This is a working overview of Telomerase, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-03-29. Anything still debated is marked as such rather than presented as settled.
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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 |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
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.
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.
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.
== Function == The pituitary glycoprotein hormone family includes follicle-stimulating hormone, luteinizing hormone, chorionic gonadotropin, and thyroid-stimulating hormone. All of these glycoproteins consist of an identical alpha subunit and a hormone-specific beta subunit. This gene encodes the beta subunit of follicle-stimulating hormone. In conjunction with luteinizing hormone, follicle-stimulating hormone induces egg and sperm production. The FSHB gene in human DNA encodes the follicle-stimulating hormone subunit beta protein (FSH-B), or Follitropin Beta. More specifically, the FSHB gene encodes for the beta subunit of follicle-stimulating hormone (FSH). Therefore, proper transcription of FSHB allows for the proper production of FSH. FSH is a peptide hormone the pituitary gland produces that is involved with the reproductive system. FSH promotes follicular oocyte (egg) production, growth, and maturation and helps control a female's menstrual cycle. Additionally, FSH is involved in the male reproductive system by stimulating spermatogenesis (maturation of sperm cells) and initiating puberty. Studies show that variations in the FSHB gene can contribute to the likelihood of a woman becoming pregnant with fraternal, or dizygotic, twins. This is because certain heritable variations of FSHB contribute to increased production of FSH from the pituitary gland, raising the levels of FSH found in a woman's blood. It is also shown that women with these FSHB variants had their first menstrual cycle, children, and menopause at an earlier age than women without the variant.
None of these measures proved effective in significantly reducing opium use. In the following years, opioids, cocaine, and cannabis were associated with various ethnic minorities and targeted in other local jurisdictions. In 1908, Hamilton Wright was appointed United States Opium Commissioner. His wife, Elizabeth Washburn Wright, carried on much of his anti-opium campaign after his death in 1917. In 1906, the Pure Food and Drug Act, also known as the Wiley Act, addressed problems with tainted and adulterated food in the growing industrial food system, and with drug quality, by mandating ingredient labels and prohibiting false or misleading labeling. For drugs, a listing of active ingredients was required; a set of drugs deemed addictive or dangerous, that included opium, morphine, cocaine, caffeine, and cannabis, was specified. Oversight of the act was assigned to the US Department of Agriculture's Bureau of Chemistry, which evolved into the Food and Drug Administration in 1930.
A pulsed laser system facilitates the efficient coupling of a time-of-flight mass spectrometer (TOF-MS) to the resonance ionization set-up due to the instrument's abundance sensitivity. This is because TOF systems can produce an abundance sensitivity of up to 104 whereas magnetic mass spectrometers can only achieve up to 102. The total selectivity in a RIS process is a combination of the sensitivities in the various resonance transitions for multiple step-wise excitations. The probability of an atom to come in contact with the resonance of another atom is about 10−5. The addition of a mass spectrometer increases this figure by a factor of 106 such that the total elemental selectivity surpasses or at least compares to that of tandem mass spectrometry (MS/MS), the most selective technique available.
An ACS program chair, Gopal Coimbatore, said that without a proper forum the matter would never be discussed and, "with the world facing an energy crisis, it is worth exploring all possibilities." On 22–25 March 2009, the American Chemical Society meeting included a four-day symposium in conjunction with the 20th anniversary of the announcement of cold fusion. Researchers working at the U.S. Navy's Space and Naval Warfare Systems Center (SPAWAR) reported detection of energetic neutrons using a heavy water electrolysis setup and a CR-39 detector, a result previously published in Naturwissenschaften. The authors claim that these neutrons are indicative of nuclear reactions. Without quantitative analysis of the number, energy, and timing of the neutrons and exclusion of other potential sources, this interpretation is unlikely to find acceptance by the wider scientific community.
== Fabrication of porous silicon == Anodization and stain-etching are the two most common methods used for fabrication of porous silicon; however, there are almost twenty other methods to fabricate this material. Drying and surface modification might be needed afterwards. If anodization in an aqueous solution is used to form microporous silicon, the material is commonly treated in ethanol immediately after fabrication, to avoid damage to the structure that results due to the stresses of the capillary effect of the aqueous solution.
Sources: en.wikipedia.org
== Epidemiology == Donohue syndrome is an extremely rare disorder that occurs in one of every million births worldwide. Several dozen cases have been reported in the medical community, and in the reported cases of the disorder, it has been found that the females are twice as likely to have the disorder as men.
"Coronavirus Disease 2019 (COVID-19)". Centers for Disease Control and Prevention (CDC). 11 February 2020. "Coronavirus disease (COVID-19) Pandemic". World Health Organization (WHO). "SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) Sequences". National Center for Biotechnology Information (NCBI). "COVID-19 Resource Centre". The Lancet. "Coronavirus (Covid-19)". The New England Journal of Medicine. "Covid-19: Novel Coronavirus Outbreak". Wiley. Archived from the original on 24 September 2020. Retrieved 13 February 2020. "SARS-CoV-2". Virus Pathogen Database and Analysis Resource. "SARS-CoV-2 related protein structures". Protein Data Bank.
