The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-08. Anything still debated is marked as such rather than presented as settled.
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.
Documentation accompanying research peptides usually includes a certificate of analysis listing the batch number, purity figure, and test methods applied. Buyers comparing suppliers should check whether the reported purity refers to chromatographic area or to a mass-balance calculation, because the two are not equivalent. Counter-ion content, residual solvents, and water content are sometimes omitted from such certificates even though they affect the actual peptide mass present. Independent verification through a second laboratory is the most direct way to confirm that a supplied material matches its label.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Freeze-dried solid |
| Solubility class | Freely soluble in water | Aqueous buffers also suitable |
| Typical storage temperature | Minus 20 degrees Celsius or colder | Desiccated and light protected |
| Typical analytical method | RP-HPLC with UV detection | 214 nm on C18 column |
| Identity confirmation | Electrospray mass spectrometry | Sequence verified separately |
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
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.
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.
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.
== Acquisition == The company is currently being acquired by NYSE-listed health and wellness company, Hims & Hers Health in a deal worth US$1.15 billion (AU$1.6 billion). The acquisition includes a US$240 million (AU$340 million) payment when the deal closes, then deferred payments in cash or stock over the following 18 months, plus additional earn-out payments based on financial targets until 2029. Eucalyptus is also known to have an employee-friendly equity term. The value of employee shares under the deal, excluding its co-founders, is approximately AU$300 million. The average employee participant is expected to receive AU$420,000. Co-founder and CEO Tim Doyle, will become the SVP of international operations at Hims & Hers.
Dichloroacetylene (DCA) is an organochlorine compound with the formula C2Cl2. It is a colorless, pyrophoric, explosive liquid that has a sweet and "disagreeable" odor. Dichloroacetylene is neurotoxic, hepatotoxic, nephrotoxic and possibly carcinogenic.
Polymyxins are a group of cyclic non-ribosomal polypeptide (NRPs) which are biosynthesized by bacteria belonging to the genus Paenibacillus. Polymyxins consist of 10 amino acid residues, six of which are L-α,γ-diaminobutyric acid (L-DAB). The DAB residues cause polymyxins to have multiple positively charged groups at physiological pH. Seven amino acid residues form the main cyclic component, while the other three extend from one of the cyclic residues as a linear chain terminating in either 6-methyloctanoic acid or 6-methylheptanoic acid at the N-terminus. During cyclization, residue 10 is bound to the bridging residue 4. The amino acid residues and DAB monomers are generally in the L (levo) configuration, however certain strains such as P. polymyxa PKB1 have been observed to incorporate DAB with the D (dextro) configuration at position 3 producing variations of polymyxin B. Polymyxin M is also known as "mattacin".
The real chromatographic analysis starts with the introduction of the sample onto the column. The development of capillary gas chromatography resulted in many practical problems with the injection technique. The technique of on-column injection, often used with packed columns, is usually not possible with capillary columns. In the injection system in the capillary gas chromatograph the amount injected should not overload the column and the width of the injected plug should be small compared to the spreading due to the chromatographic process. Failure to comply with this latter requirement will reduce the separation capability of the column. As a general rule, the volume injected, Vinj, and the volume of the detector cell, Vdet, should be about 1/10 of the volume occupied by the portion of sample containing the molecules of interest (analytes) when they exit the column. Some general requirements which a good injection technique should fulfill are that it should be possible to obtain the column's optimum separation efficiency, it should allow accurate and reproducible injections of small amounts of representative samples, it should induce no change in sample composition, it should not exhibit discrimination based on differences in boiling point, polarity, concentration or thermal/catalytic stability, and it should be applicable for trace analysis as well as for undiluted samples. However, there are a number of problems inherent in the use of syringes for injection. Even the best syringes claim an accuracy of only 3%, and in unskilled hands, errors are much larger.
