Everything below concerns Aspartimide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-26. Numbers and descriptions here follow the published literature rather than marketing material.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
Regulatory treatment differs by country. No formulation of epitalon holds a marketing authorisation as a medicine in the United States or the European Union, where material sold for laboratory use is handled as a research chemical and is not intended for human consumption. In Russia, several short peptide preparations from the same institute's peptide series are registered medicinal products, and epitalon appears in that national context. Elsewhere it is frequently offered as a cosmetic ingredient, a category with lighter requirements. Advertising claims about longevity or disease prevention are restricted in most jurisdictions, which limits how sellers describe the compound.
Freeze-dried epitalon is normally kept at minus twenty degrees Celsius in a sealed, desiccated container, protected from light. Short excursions at ambient temperature during shipping are generally tolerated, but repeated warming and cooling cycles encourage moisture uptake, which shortens shelf life. Once dissolved, the peptide is far less stable than the solid: aqueous solutions are subject to hydrolysis and to deamidation at the aspartate and glutamate residues. Working solutions are therefore held refrigerated and used within days, and repeated freezing and thawing of the same vial is best avoided.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
Epitalon is a synthetic tetrapeptide whose sequence is alanine–glutamate–aspartate–glycine, commonly abbreviated AEDG. It was developed in Russia during the 1980s and 1990s by investigators associated with the St. Petersburg Institute of Bioregulation and Gerontology, who studied short peptides as regulators of gene expression and tissue function. The alternative spelling epithalon appears interchangeably in the literature, and the two names refer to the same molecule. Outside Russia it is encountered chiefly as a research chemical rather than a licensed medicine, and it holds no approval from the United States Food and Drug Administration or the European Medicines Agency.
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
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.
Su ji (素鸡, "vegetarian chicken"), either by being rolled up or by being pressed together and fried. Baiye jie (百叶结 "baiye knots"), by slicing into 2 cm × 10 cm slices and tying the slice up. Various dishes that roll other food items inside a piece of baiye.
Albania (Entry & Exit stamp may be issued upon request) Australia (Exit stamp issued upon explicit request) China (Exit stamp issued upon request when using e-Gate) Costa Rica (only at Costa Rican airports; different entry and exit stamps are made at the border crossing with Panama) El Salvador Fiji Hong Kong (no entry or exit stamps are issued; instead, landing slips are issued upon arrival only) Iran Israel (no entry or exit stamps are issued at Ben Gurion Airport, instead landing slips are issued upon arrival and departure) Japan (Exit stamp issued upon request & when not using e-Gate since July 2019) Macau (no entry or exit stamps are issued; instead, landing slips are issued upon arrival only) New Zealand South Korea (since 1 November 2016) Panama (only at Panamanian airports; stamps are made at the border crossing with Costa Rica) Republic of China (exit stamp issued upon request & when not using e-Gate) Singapore (no exit stamps since 22 April 2019) Saint Kitts and Nevis Schengen Area countries (when the Entry/Exit System becomes operational, it is anticipated that the passports of third-country nationals will not be stamped when they enter and leave the Schengen Area)
=== Engineered Bacteria Therapeutics === Fischbach's team has made significant strides in engineering commensal bacteria for therapeutic purposes. They transformed the ubiquitous skin bacterium Staphylococcus epidermidis into a topical vaccine platform. This approach generated potent, durable, and specific antibody responses in mice, potentially offering a new method for vaccine delivery. In 2023, his postdoc Erin Chen led an effort to engineer skin bacteria to induce antitumor T cell responses against melanoma, highlighting the potential of the skin microbiome in cancer immunotherapy.
=== Clinical trials === Human trials began on January 26, 2021, with 60 volunteers between the ages of 18 and 65 in Toronto. Of these, 15 would receive a placebo and three groups of 15 would receive different doses of the vaccine. The volunteers will be monitored for 13 months. The company said that enough data would be available in May which could result in a Phase 2 clinical testing beginning soon after that, pending regulatory approval. If the results of a subsequent larger human trial are positive, the vaccine could enter a commercialization phase in 2022. The Phase 1 clinical trial lead was Piyush Patel. At the 29 April meeting with the House of Commons, Sorenson estimated that PTX-COVID19-B could be approved by Health Canada by "January or February 2022".
