Epithalamin 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 2025-09-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
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.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
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.
Pitolisant is an inverse agonist (antagonist) of the histamine H3 autoreceptor. As such, pitolisant is an antihistamine medication that also belongs to the class of CNS stimulants. Pitolisant is also considered a medication of eugeroic class, which means that it promotes wakefulness and alertness. Pitolisant is the first wakefulness-promoting agent that acts by blocking the H3 autoreceptor. Pitolisant has been shown to be effective and well-tolerated for the treatment of narcolepsy with or without cataplexy. Pitolisant is the only non-controlled anti-narcoleptic drug in the United States. It has shown minimal abuse risk in studies. Blocking the histamine H3 autoreceptor increases the activity of histamine neurons in the brain. The H3 autoreceptors regulate histaminergic activity in the central nervous system (and to a lesser extent, the peripheral nervous system) by inhibiting histamine biosynthesis and release upon binding to endogenous histamine. By preventing the binding of endogenous histamine at the H3, as well as producing a response opposite to that of endogenous histamine at the receptor (inverse agonism), pitolisant enhances histaminergic activity in the brain.
== Biological function == In animal tissue, BCKDC catalyzes an irreversible step in the catabolism of the branched-chain amino acids L-isoleucine, L-valine, and L-leucine, acting on their deaminated derivatives (L-alpha-keto-beta-methylvalerate, alpha-ketoisovalerate, and alpha-ketoisocaproate, respectively) and converting them to α-Methylbutyryl-CoA, Isobutyryl-CoA and Isovaleryl-CoA respectively. In bacteria, this enzyme participates in the synthesis of branched, long-chain fatty acids. In plants, this enzyme is involved in the synthesis of branched, long-chain hydrocarbons. The overall catabolic reaction catalyzed by the BCKDC is shown in Figure 1.
=== Persona non grata === The government of a country can declare a diplomat persona non grata, banning them from entering the country or expelling them if they have already entered. In non-diplomatic use, the authorities of a country may also declare a foreigner persona non grata permanently or temporarily, usually because of unlawful activity.
Sources: en.wikipedia.org
=== EC 1.14.20 With 2-oxoglutarate as one donor, and the other dehydrogenated === EC 1.14.20.1: deacetoxycephalosporin-C synthase EC 1.14.20.2: Now EC 1.14.11.59, 2,4-dihydroxy-1,4-benzoxazin-3-one-glucoside dioxygenase EC 1.14.20.3: (5R)-carbapenem-3-carboxylate synthase EC 1.14.20.4: anthocyanidin synthase EC 1.14.20.5: flavone synthase I EC 1.14.20.6: flavonol synthase EC 1.14.20.7: 2-oxoglutarate/L-arginine monooxygenase/decarboxylase (succinate-forming) EC 1.14.20.8: (–)-deoxypodophyllotoxin synthase EC 1.14.20.9: L-tyrosine isonitrile desaturase EC 1.14.20.10: L-tyrosine isonitrile desaturase/decarboxylase EC 1.14.20.11: 3-[(Z)-2-isocyanoethenyl]-1H-indole synthase EC 1.14.20.12: 3-[(E)-2-isocyanoethenyl]-1H-indole synthase EC 1.14.20.13: 6β-hydroxyhyoscyamine epoxidase EC 1.14.20.14: hapalindole-type alkaloid chlorinase EC 1.14.20.15: L-threonyl-[L-threonyl-carrier protein] 4-chlorinase
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Amino acids are a set of organic compounds that are used by living organisms to synthesise proteins. All amino acids (except glycine) have one or more pairs of stereoisomers, isomers which share the same bond order but are organized differently in 3D space. A given pair of stereoisomers that are optically active and non-superimposable mirror images of each other are called enantiomers; pairs that are not mirror images are diastereomers or epimers. Stereoisomers of the same molecule may undergo reactions (known as racemization or epimerization respective to the type of stereoisomer pair involved) that convert them to other stereoisomers. Biological systems are stereoselective, preferring certain stereoisomers for chemical reactions; living organisms keep all their amino acids in their "left-handed" (L or levo-) forms (a state called homochirality) because they are unable to use the "right-handed" (D or dextro-) forms for protein synthesis. When an organism becomes unable to keep its amino acids in that unbalanced ratio, such as by dying or shedding tissue, the system will proceed towards chemical equilibrium. Measuring the progress of this interconversion reaction allows estimation of an organism's time of death, if environmental variables like moisture and temperature are accounted for.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
Reversed-phase high-performance liquid chromatography with ultraviolet detection at 214 nanometres is the usual approach. Peak area percentage provides a purity figure relative to other components in the sample. Mass spectrometry is then applied to confirm identity.