The short version of AEDG fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-18. Anything still debated is marked as such rather than presented as settled.
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.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
| 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.
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.
=== Chromatography === Stein and Moore developed a method to quantify and separate amino acids with column chromatography, using potato starch as the stationary phase. The fractions, originally collected manually, were collected in their newly developed automated fraction collector, and the amount of each amino acid was determined by an adjusted color reaction with ninhydrin. They began testing other methods of separation, such as ion exchange chromatography, to reduce the analysis time, as it took two weeks to analyze one protein using the starch columns. Ion exchange chromatography reduced the time to 5 days during initial experiments, and eventually Stein and Moore whittled the process down even further with the help of Daryl Spackman, which resulted in the first automatic amino acid analyzer. Along with their well-known work in protein sequences, this automatic amino acid analyzer was also utilized in Stein's study of amino acids in human urine and blood plasma.
Dy2O3 + 6 HClO4 → 2 Dy(ClO4)3 + 3 H2O Solutions used in modern spectroscopic work have been prepared directly from Dy2O3 and concentrated perchloric acid. Dysprosium perchlorate hexahydrate has also been obtained by dissolving Dy2O3 in 50–60% perchloric acid, followed by removal of excess water under reduced pressure or by freeze-drying. Anhydrous Dy(ClO4)3 can be obtained by controlled dehydration of hydrated dysprosium perchlorate.
==== Financial inclusion ==== Digital agriculture technologies can expand farmers' access to credit, insurance, and bank accounts for a number of reasons. First, digital technology helps alleviate the information asymmetry that exists between farmers and financial institutions. When lenders decide a farmer's credit ceiling or insurance premium, they are usually uncertain about what risks the farmer presents. Digital technology reduces the costs of verifying farmers' expected riskiness. The Kenyan company M-Shwari uses customers' phone and mobile money records to assess creditworthiness. Organizations like FarmDrive and Apollo Agriculture incorporate satellite imagery, weather forecasts, and remote sensor data when calculating farmers' loan eligibility. Drone imagery can confirm a farmer's physical assets or land use and Asset tracking using RFID technology allows stakeholders to monitor livestock, making it easier for insurers to understand farmers' riskiness. In all instances, low-cost digital verification reduces lenders' uncertainty: the questions "will this farmer repay the loan?" and "what risks does this farmer face?" become clearer. Second, digital technology facilitates trust between farmers and financial institutions. A range of tools create trust, including real-time digital communication platforms and blockchain/distributed ledger technology/smart contracts. In Senegal, a digitalized, supply-chain-tracking system allows farmers to collateralize their rice to obtain the credit necessary for planting.
=== Apoptosis === Both internal and external signals can lead to the induction of apoptosis, or programmed cell death. The resulting deconstruction of cellular components is primarily carried out by specialized proteases known as caspases, but the proteasome also plays important and diverse roles in the apoptotic process. The involvement of the proteasome in this process is indicated by both the increase in protein ubiquitination, and of E1, E2, and E3 enzymes that is observed well in advance of apoptosis. During apoptosis, proteasomes localized to the nucleus have also been observed to translocate to outer membrane blebs characteristic of apoptosis. Proteasome inhibition has different effects on apoptosis induction in different cell types. In general, the proteasome is not required for apoptosis, although inhibiting it is pro-apoptotic in most cell types that have been studied. Apoptosis is mediated through disrupting the regulated degradation of pro-growth cell cycle proteins. However, some cell lines — in particular, primary cultures of quiescent and differentiated cells such as thymocytes and neurons — are prevented from undergoing apoptosis on exposure to proteasome inhibitors. The mechanism for this effect is not clear, but is hypothesized to be specific to cells in quiescent states, or to result from the differential activity of the pro-apoptotic kinase JNK. The ability of proteasome inhibitors to induce apoptosis in rapidly dividing cells has been exploited in several recently developed chemotherapy agents such as bortezomib and salinosporamide A.
The addition of bicarbonate to the intravenous fluids may alleviate acidosis (high acid level of the blood) and make the urine more alkaline to prevent cast formation in the kidneys; evidence suggesting that bicarbonate has benefits above saline alone is limited, and it can worsen hypocalcemia by enhancing calcium and phosphate deposition in the tissues. If urine alkalinization is used, the pH of the urine is kept at 6.5 or above. Furosemide, a loop diuretic, is often used to ensure sufficient urine production, but evidence that this prevents kidney failure is lacking.
Sources: en.wikipedia.org
The scheme might be made far more attractive to the majority of Jews if it held out to them the prospect that when in course of time the Jewish colonists in Palestine grow strong enough to cope with the Arab population they may be allowed to take the management of the internal affairs of Palestine (with the exception of Jerusalem and the holy places) into their own hands. Sykes, having seen the telegram, had discussions with Picot and proposed (making reference to Samuel's memorandum) the creation of an Arab Sultanate under French and British protection, some means of administering the holy places along with the establishment of a company to purchase land for Jewish colonists, who would then become citizens with equal rights to Arabs. Shortly after returning from Petrograd, Sykes briefed Samuel, who then briefed a meeting of Gaster, Weizmann and Sokolow. Gaster recorded in his diary on 16 April 1916: "We are offered French-English condominium in Palest[ine]. Arab Prince to conciliate Arab sentiment and as part of the Constitution a Charter to Zionists for which England would stand guarantee and which would stand by us in every case of friction ... It practically comes to a complete realisation of our Zionist programme.
