A practical reference on telomerase: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-04-30. Anything still debated is marked as such rather than presented as settled.
Epitalon is a synthetic tetrapeptide with the amino acid sequence alanine-glutamate-aspartate-glycine, abbreviated Ala-Glu-Asp-Gly or AEDG. It was developed by the Russian researcher Vladimir Khavinson and colleagues during work on peptide bioregulators derived from the pineal gland. The compound is short enough to be produced by standard solid-phase peptide synthesis and is typically handled as a lyophilized white powder. Its small size distinguishes it from larger pineal peptides such as epithalamin, a complex extract from which the tetrapeptide was conceptually derived.
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
| Property | Value | Notes |
|---|---|---|
| Amino acid sequence | Ala-Glu-Asp-Gly | Tetrapeptide, often abbreviated AEDG |
| Molecular formula | C14H22N4O9 | Free peptide, unmodified termini |
| Molecular weight | ~390.35 Da | Calculated for the free acid form |
| Appearance | White to off-white powder | Typical lyophilized product form |
| Solubility class | Freely soluble in water | Two acidic residues dominate ionic character |
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
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.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
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.
The editing involves cytidine deaminase that deaminates a cytidine base into a uridine base. An example of C-to-U editing is with the apolipoprotein B gene in humans. Apo B100 is expressed in the liver and apo B48 is expressed in the intestines. In the intestines, the mRNA has a CAA sequence edited to be UAA, a stop codon, thus producing the shorter B48 form. C-to-U editing often occurs in the mitochondrial RNA of flowering plants. Different plants have different degrees of C-to-U editing; for example, eight editing events occur in mitochondria of the moss Funaria hygrometrica, whereas over 1,700 editing events occur in the lycophytes Isoetes engelmanii. C-to-U editing is performed by members of the pentatricopeptide repeat (PPR) protein family. Angiosperms have large PPR families, acting as trans -factors for cis -elements lacking a consensus sequence; Arabidopsis has around 450 members in its PPR family. There have been a number of discoveries of PPR proteins in both plastids and mitochondria.
Dirt spawned five singles that reached the top 30 on the Billboard Mainstream Rock chart: "Would?", "Rooster", "Them Bones", "Angry Chair", and "Down in a Hole", and remained on the charts for nearly two years. Alice in Chains was added as openers to Ozzy Osbourne's No More Tours tour. Days before the tour began, Layne Staley broke his foot in an ATV accident, forcing him to use crutches on stage. Starr left the band after the release of Dirt. Staley told Rolling Stone in 1994 about Starr leaving the band, "It was just a difference in priorities. We wanted to continue intense touring and press. Mike was ready to go home." Years later, Starr claimed that he was fired due to his drug addiction. Starr was replaced by former Ozzy Osbourne bassist Mike Inez. Inez had met Alice in Chains during Ozzy Osbourne's No More Tours tour and became friends with them. When the band was in Brazil, they called Inez to join them and he accepted. Inez wanted to do the shows in Brazil and even got his immunization shots, but the band called him back saying that Starr wanted to do the last two shows in Brazil, so they would meet Inez in London instead. Inez ended up getting sick with his vaccination shots for a couple of days. Inez played his first concert with Alice in Chains on January 27, 1993, at the Camden Underworld in London. In April 1993, the band recorded two songs with Inez, "What the Hell Have I" and "A Little Bitter", for the Last Action Hero soundtrack.
We are at War, Spirit of Victory, The radio constantly broadcast war reports and allusive radio soap operas: Contraespionaje, Las ideas no se matan. Agustín Lara premiered his Cantar del Regimiento and the cinema achieved resounding successes that everyone likes to this day: ¡Mexicanos al Grito de Guerra! by Álvaro Gálvez y Fuentes, La Isla de la Pasión and Soy puro mexicano by Emilio Fernández. This was the popular sentiment.
Sources: en.wikipedia.org
=== Film === In the 1999 film, Notting Hill, Keziah, played by Emma Bernard is a vegetarian. In one scene, Keziah tells William "Will" Thacker (played by Hugh Grant), that she is a fruitarian. In the 2000 film, But I'm A Cheerleader, before Megan, one of the film's protagonists, is sent to a conversion therapy camp, her parents and others claim she is a lesbian because she is a vegetarian. Legally Blonde, a 2001 film, also featured a vegetarian—Elle Woods. When she introduces herself at Harvard Law School, she describes herself and her dog as "Gemini vegetarians". In the 2012 film, Life of Pi, Pi, played by Suraj Sharma, is a vegetarian based on his 3 religions: Hindu, Christian, and Muslim. And in the ship scene, one Taiwanese Sailor, played by Bo-Chieh Wang, is a vegetarian from his Buddhism religion to eat rice and the vegetarian gravy. In the 2018 Hollywood blockbuster, Black Panther, M'Baku (voiced by Winston Duke), the Jabari tribe leader who lives in the mountains of Wakanda, declares to a White CIA agent named Everett Ross (voiced by Martin Freeman), "if you say one more word, I'll feed you to my children!" After Everett is shaken by these words, he jokes, saying he is kidding because all those in his tribe, including himself, are vegetarians. Some praised this scene for challenging a stereotype of Black culture and the perception of what vegetarians look like. Duke later said that some Black outlets cooked vegan meals for him, and said that the scene is "kind of teaching kids that eating vegetables is cool," which is something he is for.
The compound accepts or donates the equivalent of H−. Such reactions (summarized in formula below) involve the removal of two hydrogen atoms from a reactant (R), in the form of a hydride ion (H−), and a proton (H+). The proton is released into solution, while the reductant RH2 is oxidized and NAD+ reduced to NADH by transfer of the hydride to the nicotinamide ring.
These actions, including weak DAT inhibition combined with secondary catecholaminergic, orexinergic, glutamatergic, and GABAergic modulation, are thought to underlie modafinil's ability to promote wakefulness and cognitive function with a lower risk of euphoria and abuse than traditional amphetamine-like psychostimulants. From laboratory research, modafinil has little to no affinity for serotonin or norepinephrine transporters and does not directly interact with these systems. However, studies have shown that elevated concentrations of norepinephrine and serotonin can occur as an indirect effect following modafinil administration due to increased extracellular dopamine activity. Unlike traditional psychostimulant drugs, such as cocaine or amphetamine, modafinil shows low potential for causing euphoria due to differences in how it interacts with dopamine transporters at a cellular level. In addition to its influence on dopaminergic pathways, modafinil may impact other neurotransmitter systems, such as orexin (hypocretin) and histamine. Orexinergic and histaminergic neurons are involved in promoting wakefulness and regulating arousal states. Modafinil may increase signaling within hypothalamic orexin and histamine pathways, potentially contributing to its wake-promoting effects. In animal models, modafinil-induced increases in hypothalamic histamine release require intact orexinergic neurons. The wake-promoting effects of modafinil do not appear to depend on the orexin system.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide composed of four amino acids: alanine, glutamate, aspartate, and glycine. It is written as Ala-Glu-Asp-Gly. The free peptide has a molecular weight of about 390 daltons and is normally supplied as a lyophilized powder.
No. Epitalon is chemically synthesized, not extracted. It was designed as a short synthetic fragment conceptually related to larger pineal peptides studied in the same research tradition, particularly the extract known as epithalamin. The two are distinct materials with different compositions.
The term bioregulator is used in this research tradition for short peptides proposed to influence gene expression or cell function. Epitalon is grouped with other synthetic short peptides under this label. The term reflects a proposed mechanism rather than an established drug classification.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.