This is a working overview of electrospray ionisation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-06-26 and is reviewed periodically as new material appears.
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.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
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.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Often abbreviated AEDG in research literature |
| Common synonyms | Epithalon, epitalon, AEDG | Spelling variants refer to the same tetrapeptide |
| Molecular formula | C14H22N4O9 | Theoretical monoisotopic mass near 390.35 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Freely soluble in water | Hydrophilic peptide; dissolves in aqueous buffer |
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
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.
When in 1863 the Association of Serbian Philology commemorated the death of Cyril a thousand years earlier, its president Dimitrije Matić talked of the creation of an "ethnically pure" Slavonic people, "With God’s help, there should be a whole Slavonic people with purely Slavonic faces and of purely Slavonic character." After World War I the creation of the Kingdom of Yugoslavia, under Serbian royalty of the Karađorđević dynasty, united most Southern Slavic-speaking nations regardless of religion and cultural background. The only ones they did not unite with were the Bulgarians. Still, in the years after the Second World War, there were proposals to incorporate Bulgaria into a Greater Yugoslavia thus uniting all south Slavic-speaking nations into one state. The idea was abandoned after the split between Josip Broz Tito and Joseph Stalin in 1948. This led to some bitter sentiment between the people of Yugoslavia and Bulgaria in the aftermath. At the end of the Second World War, the Partisans' mixed heritage leader Josip Broz Tito became Yugoslav president, and the country become a socialist republic, with the motto of "Brotherhood and Unity" between its various Slavic peoples.
Rocky Mountain spotted fever, typhus fever and the typhus group, scrub typhus, Q fever, rickettsialpox, and tick fevers caused by Rickettsia, respiratory tract infections caused by Mycoplasma pneumoniae, Lymphogranuloma venereum, trachoma, inclusion conjunctivitis, and uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis, psittacosis, non-gonococcal urethritis caused by Ureaplasma urealyticum, relapsing fever due to Borrelia recurrentis, chancroid caused by Haemophilus ducreyi, plague due to Yersinia pestis, tularemia, cholera, campylobacter fetus infections, brucellosis caused by Brucella species (in conjunction with streptomycin), bartonellosis, granuloma inguinale (Klebsiella species), Lyme disease (Borrelia species). Leptospirosis
The enteric nervous system consists of some one hundred million neurons that are embedded in the peritoneum, the lining of the gastrointestinal tract extending from the esophagus to the anus. These neurons are collected into two plexuses – the myenteric (or Auerbach's) plexus that lies between the longitudinal and the smooth muscle layers, and the submucosal (or Meissner's) plexus that lies between the circular smooth muscle layer and the mucosa. Parasympathetic innervation to the ascending colon is supplied by the vagus nerve. Sympathetic innervation is supplied by the splanchnic nerves that join the celiac ganglia. Most of the digestive tract is innervated by the two large celiac ganglia, with the upper part of each ganglion joined by the greater splanchnic nerve and the lower parts joined by the lesser splanchnic nerve. It is from these ganglia that many of the gastric plexuses arise.
On 12 June 1944 U.S. carriers made air strikes on the Marianas, convincing Admiral Soemu Toyoda that the U.S. was preparing to invade. This move came as a surprise; the Japanese had expected the next U.S. target to be further south, either at the Carolines or the Palaus, and had protected the Marianas with only 50 land-based aircraft. On 13–15 June, American carriers made additional airstrikes while surface forces bombarded the Marianas. On 15 June, the first American troops went ashore on Saipan. Since control of the Marianas would bring American strategic bombers within range of the Japanese home islands, the IJN decided it was time for the long-awaited Kantai Kessen (decisive battle). Toyoda immediately ordered a fleet-based counterattack, committing nearly all of the Japanese navy's serviceable ships. The main portions of the fleet rendezvoused on 16 June in the western part of the Philippine Sea and completed refueling on 17 June. Admiral Jisaburō Ozawa commanded this force from his newly commissioned flagship, Taihō. In addition to extensive command facilities, reinforced torpedo blisters and a large air group, Taihō was the first Japanese carrier with an armor-plated flight deck, designed to withstand bomb hits with minimal damage. At 18:35 on 15 June the submarine USS Flying Fish sighted a Japanese carrier and battleship force coming out of the San Bernardino Strait. An hour later USS Seahorse spotted a battleship and cruiser force steaming up from the south, 200 miles (320 km) east of Mindanao.
