AEDG is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-06-10. Numbers and descriptions here follow the published literature rather than marketing material.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
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.
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 |
|---|---|---|
| Sequence | Ala-Glu-Asp-Gly | Written in three-letter amino acid code |
| Single-letter code | AEDG | Form used in most catalogue entries |
| Typical purity specification | 95 percent or higher | Value read from the HPLC chromatogram |
| Storage, dry solid | Minus 20 degrees Celsius, desiccated | Sealed container, protected from light |
| Handling, solution | Divide into single-use portions | Limits losses from freeze-thaw cycling |
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.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
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.
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.
=== Conservative whip suspension === In May 2019, he had the Conservative Party whip suspended after saying he would vote for the Liberal Democrats, rather than the Conservatives, at the 2019 European Parliament election. On 26 November 2019, in preparation for the 2019 general election, Heseltine said he could not support Boris Johnson because the Prime Minister was pursuing an "utterly disastrous" policy that would make Britain poorer and less influential, and he called on voters to back the Liberal Democrats to deny Johnson a majority in Parliament. In June 2023, following the report by the Commons Privileges Committee, he said that Johnson had lied to parliament. Speaking on Sky News, he said that Johnson had resigned before the Partygate report was published because he "saw it coming", adding "We've had four days of this report and the story doesn't change: Boris Johnson told a pack of lies. Boris Johnson got out from under, he saw it coming, he knew he hadn't a case to defend. So he resigned before the suspension that he feared could be relevant." In July 2024, the Conservatives restored Heseltine's whip.
== Frequency and depth == The depth of penetration depends on the frequency of the microwaves and the tissue type. The Active Denial System ("pain ray") is a less-lethal directed energy weapon that employs a microwave beam at 95 GHz; a two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1/64th of an inch (0.4 mm) and is claimed to cause skin pain without lasting damage. Conversely, lower frequencies penetrate deeper; at 5.8 GHz (3.2 mm) the depth most of the energy is dissipated in the first millimeter of the skin; the 2.45 GHz frequency microwaves commonly used in microwave ovens can deliver energy deeper into the tissue; the generally accepted value is 17 mm for muscle tissue. As lower frequencies penetrate deeper into the tissue, and as there are fewer nerve endings in deeper-located parts of the body, the effects of the radio frequency waves (and the damage caused) may not be immediately noticeable. The lower frequencies at high power densities present a significant risk. The microwave absorption is directed by the dielectric constant of the tissue. At 2.5 GHz, this ranges from about 5 for adipose tissue to about 56 for cardiac muscle. As the speed of electromagnetic waves is proportional to the reciprocal of the square root of the dielectric constant, the resulting wavelength in the tissue can drop to a fraction of the wavelength in air; e.g. at 10 GHz the wavelength can drop from 3 cm to about 3.4 mm.
== Description == The death cap has a large and imposing epigeous (aboveground) fruiting body (basidiocarp), usually with a pileus (cap) from 5 to 15 cm across (2 to 5.8 inches) across, initially rounded and hemispherical, but flattening with age. The color of the cap can be pale-green, yellowish-green, olive-green, bronze, or (in one form) white; it is often paler toward the margins, which can have darker streaks; it is also often paler after rain. The cap surface is sticky when wet and easily peeled—a troublesome feature, as that is allegedly a feature of edible fungi. The remains of the partial veil are seen as a skirtlike, floppy annulus usually about 1 to 1.5 cm (3⁄8 to 5⁄8 in) below the cap. The crowded white lamellae (gills) are free. The stipe is white with a scattering of grayish-olive scales and is 8 to 15 cm (3+1⁄8 to 5+7⁄8 in) long and 1 to 2 cm (3⁄8 to 3⁄4 in) thick, with a swollen, ragged, sac-like white volva (base). As the volva, which may be hidden by leaf litter, is a distinctive and diagnostic feature, it is important to remove some debris to check for it. Spores: 7-12 x 6-9 μm. Smooth, ellipsoid, amyloid. The smell has been described as initially faint and honey-sweet, but strengthening over time to become overpowering, sickly-sweet and objectionable. Young specimens first emerge from the ground resembling a white egg covered by a universal veil, which then breaks, leaving the volva as a remnant. The spore print is white, a common feature of Amanita.
=== Functional genomics === Approaches to the design of genome-wide RNAi libraries can require more sophistication than the design of a single siRNA for a defined set of experimental conditions. Artificial neural networks are frequently used to design siRNA libraries and to predict their likely efficiency at gene knockdown. Mass genomic screening is widely seen as a promising method for genome annotation and has triggered the development of high-throughput screening methods based on microarrays.
