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 2025-08-12 and is reviewed periodically as new material appears.
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.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Electrospray or MALDI mass spectrometry | Observed mass compared with theoretical 390.35 Da |
| Purity specification | 95 percent or greater by RP-HPLC | Common convention for research-grade peptide |
| Counter-ion | Acetate or trifluoroacetate | Affects net peptide content of a weighed sample |
| Solution storage | −80 °C as single-use aliquots | Repeated freeze–thaw cycles accelerate loss |
| Main degradation route | Aspartimide formation at Asp-Gly | Produces isoaspartate and related species |
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.
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.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
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.
=== U.S. News & World Report's Best High Schools === Since 2007, U.S. News & World Report has ranked high schools in PGCPS among the Best High Schools in America. High Point High School, Northwestern High School, and Eleanor Roosevelt High School have been recognized as Silver Medal Schools.
In 1857, the American Watch Company in Waltham, Massachusetts, introduced the Waltham Model 57, the first to use interchangeable parts. This cut the cost of manufacture and repair. Most Model 57 pocket watches were in a coin silver ("one nine fine"), a 90% pure silver alloy commonly used in dollar coinage, slightly less pure than the British (92.5%) sterling silver, both of which avoided the higher purity of other types of silver to make circulating coins and other utilitarian silver objects last longer with heavy use.
=== Philanthropy === Pfizer sponsors the Royal Society Pfizer Award and The Pfizer Award. In 2022, Pfizer launched the "An Accord for a Healthier World" initiative, which provides Pfizer's medicines and vaccines to 45 lower-income countries on a not-for-profit basis. Notable organizations to which Pfizer has provided funding include the Institute for Advanced Study, University of Toronto, and member of the President's Circle. University of Washington, Habitat for Humanity, Human Rights Campaign, National Women's Law Center, Share Our Strength, WaterAid, National Geographic, National Geographic Society, 94th Academy Awards, National Press Foundation, 19 to Zero, American Society of Hematology, Canadian Cancer Society, Canadian Paediatric Society, Endocrine Society, and European Society of Cardiology. Notable professional associations to which Pfizer has contributed include American Statistical Association, Canadian Association of Emergency Physicians, Canadian Medical Association, Canadian Pharmacists Association, Canadian Pharmacists Journal, Canadian Public Health Association, Ontario Medical Association, Centre for Addiction and Mental Health, Dana–Farber Cancer Institute, Hospital for Sick Children (SickKids), North Bay Regional Health Center, Princess Margaret Cancer Centre, Scarborough Health Network, Sinai Health Foundation, including Mount Sinai Hospital, Bridgepoint Active Healthcare, and the Lunenfeld-Tanenbaum Research Institute, Sunnybrook Health Sciences Centre – Donor.
Sources: en.wikipedia.org
Ancient philosophers as far back as Thales of Miletus c. 550 BCE had inklings of the conservation of some underlying substance of which everything is made. However, there is no particular reason to identify their theories with what we know today as "mass-energy" (for example, Thales thought it was water). Empedocles (490–430 BCE) wrote that in his universal system, composed of four roots (earth, air, water, fire), "nothing comes to be or perishes"; instead, these elements suffer continual rearrangement. Epicurus (c. 350 BCE) on the other hand believed everything in the universe to be composed of indivisible units of matter—the ancient precursor to 'atoms'—and he too had some idea of the necessity of conservation, stating that "the sum total of things was always such as it is now, and such it will ever remain." In 1605, the Flemish scientist Simon Stevin was able to solve a number of problems in statics based on the principle that perpetual motion was impossible. In 1639, Galileo published his analysis of several situations—including the celebrated "interrupted pendulum"—which can be described (in modern language) as conservatively converting potential energy to kinetic energy and back again. Essentially, he pointed out that the height a moving body rises is equal to the height from which it falls, and used this observation to infer the idea of inertia. The remarkable aspect of this observation is that the height to which a moving body ascends on a frictionless surface does not depend on the shape of the surface.
The stratosphere is the second-lowest layer of Earth's atmosphere, located above the troposphere and below the mesosphere. Pronounced , the name originates from Ancient Greek στρωτός (strōtós) 'layer, stratum' and -sphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher (closer to outer space) and the cooler layers lower (closer to the planetary surface of the Earth). The increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet (UV) radiation by the ozone layer, where ozone is exothermically photolyzed into oxygen in a cyclical fashion. This temperature inversion is in contrast to the troposphere, where temperature decreases with altitude, and between the troposphere and stratosphere is the tropopause border that demarcates the beginning of the temperature inversion. Near the equator, the lower edge of the stratosphere is as high as 20 km (66,000 ft; 12 mi), at mid-latitudes around 10 km (33,000 ft; 6.2 mi), and at the poles about 7 km (23,000 ft; 4.3 mi). Temperatures range from an average of −51 °C (−60 °F; 220 K) near the tropopause to an average of −15 °C (5.0 °F; 260 K) near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near 60 m/s (220 km/h; 130 mph) in the Southern polar vortex.
== Interactions == GLUT4 has been shown to interact with death-associated protein 6, also known as Daxx. Daxx, which is used to regulate apoptosis, has been shown to associate with GLUT4 in the cytoplasm. UBX-domains, such as the one found in GLUT4, have been shown to associate with apoptotic signaling. So this interaction aids in the translocation of Daxx within the cell. In addition, recent reports demonstrated the presence of GLUT4 gene in central nervous system such as the hippocampus. Moreover, impairment in insulin-stimulated trafficking of GLUT4 in the hippocampus result in decreased metabolic activities and plasticity of hippocampal neurons, which leads to depressive like behaviour and cognitive dysfunction.