== Terminology == A child is referred to as the stepdaughter or stepson of their biological or adoptive parent's new spouse, and the spouse is referred to as the stepparent (father or mother) of the child. A stepparent is the spouse of someone's parent, and not their biological parent, stepfather being the male spouse and stepmother the female spouse. A step-grandparent is the step-parent of someone's parent or the parent of one's step-parent, and not someone's biological grandparent, stepgrandfather being the male one, and stepgrandmother the female one. A step-uncle is the spouse of someone's parent's sister (aunt) or brother (uncle) and is not the father of someone's cousin, except when the sibling marries another and never has children (no cousins). The sister's niece/nephew should refer to a new spouse as uncle, not step-uncle. A step-aunt is the spouse of someone's parent's brother (uncle) or sister (aunt) and is not the mother of someone's cousin, except when the sibling marries another and never had children (no cousins). The sister's niece or nephew should refer to the newest spouse as aunt, not step-aunt. Similarly, a stepsibling is the offspring of a stepparent to whom one is not biologically or adoptive related, stepbrother being the male one and stepsister the female one. A stepgrandson is the grandson of someone's spouse who one is not biologically related to. A step-granddaughter is the granddaughter of someone's spouse to whom one is not biologically or adoptive related.
== Glycosylation == Thy-1 is one of the most heavily glycosylated membrane proteins with a carbohydrate content up to 30% of its molecular mass. Thy-1 in most species has 3 N-glycosylation sites (Asn 23, 74 and 98) but no O-glycosylation. The composition of Thy-1 carbohydrate moieties varies considerably between different tissues or even among cells of the same lineage at different stages of differentiation: e.g., galactosamine only in brain Thy-1, sialic acid in thymic Thy-1 in far excess than brain Thy-1, that too increasing in parallel with T cell maturation. In this regard it has yet another historic association: Thy-1 happens to be the first glycoprotein in which cell type specificity of variant glycosylation on an invariant protein was demonstrated. Analysis of Differencial glycosylation of Thy-1 from brain and thymus showed that all the complex N-linked structures differed between the two forms, superimposed upon a site specific common core. In case of Thy-1 this core pattern was constituted by Asn23 carrying mostly oligomannose structures, Asn74 carrying the most extended complex structures, and Asn98 carrying smaller complex structure. The structure of the sugar residues in the GPI anchor and their associated esterified structures (e.g. additional fatty acids and alcohols) also can be cell type and species specific.
There are an enormous number of different ways in which a chain can be curled around in a relatively compact shape, like an unraveling ball of twine with much open space, and comparatively few ways it can be more or less stretched out. So, if each conformation has an equal probability or statistical weight, chains are much more likely to be ball-like than they are to be extended –a purely entropic effect. In an ensemble of chains, most of them will, therefore, be loosely balled up. This is the type ofshape any one of them will have most of the time. Consider a linear polymer to be a freely-jointed chain with N subunits, each of length
Sources: en.wikipedia.org
== External links == Richard L.M. Synge on Nobelprize.org Synge's Nobel Lecture Applications of Partition Chromatography Sidney Elsden (21 June 2016), Richard Laurence Millington Synge (PDF), archived from the original (PDF) on 29 October 2007, retrieved 17 October 2007
=== Vasco da Gama === In February 2022, 777 Partners bought 70% of CR Vasco da Gama, a Campeonato Brasileiro Série A club from Rio de Janeiro for R$700 million, valuing the club at R$1.7 billion. The transaction was the biggest in the history of Brazilian football, and came off the back of a change in legislation allowing clubs to adopt new legal structures by becoming limited companies and sourcing finance from private equity markets. Fans protested against 777 Partners in the 2023 Campeonato Brasileiro Série A season, as the club found itself in the relegation zone. The team survived, and signed players including France international Dmitri Payet, but fans continued to protest, vandalizing the stadium in May 2024. Within a month of taking over, Wander said that Vasco would have a comparable budget the next time they played city rivals CR Flamengo, one of the wealthiest clubs in Brazil. Plans to renovate the training complex were held up by municipal ownership of the land. After delays in payment, a local judge in May 2024 suspended the contract by which 777 Partners took over Vasco da Gama, in a preliminary ruling.
The field of protease research is enormous. Since 2004, approximately 8000 papers related to this field were published each year. Proteases are used in industry, medicine and as a basic biological research tool. Digestive proteases are part of many laundry detergents and are also used extensively in the bread industry in bread improver. A variety of proteases are used medically both for their native function (e.g. controlling blood clotting) or for completely artificial functions (e.g. for the targeted degradation of pathogenic proteins). Highly specific proteases such as TEV protease and thrombin are commonly used to cleave fusion proteins and affinity tags in a controlled fashion. Protease-containing plant-solutions called vegetarian rennet have been in use for hundreds of years in Europe and the Middle East for making kosher and halal cheeses. Vegetarian rennet from Withania coagulans has been in use for thousands of years as a Ayurvedic remedy for digestion and diabetes in the Indian subcontinent. It is also used to make Paneer.
Even within the Joseon government, there were indications of a shift in attitude toward the nobi. King Yeongjo implemented a policy of gradual emancipation in 1775, and he and his successor King Jeongjo made many proposals and developments that lessened the burden on nobi, which led to the emancipation of the vast majority of government nobi in 1801. In addition, population growth, numerous escaped slaves, growing commercialization of agriculture, and the rise of the independent small farmer class contributed to the decline in the number of nobi to about 1.5% of the total population by 1858. The hereditary nobi system was officially abolished around 1886–87, and the rest of the nobi system was abolished with the Gabo Reform of 1894. However, slavery did not completely disappear in Korea until 1930, during Imperial Japanese rule. During the Imperial Japanese occupation of Korea around World War II, some Koreans were used in forced labour by the Imperial Japanese, in conditions which have been compared to slavery. These included women forced into sexual slavery by the Imperial Japanese Army before and during World War II, known as "comfort women". After the Portuguese first made contact with Japan in 1543, slave trade developed in which Portuguese purchased Japanese as slaves in Japan and sold them to various locations overseas, including Portugal, throughout the 16th and 17th centuries. Many documents mention the slave trade along with protests against the enslavement of Japanese.
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
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.