=== Macromolecular therapeutics for brain delivery === Nanomedicines designed for brain delivery/action have a difficult hurdle to overcome; they need to cross the blood brain barrier. We focus on receptor binding peptides that transcytose bound cargo into the brain. In particular, angiopep-2 (TFFYGGSRGKRNNFKTEEY) binds to LDLR (low-density lipoprotein receptor)-related protein (LRP)-1 followed by transcytosis. In collaboration with the University of Utah Department of Radiology we are developing conjugates suitable for the treatment of traumatic brain injury and Alzheimer disease.
Sources: en.wikipedia.org
The enzyme 2-dehydro-3-deoxy-phosphogluconate aldolase (EC 4.1.2.14), commonly known as KDPG aldolase, catalyzes the chemical reaction 2-dehydro-3-deoxy-D-gluconate 6-phosphate ⇌ {\displaystyle \rightleftharpoons } pyruvate + D-glyceraldehyde 3-phosphate This enzyme belongs to the family of lyases, specifically the aldehyde-lyases, which cleave carbon-carbon bonds. It is used in the Entner–Doudoroff pathway in prokaryotes, feeding into glycolysis. 2-dehydro-3-deoxy-phosphogluconate aldolase is one of the two enzymes distinguishing this pathway from the more commonly known Embden–Meyerhof–Parnas pathway. This enzyme also participates in following 3 metabolic pathways: pentose phosphate pathway, pentose and glucuronate interconversions, and arginine and proline metabolism. In addition to the cleavage of 2-dehydro-3-deoxy-D-gluconate 6-phosphate, it is also found to naturally catalyze Schiff base formation between a lysine ε-amino acid group and carbonyl compounds, decarboxylation of oxaloacetate, and exchange of solvent protons with the methyl hydrogen atoms of pyruvate.
== Cited sources == Charatan, Fred (2006). "Gulf war symptoms do not constitute a syndrome". BMJ. 333 (7569): 618. doi:10.1136/bmj.333.7569.618-b. JSTOR 40700302. PMC 1570822. PMID 16990302. Greenberg, Neil; Iversen, Amy C.; Unwin, Catherin; Hull, L.; Wessely, S. (2004). "Screening for depleted uranium in the United Kingdom armed forces: who wants it and why?". Journal of Epidemiology and Community Health. 58 (7): 558–561. doi:10.1136/jech.2003.014142. PMC 1732813. PMID 15194715. Moszynski, Peter (2003). "Royal Society warns of risks from depleted uranium". BMJ. 326 (7396): 952. doi:10.1136/bmj.326.7396.952. JSTOR 25454350. PMC 1125878. PMID 12727744. Mould, Richard F. (2001). "Radiation dose from depleted uranium can now be measured". BMJ. 322 (7290): 865–866. doi:10.1136/bmj.322.7290.865/a. JSTOR 25466697. PMC 1120031. PMID 11321019. S2CID 683662. Royal Society working group on the health hazards of depleted uranium munitions (2002). The health hazards of depleted uranium munitions: Part II (Report). London, England: The Royal Society.