==== Females ==== Outcomes have generally indicated that early onset of puberty in females can be psychologically damaging. The main reason for this detrimental effect is the issue of body image. As they physically develop, gaining weight in several areas of the body, early-maturing females usually look larger than females who have not yet entered puberty. A result of the social pressure to be thin, the early-maturing females develop a negative view of their body image. In addition, people may tease the females about their visible breasts, forcing the early-maturing female to hide her breasts by dressing differently. Embarrassment about a more developed body may also result in the refusal to undress for gym. These experiences lead to lower self-esteem, more depression and poorer body image in these early-maturing females. Furthermore, as physical and emotional differences set them apart from people in their same age group, early-maturing females develop relationships with older people. For instance, some early-maturing females have older malefriends, "attracted to the females' womanly physique and femaleish innocence." While having an older malefriend might improve popularity among peers, it also increases the risk of alcohol and drug use, increased sexual relations (often unprotected), eating disorders and bullying. Generally, later onset of puberty in females produces positive outcomes. They exhibit positive behaviors in adolescence that continue to adulthood.
Sources: en.wikipedia.org
=== Analysers === The Microtox Model 500 is a laboratory-based photometer that measures acute toxicity. This analyser is a temperature-controlled, self-calibrating biosensor measuring system that uses the bioluminescence of Allivibrio fischeri to determine the toxicity of contaminated water, or elutriates of contaminated soils and sediments. Microtox Continuous Toxicity Monitor (CTM) is a site-specific Microtox analyser that continuously measures the toxicity of a water source and provides results instantly. This fully automatic analyser has a broad detection range that can identify several thousand contaminants simultaneously whether or not there is knowledge of the source of contamination. This device has the ability to run continuously for up to 4 weeks, and is easy to operate and maintain. The DeltaTox II is a portable instrument that can be used to conduct acute toxicity and adenosine triphosphate (ATP) testing. Also known as the portable version of the Microtox Model 500, this device provides simple testing, uses small sample sizes, and is a cost-effective approach to analyzing water samples. This sensitive and rapid testing analyser has the ability to detect microbial contamination, as well as more than 2,700 different chemicals.
=== Load carrying equipment === 1937 pattern web equipment - Used until the early 1960s, in limited use with Territorial Army and other second-line troops until the mid to late 1970s. 1944 pattern web equipment - Used in tropical conditions 1958 pattern web equipment - Used from the late 1950s until the early 1990s Personal Load Carrying Equipment - Trialled from the mid-1980s to the late 1980s, adopted by the (very) late 1980s
John Martin Shaw, Director of Planning and Transportation, Norfolk County Council. For services to Local Government. William Francis Sheridan, Head of International Policy, Forestry Commission. Francis Edward Shields, , lately Chief Executive, National Federation of Young Farmers' Clubs. For services to the Young Farmers Club Movement. Ian Skipper. For charitable services. Brian William Smith, lately Head of Operations, Securities and Investments Board. For services to Financial Regulation. Clifford John Smith. For services to the Newspaper Industry and to the community in Lincolnshire. Dennis Alfred Smith, lately Network Director, Southern Division, Central Office of Information. John Stanley Walter Smith, Head of Corporate Services Group, Her Majesty's Board of Customs and Excise. Neil Durden-Smith. For charitable services. Ian Nelson Sneddon, Chairman, Central Scotland Committee for the Employment of People with Disabilities. For services to the employment of disabled people. Kenneth Speakman, lately Pollution Inspector, Environment Agency. For services to Environmental Protection. Francis Richard Stanhope. For services to the Royal Air Force Association. Robert Russell Steedman, lately Member, Royal Fine Art Commission for Scotland. For services to the Built Environment in Scotland. Susan Elizabeth Stockley, Chairman, National Executive of the National Federation of Women's Institutes. For services to the Women's Institute Movement. John Howard Stoner, Regional General Manager, National Rivers Authority (Welsh Region). For services to the Environment in Wales.
=== Forms === Spironolactone is available in the form of tablets (25, 50, and 100 mg; brand name Aldactone, others) and suspensions (25 mg/5 mL; brand name Carospir) for oral administration. It had also been marketed in the form of 2 or 5% topical cream in Italy for the treatment of acne and hirsutism under the brand name Spiroderm, but this product is no longer available. The medication is also available in combination with other medications, such as hydrochlorothiazide (brand name Aldactazide, others). Spironolactone has poor water solubility, so only oral and topical formulations have been developed; other routes of administration such as intravenous injection are not used. The only antimineralocorticoid that is available as a solution for parenteral use is the related medication potassium canrenoate.
== Biochemical function == β-Alanine residues are rare. It is a component of the peptides carnosine and anserine and also of pantothenic acid (vitamin B5), which itself is a component of coenzyme A. β-alanine is metabolized into acetic acid.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.
Long-term holding is usually at minus twenty degrees Celsius in a sealed, desiccated container. A refrigerator is adequate for short intervals before use. Light exposure is normally avoided as well. Allowing a cold container to warm before opening reduces moisture condensation on the contents.
Repeated cycles are generally avoided. Each freeze and thaw can promote aggregation or loss of peptide to container surfaces, which reduces the amount available for later work. Dividing a solution into single-use portions at the outset is the usual way to limit this problem.
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.