The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-10 and is reviewed periodically as new material appears.
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.
Stability of the tetrapeptide follows ordinary peptide chemistry rather than any unusual structural feature. The aspartate-glycine pair is prone to aspartimide formation under mildly basic or neutral conditions, and deamidation can follow, altering both mass and chromatographic retention. Dry lyophilised powder kept at or below minus twenty degrees Celsius is the usual handling recommendation, with repeated freeze-thaw cycles avoided. Once dissolved in neutral aqueous buffer, degradation proceeds over days to weeks depending on pH and temperature, while acidic conditions generally slow the aspartimide route. A formal stability-indicating study has not been published in the indexed literature.
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.
| Property | Value | Notes |
|---|---|---|
| Analytical method | Reversed-phase HPLC | Purity determination, typically 214 nm |
| Mass confirmation | ESI or MALDI mass spectrometry | Compared with mass near 390 Da |
| Common synonyms | Epitalon, epithalon, AEDG | Naming differs between suppliers |
| Storage temperature | −20 °C or lower | Lyophilised powder, kept desiccated |
| Solution stability | Limited in neutral aqueous buffer | Aspartimide and hydrolysis pathways |
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.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
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.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
Corticotropin-like intermediate [lobe] peptide (CLIP), also known as adrenocorticotropic hormone fragment 18-39 (ACTH(18-39)), is a naturally occurring, endogenous neuropeptide with a docosapeptide structure and the amino acid sequence Arg-Pro-Val-Lys-Val-Tyr-Pro-Asn-Gly-Ala-Glu-Asp-Glu-Ser-Ala-Glu-Ala-Phe-Pro-Leu-Glu-Phe. CLIP is generated as a proteolyic cleavage product of adrenocorticotropic hormone (ACTH), which in turn is a cleavage product of proopiomelanocortin (POMC). Its physiological role has been investigated in various tissues, specifically in the central nervous system. It has been suggested to function as an insulin secretagogue in the pancreas.
=== Generic names === Finasteride is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and JANTooltip Japanese Accepted Name, while finastéride is its DCFTooltip Dénomination Commune Française. It is also known by its former developmental code names MK-906, YM-152, and L-652,931.
In 2022, Church's Texas Chicken operated more than 1,500 locations worldwide. Its international locations include Bahrain, Belarus, Cambodia, Canada, Costa Rica, Curaçao, Guyana, Honduras, Indonesia, Iraq, Jordan, Laos, Malaysia, Mexico, New Zealand, Oman, Pakistan, Puerto Rico, Saudi Arabia, Qatar, Singapore, St. Lucia, Thailand, Trinidad & Tobago, United Arab Emirates, Venezuela and Vietnam. However, Church's Texas Chicken's operation in Thailand, which is operated under license by PTT OR (PTT Oil and Retail Business Public Company Limited) as Texas Chicken was discontinued on 30 September 2024 as it was announced in their official Facebook page after 9 years of its operation. As of 30 September 2024, PTT OR operates 97 Texas Chicken locations nationwide in Thailand.
