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 2025-11-29 and is reviewed periodically as new material appears.
Identity and purity are checked by reversed-phase high-performance liquid chromatography, usually with ultraviolet detection near 214 nanometres, where the peptide bond absorbs. Mass spectrometry confirms the expected mass and reveals whether truncation products or adducts are present. Acid hydrolysis followed by amino acid analysis gives the residue ratio, which should approximate one alanine, one glutamate, one aspartate and one glycine. Counter-ions such as acetate or trifluoroacetate remain in the dried product and lower net peptide content, so a stated purity figure on a label does not by itself describe how much peptide a vial holds.
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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
| Property | Value | Notes |
|---|---|---|
| Storage temperature, solid | Approximately -20 C | Sealed, desiccated, protected from light |
| Typical identity method | Electrospray mass spectrometry | Protonated ion expected near 391 |
| Typical purity method | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Common synonyms | Epithalon, epithalone, AEDG | Spelling variants appear in supplier catalogues |
| Solution stability | Days at 2-8 C | Hydrolysis and deamidation limit shelf life |
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.
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.
The preparation of THC was reported in JACS in 1965. That procedure called for the intramolecular alkyl lithium attack on a starting carbonyl to form the fused rings, and a tosyl chloride mediated formation of the ether.
Scott Tanner is a Canadian scientist, inventor, and entrepreneur. His areas of expertise include mass spectroscopy, especially inductively coupled plasma mass spectrometry (ICP-MS), and mass cytometry. Tanner is best known for his work on the fundamentals of inductively coupled plasma mass spectrometry, for the invention of mass cytometry, and co-founding (with Dmitry Bandura, Vladimir Baranov and Olga Ornatsky) DVS Sciences in 2004,(acquired by Fluidigm in 2014 and then renamed to Standard BioTools in 2022) the company that first commercialized the instrument and reagents of mass cytometry.
Compound 22 is a low-potency and non-selective trace amine-associated receptor 1 (TAAR1) antagonist that was identified in 2015 and was further studied in animals in 2018. The drug enhances the firing rates of dopaminergic neurons ex vivo and potentiates psychostimulant-induced hyperlocomotion and stereotypy in rodents in vivo. The latter effects are partially or fully independent of the TAAR1 however, with the mechanisms underlying these effects being unknown. Compound 22, along with EPPTB and RTI-7470-44, is one of the only TAAR1 antagonists that has been identified as of 2022.
The "mirror world" would contain copies of all existing fundamental particles. On 2 May, another twin/pair-world or "bi-worlds" cosmology is shown to theoretically be able to solve the cosmological constant (Λ) problem, closely related to dark energy: two interacting worlds with a large Λ each resulting in a small shared effective Λ. Previous similar models e.g. attempt to explain the baryon asymmetry – why there was more matter than antimatter at the beginning – with a mirror anti-universe. 19 May Scientists report that RNA was found to be formed spontaneously on prebiotic basalt lava glass which is presumed to have been abundantly available on the early Earth. The yellow-billed hornbill of southern Africa, famous for its role in Disney's The Lion King, is reported to be at risk of extinction due to rising temperatures in the region. Boeing starts the one-week second uncrewed test flight of its Starliner space capsule in advance of its first crewed test flight later in 2022. A study estimates losses of 61 metals to help the development of circular economy strategies, showing that usespans of, often scarce, tech-critical metals are short. 20 May – Global warming is projected to substantially erode sleep worldwide.
== In literature == Michael Morpurgo's children's book The Sleeping Sword (2002, ISBN 978-0749748524) was inspired by the discovery of the sword on Bryher, combining it with Arthurian legend. He dedicated the book to the people of Bryher, where he has spent many holidays.
Sources: en.wikipedia.org
Skeletal advancement to physically increase the pharyngeal airspace is often an option for craniofacial patients with upper airway obstruction and small lower jaws (mandibles). These syndromes include Treacher Collins syndrome and Pierre Robin sequence. Mandibular advancement surgery is one of the modifications needed to improve the airway; others may include reduction of the tongue, tonsillectomy, or modified uvulopalatoplasty.
== Research == Soft-tissue sarcoma research requires significant effort due to its rarity; successful research requires substantial collaboration. Year by year, the medical field is learning that the various types cannot be lumped together and each sarcoma needs to be considered a different type of cancer. As a novel form of treatment used in other cancers, immunotherapy may have a role in treating soft-tissue sarcomas like alveolar soft part sarcoma and pleomorphic undifferentiated sarcoma. However, as of 2023, only alveolar soft part sarcoma has a regulatory approval for such an agent, in this case atezolizumab.
=== Cellular biophysics === By rectifying the motion of individual swimming bacteria, microfluidic structures can be used to extract mechanical motion from a population of motile bacterial cells. This way, bacteria-powered rotors can be built.
China's efforts under Xi has been for the European Union (EU) to stay in a neutral position in their contest with the U.S. China and the EU announced the Comprehensive Agreement on Investment (CAI) in 2020, although the deal was later frozen due to mutual sanctions over Xinjiang. Xi has cultivated stronger relations with Russia, particularly in the wake of the Ukraine crisis of 2014. Following the 2022 Russian invasion of Ukraine and during the Russo-Ukrainian war, Xi expressed opposition to sanctions against Russia and asserted China's support for Russia on issues of sovereignty and security, but also said China is committed to respecting "the territorial integrity of all countries", while China has cast itself as a neutral party. Xi's stance during the war has been criticized by Ukraine and several Western governments, which argued that China's support for Russia and its defense industrial base was inconsistent with its stated neutrality.
