epithalamin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-06-21. Numbers and descriptions here follow the published literature rather than marketing material.
Literature searches for this compound must account for several spelling variants. Indexing databases contain epitalon, epithalon, epithalone, and AEDG, and relevant records are scattered across Russian-language and English-language journals that do not consistently cross-cite. Early publications describe the parent extract as a mixture of many peptides, whereas later work addresses the single synthetic tetrapeptide. That shift in nomenclature complicates comparison between studies, because extract data and tetrapeptide data are sometimes cited interchangeably. A search strategy omitting the alternate spellings will return an incomplete set of references.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four amino acid residues |
| Residue sequence | Ala-Glu-Asp-Gly | Abbreviated AEDG |
| Approximate mass | 390.35 Da | Monoisotopic, free base form |
| Parent preparation | Epithalamin extract | Derived from pineal tissue |
| Common spelling variants | Epithalon, epithalone, AEDG | Affects literature retrieval |
Discussions in the literature often conflate three distinct entities: the pineal extract epithalamin, the isolated tetrapeptide AEDG, and commercial preparations sold under similar names. Reviews citing older Russian-language studies sometimes omit detail on purity, route of administration and control groups, which makes cross-study comparison difficult. Researchers working with the compound generally note the need for independent replication, standardized enzyme assays, and clearer reporting of peptide identity. These caveats are relevant when weighing claims that appear in secondary sources rather than in primary reports.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
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.
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.
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.
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.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
=== Brazil === The rate of overweight and obesity in Brazilian children increased from 4% in the 1980s to 14% in the 1990s. In 2007 the prevalence of children overweight and childhood obesity was 11.1% and 2.7% in girls, 8.2% and 1.5% in boys, respectively.
=== Diagnosis and assessment === The assessment of riboflavin status is essential for confirming cases with non-specific symptoms whenever deficiency is suspected. Total riboflavin excretion in healthy adults with normal riboflavin intake is about 120 micrograms per day, while excretion of less than 40 micrograms per day indicates deficiency. Riboflavin excretion rates decrease as a person ages, but increase during periods of chronic stress and the use of some prescription drugs. Indicators used in humans are erythrocyte glutathione reductase (EGR), erythrocyte flavin concentration and urinary excretion. The erythrocyte glutathione reductase activity coefficient (EGRAC) provides a measure of tissue saturation and long-term riboflavin status. Results are expressed as an activity coefficient ratio, determined by enzyme activity with and without the addition of FAD to the culture medium. An EGRAC of 1.0 to 1.2 indicates that adequate amounts of riboflavin are present; 1.2 to 1.4 is considered low, greater than 1.4 indicates deficient. For the less sensitive "erythrocyte flavin method", values greater than 400 nmol/L are considered adequate and values below 270 nmol/L are considered deficient. Urinary excretion is expressed as nmol of riboflavin per gram of creatinine. Low is defined as in the range of 50 to 72 nmol/g. Deficient is below 50 nmol/g. Urinary excretion load tests have been used to determine dietary requirements.
=== Solvent extractions === Whether to add organic solvent into aqueous solvent, or vice versa, becomes important on the industrial scale. Depending on the solvents used, emulsions can form, and the time needed for the layers to separate can be extended if the mixing between solvents is not optimal. When adding organic solvent to aqueous, stoichiometry must be considered again, as the excess of water could hydrolyze organic compounds in only mildly acidic or basic conditions. In an even wider scope, the location of the chemical plant can play a role in the ambient temperature of the reaction vessel. A difference of even a couple of degrees can yield much different levels of extractions between plants located across countries.
== Mechanism == Non-enzymatic malonylation occurs spontaneously through direct transfer of a malonyl group from malonyl‑CoA to the ε-amino group (–NH2) of a deprotonated lysine residue, without enzyme involvement. Only the deprotonated lysine residue can react in this way because its ε-amino group carries a free electron pair that can attack the carbonyl carbon of the highly reactive malonyl-CoA thioester, whose electron-withdrawing carboxyl group further increases its reactivity. Since the lysine residue has a pKa of about 10.5, however, it exists almost entirely in its protonated form at physiological pH (~7.4), with less than 0.1% deprotonated as calculated from the Henderson–Hasselbalch equation. Local protein microenvironments, such as near negatively charged residues or within hydrophobic pockets, can additionally enable lysine deprotonation, while broader conditions such as the more alkaline pH (~8.0) of the mitochondrial matrix increase the fraction of deprotonated lysine residues to about 0.3%, thereby favoring non-enzymatic malonylation. In compartments with near-neutral pH (~7.2), such as the cytosol or nucleus, lysine residues are therefore almost fully protonated and rely more on enzymatic malonylation there, suggesting that both mechanisms contribute to the overall malonylation pattern in cells. In enzymatic malonylation, protonated lysine residues (–NH3+), which is the form in which they almost all exist (≈ 99.9%) at physiological pH (~7.4), can also be modified.
Sources: en.wikipedia.org
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Rhodophyta, Chlorophyta, and Heterokontophyta, the three main algal divisions, have life cycles which show considerable variation and complexity. In general, an asexual phase exists where the seaweed's cells are diploid, a sexual phase where the cells are haploid, followed by fusion of the male and female gametes. Asexual reproduction permits efficient population increases, but less variation is possible. Commonly, in sexual reproduction of unicellular and colonial algae, two specialized, sexually compatible, haploid gametes make physical contact and fuse to form a zygote. To ensure a successful mating, the development and release of gametes is highly synchronized and regulated; pheromones may play a key role in these processes. Sexual reproduction allows for more variation and provides the benefit of efficient recombinational repair of DNA damage during meiosis, a key stage of the sexual cycle. However, sexual reproduction is more costly than asexual reproduction. Meiosis has been shown to occur in many different species of algae.
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In October 2023, the company announced it would acquire ocedurenone – an experimental drug for uncontrolled hypertension and potentially beneficial in treating cardiovascular and kidney diseases – from KBP Biosciences for $1.3 billion. After a failed clinical trial the following year, Novo initiated legal action against KBP alleging that the company misrepresented the drug's effectiveness by concealing unfavorable clinical trial data. Seeking up to $830 million in damages, the Singapore International Commercial Court granted Novo's request for a freeze on KBP's assets and those of its founder, Huang Zhenhua. In November 2023, Novo announced investment of €2.1 billion in a French production facility to increase the production capacity and manufacturing of its popular anti-obesity medication. In February 2024, parent company Novo Holdings agreed to acquire Catalent for $16.5 billion. On completion, Novo said it would acquire three manufacturing facilities from its parent for $11 billion to scale up production to meet the massive demand for Wegovy and Ozempic. In March 2024, Novo reached a $604 billion market capitalization and became the 12th most valuable company in the world. The company's stock jumped to a record high after early trial data showed positive results for its new experimental weight loss pill amycretin. The company also announced it would acquire Cardior Pharmaceuticals and its cardiovascular disease portfolio for up to $1.1 billion.
Sources: en.wikipedia.org
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.
No. Epithalamin is a heterogeneous extract containing many peptides, while epitalon is a single synthesised tetrapeptide. Publications sometimes treat findings from the two as equivalent, which is a common source of confusion. Their compositions differ and they are not interchangeable in analytical terms.
Most published work uses cell cultures or rodents because those models are faster and less costly to run. The few human trials that have been reported are small, and several lack control groups or blinding. This restricts what can reasonably be concluded about effects in people.
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.