If you have been reading about tetrapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-10-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
| 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 |
After independence, the government began a deliberate process of crafting a uniquely Singaporean identity and culture. Singapore has a reputation as a nanny state. The government also places a heavy emphasis on meritocracy, where one is judged based on one's ability. The national flower of Singapore is the hybrid orchid, Vanda Miss Joaquim, named in memory of Agnes Joaquim, who crossbred the flower in her garden at Tanjong Pagar in 1893. Singapore is known as the Lion City and many national symbols such as the coat of arms and the lion head symbol make use of a lion. Major religious festivals are public holidays. UNESCO recognises Singapore as a "Design City."
The use of animal gut strings by musicians can be traced back to the third dynasty of Egypt. In the recent past, strings were made out of lamb gut. With the advent of the modern era, musicians have tended to use strings made of silk, or synthetic materials such as nylon or steel. Some instrumentalists, however, still use gut strings in order to evoke the older tone quality. Although such strings were commonly referred to as "catgut" strings, cats were never used as a source for gut strings. Sheep gut was the original source for natural gut string used in racquets, such as for tennis. Today, synthetic strings are much more common, but the best gut strings are now made out of cow gut. Gut cord has also been used to produce strings for the snares that provide a snare drum's characteristic buzzing timbre. While the modern snare drum almost always uses metal wire rather than gut cord, the North African bendir frame drum still uses gut for this purpose. "Natural" sausage hulls, or casings, are made of animal gut, especially hog, beef, and lamb. The wrapping of kokoretsi, gardoubakia, and torcinello is made of lamb (or goat) gut. Haggis is traditionally boiled in, and served in, a sheep stomach. Chitterlings, a kind of food, consist of thoroughly washed pig's gut. Animal gut was used to make the cord lines in longcase clocks and for fusee movements in bracket clocks, but may be replaced by metal wire. The oldest known condoms, from 1640 AD, were made from animal intestine.
Although both DHLA and LA have been found inside cells after administration, most intracellular DHLA probably exists as mixed disulfides with various cysteine residues from cytosolic and mitochondrial proteins. Recent findings suggest therapeutic and anti-aging effects are due to modulation of signal transduction and gene transcription, which improve the antioxidant status of the cell. However, this likely occurs via pro-oxidant mechanisms, not by radical scavenging or reducing effects. All the disulfide forms of LA (R/S-LA, RLA and SLA) can be reduced to DHLA although both tissue specific and stereoselective (preference for one enantiomer over the other) reductions have been reported in model systems. At least two cytosolic enzymes, glutathione reductase (GR) and thioredoxin reductase (Trx1), and two mitochondrial enzymes, lipoamide dehydrogenase and thioredoxin reductase (Trx2), reduce LA. SLA is stereoselectively reduced by cytosolic GR whereas Trx1, Trx2 and lipoamide dehydrogenase stereoselectively reduce RLA. (R)-(+)-lipoic acid is enzymatically or chemically reduced to (R)-(-)-dihydrolipoic acid whereas (S)-(-)-lipoic acid is reduced to (S)-(+)-dihydrolipoic acid. Dihydrolipoic acid (DHLA) can also form intracellularly and extracellularly via non-enzymatic, thiol-disulfide exchange reactions. RLA may function in vivo like a B-vitamin and at higher doses like plant-derived nutrients, such as curcumin, sulforaphane, resveratrol, and other nutritional substances that induce phase II detoxification enzymes, thus acting as cytoprotective agents.
Freemasonry in Cuba has a history in three primary eras; the Spanish era of Cuba, the Republican era of Cuba, and the Communist–Republican era of Cuba. Many of Cuba's independence fighters and revolutionaries were Freemasons, including Carlos Manuel de Céspedes, Francisco Javier de Céspedes, José Martí, Ignacio Agramonte, and others. While there is archaeological evidence that Speculative Masonry arrived in Cuba in 1716, Freemasonry in Cuba can definitively trace its origins back to 1762, with various lodges forming and evolving over the centuries. The Grand Lodge of Cuba officially recognizes 1859 as their conception, however, the current Grand Lodge of Cuba and its Supreme Council dates to 1899, at the collapse of Spanish rule in Cuba. Despite being expelled from the Conference of North America in 1962, following the Cuban Revolution, the Grand Lodge of Cuba is recognized as "Regular and Correct," by the majority of Lodges around the world. The Grand Lodge of Cuba is one of the 92 members of the Inter‑American Masonic Confederation (CMI), which also includes the United States. As of a survey in 2010, the islands of Cuba have 316 Masonic Lodges. Some confusion has existed about the role of freemasonry and women in Cuba; while some sources have stated that the Grand Lodge of Cuba is unique in that it allows women to be regular masons in the fraternal brotherhood, in actuality, the Grand Lodge of Cuba oversees a body for women called the Daughters of Acacia.
