The short version of Aspartimide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-20 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Derived from the four constituent residues |
| Molecular mass | About 390.35 Da | Monoisotopic value, confirmed by mass spectrometry |
| Residue sequence | Ala-Glu-Asp-Gly | Read from the N-terminus to the C-terminus |
| Common synonyms | Epithalon; AEDG | Both forms appear in reference catalogues |
| Net charge near neutral pH | Negative | Two acidic side chains give a low isoelectric point |
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.
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.
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.
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.
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.
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.
== Applications == Capillary electrophoresis may be used for the simultaneous determination of the ions NH4+,, Na+, K+, Mg2+ and Ca2+ in saliva. One of the main applications of CE in forensic science is the development of methods for amplification and detection of DNA fragments using polymerase chain reaction (PCR), which has led to rapid and dramatic advances in forensic DNA analysis. DNA separations are carried out using thin CE 50-mm fused silica capillaries filled with a sieving buffer. These capillaries have excellent capabilities to dissipate heat, permitting much higher electric field strengths to be used than slab gel electrophoresis. Therefore, separations in capillaries are rapid and efficient. Additionally, the capillaries can be easily refilled and changed for efficient and automated injections. Detection occurs via fluorescence through a window etched in the capillary. Both single-capillary and capillary-array instruments are available with array systems capable of running 16 or more samples simultaneously for increased throughput. A major use of CE by forensic biologists is typing of STR from biological samples to generate a profile from highly polymorphic genetic markers which differ between individuals. Other emerging uses for CE include the detection of specific mRNA fragments to help identify the biological fluid or tissue origin of a forensic sample.
Some species of Streptococcus and Staphylococcus are part of the normal skin microbiota and typically reside on healthy skin or in the nasopharyngeal region. Yet these species can potentially initiate skin infections. Streptococcal infections include sepsis, pneumonia, and meningitis. These infections can become serious creating a systemic inflammatory response resulting in massive vasodilation, shock, and death. Other bacteria are opportunistic pathogens and cause disease mainly in people with immunosuppression or cystic fibrosis. Examples of these opportunistic pathogens include Pseudomonas aeruginosa, Burkholderia cenocepacia, and Mycobacterium avium.
Our politics seems more vulnerable to conspiracy theories and outright fabrication." He continued, "Bigotry in any form is blasphemy against the American creed and it means the very identity of our nation depends on the passing of civic ideals to the next generation", while urging citizens to oppose threats to American democracy and be positive role models for young people. The speech was widely interpreted as a denouncement of Donald Trump and his ideologies, despite Bush not mentioning Trump by name. On September 1, 2018, Bush and his wife attended the funeral of John McCain at the Washington National Cathedral in Washington, D.C. where Bush delivered remarks at the service. On November 30, his father died at his home. Shortly before his death, Bush was able to talk with his father on the phone; his father responded with what would be his last words, "I love you too". Bush attended his father's funeral on December 5, delivering a eulogy. In May 2019, on the tenth anniversary of former South Korean president Roh Moo-hyun's death, Bush visited South Korea to pay his respects to Roh, delivering a short eulogy. On June 1, 2020, Bush released a statement addressing the murder of George Floyd and the subsequent nationwide reaction and protests. In the statement, Bush wrote that he and former first lady Laura Bush "are anguished by the brutal suffocation of George Floyd and disturbed by the injustice and fear that suffocate our country".
Through the late 1950s and early 1960s, numerous papers were published on various topics in RNA structure, including RNA-DNA hybridization, triple stranded RNA, and even small-scale crystallography of RNA di-nucleotides—G-C, and A-U—in primitive helix-like arrangements. For a more in-depth review of the early work in RNA structural biology, see the article The Era of RNA Awakening: Structural biology of RNA in the early years by Alexander Rich.
Pattern hair loss is classified as a form of noncicatricial alopecia, i.e. a sort of non-inflammatory non-scarring hair loss. Male-pattern hair loss begins above the temples and at the vertex (calvaria) of the scalp. As it progresses, a rim of hair at the sides and rear of the head remains. This has been referred to as a "Hippocratic wreath" and rarely progresses to complete baldness. Female-pattern hair loss more often causes diffuse thinning without hairline recession; similar to its male counterpart, female androgenic alopecia rarely leads to total hair loss. The Ludwig scale grades severity of female-pattern hair loss. These include Grades 1, 2, 3 of balding in women based on their scalp showing in the front due to thinning of hair. In most cases, receding hairline is the first starting point; the hairline starts moving backwards from the front of the head and the sides.
