The short version of Epithalamin fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-18 and is reviewed periodically as new material appears.
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.
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 |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised and often hygroscopic |
| Solubility class | Freely soluble in water | Poor solubility in non-polar solvents |
| Typical storage temperature | -20 degrees Celsius or colder | Sealed, desiccated, protected from light |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Establishes purity and confirms mass |
| Common salt form | Trifluoroacetate or acetate | Counterion reported alongside purity values |
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.
In Thailand, soy sauce is called sii-íu (Thai: ซีอิ๊ว). Sii-íu kǎao (Thai: ซีอิ๊วขาว, 'white soy sauce') is used as regular soy sauce in Thai cuisine, while sii-íu dam (Thai: ซีอิ๊วดำ, 'black soy sauce') is used primarily for colour. Another darker-coloured variety, sii-íu wǎan (Thai: ซีอิ๊วหวาน, 'sweet soy sauce') is used for dipping sauces. Sɔ́ɔt prung rót (Thai: ซอสปรุงรส, 'seasoning sauce') is also commonly used in modern Thai cuisine.
== Stable isotope mass spectrometry == Stable isotope mass spectrometry is conducted in the Department of Geography, and was recently used by the Landmark Trust to determine very precisely the age of the timber from Llwyn Celyn farmhouse to the year 1420.
The ancestors of modern reptiles (which belong to the clade Sauria) had diverged from each other by the Late Permian, as evidenced by species such as the monitor lizard-like Protorosaurus known from the Late Permian of Europe, which is clearly an archosauromorph, more closely related to archosaurs (crocodilians and birds) than to lizards, snakes or turtles.
Sources: en.wikipedia.org
== Education == McAlpine was awarded an honours bachelor's degree at Western University where she won a gold medal in zoology. She received a master's degree from the University of Toronto in 1966. Her thesis was called An assessment of the creatine kinase test in the detection of carriers of Duchenne muscular dystrophy. She went on to complete a PhD at University College London in 1970 with a thesis entitled Studies on the genetic variation of phosphoglucomutase in man. McAlpine was mentored and supervised by women in her field throughout her education. Her undergraduate work was performed under Helen Battle, and Margaret Thompson was her advisor in Toronto. Her PhD supervisor was Harry Harris.
=== Controversy over ballot traceability === The Election Commission also faced allegations that the barcodes and QR codes on the election ballots compromised voter secrecy and might be unconstitutional. The controversy began after social media users analyzed the codes from photos of ballot papers, discovering that they were unique per ballot and could be matched to the counterfoil containing individual voters' signatures, theoretically allowing any individual's vote to be determined. On 14 February, the Election Commission acknowledged that the ballot codes could indeed be used to link voters to their ballots, but defended the process as a legal measure intended to prevent voter fraud, stating that the ballots, counterfoils, and voter registration data were stored separately. In response, critics argued that the possibility of voter traceability is already inherently unconstitutional, with many citing as precedent the Constitutional Court decision nullifying the 2006 election due to voting booths being positioned with voters' backs towards the public. Legal scholar Prinya Thaewanarumitkul also pointed out that the Election Commission's regulations actually require counterfoils to be kept with the ballots and argued that regardless of storage, the ballots could be photographed during the counting process. On 13 February, 12 petitions were submitted to the Office of the Ombudsman, which on 16 February sent a letter to the Election Commission asking it to address the complaints within seven days, which was later extended by seven more days on the Commission's request.
The initial absence of U-233 and its daughter products in the MOX fuel results in a lower activity in region 3 of the figure at the bottom right, whereas for RGPu and WGPu the curve is maintained higher due to the presence of U-233 that has not fully decayed. Nuclear reprocessing can remove the actinides from the spent fuel so they can be used or destroyed (see Long-lived fission product § Actinides).
== Transportation == Retford railway station, Nottinghamshire, England (station code: RET) Rotterdamse Elektrische Tram, the main public transport operator of Rotterdam, the Netherlands Røst Airport, Norway (IATA code) Rapid-exit taxiway allowing an aircraft to leave a runway quickly
Sources: en.wikipedia.org
There are as many mass-balance equations as there are reagents, A, B..., so if the equilibrium constant values are known, there are n mass-balance equations in n unknowns, [A], [B]..., the so-called free reagent concentrations. Solution of these equations gives all the information needed to calculate the concentrations of all the species. Thus, the importance of equilibrium constants lies in the fact that, once their values have been determined by experiment, they can be used to calculate the concentrations, known as the speciation, of mixtures that contain the relevant species.
=== Mosaic Viruses === In 1955, Robert Rice and Kaesberg researched why the tobacco mosaic virus breaks apart after preservation via freeze-drying. Although they did not figure out what caused it specifically, their research allowed them to rule out several possibilities. They found that the act of freeze-drying did not cause the virus to break, as freeze-drying did not cause insulin fibrils or flagella to break. In 1956, Kaesberg discovered a new virus shape, the icosahedral shape. After taking electron micrographs of the bromegrass mosaic virus and the yellow turnip mosaic virus under light shadowing and heavy shadowing, respectfully, Kaesberg was able to come up with an icosahedral model of the viruses. This shape became the modern-day symbol for a virus because, after much more research, the icosahedral shape was one of the most commonly found virus shapes. In 1958, Kaesberg and colleagues discovered a mosaic virus found in alfalfa creates three macromolecules after infecting a plant. Only one of the types of particles produced the virus, but all three had a similar bacillus-like shape and size. These particles looked nothing like the known spherical species of the alfalfa mosaic virus, so they discovered a new isolate in their work. In 1964, Paul Kaesberg and a colleague studied the effects of pH changes on the bromegrass mosaic virus. They found that when the environment's pH is higher than 6.7, there is a decrease in the virus’ sedimentation coefficient. The coefficient goes back up if the pH goes below 6.7.
=== Cancer === Based on cell growth experiments, animal cancer models, and epidemiological studies, it appears that IGFBP-3 functions as a low-penetrance tumor suppressor gene. Dysregulation of IGFBP-3 has been implicated in many cancers. Downregulation of its tissue expression by promoter hypermethylation in some cancers, such as hepatoma and non-small cell lung cancer may be associated with poor patient outcome. However, consistent with the dual inhibitory and stimulatory roles of IGFBP-3 seen in cell culture, there are other cancer types, such as breast cancer, pancreatic cancer, and clear cell renal cell cancer in which high tissue IGFBP-3 expression has been linked to poor prognostic features or patient outcome. The mechanisms regulating these contrasting effects of IGFBP-3 in vivo are not well understood. Since IGFBP-3 is abundant in the bloodstream of healthy adults (typically 2–4 mg/L), and is largely stabilized by its complex formation with IGFs and ALS, it is unlikely that tumor-derived IGFBP-3 has a large influence on circulating levels. There have been many studies linking circulating IGFBP-3 levels to the presence, or risk, of various cancers, or to patient outcomes. but unequivocal conclusions have often been lacking. For example, high plasma IGFBP-3 levels were associated with a reduced prospective risk of colorectal cancer in women. but in a study including men and women, colon cancer risk was positively associated with plasma IGFBP-3, while there was no significant association for rectal cancer.
Sources: en.wikipedia.org
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase HPLC establishes purity and separation from related peptides, and mass spectrometry confirms the molecular mass. Amino acid analysis can verify residue composition. No single method proves identity on its own, so the results are read together.
Yes. Residual trifluoroacetate or acetate from purification adds mass and can shift the value obtained by certain assays. Purity figures are therefore meaningful only when the counterion form is stated. Reporting both peptide content and salt form gives a clearer picture.
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.