The short version of Epithalamin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-10-22. Anything still debated is marked as such rather than presented as settled.
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.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
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.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
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.
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Src homology 2 (SH2) domain SH2 domains are structurally composed by three-stranded twisted beta sheet sandwiched flanked by two alpha-helices. The existence of a deep binding pocket with high affinity for phosphotyrosine, but not for phosphoserine or phosphothreonine, is essential for the recognition of tyrosine phosphorylated proteins, mainly autophosphorylated growth factor receptors. Growth factor receptor binding proteins and phospholipase Cγ are examples of proteins that have SH2 domains. Src homology 3 (SH3) domain Structurally, SH3 domains are constituted by a beta barrel formed by two orthogonal beta sheets and three anti-parallel beta strands. These domains recognize proline enriched sequences, as polyproline type II helical structure (PXXP motifs) in cell signaling proteins like protein tyrosine kinases and the growth factor receptor bound protein 2 (Grb2). Phosphotyrosine-binding (PTB) domain PTB domains interact with sequences that contain a phosphotyrosine group. These domains can be found in the insulin receptor substrate. LIM domain LIM domains were initially identified in three homeodomain transcription factors (lin11, is11, and mec3). In addition to this homeodomain proteins and other proteins involved in development, LIM domains have also been identified in non-homeodomain proteins with relevant roles in cellular differentiation, association with cytoskeleton and senescence. These domains contain a tandem cysteine-rich Zn2+-finger motif and embrace the consensus sequence CX2CX16-23HX2CX2CX2CX16-21CX2C/H/D.
=== Endothelin-1(ET-1) === Is a vasoconstrictor peptide released from vascular endothelial cells. At the cellular level, the balance between vasodilator (Nitric oxide) and vasoconstrictor (ET-1) actions determines the vascular response to insulin. So, high levels of ET-1, which achieved in insulin resistance states that includes patients that have T2DM or metabolic syndromes or they are obese, have inhibitory effect on nitric oxide production which results in low nitric oxide and heightened levels of ET-1. ET-1 activity is also enhanced secondary to abnormalities in vascular insulin signalling, In addition to its direct vasoconstrictor effects. Furthermore, ET-1 induces a reduction in insulin sensitivity and may take part in the development of the metabolic syndrome.
Sources: en.wikipedia.org
The civil status records from 1860 to 1902 and the index of reconstructed records prior to 1860 (December 15, 2009). The ten-year tables of births, marriages, and deaths from 1903 to 1932; the annual tables of marriages from 1933 to 1939; the annual tables of deaths from 1933 to 1954; and the ten-year tables of marriages and deaths from 1955 to 1974 (January 12, 2016). Birth records from 1903; marriage records from 1903 to 1940. Death records from 1903 to 1986; ten-year tables of deaths from 1975 to 1984. Marriage records from 1941 to 1945; annual tables of deaths for 1985 and 1986. Reconstructed civil status records prior to 1860: Birth records (November 2020). Marriage records (January 2021). Death records (November 2021). Currently, all old Parisian civil records are accessible online.
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Sources: en.wikipedia.org
Jack Throck Watson (May 2, 1939 – September 3, 2016) was an American biochemist who was a professor of biochemistry and chemistry at the Michigan State University, where he was also director of the MSU Mass Spectrometry Facility. While at MIT, Watson developed a gas chromatography–mass spectrometry interface, known as the Watson–Biemann separator, that removes helium from the gas chromatograph column effluent, thereby allowing analysis of less volatile and more polar compounds. Watson later worked on methods for the structure elucidation of peptides and proteins using fast atom bombardment and matrix-assisted laser desorption ionization (MALDI) mass spectrometry. After retirement in 2006, he continued to work on his introductory mass spectrometry textbook and teach short-courses in mass spectrometry.
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The gingiva often possess a textured surface that is referred to as being stippled (engraved points). Stippling only presents on the attached gingiva bound to underlying alveolar bone, not the freely moveable alveolar mucosa or free gingiva. Stippling used to be thought to indicate health, but it has since been shown that smooth gingiva is not an indication of disease, unless it is smooth due to a loss of previously existing stippling. Stippling is a consequence of the microscopic elevations and depressions of the surface of the gingival tissue due to the connective tissue projections within the tissue. The degree of keratinization and the prominence of stippling appear to be related. To be more specific, stippling occurs at sites of fusion of the epithelial ridges (also known as rete pegs – depression of epithelium) and correspond to the fusion of the valleys created by the connective tissue papillae (elevation of connective tissue papilla). An example of stippling could be dots found on a basketball or an orange.
Sources: en.wikipedia.org
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.