Khavinson is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-05-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
| 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 |
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. The chromatogram shows the main peak and any truncated or oxidised by-products, while the mass spectrum confirms the expected 390 dalton mass. Amino acid analysis can corroborate composition when a sample's origin is uncertain. Counterion content, particularly residual trifluoroacetate from purification, is frequently reported alongside purity because it shifts the net mass of the solid.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
== Early career == Stansbury began her career as an ecology instructor at the New Mexico Museum of Natural History and Science. As a White House Fellow, she worked as a policy advisor on the Council on Environmental Quality. She was a consultant at Sandia National Laboratories and later served as a program examiner in the Office of Management and Budget during the Obama administration. She worked on the staff of the United States Senate Committee on Energy and Natural Resources and as an aide to Senator Maria Cantwell. Since 2017, she has worked as a consultant and senior advisor at the Utton Transboundary Resources Center of the University of New Mexico.
=== Agar plate method === Variations are seen in the media used for inoculation. Many studies use media with 1 to 2 mg/L of imipenem. However, bacteria that produce OXA-48 or OXA-181 result in low-level resistance, which cannot be detected efficiently due to the high concentration. Therefore, more recent screening media use broth containing 0.5–1 mg/L imipenem or 0.5 mg/L ertapenem. The downsides to this approach include the delay of results from the inoculation and the inability to identify the type of carbapenemase.
Second, Downstream-peptides are consistently positioned in a place that is consistent with a cis-regulatory role in regulating the downstream ORFs, although the biological role of the ORFs is unknown. Third, the pseudoknot structure has a moderate complexity that is typical of riboswitches. Finally, the observation of regulation of a downstream ORF by nitrogen availability also suggests a cis-regulatory role of the element. This hypothesis is supported by biochemical and genetic data. First, both Downstream-peptide RNAs and glnA RNAs selectively bind glutamine. Second, reporter gene analysis of the Downstream-peptide motif revealed that this RNA promotes reporter gene expression upon binding of glutamine and can therefore be considered an activating riboswitch. Possible candidates to be regulated by the Downstream-peptide motif are genes that frequently carry the Downstream-peptide motif in their 5′UTR and encode small, unknown proteins that contain DUF4278 and are putative regulators of glutamine synthetase. This hypothesis is supported by the finding that expression of the DUF4278-containing glutamine synthetase inhibitory factor IF17 encoding gene gifB was shown to be regulated by the structurally related glnA RNA motif. Downstream-peptide RNAs overlap a predicted non-coding RNA called yfr6 that is over 200 nucleotides in length, but it was proposed that only the upstream region (corresponding to the Downstream-peptide motif) functions as an RNA structure. A distinct predicted non-coding RNA called yfr14 overlaps both yfr6 and Downstream-peptide RNAs.
They have a cloaca into which the urinary and genital passages open, but not a swim bladder. Cartilaginous fish produce a small number of large, yolky eggs. Some species are ovoviviparous and the young develop internally but others are oviparous and the larvae develop externally in egg cases. The bony fish lineage shows more derived anatomical traits, often with major evolutionary changes from the features of ancient fish. They have a bony skeleton, are generally laterally flattened, have five pairs of gills protected by an operculum, and a mouth at or near the tip of the snout. The dermis is covered with overlapping scales. Bony fish have a swim bladder which helps them maintain a constant depth in the water column, but not a cloaca. They mostly spawn a large number of small eggs with little yolk which they broadcast into the water column.
=== Storage === Chocolate is very sensitive to temperature and humidity. Ideal storage temperatures are between 15 and 17 °C (59 and 63 °F), with a relative humidity of less than 50%. If refrigerated or frozen without containment, chocolate can absorb enough moisture to cause a whitish discoloration, the result of fat or sugar crystals rising to the surface. Various types of "blooming" effects can occur if chocolate is stored or served improperly. Chocolate bloom is caused by storage temperature fluctuating or exceeding 24 °C (75 °F), while sugar bloom is caused by temperature below 15 °C (59 °F) or excess humidity. A fat bloom can be distinguished by touch; it disappears if the surface of affected chocolate is lightly rubbed. Although visually unappealing, chocolate suffering from bloom is safe for consumption and taste is unaffected. Bloom can be reversed by retempering the chocolate or using it for any use that requires melting the chocolate. Chocolate is generally stored away from other foods, as it can absorb aromas. To avoid this, chocolate is packed or wrapped, then stored in darkness, in ideal humidity and temperature conditions.
