The short version of Epitalon fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-10. Anything still debated is marked as such rather than presented as settled.
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.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
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.
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.
Typical storage for the lyophilized powder is −20 °C or lower, in a sealed container protected from light and moisture. Hygroscopic material should be allowed to equilibrate to room temperature before the vial is opened, which limits condensation on the contents. Working solutions are commonly divided into single-use aliquots and frozen to avoid repeated freeze-thaw cycles. Dilute solutions are more prone to adsorption onto plastic surfaces and to loss during filtration, so procedures that minimize transfers and use low-binding labware are preferable.
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.
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.
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.
All FSL Kode constructs disperse in water and are therefore compatible with inkjet printers. FSL constructs can be printed with a standard desktop inkjet printer directly onto paper to create immunoassays. An empty ink cartridge is filled with an FSL construct and words, barcodes, or graphics are printed. A Perspex template is adhered to the surface to create reaction wells. The method is then a standard EIA procedure, but blocking of serum is not required and undiluted serum can be used. A typical procedure is as follows: add serum, incubate, wash by immersion, add secondary EIA conjugate, incubate, wash, add NBT/BCIP precipitating substrate and stop the reaction when developed by washing (Fig. 9). The result is stable for years.
The taxonomic workforce remains insufficient for documenting lichen diversity. Lendemer (2021) found that only 14% of lichen-related research papers published in 2018–2020 included taxonomic work, while Lücking (2020) estimated that the current community of lichen taxonomists is only a fraction of what would be needed for a complete inventory. Expertise is particularly lacking in biodiversity-rich tropical regions where most undescribed species likely occur. However, infrastructure improvements are helping address these gaps. Since 2012–2013, mandatory registration of new fungal names in repositories like MycoBank has been widely adopted, with over 97% of new lichen species from 2018 to 2020 properly registered. Additionally, citizen scientists using platforms such as iNaturalist increasingly contribute to species discovery when collaborating with professional taxonomists. Nomenclatural challenges arise as lichen systematics increasingly encounters cryptic species. Environmental DNA studies reveal numerous uncharacterized fungal lineages, including potential lichenicolous fungi, but ICN rules require physical type specimens for species description. This creates difficulties for documenting diversity found only in environmental samples. The community generally discourages naming taxa known only from sequences to avoid proliferating dubious names. A related concern is taxonomic inflation—the risk that genomic data could lead to naming every population variant.
In biochemistry and molecular biology, a binding site is a region on a macromolecule such as a protein that binds to another molecule with specificity. The binding partner of the macromolecule is often referred to as a ligand. Ligands may include other proteins (resulting in a protein–protein interaction), enzyme substrates, second messengers, hormones, or allosteric modulators. The binding event is often, but not always, accompanied by a conformational change that alters the protein's function. Binding to protein binding sites is most often reversible (transient and non-covalent), but can also be covalent reversible or irreversible.
Foods rich in calcium include dairy products such as milk, yogurt, and cheese, as well as sardines, salmon, soy products, kale, and fortified breakfast cereals. Because of concerns for long-term adverse side effects, including calcification of arteries and kidney stones, both the U.S. Institute of Medicine (IOM) and the European Food Safety Authority (EFSA) set tolerable upper intake levels (ULs) for combined dietary and supplemental calcium. From the IOM, people of ages 9–18 years are not to exceed 3 g/day combined intake; for ages 19–50, not to exceed 2.5 g/day; for ages 51 and older, not to exceed 2 g/day. EFSA set the UL for all adults at 2.5 g/day, but decided the information for children and adolescents was not sufficient to determine ULs.
Sources: en.wikipedia.org
==== Korea ==== The earliest soy sauce brewing in Korea seems to have begun in the era of the Three Kingdoms. Jangdoks used for soy sauce brewing are found in the mural paintings of Anak Tomb No. 3 from the 4th century Goguryeo. In Samguk sagi, a historical record of the Three Kingdoms era, it is written that ganjang (soy sauce) and doenjang (soybean paste), along with meju (soybean block) and jeotgal (salted seafood), were prepared for the wedding ceremony of the King Sinmun in February 683. Sikhwaji, a section from Goryeosa (History of Goryeo), recorded that ganjang and doenjang were included in the relief supplies in 1018, after a Khitan invasion, and in 1052, when a famine occurred. Joseon texts such as Guhwangchwaryo and Jeungbo sallim gyeongje contain the detailed procedures on how to brew good quality ganjang and doenjang. Gyuhap chongseo explains how to pick a date for brewing, what to forbear, and how to keep and preserve ganjang and doenjang.
FAPLA's Cuban allies were less optimistic: they noted that the brigades were isolated, incapable of reinforcing each other quickly, and possessed insufficient mobile anti-aircraft weapons to protect them outside their bases. The Soviets recommended a static defence, appealing directly to Angolan President José Eduardo dos Santos, while the Cubans urged a withdrawal. Caught between two conflicting recommendations, dos Santos hesitated, and the brigades were ultimately annihilated piecemeal by the advancing South African armoured columns. Amid the confusion, a number of Angolan troops managed to break out of the South African encirclement and move north to link up with Cuban units, but a total of 471 FAPLA/PLAN personnel were killed or captured. Despite achieving their objectives during Operation Askari, the South African forces had encountered unexpectedly determined resistance from PLAN and FAPLA. The SADF acknowledged 25 killed in action and 94 wounded, the highest number of casualties suffered in any single operation since Operation Savannah. FAPLA also claimed to have shot down 4 South African aircraft.
The dose of 1S-LSD is reported to be similar to that of LSD. Blotter tabs containing 129 μg 1S-LSD have been encountered. 1S-LSD is thought to be a prodrug and produces similar effects as LSD and other LSD prodrugs.
== Nomenclature == This enzyme belongs to the family of oxidoreductases, specifically those acting on NADH or NADPH with a quinone or similar compound as acceptor. The systematic name of this enzyme class is 2-hydroxy-1,4-benzoquinone:NADH oxidoreductase. Other names in common use include hydroxybenzoquinone reductase, 1,2,4-trihydroxybenzene:NAD oxidoreductase, and NADH:2-hydroxy-1,4-benzoquinone oxidoreductase.
Personal website Sweeney, Brigid (2011). "Crain's 40 Under 40". Chicago Business. Mitroff, Sarah (October 17, 2012). "Braintree Seeks Online Payment Domination". Wired. Bryan Johnson's channel on YouTube
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
Small studies with human participants have been reported, chiefly in Russian-language journals, but they are limited in size and design. No large randomised controlled trial with published results is available.