Telomerase induction 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.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four-residue sequence |
| Molar mass | About 390.35 g/mol | Free peptide, counter-ion not included |
| Appearance | White to off-white powder | Lyophilised solid from aqueous solution |
| Water solubility | Freely soluble | Short, polar peptide chain |
| Common synonyms | AEDG; epithalone | Catalogues use the names interchangeably |
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.
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.
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.
Epitalon is a synthetic tetrapeptide whose four residues are alanine, glutamate, aspartate and glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9 and its monoisotopic mass is near 390.35 daltons. The peptide carries two acidic side chains, so it is neutral to negatively charged in most aqueous buffers. Published reference summaries usually list it under both spellings, epitalon and epithalon, and treat the two names as the same material.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
Residue composition is the property that most cleanly separates verified material from mislabelled samples. Alanine, glutamate, aspartate and glycine appear in that order from the N-terminus, and the two acidic residues sit in the middle of the chain. Because the peptide is short, it can be produced by solid-phase synthesis and characterised by mass spectrometry without ambiguity. Any reported sample whose measured mass departs substantially from 390 daltons is a different compound or a degraded mixture rather than epitalon.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Plants that are not native to an area often require mycorrhizal symbionts to thrive. The vast majority of arbuscular mycorrhizas are non-specific, and so plants that interact with these mycorrhizas often become invasive quickly and easily. However, ectomycorrhizal symbioses are often relatively specific. In exotic forestry, compatible EcM fungi are often introduced to the foreign landscape to ensure the success of forest plantations. This is most common in eucalypts and pines, which are obligate ectomycorrhizal trees in natural conditions. Pines were difficult to establish in the southern hemisphere for this reason, and many Eucalyptus plantations required inoculation by EcM fungi from their native landscape. In both cases, once the EcM networks were introduced the trees were able to naturalize and then began to compete with native plants. Many EcM species co-invade without the help of human activity, however. The family Pinaceae often invade habitats along with specific EcM fungi from the genera Suillus and Rhizopogon. There are also ectomycorrhiza-forming fungi with cosmopolitan distributions which can allow non-native plant species to spread in the absence of their specific EcM fungi from the native ecosystem. Plants can compete through attacking each other's fungal networks. Dominant native plants can inhibit EcM fungi on the roots of neighboring plants, and some invasive plants can inhibit the growth of native ectomycorrhizal fungi, especially if they become established and dominant.
=== Sales === Counter-Strike became the first fan-made video game to be released commercially. By July 2001, global retail sales of the game had surpassed 250,000 units. By October 2002, sales had exceeded 1.3 million copies. Sales continued to rise, reaching 1.5 million units and generating $40 million in revenue by February 2003. By August 2004, Counter-Strike had grossed $75 million in revenue and had an estimated two million players worldwide. In the United States, its retail version sold 550,000 copies and earned $15.7 million by August 2006, making it the 22nd best-selling PC game in the country between January 2000 and August 2006. The Xbox version of the game sold 1.5 million copies. As of December 2008, Counter-Strike had sold approximately 4.2 million copies, surpassing all other Valve games except Half-Life and Half-Life 2. A portion of Half-Life sales is often attributed to Counter-Strike since the game was originally available as a modification of Half-Life. Half-Life experienced an unusual increase in sales year-over-year following its release, which Gabe Newell attributed to the popularity of Counter-Strike. He described the release of the mod as one of the best things that could have happened to Half-Life.
Laser spectroscopy (or cavity ring-down spectroscopy, CRDS) is able to directly measure 2H/1H, 17O/16O and 18O/16O isotopic composition in water or methane. The use of laser spectroscopy on hydrogen isotopes was first reported by Bergamaschi et al. in 1994. They directly measured 12CH3D/12CH4 in atmospheric methane using a lead salt tunable diode laser spectroscopy. The development of CRDS was first reported by O'Keefe et al. in 1988. In 1999, Kerstel et al. successfully applied this technique to determine HIC in water. The system consists of a laser and a cavity equipped with high finesse reflectivity mirrors. Laser light is injected into the cavity, where the resonance takes place due to the constructive interference. The laser then is turned off. The decay of light intensity is measured. In the presence of a water sample, the photo-absorption by water isotopologues follows the kinetic law. The optical spectrum is obtained by recording ring-down time of the H2O spectral features of interest at certain laser wavelength. The concentration of each isotopologue is proportional to the area under each measured isotopologue spectral feature. Laser spectroscopy is quick, simple, and relatively cheap; and the equipment is portable. So it can be used in the field for measuring water samples. 2H/1H and 18O/16O can be determined simultaneously from a single injection. It requires a small sample size, < 1 μL for water. Typical precision is ~ 1‰. However, this is a compound-specific instrument, i.e. only one specific compound can be measured. And coexisting organic compounds (i.e.