Sources: en.wikipedia.org
=== EC 1.14.18 With another compound as one donor, and incorporation of one atom of oxygen into the other donor === EC 1.14.18.1: tyrosinase EC 1.14.18.2: CMP-N-acetylneuraminate monooxygenase EC 1.14.18.3: methane monooxygenase (particulate) EC 1.14.18.4: phosphatidylcholine 12-monooxygenase EC 1.14.18.5: sphingolipid C4-monooxygenase EC 1.14.18.6: 4-hydroxysphinganine ceramide fatty acyl 2-hydroxylase EC 1.14.18.7: dihydroceramide fatty acyl 2-hydroxylase EC 1.14.18.8: Now included with EC 1.14.14.139, 5β-cholestane-3α,7α-diol 12α-hydroxylase EC 1.14.18.9: 4α-methylsterol monooxygenase EC 1.14.18.10: plant 4,4-dimethylsterol C-4α-methyl-monooxygenase EC 1.14.18.11: plant 4α-monomethylsterol monooxygenase EC 1.14.18.12: 2-hydroxy fatty acid dioxygenase
== Personal life == Carrey has depression and took Prozac to combat the symptoms for years. He later said that he no longer takes medications of any kind and abstains from coffee, alcohol, and drugs. He received U.S. citizenship in October 2004 and remains a dual citizen of the United States and his native Canada. Carrey owns various properties in Los Angeles and has lived in Brentwood since 1994. In November 2022, the Russian Ministry of Foreign Affairs banned 100 Canadians, including Carrey, from entering Russia as a reciprocity for the international sanctions which had been introduced due to the 2022 Russian invasion of Ukraine.
=== January === 1 January – In his New Year address, Archbishop of Canterbury Justin Welby urges politicians to treat their opponents as human beings rather than enemies. Secretary of State for Defence Grant Shapps says that British forces are ready to act against Houthi rebels targeting cargo ships in the Red Sea. Writing on X, Doug Barrowman, husband of Michelle, Baroness Mone, said it "suits the agenda" of ministers to "scapegoat" him and his wife as a means of distracting from government "incompetence" at failing to procure personal protective equipment during the COVID-19 pandemic. 2 January – The Home Office says it has fulfilled a pledge to clear a "legacy" backlog of 92,000 asylum applications lodged before July 2022. But after it subsequently emerges that over 4,000 cases are still waiting for a decision, the Office for Statistics Regulation (OSR) announces an examination of the figures the next day. 3 January – Sir Ed Davey, leader of the Liberal Democrats, launches the party's election campaign by targeting constituencies with Conservative MPs. Former chancellor of the exchequer Nadhim Zahawi makes a guest appearance in the ITV drama Mr Bates vs The Post Office as himself, questioning Post Office chief executive Paula Vennells in a 2015 House of Commons committee inquiry into the Horizon computer system. Richard Tice, leader of Reform UK, rules out a pact with the Conservative Party at the next general election. 4 January – Prime Minister Rishi Sunak says his "working assumption" is that the general election will take place in the second half of this year.
== Activity and regulation == Cells typically maintain low NADP+/NADPH ratios by rapidly reducing NADP+ to NADPH using glutathione reductase in a cyclical NADPH replenishing reaction. These cells rapidly reduce ambient 5-oxo-ETE to 5(S)-HETE. However, cells suffering oxidative stress generate excesses in toxic reactive oxygen species such as hydrogen peroxide (H2O2). Cells use glutathione peroxidase to detoxify this H2O2 by converting it to H2O in a reaction that consumes glutathione by converting it to glutathione disulfide; the cells then metabolize glutathione disulfide back to glutathione in a glutathione reductase-dependent reaction that converts NADPH to NADP+. While cells suffering oxidative stress can replenish NADPH by reducing NADP+ through the pentose phosphate pathway, they often develop very high NADP+/NADPH ratios and therefore preferentially convert 5-(S)-HETE to 5-oxo-ETE. Cells that function as phagocytes have a second pathway that dramatically raises NADP+/NADPH ratios. Neutrophils and macrophages, for example, after phagocytosing bacteria or otherwise strongly stimulated to activate their respiratory burst generate reactive oxygen species including H2O2 by activating NADPH. The latter cell types have particularly high levels of 5-HEDH and therefore are particularly important producers of 5-oxo-ETE when so stimulated. The death of neutrophils and tumor cells also strongly promotes the oxidation of 5-HETE to 5-oxo-ETE, probably as a result of associated oxidative stress.
Sources: en.wikipedia.org
It is a four-amino-acid peptide built from alanine, glutamate, aspartate and glycine in that order. Its formula is C14H22N4O9, and it is made by chemical synthesis rather than extracted from tissue. The synthetic peptide is a single defined molecule, unlike the pineal extracts it is often compared with.
No. The two spellings refer to the same tetrapeptide, and the difference reflects transliteration from Russian. Laboratories and catalogues use both forms interchangeably. The material is also indexed as AEDG, taken from the one-letter codes of its residues.
Epithalamin is a mixed preparation derived from animal pineal tissue and contains many peptides. Epitalon is one synthetic sequence chosen for study from that broader mixture. Statements about one do not transfer directly to the other.
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.