Sources: en.wikipedia.org
By the 1820s, the different Nonconformists, including Wesleyan Methodists, Baptists, Congregationalists and Unitarians, had formed the Committee of Dissenting Deputies and agitated for repeal of the highly restrictive Test and Corporation Acts. These Acts excluded Nonconformists from holding civil or military office or attending Oxford or Cambridge, compelling them to set up their own Dissenting Academies privately. The Tories tended to be in favour of these Acts and so the Nonconformist cause was linked closely to the Whigs, who advocated civil and religious liberty. After the Test and Corporation Acts were repealed in 1828, all the Nonconformists elected to Parliament were Liberals. Nonconformists were angered by the Education Act 1902, which integrated Church of England denominational schools into the state system and provided for their support from taxes. John Clifford formed the National Passive Resistance Committee and by 1906 over 170 Nonconformists had gone to prison for refusing to pay school taxes. They included 60 Primitive Methodists, 48 Baptists, 40 Congregationalists and 15 Wesleyan Methodists. The political strength of Dissent faded sharply after 1920 with the secularisation of British society in the 20th century. The rise of the Labour Party reduced the Liberal Party strongholds into the nonconformist and remote "Celtic Fringe", where the party survived by an emphasis on localism and historic religious identity, thereby neutralising much of the class pressure on behalf of the Labour movement.
Erastin is a small molecule capable of initiating ferroptotic cell death. Erastin binds and activates voltage-dependent anion channels (VDAC) by reversing tubulin's inhibition on VDAC2 and VDAC3, and functionally inhibits the cystine-glutamate antiporter enzyme SLC7A11 Cells treated with erastin are deprived of cysteine and are unable to synthesize the antioxidant glutathione. Depletion of glutathione eventually leads to excessive lipid peroxidation and cell death. Erastin was first described in 2003. Its name is short for "eradicator of RAS and ST-expressing cells".
The second proposed mechanism via an anhydride has similar steps but there is a direct attack of Glu270 on the carbonyl group, and then the interaction of Glu270 on the Zn2+-bound amide forms an anhydride instead which can subsequently be hydrolyzed by water.
When the Atlantic slave trade began, many of the local slave systems began supplying captives for chattel slave markets outside Africa. Although the Atlantic slave trade was not the only slave trade from Africa, it was the largest in volume and intensity. As Elikia M'bokolo wrote in Le Monde diplomatique:
=== Osteoconduction === Osteoconduction is termed as "the property of a material to support tissue ingrowth, osteoprogenitor cell growth, and development for bone formation to occur". In the context of bone grafting it occurs when the bone graft material serves as a scaffold for new bone growth that is perpetuated by the native bone. Osteoblasts from the margin of the defect that is being grafted utilize the bone graft material as a framework upon which to spread and generate new bone. Osteoblasts do not originate from the donor tissue, but through the internal ingrowing of the host's cells. The proper bonding of bioactive chemicals (Beta-Tricalcium Phosphate) in implants used in bone grafting surgery allow the promotion of osteoconductivity in the area of a defect. In the very least, a bone graft material should be osteoconductive by being made up of these bioactive chemicals.