Sources: en.wikipedia.org
== Function == While the whole hCG glycoprotein hormone is a heterodimer consisting of an alpha and a beta subunit, it is the beta subunit alone that is responsible for the specificity of function of hCG. Thus, in this section, we will be referring to hCG as the specific beta subunit CGB, due to the subunit being solely responsible for its relevant function in pregnancy. CGB is only produced by the human body during pregnancy. CGB is the very first specific molecule synthesized by the embryo, with its RNA transcribed as early as the eight-cell stage. It is the trophoblast, which is the outer layer of the blastocyst, that first synthesizes this glycoprotein hormone. The blastocyst will become the embryo, and the trophoblast will eventually become part of the placenta. The blastocyst/trophoblast release CGB into the uterine space, which is somehow able to reach the hCG/LH receptor on the endometrial surface. Again, it is specifically the beta subunit of hCG (and also LH) that binds to the receptor, as the alpha subunits of both hormones, as well as FSH and TSH, are the same. This nonvascular communication by CGB is highly remarkable, and it is still not fully understood how CGB is able to communicate with the endometrial surface without being attached to it. Binding of CGB to the hCG/LH receptor prepares the endometrium for the impending implantation of the blastocyst. CGB implements immunotolerance and angiogenesis at the endometrial maternal-fetal interface, which is particularly critical to the establishment of a successful pregnancy.
== Career == Goodacre joined the University of Oxford as a research fellow in 1999. She was a research fellow at the University of East Anglia from 2002. She was described by the BBC as Spider Woman. As of 2018, Goodacre is based at the University of Nottingham, where she founded the SpiderLab in 2007 and leads the ArachNotts research group. As a geneticist, Goodacre studies the evolution, population and conservation of spiders. She monitored the mating behaviour and sex ratio of the linyphiid spider Pityohyphantes phrygianus with Bengt Gunnarsson at the University of Gothenburg. She also studied the silk of Mygalomorphae spiders and the genetic diversity of spider silk genes and found evidence for antimicrobial activity in the silk of common house spiders. She found that Erigone atra, a pest controlling spider, uses long-distance airborne dispersal. Goodacre contributed to the 2011 book Spider Physiology and Behaviour: Physiology. In 2015 Goodacre reported that spiders could survive "sailing" across oceans. ArachNotts study the diving bell spider and its silk, which it uses to build a diving bell in which it stores air underwater, and have so far identified some of the silk genes used by this spider. They also work on the relationship between spiders and the microbes that they carry with them, including the mating behaviour and sex-ratio of offspring, the ecology and biological control potential of spiders in agriculture and the use of genetic tools in the conservation of the endangered raft spider.
Bilberries are non-climacteric berries with a smooth, circular outline at the end opposite the stalk, whereas American blueberries retain persistent sepals there, leaving a rough, star-shaped pattern of five flaps. Bilberries grow singly or in pairs rather than in clusters, as American blueberries do, and American blueberries have more evergreen leaves. Bilberries are dark in colour, and often appear near black with a slight shade of purple.
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=== Stem cell biology === Synthetic retinoic acid is used in differentiation of stem cells to more committed fates, echoing retinoic acid's importance in natural embryonic developmental pathways. It is thought to initiate differentiation into several different cell lineages through activation of the Retinoic acid receptor. It has numerous applications in the experimental induction of stem cell differentiation; amongst these is the differentiation of human embryonic stem cells to posterior foregut lineages.
Work by scientists such as Anton Yuryev has contributed to understanding mitochondrial-associated proteins and their interactions. During his postdoctoral research, Yuryev demonstrated that the A-RAF kinase, a signaling protein, can localize to mitochondria, providing insight into how cellular signaling pathways intersect with mitochondrial function. His broader work in molecular biology and bioinformatics has also explored gene regulation, protein interactions, and biological networks, helping to contextualize mitochondrial processes within larger cellular systems.
The β and γ phases are obtained by annealing the most stable α-Al2S3 phase at several hundred degrees Celsius. Compressing aluminum sulfide to 2–65 bar results in the δ phase where vacancies are arranged in a superlattice of tetragonal symmetry. Unlike Al2O3, in which the Al(III) centers occupy octahedral holes, the more expanded framework of Al2S3 stabilizes the Al(III) centers into one third of the tetrahedral holes of a hexagonally close-packed arrangement of the sulfide anions. At higher temperature, the Al(III) centers become randomized to give a "defect wurtzite" structure. And at still higher temperatures stabilize the γ-Al2S3 forms, with a structure akin to γ-Al2O3. Molecular derivatives of Al2S3 are not known. Mixed Al-S-Cl compounds are however known. Al2Se3 and Al2Te3 are also known.
=== Leaves === The leaves are generally simple, elongated, entire (smooth and even), linear, oval to filiform (threadlike), mostly with parallel veins, but occasionally net-veined. They are alternate (single and alternating direction) and spiral, but may be whorled (three or more attached at one node, e.g. Lilium, Fritillaria), cauline (arranged along the aerial stem) or sheathed in a basal rosette. They are rarely petiolate (stalked), and lack stipules. The aerial stem is unbranched.
Sources: en.wikipedia.org
It is a synthetic tetrapeptide built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.
The name derives from epithalamin, a pineal gland extract studied in the former Soviet Union. Researchers proposed that short fragments of that extract carried the biological activity of interest.
No major regulatory agency has approved it as a medicine. It is handled as a research chemical, and products sold under this name are not standardised drugs with defined clinical labelling.
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.