A practical reference on Epithalamin: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-20. Anything still debated is marked as such rather than presented as settled.
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.
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.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Synthetic tetrapeptide, four residues |
| Nominal mass | Approximately 390 Da | Free peptide; salt forms differ |
| Appearance | White to off-white powder | Commonly supplied lyophilised |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffer |
| Typical storage | −20 °C, desiccated | Cold packs used during transport |
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
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.
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.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
==== Azetidine based compounds ==== Informations for this group of inhibitors are quite restricted. Azetidine-based DPP-4 inhibitors can roughly be grouped into three main subcategories: 2-cyanoazetidines, 3-fluoroazetidines, and 2-ketoazetidines. The most potent ketoazetidines and cyanoazetidines have large hydrophobic amino acid groups bound to the azetidine nitrogen and are active below 100nM.
=== Pollution and phytoremediation === EcM fungi have been found to have beneficial effects in several types of polluted environments, including: • High salt: A number of studies have shown that certain EcM fungi can help their hosts survive high soil salinity conditions. • Radionuclides: Many species of ectomycorrhizal fungi, including the Cortinariaceae, can hyperaccumulate radionuclides • Organic pollutants: Some EcM species are capable of decomposing persistent organic pollutants (POPs) such as organochlorides and polychlorinated biphenyls (PCBs). Chemicals that can be detoxified by EcM fungi, either alone or in association with their host plant, include 2,4-dichlorophenol and tetrachloroethylene.
== Legacy == Laidlaw's "Epistle 3" story triggered a backlash from fans who took it as evidence that Valve had abandoned the Half-Life series. Some review bombed Valve's game Dota 2 on Valve's distribution service, Steam. The "Epistle 3" story also inspired fan games. After canceling several further Half-Life games, Valve released a VR game, Half-Life: Alyx, in 2020. Walker said the team saw VR as a way to return to the series. Phil Iwaunik of PCGamesN wrote in 2021 that the cancelation of Episode Three may have benefited the legacy of Half-Life 2, citing the lack of cultural impact of Alyx and the "mystery, speculation and melancholy" of an unfinished sequel. In 2024, Valve released footage and concept art of Episode Three as part of a documentary about the making of Half-Life 2.
Additional antiandrogen therapy is not necessarily required if testosterone levels are in the normal female range or if the person has undergone orchiectomy. However, individuals with testosterone levels in the normal female range and with persisting androgen-dependent skin and/or hair symptoms, such as acne, seborrhea, oily skin, or scalp hair loss, can potentially still benefit from the addition of an antiandrogen, as antiandrogens can reduce or eliminate such symptoms.
Sources: en.wikipedia.org
A sequential deterministic wallet utilizes a simple method of generating addresses from a known starting string or "seed". This would utilize a cryptographic hash function, e.g. SHA-256 (seed + n), where n is an ASCII-coded number that starts from 1 and increments as additional keys are needed.
== Publications == J. Kopeček, J. Yang, "Polymer Nanomedicines". Advanced Drug Delivery Reviews 156, 40–66 (2020) L. Li, Y. Li, C.-H. Yang, D.C. Radford, J. Wang, M. Janát-Amsbury, J. Kopeček, J. Yang, "Inhibition of Immunosuppresive Tumors by Polymer-Assisted Inductions of Immunogenic Cell Death and Multivalent PD-L1 Crosslinking". Advanced Functional Materials 30:1908961 (2020) L. Li, J. Wang, Y. Li, D.C. Radford, J. Yang, J. Kopeček, "Broadening and Enhancing Functions of Antibodies by Self-Assembling Multimerization at Cell Surface". ACS Nano 13, 11422–11432 (2019) J. Yang, L. Li, J. Kopeček, "Biorecognition: A Key to Drug-free Macromolecular Therapeutics". Biomaterials 190–191, 11–23 (2019) J. Wang, L. Li, J. Yang, P.M. Clair, M. Glenn, D.M. Stephens, D.C. Radford, K.M. Kosak, M.W. Deininger, P.J. Shami, J. Kopeček, "Drug-free Macromolecular Therapeutics Induce Apoptosis in Cells Isolated from Patients with B Cell Malignancies with Enhanced Apoptosis Induction by Pretreatment with Gemcitabine". Nanomedicine: Nanotechnology, Biology and Medicine 16, 217–225 (2019). J. Yang, R. Zhang, H. Pan, Y. Li, Y. Fang, L. Zhang, J. Kopeček, "Backbone Degradable HPMA Copolymer Conjugates with Gemcitabine and Paclitaxel: Impact of Molecular Weight on Activity toward Human Ovarian Carcinoma Xenografts". Molecular Pharmaceutics 14, 1384–1394 (2017) J.M. Hartley, T.-W. Chu, E.M. Peterson, R. Zhang, J. Yang, J. Harris, J.
