This is a working overview of aspartimide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-28. Anything still debated is marked as such rather than presented as settled.
Verification of a sample usually begins with reversed-phase high-performance liquid chromatography, which resolves the peptide from truncated sequences and other impurities and expresses purity as a percentage of total peak area. Mass spectrometry by electrospray ionisation or matrix-assisted laser desorption supplies an independent check, because the measured mass can be compared against the theoretical value for AEDG. Amino acid analysis or tandem mass spectrometry sequencing can confirm residue order. Each of these methods answers a different question: a purity figure does not establish identity, and an identity match does not establish how much of the material is intact peptide.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Electrospray or MALDI mass spectrometry | Observed mass compared with theoretical 390.35 Da |
| Purity specification | 95 percent or greater by RP-HPLC | Common convention for research-grade peptide |
| Counter-ion | Acetate or trifluoroacetate | Affects net peptide content of a weighed sample |
| Solution storage | −80 °C as single-use aliquots | Repeated freeze–thaw cycles accelerate loss |
| Main degradation route | Aspartimide formation at Asp-Gly | Produces isoaspartate and related species |
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
The atherosclerotic process is not well understood. Atherosclerosis is associated with inflammatory processes in the endothelial cells of the vessel wall associated with retained low-density lipoprotein (LDL) particles. This retention may be a cause, an effect, or both of the underlying inflammatory process. The presence of the plaque induces the muscle cells of the blood vessel to stretch, compensating for the additional bulk. The endothelial lining then thickens, increasing the separation between the plaque and the lumen. The thickening somewhat offsets the narrowing caused by the plaque's growth. Moreover, it causes the wall to stiffen and become less compliant to stretching with each heartbeat.
=== Use in the removal of phenolic compounds from wastewater === Researchers have found spongin to be useful in the photocatalytic degradation and removal of bisphenols (such as BPA) in wastewater. A heterogeneous catalyst consisting of a spongin scaffold for iron phthalocyanine (SFe) in conjunction with peroxide and UV radiation has been shown to remove phenolic wastes more quickly and efficiently than conventional methods. Other research using spongin scaffolds for the immobilization of Trametes versicolor Laccase has shown similar results in phenol degradation.
== Clinical significance == Proline hydroxylation requires ascorbic acid (vitamin C). The most obvious, first effects (gingival and hair problems) of absence of ascorbic acid in humans come from the resulting defect in hydroxylation of proline residues of collagen, with reduced stability of the collagen molecule, causing scurvy. Increased serum and urine levels of hydroxyproline have also been demonstrated in Paget's disease. Mass spectrometry analysis showed decreased amount of hydroxyproline post-translational modifications in non inflamed tissue from ulcerative colitis patients when compared to tissue from donors without the disease.
Sources: en.wikipedia.org
=== In Singapore === On 3 August, Arcturus Therapeutics confirmed that the company had received approval for a clinical trial of ARCT-154 and another vaccine called ARCT-165 in Singapore. The Phase I-II clinical trial will evaluate the vaccines as a primary vaccination series and a booster following first dose with Pfizer–BioNTech COVID-19 vaccine. The study is being partially funded by a grant from the Singapore Government.
==== Subunit Composition and Ion Permeability ==== The AMPAR's permeability to calcium and other cations, such as sodium and potassium, is governed by the GluA2 subunit. If an AMPAR lacks a GluA2 subunit, then it will be permeable to sodium, potassium, and calcium. The presence of a GluA2 subunit will render the channel impermeable to calcium. This is determined by post-transcriptional modification — RNA editing — of the Q-to-R editing site of the GluA2 mRNA. Here, A→I editing alters the uncharged amino acid glutamine (Q) to the positively charged arginine (R) in the receptor's ion channel. The positively charged amino acid at the critical point makes it energetically unfavorable for calcium to enter the cell through the pore. Almost all of the GluA2 subunits in CNS are edited to the GluA2(R) form. This means that the principal ions gated by AMPARs are sodium and potassium, distinguishing AMPARs from NMDA receptors (the other main ionotropic glutamate receptors in the brain), which also permit calcium influx. Both AMPA and NMDA receptors, however, have an equilibrium potential near 0 mV. The prevention of calcium entry into the cell on activation of GluA2-containing AMPARs is proposed to guard against excitotoxicity. The subunit composition of the AMPAR is also important for the way this receptor is modulated. If an AMPAR lacks GluA2 subunits, then it is susceptible to being blocked in a voltage-dependent manner by a class of molecules called polyamines.
Wilmer David "Vinegar Bend" Mizell Sr. (August 13, 1930 – February 21, 1999) was an American baseball player and politician. From 1952 to 1962, he was a left-handed pitcher for the St. Louis Cardinals, Pittsburgh Pirates and New York Mets of Major League Baseball. Six years after retiring, he was elected to the United States House of Representatives from North Carolina's 5th congressional district. He served three terms as a Republican from 1969 to 1975. Mizell was born in Leakesville, Mississippi, but started playing baseball in nearby Vinegar Bend, Alabama, the town from which he drew his nickname. Signed by the Cardinals in 1949, he debuted with them in 1952, ranking among the Top 10 in the National League (NL) in strikeouts for two years before spending 1954 and 1955 in military service. He returned to the Cardinals in 1956 and was named to two Major League Baseball All-Star Games in 1959, but St. Louis felt like he never attained his full potential. They traded him to Pittsburgh early in the 1960 season, and Mizell led the NL in winning percentage (.636) as the Pirates defeated the New York Yankees in the 1960 World Series. He remained with the Pirates until early in the 1962 season, last pitching in the major leagues with the Mets. While pitching for the Winston-Salem Cardinals in 1951, Mizell had settled in Midway, North Carolina. Six years after he threw his last major league pitch, he was elected to the House of Representatives, serving North Carolina's newly aligned 5th district.