Sources: en.wikipedia.org
Other clinicians described a cluster of near‑fatal collapses between March and June 2016, including the deaths of two triplets on consecutive days. The prosecution alleged that two infants, Baby F and Baby L, had been deliberately poisoned with insulin, citing blood test results identified during the police investigation. Their lead expert witness described this as key evidence, though their interpretation has since been questioned by some specialists. The prosecution also argued that Baby M, the twin of Baby L, collapsed after air was injected into his bloodstream. Letby had volunteered for the shift on which Baby L collapsed, despite not being scheduled for night duty. Several consultants told the court they had previously raised concerns about Letby but were discouraged by hospital managers. One doctor recalled Letby making a remark shortly before an infant's death that he interpreted as inappropriate. The prosecution also presented a shift‑pattern chart showing Letby on duty for 25 incidents, supported by swipe‑card data. The chart has since been criticised by some statisticians as misleading. After Letby was removed from clinical duties, the unit's admission criteria were tightened to stop receiving the sickest babies, and more consultants were hired; the unexpected deaths ceased. The prosecution further alleged that Letby altered times on patient records; she denied this, saying any discrepancies were errors.
=== Judges' Costumes === Episode 1: Carla Hall as a neuroscientist with an exposed brain, Stephanie Boswell as a chemist mutated by a chemical spill, and Zac Young as a beaker of green slime Episode 2: Carla Hall as a victim of an exploding stand mixer, Stephanie Boswell as a victim of killer macarons, and Zac Young as a victim of a sprinkles allergy Episode 3: Carla Hall as a creepy psychedelic bunny, Stephanie Boswell as a cutesy bunny, and Zac Young as a monstrous bunny Episode 4: Carla Hall as a skeleton lady, Stephanie Boswell as a mummy influencer, and Zac Young as Mummy Dearest Episode 5: Carla Hall as a house's front door, Stephanie Boswell as a tornado, and Zac Young as a cow Episode 6: Carla Hall as a headless demon, Stephanie Boswell as the nosey neighbor from Hades, and Zac Young as a goat demon Episode 7: Carla Hall as a were-chicken, Stephanie Boswell as a reanimated lady, and Zac Young as a vampire agent
The catshark spends the daytime resting at the bottom, usually in contact with certain structures. It has been observed with large burrowing cerianthid anemone tubes and boulders. The bottom rubble is thought to be used as a camouflage with the shark's spotted surface. Adult sharks tend to prefer rough bottoms, creating a difficulty for trawl sampling, while the immature forms are found near smoother regions. The chain catshark has been known to feed on squid, bony fish, polychaetes and crustaceans. In aquaria, they are relatively motionless, spending the day resting on the bottom, but during the night and when fed they are very active.
== Assembly == The assembly of the proteasome is a complex process due to the number of subunits that must associate to form an active complex. The β subunits are synthesized with N-terminal "propeptides" that are post-translationally modified during the assembly of the 20S particle to expose the proteolytic active site. The 20S particle is assembled from two half-proteasomes, each of which consists of a seven-membered pro-β ring attached to a seven-membered α ring. The association of the β rings of the two half-proteasomes triggers threonine-dependent autolysis of the propeptides to expose the active site. These β interactions are mediated mainly by salt bridges and hydrophobic interactions between conserved alpha helices whose disruption by mutation damages the proteasome's ability to assemble. The assembly of the half-proteasomes, in turn, is initiated by the assembly of the α subunits into their heptameric ring, forming a template for the association of the corresponding pro-β ring. The assembly of α subunits has not been characterized. Only recently, the assembly process of the 19S regulatory particle has been elucidated to considerable extent. The 19S regulatory particle assembles as two distinct subcomponents, the base and the lid. Assembly of the base complex is facilitated by four assembly chaperones, Hsm3/S5b, Nas2/p27, Rpn14/PAAF1, and Nas6/gankyrin (names for yeast/mammals). These assembly chaperones bind to the AAA-ATPase subunits and their main function seems to be to ensure proper assembly of the heterohexameric AAA-ATPase ring.
methyl Also carbinyl. The alkyl functional group derived from methane, consisting of one carbon atom bonded to three hydrogen atoms, with the chemical formula CH3. It is the simplest hydrocarbon and occurs as a substituent in numerous organic compounds, though it may also exist independently as an ion or radical. In IUPAC nomenclature, the presence of a methyl substituent is indicated with the prefix methyl in the name of the compound, or with the abbreviation Me in chemical formulae; e.g. methyl alcohol (methanol) is often written with the formula CH3OH or MeOH.
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.
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.