== Career and writing == After leaving Oxford, Halliwell briefly lectured at the Portsmouth Polytechnic (1973–74). He took up a position as lecturer at King's College London in 1974, remaining there until 2000, rising to the position of Professor of Medical Biochemistry in the Division of Pharmacology. He also simultaneously held a visiting professorship at the University of California, Davis, United States (1995–99). After a 1998 sabbatical at the National University of Singapore (NUS), he moved there in 2000 as chair of the biochemistry department. As of 2018 he is a professor in the department of biochemistry at the NUS Yong Loo Lin School of Medicine. Halliwell is currently the Senior Advisor, Academic Appointments and Research Excellence, Office of the Provost, at the National University of Singapore (NUS). He is also Chairman of the Biomedical Research Advisory Council (BMAC), Agency for Science, Technology & Research (A*STAR). Halliwell served as the NUS's first Deputy President (Research and Technology) in 2006–15, founding the Graduate School for Integrative Sciences and Engineering, and overseeing a more than doubling in the university's research grants and the creation at NUS of Singapore's first Research Centre of Excellence (RCEs). He was subsequently appointed Senior Advisor to the NUS President. His textbook, Free Radicals in Biology and Medicine, co-written with John M. C. Gutteridge, is considered "an authoritative text in the field".
Sources: en.wikipedia.org
=== Isomers === 3-CMC is a chloromethcathinone, which has two other positional isomers, namely 2-CMC and 4-CMC. These differ in the position of the chlorine atom on the phenyl ring. As well as 3-CMC, these molecules are both known designer drugs. Since 3-CMC contains a chiral center, there are two enantiomers, namely (S)-3-CMC and (R)-3-CMC. The products are most likely on the market as a racemic mixture of the two enantiomers, since separation would result in very high costs.
== B == B cell - bacteria - bacterial conjugation - bacterial outer membrane protein - bacterial protein - bacteriorhodopsin - base (chemistry) - base pair - base sequence - basic fibroblast growth factor - Bcl-2 - bcr-abl fusion protein - benzene - benzene ring - beta-2 microglobulin - beta adrenergic receptor - beta sheet - beta-1 adrenergic receptor - beta-2 adrenergic receptor - beta-thromboglobulin - bioaccumulation - biochemistry - biodiversity - bioethics - biogenic amine receptor - bioinformatics - biological membrane - biologist - biology - biomechanics - biomedical model - biomolecule - biophysics - biopolymer - biosalinity - biotechnology - BLAST - blood proteins - boiling point - Boltzmann distribution - Boltzmann principle - bombesin - bombesin receptor - bone morphogenetic protein - bradykinin - bradykinin receptor - BRCA1 - buffer solution
== Pharmacology == Rimonabant is an inverse agonist of the cannabinoid CB1 receptor. Originally thought to be selective for the CB1 receptor, rimonabant was subsequently also found to act as an antagonist of the μ-opioid receptor. These properties may make this drug useful in cases of cannabinoid or opioid overdose but more research and safety testing is required.
== Symptoms == D. dadantii is phytopathogenic bacterium causing soft rot diseases on many host plants including some which are economically important. D. dadantii, more commonly known as: soft rot, brown rot or blackleg, causes characteristic symptoms associated with other bacterial wilts, causing final diagnosis to be difficult. The pathogen primarily seeks to attack the plant's xylem vessels located in leaves, stems, blossoms and storage organs of herbaceous plants. D. dadantii is able to infect hosts at any point in its life cycle. In addition to symptoms of wilt, the disease appears as sunken and cracked external lesions also having a brown interior in cross section in subterranean bulbs and tubers Diseased plants will display a variety of symptoms including: wilting, stunting and vascular discoloration of the stems. Early symptoms include water soaked lesions at the site of infection, gradually expanding chlorotic leaves and loss of turgor in tissues. The intensity of D. dadantii colonization relates to the amount of disease and degree of damage. The pathogen is very successful at infiltrating host tissues due to the many pectinases responsible for disassembly of plant cell wall polysaccharides. Once the cell wall is degraded cellular structure collapses and this cell maceration gives a characteristic "water-soaked" or rotted appearance. D. dadantii grow intercellularly, continuing to degrade cells and colonize, until it eventually reaches xylem tissues. Upon reaching the xylem vessels D.
Sources: en.wikipedia.org
=== Antibacterial activity === Certain antimicrobial biomolecules found in the spider silk of P. phalangioides are able to elicit an inhibitory effect on drug-resistant human pathogens including gram-positive bacteria L. monocytogenes, gram-negative E. coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. More generally, researchers are hoping that the anti-microbial biomolecules of this spider silk could serve as a natural anti-microbial agent in the future against a host of infectious bacterial diseases that are resistant to antibiotics.