== Further reading == Payne M.G., Hurst G.S. (1985) Theory of Resonance Ionization Spectroscopy. In: Martellucci S., Chester A.N. (eds) Analytical Laser Spectroscopy. NATO ASI Series (Series B: Physics), vol 119. Springer, Boston, MA. Parks J.E., Young J.P. (2000) Resonance Ionization Spectroscopy 2000: Laser Ionization and Applications Incorporating RIS; 10th International Symposium, Knoxville, Tennessee (AIP Conference Proceedings).
Sources: en.wikipedia.org
== Contraindications == Dihydroergotamine is contraindicated with potent CYP3A4 inhibitors, like macrolide antibiotics. Contraindications for dihydroergotamine include: pregnancy, kidney failure or liver failure, coronary, cerebral, and peripheral vascular disease, hypersensitivity reactions, sepsis, and uncontrolled hypertension.
20983Bi + 7030Zn → 279113* → 278113 + n The Riken team observed four alpha decays from 278113, creating a decay chain passing through 274Rg, 270Mt, and 266Bh before terminating with the spontaneous fission of 262Db. The decay data they observed for the alpha decay of 266Bh matched the 2000 data, lending support for their claim. Spontaneous fission of its daughter 262Db had not been previously known; the American team had observed only alpha decay from this nuclide.
A basic slow cooker consists of a lidded round or oval cooking pot made of glazed ceramic, surrounded by a housing, usually metal, containing an electric heating element. The lid is often made of glass, and seated in a groove in the pot edge; condensed vapor collects in the groove and provides a seal to the atmosphere. The contents of a crock pot are effectively at atmospheric pressure, despite the water vapor generated inside the pot. A slow cooker is different from a pressure cooker and presents no danger of an abrupt pressure release. The crock, or ceramic pot, acts as both a cooking container and a thermal reservoir. Slow cookers come in capacities from 500 mL (17 US fl oz) to 7 L (7.4 US qt). Because the heating elements are generally located at the bottom and often also partway up the sides, most slow cookers have a minimum recommended liquid level to avoid uncontrolled heating. Some newer models have coated aluminium or steel crocks which, while not as efficient as ceramic at retaining heat, do allow for quicker heating and cooling, as well as the ability to use the crock on the stove top to brown meat prior to cooking. Many slow cookers have two or more heat settings, e.g., low, medium, high, and sometimes a "keep warm" setting; some have continuously variable power. Early slow cookers had no temperature control and delivered a constant heat to the contents. The temperature of the contents rises until it reaches the boiling point, at whereupon the energy goes into gently boiling the liquid closest to the hot surface.
Paradoxical effects: In some cases, paradoxical effects can occur with benzodiazepines, such as increased hostility, aggression, angry outbursts, and psychomotor agitation. These effects are seen more commonly with lorazepam than with other benzodiazepines. Paradoxical effects are more likely to occur with higher doses, in people with pre-existing personality disorders and those with a psychiatric illness. Frustrating stimuli may trigger such reactions, though the drug may have been prescribed to help the person cope with such stress and frustration in the first place. As paradoxical effects appear to be dose-related, they usually subside on dose reduction or on complete withdrawal of lorazepam. Suicidality: Benzodiazepines are associated with an increased risk of suicide, possibly due to disinhibition. Higher dosages appear to confer greater risk. Amnesic effects: Among benzodiazepines, lorazepam has relatively strong amnesic effects, but people soon develop tolerance to this with regular use. An initial total daily lorazepam dose that does not exceed 2 mg may help avoid amnesia (or excess sedation) being a problem. This also applies to use for night sedation. Five participants in a sleep study were prescribed lorazepam 4 mg at night, and the next evening, three subjects unexpectedly volunteered memory gaps for parts of that day, an effect that subsided completely after two to three days' use. Amnesic effects cannot be estimated from the degree of sedation present, since the two effects are unrelated.
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.
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.