A practical reference on bioregulator: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-03-06 and is reviewed periodically as new material appears.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
Interest in epitalon is usually discussed within the broader field of short peptide bioregulators, a category that includes other synthetic di-, tri-, and tetrapeptides studied by the same research group. These compounds share a common rationale: that small fragments of tissue-derived proteins can retain biological activity and can be produced reproducibly. The category as a whole remains outside mainstream pharmacological consensus, and epitalon specifically has a limited presence in independent, non-Russian research literature, which shapes how its evidence base is described.
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.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
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.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
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.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Also, during the 1981 tour, veteran session drummer Andy Newmark stepped in briefly for Knudsen, who was then in rehab. And by the end of 1981, even Simmons had left the band. Now with no remaining original members and a "leader" in McDonald who was ready for a solo career, the group elected instead to disband after a rehearsal without Simmons, according to an interview with McDonald for Listen to the Music, the Doobie Brothers' official video history/documentary released in 1989. He went on to say that by that point they could not have gotten further away from the Doobies sound if they had tried. Simmons, already at work on his first solo album, Arcade, rejoined for a 1982 farewell tour on the condition that this truly would be the end of the Doobie Brothers. At their last concert at the Greek Theatre in Berkeley, California, on September 11, 1982, they were joined onstage by founding member Tom Johnston for what was presumed to be the final rendition of his staple, "China Grove". Former members Porter, Hossack and Hartman subsequently took the stage for an extended version of "Listen to the Music". Knudsen sang lead vocals while Johnston, Simmons and McFee traded licks on guitar. The live album Farewell Tour was released in 1983 and the Greek Theatre concert was released in 2011 as Live at the Greek Theatre 1982.
The reduction and subsequent reoxidation of vitamin K coupled with carboxylation of Glu is called the vitamin K cycle. Humans are rarely deficient in vitamin K because, in part, vitamin K2 is continuously recycled in cells. Warfarin and other 4-hydroxycoumarins block the action of VKOR. This results in decreased concentrations of vitamin K and vitamin K hydroquinone in tissues, such that the carboxylation reaction catalyzed by the glutamyl carboxylase is inefficient. This results in the production of clotting factors with inadequate Gla. Without Gla on the amino termini of these factors, they no longer bind stably to the blood vessel endothelium and cannot activate clotting to allow formation of a clot during tissue injury. As it is impossible to predict what dose of warfarin will give the desired degree of clotting suppression, warfarin treatment must be carefully monitored to avoid underdose and overdose.
=== 18th century === In December 1770, Joel Lane successfully petitioned the North Carolina General Assembly to create a new county. On January 5, 1771, the bill creating Wake County was passed in the General Assembly. The county was formed from portions of Cumberland, Orange, and Johnston counties, and was named for Margaret Wake Tryon, the wife of Governor William Tryon. The first county seat was Bloomsbury. New Bern, a port town on the Neuse River 35 mi (56 km) from the Atlantic Ocean, was the largest city and the capital of North Carolina during the American Revolution. When the British Army laid siege to the city, that site could no longer be used as the capital. From 1789 to 1794, when Raleigh was being built, the state capital was Fayetteville. Raleigh was chosen as the site of the new capital in 1788, as its central location protected it from attacks from the coast. It was officially established in 1792 as both county seat and state capital. The city was incorporated on December 31, 1792, and a charter granted January 21, 1795. The city was named for Sir Walter Raleigh, sponsor of Roanoke, the "lost colony" on Roanoke Island. No known city or town existed previously on the chosen city site. Raleigh is one of the few cities in the United States that was planned and built specifically to serve as a state capital. Its original boundaries were formed by the downtown streets of North, East, West and South. The plan, a grid with two main axes meeting at a central square and an additional square in each corner, was based on Thomas Holme's 1682 plan for Philadelphia.