Afamelanotide, sold under the brand name Scenesse, is a medication used to prevent phototoxicity and to reduce pain from light exposure for people with erythropoietic protoporphyria, a rare form of genetic sun sensitivity. Afamelanotide is a melanocortin 1 receptor (MC1 receptor) agonist and a synthetic peptide and analogue of α-melanocyte stimulating hormone. It is administered as subcutaneous implant. In the European Union, afamelanotide is indicated for the prevention of phototoxicity in adults with erythropoietic protoporphyria. In the United States, afamelanotide is indicated for increasing pain-free light exposure in adults with a history of reactions to light (phototoxicity) from erythropoietic protoporphyria.
The protein is 82.3 kDa and has a 40 amino acid long LEM domain located at its amino-terminal region. In its carboxyl end it has a RNA recognition motif (RRM). The LEM domain is also common to two other integral proteins of the INM: lamina-associated polypeptide 2 (LAP2) and emerin. The LEM segment enables LEMD3 to attach to the barrier-to-autointegration factor (BAF), and therefore, indirectly interact with the chromatin. LEMD3 also has several implications in regulating the cytokine family such as the transforming growth factor beta (TGF-β) and bone morphogenic protein (BMPs). The RRM domain in its carboxylic region attaches to the SMAD (protein) proteins, which is involved in mediating TGF-β cellular signalling. Consequently, LEMD3 indirectly regulates downstream genes. LEMD3 seems to play an important role in regulating the expression of several fundamental genes. LEMD3 has been associated with laminopathies as well as osteopoikilosis. Mutations in the LEMD3 gene have been linked to several genetic diseases such as osteopoikilosis, melorheostosis and Buschke–Ollendorff syndrome.
In vitro testing suggests that unidentified wolfberry phytochemicals in goji tea may inhibit metabolism of medications, such as those processed by the cytochrome P450 liver enzymes, including such drugs as warfarin. Organochlorine pesticides are conventionally used in commercial wolfberry cultivation to mitigate infestation by insects. China's Green Food Standard, administered by the Chinese Ministry of Agriculture's China Green Food Development Center, permits some pesticide and herbicide use. Agriculture in the Tibetan Plateau (where many "Himalayan" or "Tibetan"-branded berries supposedly originate) conventionally uses fertilizers and pesticides, making organic claims for berries originating there dubious. Since the early 21st century, high levels of insecticide residues (including fenvalerate, cypermethrin, and acetamiprid) and fungicide residues (such as triadimenol and isoprothiolane), have been detected by the United States Food and Drug Administration in some imported wolfberries and wolfberry products of Chinese origin, leading to the seizure of these products.
Sources: en.wikipedia.org
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.
No endogenous peptide with this exact sequence has been described as a circulating hormone or signalling molecule. The tetrapeptide was designed as a synthetic analogue based on fragments observed in pineal preparations. Any activity discussed in the literature therefore refers to administered material rather than to a natural pool of the compound.
It is not an approved medicine in major jurisdictions and does not appear in the major pharmacopoeias. Material is usually distributed as a research chemical or laboratory reagent. Such labelling places handling responsibility on the purchaser and does not indicate that a regulatory body has reviewed the substance.
The powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.