telomerase 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 2026-05-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
Most experimental work has been carried out in cell culture and animal models. Several reports describe changes in telomerase activity and proliferation in cultured cells, while rodent studies have examined lifespan, melatonin rhythm and reproductive endpoints. Human data remain limited, and much of the published clinical material consists of small trials with incomplete reporting of methods and controls. Whether the cell and animal findings translate into measurable effects in people is an open question, and the mechanistic basis of the reported telomerase changes is not fully established.
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
| 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 |
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.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
SeV can replicate to high titers in human monocyte-derived DCs. With the multiplicity of infection of 2, approximately 1/3 of the DCs begin to express encoded SeV proteins 8 hours after infection. This proportion increases to 2/3, 24 hours and decreases to 1/3, 48 hours after infection. SeV demonstrates high cytopathic effect on DCs; the virus can kill a third of DC even with a very low multiplicity of infection such as 0.5. Most important observation is that SeV infection triggers DC maturation, which is manifested in DC cell surface markers composition. The virus increases the expression of class I and class II molecules of the major histocompatibility complex (MHC) (HLA-A, HLA-B, HLA-C and HLADR), CD83, as well as costimulatory molecules CD40 and CD86.
Monocryl is a synthetic, absorbable suture manufactured in Cornelia, Georgia, USA, and trademarked by Ethicon. It is composed of poliglecaprone 25, which is a copolymer of glycolide and ε-caprolactone. It comes both dyed (violet) and undyed (clear) and is an absorbable monofilament suture. It is generally used for soft-tissue approximation and ligation. It is used frequently for subcuticular dermis closures of the face. It has less of a tendency to exit through the skin after it breaks down, in contrast to Vicryl. It is contraindicated for use in cardiovascular and neurologic tissues and for usage in ophthalmic and microsurgery. The use of poliglecaprone suture may be inappropriate in patients who are older, malnourished, or debilitated, as well as in patients with conditions that may delay wound healing. Monocryl has a low tissue reactivity, maintains high tensile strength, and has a half-life of 7 to 14 days. At 1 week, its in vivo tensile strength is at 50–60% undyed (60–70% dyed), 20–30% undyed (30–40% dyed) at two weeks, and essentially completely hydrolyzed by 91–119 days. When removed from the package, it has a high degree of "memory", or coil. It is slippery, making it easier to pass than a braided suture. It has a consistency close to nylon suture material. It is rarely used for percutaneous skin closure and is not used in areas of high tension (e.g., fascia).
The three substrates of this enzyme are 3-oxopropanoic acid, reduced nicotinamide adenine dinucleotide (NAD+), and water. Its products are malonic acid, reduced NADH, and a proton. This enzyme can use the alternative cofactor, nicotinamide adenine dinucleotide phosphate. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 3-oxopropanoate:NAD(P)+ oxidoreductase. This enzyme participates in beta-alanine metabolism.
Most notably, the oldest samples of European cheese (5500 BC) were found in the region of Kuyavia, and a pot from Bronocice is incised with what is now believed to be the earliest-known portrayal of a wheeled vehicle (3400 BC). Toolmaking became more advanced and material was primarily sourced from quarries and mines in the Świętokrzyskie (Holy Cross) Mountains. Artifacts that originated in this mountain region were excavated as far as Moravia and near the Baltic Sea. It is estimated that the UNESCO-protected neolithic flint mines at Krzemionki, one of Europe's largest, were utilised by the Funnelbeaker and Globular Amphora cultures from 3900 BC to 1600 BC. The only surviving example of ancient parietal art in Poland is at a flint shaft in Krzemionki and features a linear charcoal pictogram of a female figure or deity that has been since associated with fertility.
E. × cantabrigiense Stearn, hybrid between E. alpinum and E. pubigerum E. × perralchicum Stearn, hybrid between E. perralderianum and E. pinnatum subsp. colchicum E. × rubrum Morr., hybrid between E. alpinum and E. grandiflorum E. × versicolor Morr., hybrid between E. grandiflorum and E. pinnatum subsp. colchicum E. × warleyense Stearn, hybrid between E. alpinum and E. pinnatum subsp. colchicum E. × youngianum Fisch & C.A.Mey, hybrid between E. diphyllum and E. grandiflorum
Sources: en.wikipedia.org
Many derivatives and structural analogs of modafinil have been synthesized. Examples include adrafinil, CE-123, fladrafinil (CRL-40941; fluorafinil), flmodafinil (CRL-40940; bisfluoromodafinil, lauflumide), RDS03-94, JJC8-088, modafiendz and modafinil sulfone.
=== 25 February === An SAF Antonov An-26 transport aircraft crashed into a residential area of Karari, Omdurman, during takeoff from Wadi Seidna Air Base, killing at least 46 people including Major-General Bahr Ahmed, a senior commander in Khartoum. The SAF recaptured Al-Khiwai, advancing closer to relieve the siege of El-Khiwai.
== Further reading == Katz, Alan (1 May 2009), "Lab Automation Protocols and Virtual Workcells", Genetic Engineering & Biotechnology News, OMICS, vol. 29, no. 9, Mary Ann Liebert, pp. 40–41, ISSN 1935-472X, OCLC 77706455, archived from the original on 25 February 2012, retrieved 25 July 2009
== External links == World Health Organization guidelines for the availability and accessibility of controlled substances Reference list to the previous publication Links to all language versions of the previous publication CDC Guideline for Prescribing Opioids for Chronic Pain — United States, 2016
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.
It is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, often abbreviated AEDG. The molecule is linear and contains no modified residues, so it is fully described by its sequence.