=== Measurements of elevated copper status === Although a number of indicators are useful in diagnosing copper deficiency, there are no reliable biomarkers of copper excess resulting from dietary intake. The most reliable indicator of excess copper status is liver copper concentration. However, measurement of this endpoint in humans is intrusive and not generally conducted except in cases of suspected copper poisoning. Increased serum copper or ceruolplasmin levels are not reliably associated with copper toxicity as elevations in concentrations can be induced by inflammation, infection, disease, malignancies, pregnancy, and other biological stressors. Levels of copper-containing enzymes, such as cytochrome c oxidase, superoxide dismutase, and diaminase oxidase, vary not only in response to copper state but also in response to a variety of other physiological and biochemical factors and therefore are inconsistent markers of excess copper status. A new candidate biomarker for copper excess as well as deficiency has emerged in recent years. This potential marker is a chaperone protein, which delivers copper to the antioxidant protein SOD1 (copper, zinc superoxide dismutase). It is called "copper chaperone for SOD1" (CCS), and excellent animal data supports its use as a marker in accessible cells (e.g., erythrocytes) for copper deficiency as well as excess. CCS is currently being tested as a biomarker in humans.
Sources: en.wikipedia.org
Normally in humans only one follicle becomes dominant and survives to grow to 18–30 mm in size and ovulate, the remaining follicles in the cohort undergo atresia. The sharp increase in estradiol production by the dominant follicle (possibly along with a decrease in gonadotrophin surge-attenuating factor) cause a positive effect on the hypothalamus and pituitary and rapid GnRH pulses occur and an LH surge results. The increase in serum estradiol levels causes a decrease in FSH production by inhibiting GnRH production in the hypothalamus. The decrease in serum FSH level causes the smaller follicles in the current cohort to undergo atresia as they lack sufficient sensitivity to FSH to survive. Occasionally two follicles reach the 10 mm stage at the same time by chance and as both are equally sensitive to FSH both survive and grow in the low FSH environment and thus two ovulations can occur in one cycle possibly leading to non-identical (dizygotic) twins.
== TNF inhibitors == TNF inhibitors are commonly the first drug prescribed when a patient begins biologic therapy. They have the most extensive history of clinical evidence because they have been available the longest, are the most accessible, and are often the least expensive. Initially, it was thought that TNF inhibitors inactivate the proinflammatory cytokine by direct neutralization, but TNF signaling is a very complex process. Many recent studies suggest that TNF inhibitors may act with a more complex mechanism than simple blockade. They are all administered systemically either subcutaneously or intravenously.
=== Natural non-canonical bases === In a cell, there are several non-canonical bases present: CpG islands in DNA (often methylated), all eukaryotic mRNA (capped with a methyl-7-guanosine), and several bases of rRNAs (methylated). Often, tRNAs are heavily modified postranscriptionally in order to improve their conformation or base pairing, in particular in or near the anticodon: inosine can base pair with C, U, and even with A, whereas thiouridine (with A) is more specific than uracil (with a purine). Other common tRNA base modifications are pseudouridine (which gives its name to the TΨC loop), dihydrouridine (which does not stack as it is not aromatic), queuosine, wyosine, and so forth. Nevertheless, these are all modifications to normal bases and are not placed by a polymerase.
==== Absorption ==== Pregabalin is absorbed from the intestines by an active transport process mediated via the large neutral amino acid transporter 1 (LAT1, SLC7A5), a transporter for amino acids such as L-leucine and L-phenylalanine. Few (less than 10 drugs) are known to be transported by this transporter. Unlike gabapentin, which is transported solely by the LAT1, pregabalin seems to be transported by the LAT1 and by other carriers as well. The LAT1 is easily saturable, so the pharmacokinetics of gabapentin are dose-dependent, with diminished bioavailability and delayed peak levels at higher doses. In contrast, this is not the case for pregabalin, which shows linear pharmacokinetics and no saturation of absorption. The oral bioavailability of pregabalin is greater than or equal to 90% across and beyond its entire clinical dose range (75 to 600 mg/day). Food does not significantly influence the oral bioavailability of pregabalin. Pregabalin is rapidly absorbed when administered on an empty stomach, with a Tmax (time to peak levels) of generally less than or equal to 1 hour at doses of 300 mg or less. Food has been found to substantially delay the absorption of pregabalin and to significantly reduce peak levels without affecting the bioavailability of the drug; Tmax values for pregabalin of 0.6 hours in a fasted state and 3.2 hours in a fed state (5-fold difference), and the Cmax is reduced by 25–31% in a fed versus fasted state.
== Structure == Both form of PGA are linked together by peptide bonds. Because the glutamic acid has a chiral center, both forms of PGA can be made from L-glutamic acid, D-glutamic acid, or a mixture of both. In practical use, alpha PGA is composed mostly of L-glutamic acid, while gamma PGA tends to have a mixture of both.
Sources: en.wikipedia.org
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.
Yes. Trifluoroacetate and acetate ions remain associated with the peptide after purification, so a weighed quantity of powder contains less peptide than the nominal mass suggests. Certificates that report net peptide content rather than raw weight are more directly comparable between suppliers.
Dilute aqueous solutions are less stable than the dry powder and are usually aliquoted and frozen to avoid repeated freeze–thaw cycles. Lyophilised material is best stored desiccated at −20 °C, protected from light. Working solutions are typically prepared fresh from a frozen aliquot.
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.