The short version of reversed-phase HPLC fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-12. 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.
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.
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.
| 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 generally presented as a synthetic fragment of epithalamin, a pineal gland extract investigated in the former Soviet Union from the 1970s onward. Vladimir Khavinson and colleagues in Saint Petersburg developed short peptides modelled on such extracts, and epitalon became the most widely cited of those sequences. Most primary reports appeared in Russian-language journals or in proceedings with limited international circulation. Independent replication in laboratories outside that network remains sparse, and much repeated secondary material traces back to a small number of originating groups.
Laboratory work has examined effects on telomerase activity in cultured cells, on melatonin rhythms in animals, and on markers of oxidative stress. Some experiments report measurable changes while others show none, and the reported findings rest largely on small studies. The absence of large independent trials means the generality of these results is unresolved rather than settled. Review articles occasionally apply the label geroprotector, a term that reflects a research hypothesis about ageing rather than an established clinical finding.
Epitalon is the common name for a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, usually abbreviated AEDG. All four residues are proteinogenic amino acids, and the free peptide has a calculated mass near 390 grams per mole. Because the chain is short and carries no modifications, it is assembled readily by solid-phase synthesis and is distributed mainly as a freeze-dried solid for laboratory work. Catalogue listings use the spellings epitalon, epithalone, and simply AEDG, and the three refer to the same sequence.
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.
Le Cake-Walk infernal, sold in the United States as The Cake Walk Infernal and in Britain as The Infernal Cake Walk, is a 1903 French silent trick film by Georges Méliès. It was sold by Méliès's Star Film Company and is numbered 453–457 in its catalogues. The film features the cakewalk, which was booming in popularity in 1903. Méliès appears in the film as Pluto/Satan and as the grotesque dancing demon. This rhythm-dependent film was probably filmed to piano accompaniment in the studio. Special effects in the film were worked with trapdoors, stage machinery, pyrotechnics, substitution splices, and multiple exposures. The Infernal Cake Walk features several examples of elements reused from, or later reused in, other films also made by Méliès. The demon masks in the film were originally made for Méliès's A Trip to the Moon (1902), where they are worn by the Selenites (Moon dwellers); similarly, the effect of dancing limbs had previously been used in Dislocation Extraordinary (1901). Conversely, Méliès reused The Infernal Cakewalk's grotto set in his later film The Damnation of Faust (1903), and recycled the will-o'-the-wisp effect in The Infernal Cauldron (1903).
The "lobe" classification describes lobes that, while originally defined in the fetus, are also visible in gross anatomy, including dissection and when viewed endoscopically. The five lobes are the anterior lobe or isthmus, the posterior lobe, the right and left lateral lobes, and the middle or median lobe.
It has a very wide native distribution, ranging from East Asia (north to the Amur region) through northern Indochina and central and northern India (at altitudes up to 1,400 m (4,600 ft) in the southern Himalayas),; the Russian populations have sometimes been referred to as Nelumbo komarovii, with isolated locations at the Caspian Sea. Today, the species also occurs in southern India, Sri Lanka, virtually all of Southeast Asia, New Guinea, and northern and eastern Australia, but this is probably the result of human translocations. It has a very long history (c. 3,000 years) of being cultivated for its edible seeds and is commonly cultivated in water gardens. It is a highly symbolic and versatile plant used in religious offerings (especially in Hinduism and Buddhism) and diverse culinary traditions across Asia, with its flowers, seeds, and rhizomes valued for spiritual, cultural, and nutritional purposes. It holds deep cultural, spiritual, and religious significance across Hinduism, Buddhism, Jainism, Ismailism, and Chinese culture, symbolizing purity, enlightenment, spiritual awakening, and divine beauty, and is widely depicted in art, architecture, and literature. The leaves of Nelumbo nucifera contain the flavonol miquelianin and alkaloids such as coclaurine and norcoclaurine, while the plant as a whole contains bioactive compounds including nuciferine and neferine. These constituents have been studied for their potential pharmacological effects, and the plant is used in traditional medicine and marketed as a functional food in various cultures.
