Mass spectrometry raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-06-14. Anything still debated is marked as such rather than presented as settled.
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.
The compound is generally described as a synthetic analogue of a fragment isolated from a pineal gland extract. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology introduced it during the 1980s and 1990s while studying short peptides from animal tissue. The original extract, called epithalamin, is a heterogeneous mixture, whereas epitalon is a single defined sequence. That distinction matters because findings reported for the extract are not automatically findings about the pure tetrapeptide, and claims about broader biological effects remain a separate question from the chemical identity described here.
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.
| 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 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.
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.
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.
==== Gang crackdown ==== From 25 to 27 March 2022, gangs in El Salvador committed 87 homicides; 62 were committed on 26 March alone, the deadliest day in Salvadoran history since the end of the Salvadoran Civil War (1979–1992). Florida International University research director José Miguel Cruz attributed the killings to a breakdown in a secret truce between the government and the gangs, a truce that Bukele has denied. Cruz believed that the killings were a message from the gangs to the government for more concessions as a part of the secret truce.
=== March === March 1 2026 Austin bar shooting: Four people are killed, including the perpetrator, and 15 others are injured in a mass shooting at a bar in Austin, Texas. The FBI investigates the attack as potential terrorism, with the possible motive being linked to the U.S. strikes on Iran. 2026 attack on the United States consulate in Karachi: In Karachi, Pakistan, protesters supportive of the Iranian government attempt to storm the U.S. consulate. The Marine Security Guard opened fire, killing several protesters. March 2 The U.S. military reports that three of its fighter jets crashed in Kuwait due to an "apparent friendly fire incident," but all six crew members ejected safely. Iran strikes the American embassy in Saudi Arabia. March 3 Six U.S. soldiers are reported to have died when an "unmanned aircraft system" evaded air defenses to hit a command centre in Port Shuaiba, Kuwait. These are the first American troops killed in the Iran War. Trump orders Treasury Secretary Bessent to "cut off all dealings" with Spain, after Spain refuses to grant the U.S. permission to use jointly operated bases to continue its attacks in Iran. March 4 – Defense Secretary Hegseth announces that a U.S. submarine has sunk an Iranian naval frigate in the Indian Ocean with a single Mark 48 torpedo, the first such sinking of an enemy ship since World War II. The Sri Lankan navy reports the IRIS Dena went down in the Indian Ocean, with 140 people on board missing. On the same day, the U.S. House Ethics Committee launches a formal investigation into Tony Gonzales.
=== Medical use === Cryosurgery procedures such as cryoablation use liquid argon to destroy tissue such as cancer cells. It is used in a procedure called "argon-enhanced coagulation", a form of argon plasma beam electrosurgery. The procedure carries a risk of producing gas embolism and has resulted in the death of at least one patient. Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects. Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox, to speed the elimination of dissolved nitrogen from the blood.
According to the procedure described in the 1975 Aron patent, and the Pharmaceutical Manufacturing Encyclopedia, equimolar amounts of dimethylamine and 2-cyanoguanidine are dissolved in cold toluene to make a concentrated solution, and an equimolar amount of hydrogen chloride is slowly added. The mixture begins to boil, and after cooling, metformin hydrochloride precipitates with a 96% yield. Excess addition of hydrogen chloride results in the formation of the more soluble metformin dichloride salt, a recently reported impurity.
Nicotine also activates the sympathetic nervous system, acting via splanchnic nerves to the adrenal medulla, stimulating the release of epinephrine. Acetylcholine released by preganglionic sympathetic fibers of these nerves acts on nicotinic acetylcholine receptors, causing the release of epinephrine (and norepinephrine) into the bloodstream.
Sources: en.wikipedia.org
Several studies have also found these tests to be less sensitive than skin testing for the detection of clinically relevant allergies. False positive results may be obtained due to cross-reactivity of homologous proteins or by cross-reactive carbohydrate determinants (CCDs). In the NIH food guidelines issued in December 2010 it was stated that "The predictive values associated with clinical evidence of allergy for ImmunoCAP cannot be applied to other test methods." With over 4000 scientific articles using ImmunoCAP and showing its clinical value, ImmunoCAP is perceived as "Gold standard" for in vitro IgE testing
All chemical elements derive from stellar nucleosynthesis except for hydrogen and some helium and lithium. Basic chemical ingredients of life – the carbon–hydrogen molecule (CH), the carbon–hydrogen positive ion (CH+) and the carbon ion (C+) – can be produced by ultraviolet light from stars. Complex molecules, including organic molecules, form naturally both in space and on planets. Organic molecules on the early Earth could have had either terrestrial origins, with organic molecule synthesis driven by impact shocks or by other energy sources, such as ultraviolet light, redox coupling, or electrical discharges; or extraterrestrial origins (pseudo-panspermia), with organic molecules formed in interstellar dust clouds or in the solar nebula accumulating onto the planet.
Opium poppies are popular and attractive garden plants, whose flowers vary greatly in color, size and form. A modest amount of domestic cultivation in private gardens is not usually subject to legal controls. In part, this tolerance reflects variation in addictive potency. A cultivar for opium production, Papaver somniferum L. elite, contains 91.2 percent morphine, codeine, and thebaine in its latex alkaloids, whereas in the latex of the condiment cultivar "Marianne", these three alkaloids total only 14.0 percent. The remaining alkaloids in the latter cultivar are primarily narcotoline and noscapine. Seed capsules can be dried and used for decorations, but they also contain morphine, codeine, and other alkaloids. These pods can be boiled in water to produce a bitter tea that induces a long-lasting intoxication. If allowed to mature, poppy pods (poppy straw) can be crushed and used to produce lower quantities of morphinans. In poppies subjected to mutagenesis and selection on a mass scale, researchers have been able to use poppy straw to obtain large quantities of oripavine, a precursor to opioids and antagonists such as naltrexone. Although millennia older, the production of poppy head decoctions can be seen as a quick-and-dirty variant of the Kábáy poppy straw process, which since its publication in 1930 has become the major method of obtaining licit opium alkaloids worldwide, as discussed in Morphine. Poppy seeds are a common and flavorsome topping for breads and cakes.
Chemically it is a hydantoin derivative, but does not exhibit antiepileptic activity like other hydantoin derivates such as phenytoin. The poor water solubility of dantrolene leads to certain difficulties in its use. A more water-soluble analog of dantrolene, azumolene, is under development for similar indications. Azumolene has a bromine residue instead of the nitro group found in dantrolene, and is 30 times more water-soluble.
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.
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.