In some post-Soviet republics, there is a more negative view of the USSR, although there is no unanimity on the matter. In large part due to the Holodomor, ethnic Ukrainians have a negative view of the Soviet Union. Russian-speaking Ukrainians of Ukraine's southern and eastern regions have a more positive view of the USSR. In some countries with internal conflict, there is also nostalgia for the USSR, especially for refugees of the post-Soviet conflicts who have been forced to flee their homes and have been displaced. The many Russian enclaves in the former USSR republics such as Transnistria have in a general a positive remembrance of it.
Sources: en.wikipedia.org
== Other functions == In Cullen's paper "Granzymes in Cancer and Immunity" he discusses how granzyme A has been known to be found in elevated levels within patients who currently have an infectious disease and/or in a pro-inflammatory state. Granzymes have also been found to help initiate the inflammatory response. "For example, rheumatoid arthritis patients have increased levels of granzyme A in the synovial fluid of swollen joints". When granzymes are in an extracellular state they have the ability to activate macrophages and mast cells to initiate the inflammatory response. The interaction between the granzymes and somatic cells are still unexplainable but advances in understanding the process are being made constantly. Other granzymes like granzyme K have been found in high levels of patients who have gone septic. Granzyme H has been found to have a direct correlation with patients who have a viral infection. Scientists are able to conclude that granzyme H specializes in detecting 'proteolytic degradation' which is found in viral proteins. Cullen further states in his paper that granzymes may have a role in immunomodulation, or the job of maintaining homeostasis in the immune system during an infection. "In humans, loss of perforin function leads to a syndrome called familial hemophagocytic lymphohistiocytosis […]". This syndrome can lead to death because both T cells and macrophages multiply to fight the pathogen, resulting in harmful levels of proinflammatory cytokines.
The four substrates of this enzyme are 3-hydroxybenzenepropanoic acid, reduced nicotinamide adenine dinucleotide (NADH), oxygen, and a proton. Its products are 2,3-dihydroxyphenylpropionic acid, oxidised NAD+, and water. It is a flavoprotein that uses flavin adenine dinucleotide as a cofactor. The enzyme can act on related substrates, for example to convert 3'-hydroxycinnamic acid to 2,3-dihydroxycinnamic acid:
===== Corynebacterium ===== Non-pathogenic species of the gram-positive Corynebacterium are used for the commercial production of various amino acids. The C. glutamicum species is widely used for producing glutamate and lysine, components of human food, animal feed and pharmaceutical products. Expression of functionally active human epidermal growth factor has been done in C. glutamicum, thus demonstrating a potential for industrial-scale production of human proteins. Expressed proteins can be targeted for secretion through either the general, secretory pathway (Sec) or the twin-arginine translocation pathway (Tat). Unlike gram-negative bacteria, the gram-positive Corynebacterium lack lipopolysaccharides that function as antigenic endotoxins in humans.
== Education == Valko completed her Master of Pharmacy from Semmelweis University in 1997, followed by a PhD in Pharmaceutical Chemistry and Pharmacology from the same institution in 1979. Later in 1996, she obtained a DSc degree in Drug Discovery from Hungarian Academy of Sciences.
==== Statistics ==== There have been 12 large scale, high-quality trials of rtPA in acute ischemic stroke. A meta-analysis of these trials concluded that rtPA given within 6 hours of a stroke significantly increased the odds of being alive and independent at final follow-up, particularly in patients treated within 3 hours. However a significant mortality rate was noted, mostly from intracranial haemorrhage at 7 days, but later mortality was not significant amongst treated and non-treated patients. It has been suggested that if tPA is effective in ischemic stroke, it must be administered as early as possible after the onset of stroke symptoms, given that patients present to an ED in a timely manner. Many national guidelines including the AHA have interpreted this cohort of studies as suggesting that there are specific subgroups who may benefit from tPA and thus recommend its use within a limited time window after the event. Protocol guidelines require its use intravenously within the first three hours of the event, after which its detriments may outweigh its benefits. For example, the Canadian Stroke Network guideline states "All patients with disabling acute ischemic stroke who can be treated within 4.5 hours of symptom onset should be evaluated without delay to determine their eligibility for treatment" with tPA. Delayed presentation to the ED leads to decreased eligibility; as few as 3% of people qualify for this treatment.