Ethyl carbamate (also called urethane) is an organic compound with the formula CH3CH2OC(O)NH2. It is an ester of carbamic acid and a white solid. Despite its name, it is not a component of polyurethanes. Because it is a carcinogen, it is rarely used, but naturally forms in low quantities in many types of fermented foods and drinks.
Sources: en.wikipedia.org
=== Independent investigations === In June 2021, the NIH announced that a set of sequence data had been removed from the Sequence Read Archive (SRA) in June 2020. The removal was performed according to standard practice at the request of the investigators who owned the rights to the sequences, with the investigators' rationale that the sequences would be submitted to another database. The investigators subsequently published a paper in an academic journal the same month they were removed from the NIH database which described the sequences in detail and discussed their evolutionary relationship to other sequences, but did not include the raw data. Virologist David Robertson said that it was difficult to conclude it was a cover-up rather than the more likely explanation: a mundane deletion of data without malfeasance. The missing genetic sequence data was restored in a correction published 29 July 2021 after it was stated to be a copy-edit error. In September 2024, a study published in Cell found genetic evidence that COVID-19 may have originated from the illegal trade of infected raccoon dogs in Wuhan, China, supporting the zoonotic transmission scenario. Swabs taken from the Huanan Seafood Wholesale Market in January 2020, which tested positive for coronavirus, contained large amounts of genetic material from raccoon dogs.
=== Motorsport === In line with his ongoing environmental activism, DiCaprio has been involved with the FIA Formula E World Championship since its inception. In December 2013, DiCaprio became a co-founder of the Venturi Racing team alongside Monegasque businessman Gildo Pallanca Pastor. Venturi were one of the ten Formula E founding teams, making their debut in the inaugural 2014–15 Formula E Championship. They recorded their first race victory with driver Edoardo Mortara at the 2019 Hong Kong ePrix, winning eight races in total and recording a best championship finish of second place in 2021–22 before being taken over by Stellantis and becoming Maserati MSG Racing ahead of the 2022–23 season. In October 2015, DiCaprio was named as the chairman of the Formula E Sustainability Committee by then-Formula E chief executive officer Alejandro Agag. The committee aims to "focus on urban mobility and [promote] the mass use of electric vehicles". Ahead of the 2018 Marrakesh ePrix, DiCaprio drove one of the Spark-Renault SRT01-e cars used in the series around the Circuit International Automobile Moulay El Hassan. DiCaprio produced the feature-length documentary And We Go Green, which followed the events of the 2017–18 Formula E Championship and provided access behind the scenes; it was released in May 2019.
Birch wood is fine-grained and pale in colour, often with an attractive satin-like sheen. Ripple figuring may occur, increasing the value of the timber for veneer and furniture-making. The highly decorative Masur (or Karelian) birch, from Betula verrucosa var. carelica, has ripple textures combined with attractive dark streaks and lines. Birch plywood is made from laminations of birch veneer. It is light but strong, and has many other good properties. It is among the strongest and dimensionally most stable plywoods, although it is unsuitable for exterior use. Birch plywood is used to make longboards (skateboard), giving it a strong yet flexible ride. It is also used (often in very thin grades with many laminations) for making model aircraft. Birch wood is often used in the manufacture of popsicle sticks due to its durability, smoothness and neutral flavour. Extracts of birch are used for flavoring and leather oil, and in cosmetics such as soap and shampoo. In the past, commercial oil of wintergreen (methyl salicylate) was made from the sweet birch (Betula lenta). Birch-tar or Russian oil extracted from birch bark is thermoplastic and waterproof; it was used as a glue on, for example, arrows, and also for medicinal purposes. Fragrant twigs of wintergreen group birches are used in saunas. Birch is also associated with the feast of Pentecost in Central and Eastern Europe and Siberia, where its branches are used as decoration for churches and homes on this day.
==== How shocks and stresses affect agrifood systems ==== The same shock or stress may have different impacts across the different components of agrifood systems, depending on their characteristics, risk environments, and inherent vulnerabilities and capacities. For example, given its reliance on natural processes, the agriculture sector is disproportionately exposed and vulnerable to adverse climate-related events, especially droughts, floods and storms. Over half of all shocks to crop production are the result of extreme weather events, reinforcing concern about the vulnerability of arable systems to climatic and meteorological volatility. In aquatic systems, there are well-established linkages between harvesting of fish, ocean productivity and global meteorology. Global climate plays a major role in fluctuating fishery productivity. Because agrifood systems are dependent on agricultural and natural ecosystems and encompass numerous actors along several interlinked components – from production to consumption – a shock or stress, impacting on any component, will not only affect the actors in it but will spread throughout systems upstream or downstream, eventually impacting on many if not all other actors and components. Coping mechanisms and resilience to shocks and stressors are shaped by gender inequalities, and shocks and crises have a greater negative impact on women's livelihoods in agrifood systems than they do on men's.
Sources: en.wikipedia.org
The solid is kept cold, dry and dark, typically at minus twenty degrees Celsius, in a sealed container with desiccant. Dissolved material is kept refrigerated and used promptly. Freezing and thawing a solution repeatedly is avoided because it accelerates degradation.
Reversed-phase chromatography with ultraviolet detection gives a purity percentage, while mass spectrometry confirms identity. Amino acid analysis checks the residue composition. Buyers typically request a certificate of analysis showing these measurements for the specific lot.
It is not authorised as a medicine in the United States or the European Union. Material is sold there as a research chemical or cosmetic ingredient. Some related short peptides are registered drugs in Russia, which is a distinct national situation rather than a general approval.
Vladimir Khavinson and colleagues at research institutes in Saint Petersburg developed and studied the peptide. Their program examined short peptides as regulators of aging and neuroendocrine function. Epitalon was one of several compounds produced by that group.