opened the Black Sea to Western merchants, permanently altering the empire's fortunes. Farmers and manufacturers increasingly produced goods for local use and were affected by the insecurity of constant warfare. Despite these challenges, the empire's mixed economy (characterised by state interventions, public works, and market liberalisation) remained a model of medieval economic adaptability, even as it deteriorated under external pressures.
Thyroid's secretory capacity (GT, also referred to as SPINA-GT) is the maximum stimulated amount of thyroxine the thyroid can produce in one second. GT is elevated in hyperthyroidism and reduced in hypothyroidism. GT is calculated with
=== Interactions === It is a CYP3A4 substrate and hence any inhibitor or inducer of this enzyme may alter plasma levels of alitretinoin. It should not be given to patients with excess vitamin A in their system as there is a potential for its actions on the retinoid X receptor to be exacerbated. It may also interact with tetracyclines to cause benign intracranial hypertension.
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== Pharmacokinetics == Maximum decrease in blood pressure occurs 4–6 hours after oral dosage. The half-life of methyldopa is 105 minutes. Methyldopa exhibits variable absorption from the gastrointestinal tract. It is metabolized in the liver and intestines and is excreted in urine.
== Yeast == The selection of yeast used for cider production is critical to the quality of the final product. As with other fermented beverages, like wine and beer, the strain of yeast used to carry out the alcoholic fermentation also converts precursor molecules into the odorants found in the final product. In general, two broad categories of yeast are used for cider making: commercially developed strains and wild, or autochthonous, strains. In either case, the species tend to be either Saccharomyces cerevisiae or Saccharomyces bayanus. Commercial strains are available for purchase from numerous distributors, and their characteristics are typically outlined in manuals from the companies. Selection for fermentation may be based on a yeast's ability to ferment at particular sugar concentrations, temperatures, or pH. Some producers may also select for yeasts that produce killer factors, allowing them to out-compete other yeast in the juice, or they may select yeast that contribute mouthfeel or specific aromas to the cider. "Wild fermentations" occur when autochthonous yeast are allowed to carry out fermentation; indigenous yeasts can spontaneously initiate fermentation without any addition of other yeast strains by the cider maker. Autochthonous yeasts are wild yeast strains that are endemic to the specific location in which a cider is produced; this is the traditional method used for cider making, and many producers feel that the strains unique to their cidery contribute a sense of terroir to their product.
However, the military provided him with no records of any medical discrepancies caused by actions during war. If Willie was to be diagnosed with Gulf War Illness, he would not have a course of treatment. He would have to learn to cope with the disease until a treatment becomes available in the future. Willie and his wife go to visit a Marine Veteran who was diagnosed with Gulf War Illness to be able to relate any similarities and narrow down the possibilities.
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Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase HPLC establishes purity and separation from related peptides, and mass spectrometry confirms the molecular mass. Amino acid analysis can verify residue composition. No single method proves identity on its own, so the results are read together.
Yes. Residual trifluoroacetate or acetate from purification adds mass and can shift the value obtained by certain assays. Purity figures are therefore meaningful only when the counterion form is stated. Reporting both peptide content and salt form gives a clearer picture.
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.