Sitagliptin (FDA approved in 2006, and marketed by Merck & Co. as Januvia) Vildagliptin (EU approved in 2007, and marketed in the EU by Novartis as Galvus) Saxagliptin (FDA approved in 2009, and marketed as Onglyza) Linagliptin (FDA approved in 2011, and marketed as Tradjenta by Eli Lilly and Company and Boehringer Ingelheim) Gemigliptin (approved in Korea in 2012, and marketed by LG Life Sciences as Zemiglo, among other names) Anagliptin (approved in Japan as Suiny in 2012; marketed by Sanwa Kagaku Kenkyusho Co., Ltd. and Kowa Company, Ltd.) Teneligliptin (approved in Japan as Tenelia in 2012) Alogliptin (FDA approved in 2013 as Nesina/Vipidia, and marketed by Takeda Pharmaceutical Company) Trelagliptin (approved for use in Japan as Zafatek/Wedica in 2015) Omarigliptin (MK-3102; approved as Marizev in Japan in 2015, having been developed by Merck & Co. In November 2015, Sheu and colleagues showed that omarigliptin could be used once-weekly and was generally well tolerated throughout the base and extension studies) Evogliptin (approved as Suganon/Evodine for use in South Korea) Gosogliptin (approved as Saterex for use in Russia) Dutogliptin (PHX- 1149; free base being developed by Phenomix Corporation. In a phase III trial as of April 2010) Neogliptin Retagliptin (SP-2086; approved in China) Denagliptin Cofrogliptin (HSK- 7653; compound 2) Fotagliptin Prusogliptin Cetagliptin (CGT 8012) Berberine, an alkaloid found in plants of the genus Berberis (the "barberry"), inhibits DPP-4, which may at least partly explains the chemical's antihyperglycemic activity.
==== August 2008 ==== Nezavisimaya Gazeta reported in June 2008 that when Chechen peacekeepers from Vostok Battalion began serving in South Ossetia in the autumn of 2007, they began arresting armed people with fake peacekeeping IDs. However, the Chechens were soon ordered to cease the arrest of the impostors and armed people with unknown affiliations were now freely roaming South Ossetia. On 4 August 2008, Life.ru reported that after the end of the "Kavkaz 2008" exercises, the paratroopers from Pskov remained to occupy the key positions on the Roki and Mamison passes on the border. Several battalions of 58th Army were deployed close to the border and the South Ossetian sources told the newspaper that the deployment of troops began on the night of 2–3 August 2008. Life.ru reported, "The deployment of the Russian military hardware near the Roki Tunnel will allow as soon as possible to move troops to help the peacemaking forces." On 6 August 2008, OsRadio reported that the volunteers were also arriving in Tskhinvali from Moscow. On 26 September 2008, Trud reported on the special battalion Vostok. One member of the battalion Khamzat said, "See what the "Red Star" wrote about us: Volunteers from neighboring republics arrive in South Ossetia. So we are volunteers?!" Khamzat added, "We are the regular subunit of 291-th Regiment of 42nd Guards Motor Rifle Division of the North Caucasus Military District. And we only act on orders." On 8 August 2008, Nezavisimaya Gazeta published an article by journalist who had spent previous three days in Chechnya.
=== Disinfectant === Hydrogen peroxide may be used for the sterilization of various surfaces, including surgical instruments, and may be deployed as a vapour (VHP) for room sterilization. H2O2 demonstrates broad-spectrum efficacy against viruses, bacteria, yeasts, and bacterial spores. In general, greater activity is seen against Gram-positive than Gram-negative bacteria; however, the presence of catalase or other peroxidases in these organisms may increase tolerance in the presence of lower concentrations. Lower levels of concentration (3%) will work against most spores; higher concentrations (7 to 30%) and longer contact times will improve sporicidal activity. Hydrogen peroxide is seen as an environmentally safe alternative to chlorine-based bleaches, as it degrades to form oxygen and water and it is generally recognized as safe as an antimicrobial agent by the U.S. Food and Drug Administration (FDA).
Sources: en.wikipedia.org
==== Adverse effects ==== The common side effects associated with the use of Dronabinol are diverse but generally mild. They generally resolved in a few days. Common side effects include dizziness, dry mouth and headache. Others are related to an alteration of mental state, such as euphoria, mood changes, anxiety, drowsiness and abnormal thinking. Yet, impairment of cognitive performance, including memory and alertness, is not reported. The incidence of side effects may be reduced with a delayed dosing to near bedtime. Dose reduction should be considered in patients with continual side effects.
