This is a working overview of Lyophilized powder, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-13 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | RP-HPLC | Reported as percent area, often ≥95% |
| Identity confirmation | Mass spectrometry | Observed mass compared with ~390 Da |
| Typical storage temperature | -20 °C or below | Lyophilized powder, desiccated |
| Reconstitution solvent | Sterile water or buffer | Acidic residues aid dissolution |
| Common synonyms | AEDG; epithalon | Spelling varies in 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.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
The compound is generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
=== Pharmacodynamics === In vitro, cannabidiol has low affinity for, and acts as a negative allosteric modulator of the CB1 cannabinoid receptor Cannabidiol may be an antagonist of GPR55, a G protein-coupled receptor and putative non-homologous CB3 cannabinoid receptor shown by in vitro studies to be widely distributed in the brain. Cannabidiol may interact with various neurotransmitters, such as serotonin, dopamine, and GABA. As of 2024, the cellular effects and mechanisms of cannabidiol in vivo are unknown, as research to date has been inconclusive and based on laboratory studies. The anticonvulsant effects provided by cannabidiol (Epidiolex) in people with certain forms of epilepsy do not appear to involve cannabinoid receptors. A possible mechanism for the effects of cannabidiol on seizures is by affecting the neuronal movement of calcium in brain structures involved in the excessive electrical activity of seizures.
=== Prewar and postwar eras === The club came close to reaching the First Division in their early years. In the 1921–22 season, they missed out on promotion by goal difference. During the 1930s and 1940s years, the club found themselves sliding between the Second and Third Division. In 1949, the club signed Danny Blanchflower from Glentoran, and he impressed at Oakwell that two years later he was signed by First Division side Aston Villa, later signing for Tottenham Hotspur and being voted FWA Player of the Year twice, as well as being the captain of the 20th century's first league and cup double winning team in 1960–61. Around the time of Blanchflower's departure, a young centre-forward called Tommy Taylor broke into the Barnsley team, scoring 26 goals in 44 games. In April 1953, he became one of the most expensive players in English football at the time when Sir Matt Busby signed him for Manchester United for a fee of £29,999. Taylor went on to be a prolific goalscorer at the highest level over the next five years, winning two league titles and scoring 16 goals in 19 appearances for the England national football team, before losing his life in the Munich air disaster on 6 February 1958. When the Northern and Southern sections of the Third Division were replaced by national Third and Fourth Divisions for the 1958–59 season, Barnsley were still in the Second Division, but went down to the Third Division at the end of the season. In 1965, Barnsley were relegated to the Football League Fourth Division for the first time, winning promotion three years later.
== Pathogenesis == In susceptible persons, beryllium exposure can lead to a cell-mediated immune response. The T-cells become sensitized to beryllium. Each subsequent exposure leads to an immune response involving CD4+ helper T-lymphocytes and macrophages accumulating in the lungs. As this response continues macrophages, CD4+ T-lymphocytes and plasma cells aggregate together to form the noncaseating granulomas. When beryllium is phagocytized by macrophages, the beryllium triggers macrophage apoptosis, thereby reducing beryllium clearance from the lungs and eventually resulting in secondary necrosis and lysis. Eventually, the outcome is fibrosis of the lung. Several studies have shown that there is a genetic component to beryllium sensitivity. Specifically, those beryllium-exposed workers with a mutation at the HLA-DPB1 Glu69 position have increased prevalence of beryllium sensitization and chronic beryllium disease. The HLA-DPB1 gene is important for MHC class II molecule function on antigen presenting cells. A study of the immune response to beryllium in individuals who express the HLA-DP2 allele found that CD4 T-cells do not detect the Be2+ cation itself, but instead detect surface changes in the HLA-DP2/peptide complex in which Be2+ is embedded. Those researchers concluded that chronic beryllium disease is a predisposition that lies between "allergic hypersensitivity and autoimmunity." According to the International Agency for Research on Cancer, beryllium and beryllium compounds are Category 1 carcinogens; they are carcinogenic to both animals and humans.
=== Ka--Kj === Henri B. Kagan (born 1930) French chemist, pioneer of asymmetric catalysis, 2001 Wolf Prize in Chemistry Isabella Karle (1921–2017), American chemist instrumental for extracting plutonium chloride from a mixture containing plutonium oxide Jerome Karle (1918–2013), 1985 Nobel Prize in Chemistry for the direct analysis of crystal structures by X-ray scattering Paul Karrer (1889–1971), Swiss organic chemist known for research on vitamins, 1937 Nobel Prize in Chemistry Alan R. Katritzky (1928–2014), British-American organic chemist, pioneer of heterocyclic chemistry Joyce Jacobson Kaufman (1929–2016), American chemist and inventor of conformational topology Melinda H. Keefe (PhD 2001), American chemist known for identifying solvents that can be used to remove dirt without damaging layers of paint August Kekulé (1829–1896), German organic chemist known for the theory of chemical structure, especially the structure of benzene John Kendrew (1917–1997), British biochemist and crystallographer known for solving the structure of myoglobin, 1962 Nobel Prize in Chemistry Ann Kiessling (born 1942), American chemist and reproductive biologist known for discovering reverse transcriptase activity in normal human cells Ann Kimble-Hill (21st century), American biochemist studying structure-function relationships of membrane proteins and lipids Petrus Jacobus Kipp (1808–1864), Dutch chemist, inventor of Kipp's apparatus Johan Kjeldahl (1849–1900), Danish chemist who developed a method for determining the amount of nitrogen in organic compounds
Sources: en.wikipedia.org
=== Etymology === Earlier versions of the DSM—before the multiaxial diagnosis system—classified most people with mental health problems into two categories: the psychotics and the neurotics. Clinicians noted a certain class of neurotics who, when in crisis, appeared to straddle the borderline into psychosis. The term "borderline personality disorder" was coined in American psychiatry in the 1960s. It became the preferred term over several competing names, such as "emotionally unstable character disorder" and "borderline schizophrenia", during the 1970s. Borderline personality disorder was included in DSM-III (1980) despite not being universally recognized as a valid diagnosis. Its validity was firmly established by the 1990s.