== Active site == The active site of the second structure has 2 tunnels, one with a radius of 1.21 Å and one with a radius of 1.19 Å. The 1.21 Å tunnel has a length of 26.7 Å and the 1.19 Å tunnel has a length of 27.5 Å. The active site of the first version has one tunnel that has a radius of 1.14 Å and a length of 26.0 Å. As with the structures, these parts of the enzyme can be examined further using the links in the caption.
=== 1997 constitutional crisis === The Cherokee Nation was seriously destabilized in May 1997 in what was variously described as either a nationalist "uprising" or an "anti-constitutional coup" instigated by Joe Byrd, the Principal Chief. Elected in 1995, Byrd became locked in a battle of strength with the judicial branch of the Cherokee tribe. The crisis came to a head on March 22, 1997, when Byrd said in a press conference that he would decide which orders of the Cherokee Nation's Supreme Court were lawful and which were not. A simmering crisis continued over Byrd's creation of a private, armed paramilitary force. On June 20, 1997, his private militia illegally seized custody of the Cherokee Nation Courthouse from its legal caretakers and occupants, the Cherokee Nation Marshals, the Judicial Appeals Tribunal, and its court clerks. The courts demanded the courthouse's return, but Byrd refused. The Federal authorities of the United States initially refused to intervene because of potential breach of tribal sovereignty. Byrd was required to attend a meeting in Washington, D.C. with the Bureau of Indian Affairs, at which he was compelled to reopen the courts. Byrd served the remainder of his term but lost the 1999 election for Principal Chief to Chad Smith. He was later elected to the Tribal Council in 2013. A new constitution was drafted in 1999 that included procedures for voters to remove officials from office, changed the structure of the tribal council, and removed the need to ask the Bureau of Indian Affairs' permission to amend the constitution.
=== Blood plasma and serum === In addition to purified proteins, DSC has been applied to unfractionated blood plasma and serum; the diluted fluid is measured directly, without labeling. The resulting curve, called a thermogram, approximates the sum of the combined denaturation profiles of the most abundant plasma proteins, weighted by their concentrations. Because these proteins interact, the additivity is not exact. For plasma from healthy donors scanned at 1 °C per minute, three independant research groups reported a fibrinogen transition at about 51 °C, a dominant albumin peak near 62–63 °C, immunoglobulin and other globulin transitions between roughly 68 and 75 °C, and a weak transferrin transition at about 85 °C. Serum exhibits a similar profile, except that the fibrinogen transitions are absent. Calorimetric measurements of serum and plasma from cancer patients were documented as early as the 1990s by a team in Tbilisi, who observed broadened heat-absorption curves shifted toward higher temperatures compared to healthy controls. From 2007, Chaires, Garbett and colleagues at the University of Louisville reported that plasma from healthy individuals gave a characteristic, reproducible thermogram. Samples from patients with cervical cancer, Lyme disease, rheumatoid arthritis or systemic lupus erythematosus displayed altered profiles.
The IDF said that one in five rockets launched by Hezbollah had landed in Lebanese territory and published an infographic showing failed rocket launches into Israel. On 16 December, a soldier from the IDF's 129th Battalion was killed by a Hezbollah drone strike near Margaliot, which also caused a fire in a building. Two other soldiers were injured. Another drone was shot down by the IDF, which also responded to the infiltrations by shelling targets. The IAF later hit several Hezbollah targets inside Lebanon, including rocket launch sites and military infrastructure. On 22 December, two IDF soldiers of the 188th Armored Brigade were killed by a Hezbollah rocket attack in the Shtula area. On the morning of 23 December, IDF aircraft bombed a house in Kfar Kila and intense artillery fire also took place on the outskirts of Deir Mimas The IDF conducted a raid near a UNIFL center along the Khardali River. An Al-Manar cameraman was injured in the eye after an IDF attack on a road in the al-Khardali area where correspondents of MTV and the state-owned National News Agency were also passing. Hezbollah announced that two of their members were killed on that day. On 24 December, senior IRGC general Razi Mousavi was killed by an Israeli airstrike in Damascus. On 26 December, a Hezbollah anti-tank missile hit St. Mary's Greek Orthodox Church in Iqrit, northern Israel. A civilian suffered serious injuries, and when IDF responders arrived at the scene, another missile was fired, injuring nine soldiers.
Sources: en.wikipedia.org
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.
No. Epithalamin is a peptide-rich extract prepared from bovine pineal glands, while epitalon is a short synthetic peptide designed as a defined analogue of it. The synthetic version was intended to provide a reproducible molecule with some of the same proposed biological activity.
Telomere elongation and telomerase activation have been reported in cultured human somatic cells, but evidence from living human subjects is limited and has not been independently confirmed at scale. Reported findings come largely from small studies with differing designs, so the question remains open rather than settled.
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.