== Biological role == Cadmium has no known function in most organisms, and is toxic. Cadmium is considered an environmental pollutant hazardous to living organisms. A cadmium-dependent carbonic anhydrase has been found in some marine diatoms, which live in environments with low zinc concentrations. Exposure to cadmium leads to raised levels in the blood cells for a number of months. In vertebrates cadmium is preferentially absorbed in the kidneys but also in the liver and bones. Up to about 30 mg of cadmium is commonly inhaled throughout human childhood and adolescence. Cadmium is eliminated from the body in very small amounts and mainly through urine resulting in a biological half-life of 20 to 40 years. Cadmium is under research for its potential toxicity to increase the risk of cancer, cardiovascular disease, and osteoporosis.
According to Jay Garfield, in the first chapter, Nāgārjuna argues against a reified view of causality which sees dependent origination in terms of substantial powers (kriyā) of causation (hetu) that phenomena have as part of their intrinsic nature (svabhāva). Instead, Nāgārjuna sees dependent origination as a series of conditional relationships (pratyaya) that are merely nominal designations and "explanatorily useful regularities". According to Nāgārjuna, if something could exist inherently or essentially from its own side (and thus have its own inherent causal powers), change and dependent arising would be impossible. Nāgārjuna states that "if things did not exist without essence, the phrase, "when this exists so this will be," would not be acceptable." Jan Westerhoff notes that Nāgārjuna argues that cause and effect are "neither identical nor different nor related as part and whole, they are neither successive, nor simultaneous, nor overlapping." Westerhoff states that Nāgārjuna thinks all conceptual frameworks of causality that make use of such ideas are based on a mistaken presupposition which is that "cause and effect exist with their own svabhāva". Westerhoff further argues that for Nāgārjuna, causes and effects are both dependent on one another (conceptually and existentially) and neither one can exist independently. As such, he rejects four ways that something could be causally produced: by itself, by something else, by both, by nothing at all.
Under traditional terminology, the American kestrel is the smallest raptor in the Americas, though the South American spot-winged falconet is almost as small. The American kestrel is sexually dimorphic, although there is some overlap in plumage coloration between the sexes. The bird ranges from 22 to 31 cm (8.7 to 12.2 in) in length with a wingspan of 51–61 cm (20–24 in). The female kestrel is larger than the male, though less so than larger falcons, being typically about 10% to 15% larger within a subspecies. The more northern subspecies tend to larger sizes (northern hemisphere), with a large northern female being about twice the size of a small southern male. The male typically weighs 80–143 g (2.8–5.0 oz), and the female 86–165 g (3.0–5.8 oz). In standard measurements, the wing bone is 16–21 cm (6.3–8.3 in) long, the tail is 11–15 cm (4.3–5.9 in) and the tarsus is 3.2–4 cm (1.3–1.6 in). Physically, American kestrels are leaner and less muscular than larger falcons. The pectoral flight muscles of the American kestrel make up only about 12% of its body weight, as compared to about 20% for the strongest flying falcons such as the peregrine falcon. The wings are moderately long, fairly narrow, and taper to a point. Their less muscular body type is adapted to energy-conserving ambush hunting, rather than spending large amounts of energy-consuming time on the wing and getting into long tail-chases of bird prey. For their size, they have strong talons and beaks, and can swiftly dispatch prey.
In the first decade of the 21st century, what was called "age management medicine" was considered a field of alternative medicine, and, as of 2007, was not recognized by the American Medical Association. Other names at this time included "antiaging medicine" and "regenerative medicine". Age management medicine is controversial. The field is underregulated and supported by insufficient scientific evidence. People who practice it open themselves up to legal liability on grounds of negligence–malpractice, warranty issues, and product liability. The use of growth hormone has been frequently recommended; however, such use is associated with cancer. Age management medicine is often promoted by anti-aging practitioners specializing in nutritional supplements and hormone-replacement, a practice that may lead to harmful side-effects.
Sources: en.wikipedia.org
The molecule lacks aromatic residues, so it absorbs weakly near 280 nanometres, the wavelength applied to many other peptides. The peptide bond absorbs strongly below 220 nanometres, making 214 nanometres a practical compromise. Gradient methods must therefore use mobile phases with low ultraviolet absorbance to keep the baseline clean.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.