The army throughout the spring of 1943 was significantly reinforced and grew to a strength of 1,100 tanks and 250,000 men by July 1943. It was to form the southern spearhead in the Battle of Kursk. The army tried but failed to break through the Soviet defences around Kursk. It then fought a series of defensive battles throughout the remainder of 1943 to hold back the Red Army's Lower Dnieper Strategic Offensive Operation. By November 1943, the Soviets had reached Kiev and the 4th Panzer Army was tasked to defend the city. The Soviet aim was to take the city and break the rail link with Army Group Center or envelop Army Group South. But even though the Soviets had liberated Kiev, broken the Dnieper line, and inflicted massive casualties, the 4th Panzer Army held on and the Soviets failed to break the rail link.
== Biosynthesis == Both ginger (Zingiber officinale) and turmeric (Curcuma longa) had been suspected to utilize phenylpropanoid pathway and produce putative type III polyketide synthase products based on the research of 6-gingerol biosynthesis by Denniff and Whiting in 1976 and by Schröder's research in 1997. 6-Gingerol is the major gingerol in ginger rhizomes and it possesses some interesting pharmacological activities like analgesic effect. While the biosynthesis of 6-gingerol is not fully elucidated, plausible pathways are presented here.
Sources: en.wikipedia.org
== General characteristics == Pseudomonas fluorescens has multiple flagella, an extremely versatile metabolism, and can be found in the soil and in water. It is an obligate aerobe, but certain strains are capable of using nitrate instead of oxygen as a final electron acceptor during cellular respiration. Optimal temperatures for growth of P. fluorescens are 25–30°C. It tests positive for the oxidase test, and is also a nonsaccharolytic bacterial species. Heat-stable lipases and proteases are produced by P. fluorescens and other similar pseudomonads. These enzymes cause milk to spoil, by causing bitterness, casein breakdown, and ropiness due to production of slime and coagulation of proteins.
Vanilla planifolia has been propagated clonally through cuttings rather than from seeds and selective breeding. As of 2023 there is only one patented cultivar, "Handa", and very few other named cultivars. The most important of these cultivars for commercial growing are the "Mansa" types. There are also two variegated cultivars sold for ornamental gardening. Though there are five known attempted introductions to Reunion Island between 1793 and 1875, only the 1822 introduction was successful. It is likely that almost all the vanilla grown in the areas surrounding the Indian Ocean are descended from this one introduction and this is supported by modern genetic research. Vanilla as a crop could be threatened by this genetic bottleneck and the subsequent buildup of negative mutations. Because of the low rate of natural pollination, even in areas with pollinators, which are rare to nonexistent elsewhere, the flowers must be hand-pollinated when grown on farms. Once beans in a cluster turn yellow and ripe, the whole cluster is generally harvested and cured. Curing involves fermentation and drying of the pod to develop the characteristic vanilla flavor while minimizing the loss of essential oils. Vanilla extract is obtained from this portion of the plant. It is cultivated and harvested primarily in Veracruz, Mexico, Tahiti, Indonesia, and Madagascar. V. planifolia can be grown and harvested indoors as a houseplant or in a greenhouse, but it has very precise requirements for growing conditions. It is generally only attempted by experts in orchid cultivation.
The resin can be recharged by washing it with a solution containing a high concentration of sodium ions (e.g. it has large amounts of common salt (NaCl) dissolved in it). The calcium and magnesium ions then migrate from the resin which is actively being replaced by sodium ions from the solution until a new equilibrium is reached. The salt is used to recharge an ion-exchange resin, which itself is used to soften the water.
Sources: en.wikipedia.org
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.
The powder is generally kept refrigerated or frozen, protected from light and moisture. Vials should reach room temperature before opening to prevent condensation. Reconstituted solutions are usually stored cold and used within a limited window because dilute solutions can degrade or support microbial growth.
Epitalon is not an approved drug in major Western regulatory jurisdictions. Its legal status differs between countries, and it is often distributed as a research chemical. This means product documentation and purity vary considerably between suppliers.
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.