Sources: en.wikipedia.org
== Pharmacokinetics and pharmacogenetics == It is bioactivated hepatically to its primary metabolite, N-desethylamodiaquine, by the cytochrome p450 enzyme CYP2C8. Among amodiaquine users, several rare but serious side effects have been reported and linked to variants in the CYP2C8 alleles. CYP2C8*1 is characterized as the wild-type allele, which shows an acceptable safety profile, while CYP2C8*2, *3 and *4 all show a range of "poor metabolizer" phenotypes. People who are poor metabolizers of amodiaquine display lower treatment efficacy against malaria, as well as increased toxicity. Several studies have been conducted to determine the prevalence of CYP2C8 alleles amongst malaria patients in East Africa, and have tentatively shown the variant alleles have significant prevalence in that population. About 3.6% of the population studied showed high risk for a poor reaction to or reduced treatment outcomes when treated with amodiaquine. This information is useful in developing programs of pharmacovigilance in East Africa, and have important clinical considerations for prescribing antimalarial medications in regions with high CYP2C8 variant frequency.
First, a coma is induced by intravenous administration of 1 g sodium thiopental (Nesdonal); if necessary, 1.5–2.0 g of the product is given in case of strong tolerance to barbiturates. Then, 45 mg alcuronium chloride (Alloferin) or 18 mg pancuronium bromide (Pavulon) is injected. To ensure optimal availability, these agents are preferably given intravenously. However, they can also be injected intramuscularly. In severe hepatitis or cirrhosis of the liver, alcuronium is the agent of first choice. A coma is first induced by intravenous administration of 20 mg/kg sodium thiopental in a small volume (10 ml physiological saline). Then, a triple intravenous dose of a nondepolarizing neuromuscular muscle relaxant is given, such as 20 mg pancuronium bromide or 20 mg vecuronium bromide (Norcuron). The muscle relaxant should preferably be given intravenously to ensure optimal availability. Only for pancuronium dibromide, the agent may also be given intramuscularly in a dose of 40 mg. A euthanasia machine may allow an individual to perform the process alone.
Furthermore, denatured samples of the toxin containing α, β, or both subunits have been shown not to induce platelet aggregation or tyrosine phosphorylation suggesting that pellet formation requires the native conformation of the protein. However, reduced convulxin subunits still inhibit the effect of collagen since they bind to a common receptor necessary for collagen activation of platelets. The free toxin might be evacuated through opsonization via the reticuloendothelial system (for the most part the liver and kidneys) or it might degrade through the lysosomes. Therefore, Convulxin acts as an agonist to collagen, inducing platelet activation via GPVI binding, ultimately causing blood clots accumulation in the absence of a homeostatic signal.
=== Spectrum of susceptibility === Doxycycline has been used successfully to treat sexually transmitted, respiratory, and eye infections. Representative pathogenic genera include Chlamydia, Streptococcus, Ureaplasma, Mycoplasma, and others. The minimum inhibitory concentration for a few medically significant microorganisms are:
In neonatal life, gonadal steroids are thought to influence the development of the hypothalamus. For instance, they correlate with the ability of females to exhibit a normal reproductive cycle, and of males and females to display appropriate reproductive behaviors in adult life:
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography with ultraviolet detection at 214 nanometres is the usual approach. Peak area percentage provides a purity figure relative to other components in the sample. Mass spectrometry is then applied to confirm identity.
Aspartate can cyclise into a succinimide intermediate that later hydrolyses back as isoaspartate. Both forms share the same molecular mass, so mass spectrometry alone cannot tell them apart. This shapes how purity data should be interpreted.
Freeze-dried material is normally kept desiccated below minus twenty degrees Celsius and shielded from light. Solutions are prepared shortly before use and held cold. Repeated thawing is avoided because it accelerates aggregation and degradation.
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.