Fodé Sylla - former member of the European parliament, former president of SOS Racisme Hamidou Diallo- American professional basketball player for the Oklahoma City Thunder of the National Basketball Association (NBA) Ira Frederick Aldridge – stage actor, claims to have descended from the Fulani princely line, USA Omar Ibn Said (c. 1770 – 1864) – Islamic scholar from Futa-Toro. Taken as a slave to Charleston, South Carolina in 1807. Escaped to North Carolina, Wrote a slave narrative in Arabic professing his Islamic faith. Died before end of Civil War. Richard Pierpoint - Slave, freed slave, British Army soldier and farmer in Fergus, Ontario Canada. Yarrow Mamout (or Mahmoud or Mamood or Muhammad Yaro) – was a former slave, entrepreneur, and property owner in Georgetown, Washington, DC, USA
Antibiotic sensitivity: an advantage about this method is that it gives information for patients treatment. There are also some disadvantages, one of them is that this technique is only useful in cultivable bacteria for which competent personal is required. Sequencing methods: some advantages of those methods over the AST technique are that it is rapid and sensible, it is useful on both bacteria that grow on artificial media and those that do not, and it permits compare studies in several organisms. One type of sequencing method can be used in preference to another depending on the type of the sample, for a genomic sample assembly-based methods is used; for a metagenomic sample it is preferable to use read-based methods. Metagenomic sequencing methods have provided better results than genomics, due to these present fewer false negatives. Within metagenomics sequencing, functional metagenomic is a powerful approach for characterizing resistomes; a metagenomic library is generated by cloning the total community DNA extracted from a sample into an expression vector, this library is assayed for antimicrobial resistance by plating on selective media that are lethal to the wild-type host. The selected inserts from the surviving recombinant, antimicrobial-resistant host cells are then sequenced, and resulting sequences are subsequently assembled and annotated (PARFuMS).
Sources: en.wikipedia.org
Tilidine is used in the form of hydrochloride or phosphate salt. In Germany, tilidine is available in a fixed combination with naloxone for oral administration (Valoron N and generics); the mixture of naloxone is claimed to lower the abuse liability of the opioid analgesic. This is so that if people take the medication orally (which is the way they are meant to) the opioid blocker, naloxone, has minimal effects on them but if they inject it the naloxone becomes bioavailable and hence antagonizes the effects of the tilidine producing withdrawal effects. In Switzerland the original Valoron brand with only tilidine and no naloxone is also available. As well as its use as an analgesic, tilidine is also commonly used in Germany for treatment of restless legs syndrome. The reverse ester is also known and is also a prodrug. Tilidine explicitly without Naloxone is a controlled substance in most countries, listed in the German BtMG, Austrian SMG, and in the USA under the Controlled Substances Act as ACSCN 9750 as a Narcotic under Schedule I, with an annual aggregate manufacturing quota of 10 grams in 2014. It is used as the hydrochloride (free base conversion ratio 0.882) and HCl hemihydrate (0.858).
=== ADHD === Selegiline has been limitedly studied in the treatment of attention deficit hyperactivity disorder (ADHD) in children, adolescents, and adults. In a small randomized trial of selegiline for treatment of ADHD in children, there were improvements in attention, hyperactivity, and learning/memory performance but not in impulsivity. A small clinical randomized trial compared selegiline to methylphenidate, a first line treatment for ADHD, and reported equivalent efficacy as assessed by parent and teacher ratings. In another small randomized controlled trial of selegiline for the treatment of adult ADHD, a high dose of the medication for 6 weeks was not significantly more effective than placebo in improving symptoms. Selegiline in its transdermal patch form (brand name Emsam) has also been assessed in the treatment of ADHD in children and adolescents in a small open-label pilot study sponsored by the manufacturer in 2003. However, there was a high rate of discontinuation and development was not further pursued.
The meteorite contained a mixture of left-handed and right-handed amino acids; most amino acids used by living organisms are left-handed in chirality, and most sugars used are right-handed. A team of chemists in Sweden demonstrated in 2005 that this homochirality could have been triggered or catalyzed by the action of a left-handed amino acid such as proline. Several lines of evidence indicate that the interior portions of well-preserved fragments from Murchison are pristine. A 2010 study using high resolution analytical tools including spectroscopy, identified 14,000 molecular compounds, including 70 amino acids, in a sample of the meteorite. The limited scope of the analysis by mass spectrometry provides for a potential 50,000 or more unique molecular compositions, with the team estimating the possibility of millions of distinct organic compounds in the meteorite. In November 2019, along with the Northwest Africa 801 meteorite it was the first to provide evidence of pentoses (including ribose) in space, using gas chromatography–mass spectrometry. All the straight-chain five-carbon aldoses were found but tetroses, sugar alcohols, sugar acids, and deoxyribose were not detected. In 2020, NASA announced that hexamethylenetetramine had been found in the Murchison, Murray and Tagish Lake meteorites.
==== Education and employment ==== Educational and vocational accommodations in those with JIA may include requiring extra time to get between classes or during examinations, using specialized pens or switching to typing rather than handwriting, or minimizing the load of heavy books or equipment to be carried in a child's school bag. The exact requirements will vary from child-to-child and will depend on the joints affected. In many instances, the child's treating team will be able to provide specific advice and information for teachers and coaches to smooth the transition back to school.
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.
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.