=== 1971 === c. 20 June: Charmaine West (8). Fred's stepdaughter. Charmaine was killed by Rose, likely in a fit of rage, shortly before Fred's release from Leyhill Prison on 24 June. Her remains were initially stored in the cellar at 25 Midland Road before Fred buried the child's body in the back garden of the flat.
Sources: en.wikipedia.org
Gunman Chronicles is a 2000 first-person shooter game originally created as a mod by the now-defunct Rewolf Software. It was originally a Quake deathmatch mod named Gunmanship 101, then it was moved to Quake II's engine before becoming a Half-Life mod. Gunman Chronicles was popular at the Half-Life Mod Expo in 1999, and Sierra approached Rewolf to make a retail version. After significant work, it was released as a standalone game. Plans were drawn to release Gunman Chronicles on GameCube, but it was never released.
A month later, in May 1949, Thomas and his family moved to his final home, the Boat House at Laugharne, purchased for him at a cost of £2,500 in April 1949 by Margaret Taylor. Thomas acquired a garage a hundred yards from the house on a cliff ledge which he turned into his writing shed, and where he wrote several of his most acclaimed poems. He also rented "Pelican House" opposite his regular drinking den, Brown's Hotel, for his parents who lived there from 1949 until 1953.
The escalation of American threats against Greenland has been linked by several commentators to the apparent success of the 2026 United States intervention in Venezuela. Some commentators have also linked the Greenland Crisis to Trump's threats against Canada. Former Premier of Ontario and Permanent Representative of Canada to the United Nations Bob Rae stated that Trump "doesn't take Canada's sovereignty seriously", while former Principal Secretary to the Prime Minister Gerald Butts stated that, although he didn't believe Trump would invade Canada directly, "we're going to see a lot of threats, and we're going to see a lot of seeding of pro-American activity by the Americans in Canadian life". NBC News reported in mid-January 2026 that, according to senior American officials, Trump was "privately ramping up his focus on another target in the Western Hemisphere, increasingly complaining to aides in recent weeks about Canada's vulnerability to US adversaries in the Arctic". Trump's aggressive negotiation tactics have prompted comparisons with the madman theory. James D.
In 1955, Harry Winokur worked with brother-in-law William Rosenberg, the founder of Dunkin' Donuts. After Winokur broke his partnership with Rosenberg, he went on to create Mister Donut with his son-in-law, David Slater that same year, with stores in most of North America. The Mister Donut business became so popular that Winokur and Slater decided to go into franchising. As a result, Mister Donut began a rapid expansion that resulted in the opening of 275 stores in the U.S. and Canada. In 1970, Minneapolis-based International Multifoods Corporation, one of the world's largest and most successful food companies, acquired Mister Donut and its franchising concept from Winokur. The first Mister Donut outlet in Japan opened in Minoh, Osaka in 1971. Also in the same year, a Mister Donut training center was constructed in Japan. In 1973, the French cruller became available in Japanese stores. In 1978, brothers Sutthichai and Sutthikiat Chirathiwat, on behalf of Thai Franchise Co., Ltd, opened the first Mister Donut store in Siam Square, Bangkok. The two would come to pioneer the donut market within Thailand. In 2003, Mister Donut in Thailand came under the management of CRG. Donut Thailand (Central Restaurants Group) which continues to manage the company in Thailand. In 1983, Duskin Co., Ltd. of Osaka, Japan, acquired the rights to franchise Mister Donut throughout Japan and Asia.
Ricin is very toxic if inhaled, injected, or ingested. It can also be toxic if dust contacts the eyes or if it is absorbed through damaged skin. It acts as a toxin by inhibiting protein synthesis. Ricin is resistant, but not impervious, to digestion by peptidases. By ingestion, the pathology of ricin is largely restricted to the gastrointestinal tract, where it may cause mucosal injuries. With appropriate treatment, most patients will make a good recovery.
Sources: en.wikipedia.org
Mass spectrometry provides the identity check, because the observed mass is compared with the theoretical mass of the AEDG sequence. Chromatography separates and quantifies impurities but does not by itself prove which peptide is present. The two techniques are normally used together.
Yes. Trifluoroacetate and acetate ions remain associated with the peptide after purification, so a weighed quantity of powder contains less peptide than the nominal mass suggests. Certificates that report net peptide content rather than raw weight are more directly comparable between suppliers.
Dilute aqueous solutions are less stable than the dry powder and are usually aliquoted and frozen to avoid repeated freeze–thaw cycles. Lyophilised material is best stored desiccated at −20 °C, protected from light. Working solutions are typically prepared fresh from a frozen aliquot.
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.