If you have been reading about Lyophilized powder and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Storage and handling follow conventional peptide practice. Lyophilized epitalon is typically kept refrigerated or frozen, protected from moisture and light, and allowed to equilibrate to room temperature before opening to avoid condensation. Once dissolved, aqueous solutions are usually stored cold and used within a short period, since dilute peptide solutions can support microbial growth and may slowly degrade. The absence of cysteine and methionine reduces, but does not eliminate, oxidation concerns during long-term storage.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Free acid form of the tetrapeptide |
| Molecular mass | About 390.35 Da | Calculated monoisotopic value |
| Appearance | White to off-white powder | Typical lyophilized presentation |
| Solubility | Soluble in water | Also dissolves in buffered saline |
| Storage temperature | Minus 20 degrees Celsius | Dry, dark conditions; avoid repeated thawing |
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.
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.
The Marsh-Oberhuber classification is commonly used to assess the pathological changes seen in coeliac disease. Marsh originally described three different stages of coeliac disease lesions in 1992. These three stages were updated in 1999 by Oberhuber to classify stage three further. The Marsh classification is based on three histological features: intraepithelial lymphocytes count above 25/100 enterocytes (intraepithelial lymphocytosis), elongated crypts of Lieberkuhn (crypt hyperplasia), and shortening or absence of villi (villous atrophy). As these features can be seen in other disorders, they are not diagnostic for coeliac disease without serological or clinical indications. Current guidelines do not recommend a repeat biopsy unless there is no improvement in the symptoms on a gluten-free diet
== Honors and awards == EAS Award for Outstanding Achievements in the Fields of Analytical Chemistry (2023) Martin Medal (2019) Ralph N. Adams Award in Bioanalyical Chemistry (2016) ACS Award in Chromatography (2017) CASSS Award for Outstanding Achievements in Separation Science (2017) Marcel Golay Award for Lifetime Achievement in Capillary Chromatography (2012) Eastern Analytical Symposium Award for Separation Science (2012) McKnight Award for Technical Innovations in Neuroscience (2010) Rackham Distinguished Faculty Achievement Award (2009) American Microchemical Society's Benedetti-Pichler Memorial Award (2001)
== History == This condition was first described in 1954 by Janeway, who reported five cases of the disease in children. In 1957 it was further characterized as "a fatal granulomatosus of childhood". The underlying cellular mechanism that causes chronic granulomatous disease was discovered in 1967, and research since that time has further elucidated the molecular mechanisms underlying the disease. Use of antibiotic prophylaxis, surgical abscess drainage, and vaccination led to the term "fatal" being dropped from the name of the disease as children survived into adulthood.
Sources: en.wikipedia.org
Emicerfont (GW-876,008) is a drug developed by GlaxoSmithKline which acts as a CRF-1 antagonist. Corticotropin releasing factor (CRF), also known as Corticotropin releasing hormone, is an endogenous peptide hormone which is released in response to various triggers such as chronic stress, and activates the two corticotropin-releasing hormone receptors: CRF1 and CRF2. This then triggers the release of corticotropin (ACTH), another hormone which is involved in the physiological response to stress. Emicerfont blocks the CRF1 receptor, and so reduces ACTH release. It has been investigated for the treatment of irritable bowel syndrome (IBS) and alcoholism, and while it was not effective enough to be adopted for medical use in these applications, it continues to be used for research, as the role of the CRH-ACTH system in IBS remains poorly understood.
People with hyperthyroidism absorb much more iodine than healthy people, including radioactive iodine, which is easy to measure. A thyroid scan producing images is typically conducted in connection with the uptake test to allow visual examination of the over-functioning gland. Thyroid scintigraphy is a useful test to characterize (distinguish between causes of) hyperthyroidism, and this entity from thyroiditis. This test procedure typically involves two tests performed in connection with each other: an iodine uptake test and a scan (imaging) with a gamma camera. The uptake test involves administering a dose of radioactive iodine (radioiodine), traditionally iodine-131 (131I), and more recently iodine-123 (123I). Iodine-123 may be the preferred radionuclide in some clinics due to its more favorable radiation dosimetry (i.e., less radiation dose to the person per unit administered radioactivity) and a gamma photon energy more amenable to imaging with the gamma camera. For the imaging scan, I-123 is considered an almost ideal isotope of iodine for imaging thyroid tissue and thyroid cancer metastasis. Thyroid scintigraphy should not be performed in those who are pregnant, a thyroid ultrasound with color flow doppler may be obtained as an alternative in these circumstances. Typical administration involves a pill or liquid containing sodium iodide (NaI) taken orally, which contains a small amount of iodine-131, amounting to perhaps less than a grain of salt. A 2-hour fast of no food before and for 1 hour after ingesting the pill is required.
