The short version of Tetrapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-02. Anything still debated is marked as such rather than presented as settled.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
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.
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.
| 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 whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
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.
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 eluting strength of the mobile phase is reflected by analyte retention times, as the high eluting strength speeds up the elution (resulting in shortening of retention times). For example, a typical gradient profile in reversed phase chromatography might start at 5% acetonitrile (in water or aqueous buffer) and progress linearly to 95% acetonitrile over 5–25 minutes. Periods of constant mobile phase composition (plateau) may be also part of a gradient profile. For example, the mobile phase composition may be kept constant at 5% acetonitrile for 1–3 min, followed by a linear change up to 95% acetonitrile. The chosen composition of the mobile phase depends on the intensity of interactions between various sample components ("analytes") and stationary phase (e.g., hydrophobic interactions in reversed-phase HPLC). Depending on their affinity for the stationary and mobile phases, analytes partition between the two during the separation process taking place in the column. This partitioning process is similar to that which occurs during a liquid–liquid extraction but is continuous, not step-wise. In the example using a water/acetonitrile gradient, the more hydrophobic components will elute (come off the column) later, then, once the mobile phase gets richer in acetonitrile (i.e., in a mobile phase becomes higher eluting solution), their elution speeds up. The choice of mobile phase components, additives (such as salts or acids) and gradient conditions depends on the nature of the column and sample components.
== Toxic analogues == Several non-proteinogenic amino acids are toxic due to their ability to mimic certain properties of proteinogenic amino acids, such as thialysine. Some non-proteinogenic amino acids are neurotoxic by mimicking amino acids used as neurotransmitters (that is, not for protein biosynthesis), including quisqualic acid, canavanine, caramboxin and azetidine-2-carboxylic acid. Cephalosporin C has an α-aminoadipic acid (homoglutamate) backbone that is amidated with a cephalosporin moiety. Penicillamine is a therapeutic amino acid, whose mode of action is unknown.
In this flow regime, many small vortices are responsible for the transfer of momentum between the bulk of the fluid to the pipe wall. As the friction Reynolds number Re√fD increases, the profile of the fluid velocity approaches the wall asymptotically, thereby transferring more momentum to the pipe wall, as modeled in Blasius boundary layer theory.
Sources: en.wikipedia.org
=== Growstones === Growstones, made from glass waste, have both more air and water retention space than perlite and peat. This aggregate holds more water than parboiled rice hulls. Growstones by volume consist of 0.5 to 5% calcium carbonate – for a standard 5.1 kg bag of Growstones that corresponds to 25.8 to 258 grams of calcium carbonate. The remainder is soda-lime glass.
== Naming conventions == Before reunification, Germany was divided between the Bundesrepublik Deutschland (Federal Republic of Germany; commonly known as West Germany) and the Deutsche Demokratische Republik (DDR; German Democratic Republic; commonly known as East Germany). Reunification was achieved by accession (Beitritt) of the German Democratic Republic to the Federal Republic of Germany, so Bundesrepublik Deutschland became the official name of reunified Germany. In East Germany, the terms Westdeutschland (West Germany) or westdeutsche Bundesrepublik (West German Federal Republic) were preferred during the 1950s and 1960s. This changed under its constitutional amendment in 1974, when the idea of a single German nation was abandoned by East Germany. As a result, it officially considered West Germans and West Berliners as foreigners. The initialism BRD (FRG in English) began to prevail in East German usage in the early 1970s, beginning in the newspaper Neues Deutschland. Other Eastern Bloc nations soon followed suit. In 1965, the West German Federal Minister of All-German Affairs, Erich Mende, had issued the "Directives for the Appellation of Germany", recommending avoiding the initialism BRD. On 31 May 1974, the heads of West German federal and state governments recommended always using the full name in official publications. From then on, West German sources avoided the abbreviated form, with the exception of left-leaning organisations which embraced it.
==== MeSH D12.776.624.776.355 – cyclin-dependent kinase inhibitor proteins ==== MeSH D12.776.624.776.355.100 – cyclin-dependent kinase inhibitor p15 MeSH D12.776.624.776.355.200 – cyclin-dependent kinase inhibitor p16 MeSH D12.776.624.776.355.300 – cyclin-dependent kinase inhibitor p18 MeSH D12.776.624.776.355.400 – cyclin-dependent kinase inhibitor p19 MeSH D12.776.624.776.355.500 – cyclin-dependent kinase inhibitor p21 MeSH D12.776.624.776.355.600 – cyclin-dependent kinase inhibitor p27 MeSH D12.776.624.776.355.700 – cyclin-dependent kinase inhibitor p57
Sources: en.wikipedia.org
Ceftaroline has low water solubility but this problem was overcome by attaching a N-phosphonoamino group to the molecule making the intravenous prodrug ceftaroline fosamil. The prodrug is dephosphorylated in plasma to form active ceftaroline.
Carnitine palmitoyltransferase I (CPT I) transfers the LCFAs from coenzyme A (CoA) to the hydroxyl group of the carnitine (from translocase in step 2) to make acyl-carnitine. This happens in the cytosol-facing outer membrane. The acyl-carnitine diffuses through the membrane into the intermembrane space for step two. Three types of this enzyme exist in humans: CPT IA (Found in the liver), CPT IB (found in the muscle), and CPT IC (found in the brain). This is the rate limiting step. Carnitine-acylcarnitine translocase (CACT), also known as SLC25A20, transfers acyl-carnitine to the matrix while carnitine from CPT 2 in the matrix is transferred out to CPT I in order to shuttle more LCFA's in step 1. This happens in the intermembrane space. Finally, carnitine palmitoyltransferase II (CPT II) transfers the LCFAs from carnitine to CoA to make fatty-acyl CoA while transporting out the carnitine to translocase and eventually CPT I to restart the cycle and shuttle more LCFA's. This happens in the mitochondrial matrix. The acyl-CoA is then metabolized via beta oxidation. The shuttle is regulated at the CPT-I level, being inhibited by malonyl-CoA from beta oxidation, preventing a futile cycle. Post-translational modifications, upregulation of the genes encoding the shuttle's enzymes, and cellular carnitine levels also regulate the shuttle. Only eukaryotes with membrane-bound organelles have the shuttle, as organisms with no organelles have no membranes to shuttle LCFAs into.
Bully: Marquez Height: 5'9 Weight: 167 lb Victim(s): Richard and Edward Fighter: Quinn Mulhern Height: 6'3 Weight: 177 lb Money earned by Bully: $6,000 Money earned by victim(s): $4,000 Original airing: This episode has never aired in the United States.
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.
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.