=== Treatment === Because a high load of HBV in patients is the main cause of hepatitis progression, the ultimate goal in treatment is to eradicate the virus before irreversible liver damage occurs. Unfortunately, there are no agents available with high enough efficacy and safety to fully eradicate HBV. Neither interferon alpha, including standard and pegylated forms, nor nucleotide analogues (including lamivudine, adefovir dipivoxil, and most recently, entecavir) could eradicate HBV covalently-closed-circular DNA in liver cells, which is the replication model for HBV recurrence. However, no agents are available to break through the host's immune tolerance to HBV, which is another important reason for persistent infection with HBV, although some patients respond well temporarily to administration of interferon and nucleotide analogues alone or in combination regimens. Some traditional Chinese herbs, such as kushenin (Sophora flavescens) and some complex prescriptions, have some efficacy as antivirals and in the protection of liver function, although the specific mechanism and components need to be identified. The current treatment in China is the combination of antiviral agents (lamivudine, adefovir dipivoxil), immune modulators (interferon alpha, peginterferon alpha, thymosin), and hepatic protectors (such as glycyrrhizin, glucuronolactone). The Chinese spend around ¥900 billion (US$110 billion) on these regimens every year.
If a molecule possesses the desired ligase activity, a streptavidin matrix can be used to recover the active molecules. Lincoln and Joyce used in vitro evolution to develop ribozyme ligases capable of self-replication in about an hour, via the joining of pre-synthesized highly complementary oligonucleotides. Although not true catalysts, the creation of artificial self-cleaving riboswitches, termed aptazymes, has also been an active area of research. Riboswitches are regulatory RNA motifs that change their structure in response to a small molecule ligand to regulate translation. While there are many known natural riboswitches that bind a wide array of metabolites and other small organic molecules, only one ribozyme based on a riboswitch has been described: glmS. Early work in characterizing self-cleaving riboswitches was focused on using theophylline as the ligand. In these studies, an RNA hairpin is formed which blocks the ribosome binding site, thus inhibiting translation. In the presence of the ligand, in these cases theophylline, the regulatory RNA region is cleaved off, allowing the ribosome to bind and translate the target gene. Much of this RNA engineering work was based on rational design and previously determined RNA structures rather than directed evolution as in the above examples. More recent work has broadened the ligands used in ribozyme riboswitches to include thymine pyrophosphate. Fluorescence-activated cell sorting has also been used to engineering aptazymes.
Sources: en.wikipedia.org
The hill tribe people in Indochina were "hunted incessantly and carried off as slaves by the Siamese (Thai), the Anamites (Vietnamese), and the Cambodians". A Siamese military campaign in Laos in 1876 was described by a British observer as having been "transformed into slave-hunting raids on a large scale". The census, taken in 1879, showed that 6% of the population in the Malay sultanate of Perak were slaves. Enslaved people made up about two-thirds of the population in part of North Borneo in the 1880s.
== Aging == Thailand in 2012 ranked number three of 66 nations with the most rapidly aging populations (1=most rapidly aging, 66=least rapidly aging). The Global AgeWatch Index for 2015 ranked Thailand 34 of 96 nations (1=best, 96=worst). The AgeWatch Index purports to measure "...how well...aging populations are faring."
It predominantly affects children between the ages of two and six years in the least developed countries around the world, primarily in sub-Saharan Africa. Noma survivors experience stigma, social isolation, and discrimination within their communities. These can be countered by education and community outreach programs.
=== Diagnosis === Diagnosis of uterine prolapse is based on a history of symptoms, which may include symptom questionnaires, and a physical exam. Usually, the physical exam involves a vaginal exam, often with a speculum, and a pelvic exam. The extent and severity of prolapse is commonly documented using the Pelvic Organ Prolapse Quantification (POP-Q) system.
== Production of biopharmaceuticals == Lemna has been transformed by molecular biologists to express proteins of pharmaceutical interest. Expression constructs were engineered to cause Lemna to secrete the transformed proteins into the growth medium at high yield. Since the Lemna is grown on a simple medium, this substantially reduces the burden of protein purification in preparing such proteins for medical use, promising substantial reductions in manufacturing costs. In addition, the host Lemna can be engineered to cause secretion of proteins with human patterns of glycosylation, an improvement over conventional plant gene-expression systems. Several such products are being developed, including monoclonal antibodies.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
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.