L-proline amide hydrolase (EC 3.5.1.101, S-stereoselective piperazine-2-tert-butylcarboxamide hydrolase, LaaA, L-amino acid amidase) is an enzyme with systematic name (S)-piperidine-2-carboxamide amidohydrolase. It catalyses several related hydrolysis reactions. For example, prolinamide is converted to proline:
Sources: en.wikipedia.org
Leucine-rich repeat protein SHOC-2 is a protein that in humans is encoded by the SHOC2 gene. This protein was initially identified in Caenorhabditis elegans as SUR-8/SOC2 and was found to be a critical positive regulator of the ERK1/2 signaling pathway that integrates the Ras and RAF components of the ERK1/2 pathway into a multiprotein complex. Specifically, SHOC2 tethers RAS and PP1C proteins and in close proximity to RAF to dephosphorylate “S259” to enable MAPK signaling. The best-studied role of SHOC2 is in modulating signals of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway by forming a holophosphatase complex that activates RAF proteins.
== Fission products decay and burnup == One of the common fission products is 135Te, which undergoes beta decay with half-life of 19 seconds to 135I. 135I itself is a weak neutron absorber. It builds up in the reactor at a rate proportional to the rate of fission, which is proportional to the reactor thermal power. 135I undergoes beta decay with half-life of 6.57 hours to 135Xe. The yield of 135Xe for uranium fission is 6.3%; about 95% of 135Xe originates from decay of 135I. 135Xe is the most powerful known neutron absorber, with a cross section for thermal neutrons of 2.6×106 barns, so it acts as a "poison" that can slow or stop the chain reaction after a period of operation. This was discovered in the earliest nuclear reactors built by the Manhattan Project for plutonium production. As a result, the designers made provisions in the design to increase the reactor's reactivity (the number of neutrons per fission that go on to fission other atoms of nuclear fuel). 135Xe reactor poisoning played a major role in the Chernobyl disaster. By neutron capture, 135Xe is transformed ("burned") to 136Xe, which is effectively stable and does not significantly absorb neutrons. The burn rate is proportional to the neutron flux, which is proportional to the reactor power; a reactor running at twice the power has twice the xenon burn rate. The production rate is also proportional to reactor power, but due to the half-life time of 135I, this rate depends on the average power over the past several hours.
== In diabetes == The fluctuations in the levels of chaperone HSP70 affect the homeostasis. Diabetes leads to several microvasculature and microvasculature diseases like retinopathy, Toll like receptors are integral part of innate immune system and eHSP70 binds to toll like receptors and activates the MyD88 pathway, further stimulating NF-kB, cytokines like TNFα and IL1 β, increased production of reactive oxygen species contributing to insulin resistance and diabetes. Whereas there is decrease in the levels of iHSP70.
=== Franchises in Israeli settlements === Further controversies have occurred during the company's expansion in the Middle East. The opening of a Burger King location in Ma'aleh Adumim, an Israeli settlement in the Israeli-occupied Palestinian territories, led to a breach of contract dispute between Burger King and its Israeli franchise due to the hotly contested international dispute over the legality of Israeli settlements in the Palestinian territories in accordance to international law. The controversy eventually erupted into a geopolitical dispute involving Muslim and Jewish groups on multiple continents over the application of, and adherence to, international law. The case eventually elicited reactions from the members of the 22-nation Arab League. The Islamic countries within the League made a joint threat to the company of legal sanctions, including the revocation of Burger King's business licenses within the member states' territories.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.
No naturally occurring free form of the peptide has been described. The four-amino-acid sequence can appear as a fragment within larger proteins, but that is not the same as the intact compound being present as a circulating molecule. Materials used in research are synthetic.
Purity is usually checked by reverse-phase high-performance liquid chromatography, which separates the target peptide from related impurities. Mass spectrometry is commonly used alongside it to confirm molecular mass. Some suppliers also provide amino acid analysis for additional sequence confirmation.
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.