== External links == International Chemical Safety Card 1193 CID 516889 from PubChem ATC codes: A02AC01 (WHO) and A12AA04 (WHO) The British Calcium Carbonate Association – What is calcium carbonate Archived 24 May 2008 at the Wayback Machine CDC – NIOSH Pocket Guide to Chemical Hazards – Calcium Carbonate
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Sources: en.wikipedia.org
=== Activators === 1-Aminoanthracene and propofol - activate SIRT2 activity on some substrates but inhibit it on others Nicotinamide riboside - activates SIRT2, but non selective Metformin - activates SIRT2 but has several other mechanisms of action as well SRT1720 - primarily a SIRT1 activator, but also weakly activates SIRT2 Hexapeptide-12 (VGVAPG) - upregulates SIRT2 gene expression through an indirect pathway
In October 1938, Joachim von Ribbentrop first proposed German-Polish territorial adjustments and Poland's participation in the Anti-Comintern Pact against the Soviet Union. The status of the Free City of Danzig was one of the key bones of contention. Approached by Ribbentrop again in March 1939, the Polish government expressed willingness to address issues causing German concern, but effectively rejected Germany's stated demands and thus refused to allow Poland to be turned by Adolf Hitler into a German puppet state. Hitler, incensed by the British and French declarations of support for Poland, abrogated the German–Polish declaration of non-aggression in late April 1939. To protect itself from an increasingly aggressive Nazi Germany, already responsible for the annexations of Austria (in the Anschluss of 1938), Czechoslovakia (in 1939) and a part of Lithuania after the 1939 German ultimatum to Lithuania, Poland entered into a military alliance with Britain and France (the 1939 Anglo-Polish military alliance and the Franco-Polish alliance (1921), as updated in 1939). However, the two Western powers were defense-oriented and not in a strong position, either geographically or in terms of resources, to assist Poland. Attempts were therefore made by them to induce Soviet-Polish cooperation, which they viewed as the only militarily viable arrangement. Diplomatic manoeuvers continued in the spring and summer of 1939, but in their final attempts, the Franco-British talks with the Soviets in Moscow on forming an anti-Nazi defensive military alliance failed.
=== Canada === Under Canadian regulations (C.R.C., c.870, section B.02.90), any product labelled, advertised, or sold as tequila must be manufactured in Mexico, as it would be for consumption in Mexico. Once imported to Canada for sale, it is legal for tequila to be diluted with distilled or otherwise purified water to adjust it to the desired strength and then sold.
Progesterone is available for vaginal administration in the form of capsules (Utrogestan), gels (Crinone, Prochieve), suppositories (Cyclogest), inserts/tablets (Endometrin, Lutinus), and rings (Fertiring, Progering). In addition, oral micronized progesterone capsules have been administered vaginally with success. The bioavailability of vaginal micronized progesterone insert is about 4 to 8%. Vaginal absorption of progesterone is lower in postmenopausal women with vaginal atrophy. Following administration of a single 25, 50, or 100 mg vaginal progesterone suppository in women, maximal circulating levels of progesterone occurred within 2 to 3 hours and were 7.27 ± 2.8 ng/mL, 8.84 ± 3.14 ng/mL, and 9.82 ± 9.8 ng/mL, respectively. After peak levels, progesterone levels decreased gradually, with an elimination half-life of 6 to 12 hours. Progesterone levels were less than 3 ng/mL for all three doses after 24 hours. The researchers concluded that the 25 and 50 mg doses would be appropriate for administration three times per day while the 100 mg dose would be appropriate for administration twice per day. The bioavailability of vaginal progesterone gel is about 40-fold greater than that of oral progesterone. Gel bioavailability does not seem to vary between the "Crinone 8%" formulation and two experimental generic formulations of different strengths, peaking at about 10 ng/mL after 90 mg of gel within 7 hours (with a large standard deviation).
=== 11 August === At least 40 people were killed in an RSF attack on Abu Shouk camp. The SAF claimed to have killed more than 200 RSF fighters and destroyed or captured 46 combat vehicles following an RSF attack on El Fasher. Nine people were abducted by the RSF during the event.
Sources: en.wikipedia.org
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.
Neutral and slightly basic aqueous conditions promote aspartimide formation at the aspartate-glycine step, often followed by deamidation. Elevated temperature and repeated freeze-thaw cycles accelerate the loss. Acidic solutions and dry lyophilised powder are comparatively stable over short periods.
No monograph exists in the United States Pharmacopeia or the European Pharmacopoeia, and no widely distributed certified reference standard is available. Purity and identity therefore rest on supplier methods that are not harmonised. This absence is the main reason reported purities are difficult to compare between sources.
It is a four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine. The chain is unmodified and contains only standard proteinogenic residues, which makes it straightforward to produce by solid-phase synthesis and to characterise by standard peptide methods.