epithalamin is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
The mechanism of action of bupropion in the treatment of depression and for other indications is unclear. However, it is thought to be related to the fact that bupropion is a norepinephrine–dopamine reuptake inhibitor (NDRI) and negative allosteric modulator of several nicotinic acetylcholine receptors. Bupropion does not act as a norepinephrine–dopamine releasing agent. Pharmacological actions of bupropion, to a substantial degree, are due to its active metabolites hydroxybupropion, threo-hydrobupropion, and erythro-hydrobupropion that are present in the blood plasma at comparable or much higher levels. In fact, bupropion could accurately be conceptualized as a prodrug of these metabolites. The overall action of these metabolites, particularly that of one enantiomer, S,S-hydroxybupropion, is also characterized by inhibition of norepinephrine and dopamine reuptake and nicotinic inhibition (see the chart on the right). Bupropion has no meaningful direct activity at a variety of receptors, including α- and β-adrenergic, dopamine, serotonin, histamine, and muscarinic acetylcholine receptors. The occupancy of dopamine transporter (DAT) by bupropion (300 mg/day) and its metabolites in the human brain as measured by several positron emission tomography (PET) studies is approximately 20%, with a mean occupancy range of about 14 to 26%. For comparison, the NDRI methylphenidate at therapeutic doses is thought to occupy greater than 50% of DAT sites.
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=== Parasitic disease === Ivermectin has been researched in laboratory animals, as a potential treatment for trichinosis and trypanosomiasis. Ivermectin has also been tested on zebrafish infected with Pseudocapillaria tomentosa.
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Sources: en.wikipedia.org
For the same total acid concentration, the initial pH of the weak acid is less acid than that of the strong acid; however, the maximum amount of CaCO3 which can be dissolved is approximately the same. This is because in the final state, the pH is larger than the pKa, so that the weak acid is almost completely dissociated, yielding in the end as many H+ ions as the strong acid to "dissolve" the calcium carbonate. The calculation in the case of phosphoric acid (which is the most widely used for domestic applications) is more complicated since the concentrations of the four dissociation states corresponding to this acid must be calculated together with [HCO−3], [CO2−3], [Ca2+], [H+] and [OH−]. The system may be reduced to a seventh degree equation for [H+] the numerical solution of which gives
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Determining the location in space of a given blip was a complex multi-step process. First the operator would select a set of receiver antennas using the motorized switch, feeding signals to the receiver system. The antennas were connected together in pairs, forming two directional antennas, sensitive primarily along the X and Y axes respectively, Y being the line of shoot. The operator would then "swing the gonio", or "hunt", back and forth until the selected blip reached its minimum deflection on this display (or maximum, at 90 degrees off). The operator would measure the distance against the scale, and then tell the plotter the range and bearing of the selected target. The operator would then select a different blip on the display and repeat the process. For targets at different altitudes, the operator might have to try different antennas to maximize the signal. On the receipt of a set of polar coordinates from the radar operator, the plotter's task was to convert these to X and Y locations on a map. They were provided with large maps of their operational area printed on lightweight paper so they could be stored for future reference. A rotating straightedge with the centrepoint at the radar's location on the map was fixed on top, so when the operator called an angle the plotter would rotate the straightedge to that angle, look along it to pick off the range, and plot a point. The range called from the operator is the line-of-sight range, or slant range, not the over-ground distance from the station.
There was also honorary membership bestowed on those who had made unusual services to the Catholic faith, social or economic science, the arts, education, French culture generally, or to any other ideal of the association. 1967 membership 30,424; 1979 membership 26,000. Absorbed Foresters Franco Americains in 1939. The ACA went into rehabilitation in 2008 and later was liquidated. Most of its insurance policies were assumed by the Royal Arcanum.
Sources: en.wikipedia.org
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.
No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.
Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.