Sulfur has 23 known isotopes, four of which are stable: 32S (94.99%±0.26%), 33S (0.75%±0.02%), 34S (4.25%±0.24%), and 36S (0.01%±0.01%). Other than 35S, with a half-life of 87.37 days, the radioactive isotopes of sulfur have half-lives less than 3 hours. The preponderance of 32S is explained by its production in the alpha process (one of the main classes of nuclear fusion reactions) in exploding stars. Other stable sulfur isotopes are produced in the bypass processes related with 34Ar , and their composition depends on the type of a stellar explosion. For example, proportionally more 33S comes from novae than from supernovae. It has been found that the proportion of the two most abundant sulfur isotopes 32S and 34S varies in different samples by a surprisingly large amount. Determination of the isotope ratio (δ34S) in the samples indicates their chemical history, and with support of other methods, it allows to age-date the samples, estimate temperature of equilibrium between ore and water, determine pH and oxygen fugacity, identify the activity of sulfate-reducing bacteria in the time of formation of the sample, or suggest the main sources of sulfur in ecosystems. However, there are ongoing discussions over the real reason for the δ34S shifts, biological activity or postdeposit alteration. For example, when sulfide minerals are precipitated, isotopic equilibration between solid and liquid may cause small differences in the δ34S values of co-genetic minerals. The differences between minerals can be used to estimate the temperature of equilibration.
=== Food packaging === Nylon resins are used as a component of food packaging films where an oxygen barrier is needed. Some of the terpolymers based upon nylon are used every day in packaging. Nylon has been used for meat wrappings and sausage sheaths. The high temperature resistance of nylon makes it useful for oven bags.
Many women were coerced into have the tubal ligation procedure done right after postpartum which was paid for using federal money that was dispersed into the War On Poverty first initiated by Lyndon B. Johnson. Many of these sterilizations were done involuntarily and without consent. Oftentimes, these women signed off on paperwork without being able to read the English language. This sterilization was seen as a result of barriers experienced by Spanish speaking women. Other times, they were told it was necessary in order to maintain their welfare benefits. It became common to sterilize women after giving birth whether by tubal ligation or hysterectomy. Even when the women did consent, it was often under false pretenses that the procedure could be reversed if they decided to have children again in the future.
The Bradford assay uses the spectral properties of Coomassie brilliant blue G-250 to estimate the amount of protein in a solution. A protein sample is added to a solution of the dye in phosphoric acid and ethanol. Under the acid conditions the dye is normally a brownish colour but on binding to the protein the blue form of the dye is produced. The optical absorbance of the solution is measured at a wavelength of 595 nm. The dye is noted for its high level of sensitivity: 5 μg of protein can be detected. However, among the disadvantages of the method is its variability of color development with different proteins: the absorbance change per unit mass of proteins varies with the type of the protein. On binding to a protein, the negatively charged Coomassie brilliant blue G-250 dye molecule will give an overall negative charge to the protein. This property can be used to separate proteins or protein complexes using polyacrylamide gel electrophoresis under non-denaturing conditions in a technique called blue native PAGE. The mobility of the complex in the polyacrylamide gel will depend on both the size of the protein complex (i.e., the molecular weight) and the amount of dye bound to the protein. Coomassie blue staining can also be used as a loading control staining method in western blot analysis. It is applied as an anionic pre-antibody stain.
Sources: en.wikipedia.org
These are commonly used in industry for the processing of metals such as the lanthanides; because the separation factors between the lanthanides are so small many extraction stages are needed. In the multistage processes, the aqueous raffinate from one extraction unit is fed to the next unit as the aqueous feed, while the organic phase is moved in the opposite direction. Hence, in this way, even if the separation between two metals in each stage is small, the overall system can have a higher decontamination factor. Multistage countercurrent arrays have been used for the separation of lanthanides. For the design of a good process, the distribution ratio should be not too high (>100) or too low (<0.1) in the extraction portion of the process. It is often the case that the process will have a section for scrubbing unwanted metals from the organic phase, and finally a stripping section to obtain the metal back from the organic phase.
Volume, Area, Dihedral Angle Reporter (VADAR) is a freely available protein structure validation web server that was developed as a collaboration between Dr. Brian Sykes and Dr. David Wishart at the University of Alberta. VADAR consists of over 15 different algorithms and programs for assessing and validating peptide and protein structures from their PDB coordinate data. VADAR is capable of determining secondary structure (using three different algorithms), identifying and classifying six different types of beta turns, determining and calculating the strength of C=O -- N-H hydrogen bonds, calculating residue-specific accessible surface areas (ASA), calculating residue volumes, determining backbone and side chain torsion angles (phi, psi, omega and chi angles), assessing local structure quality (through numerous quality indices), evaluating global structure quality, and identifying residue "outliers" (residues with unusual structural features). The results have been validated through extensive comparison to published data and careful visual inspection. VADAR produces both text and graphical output with most of the quantitative data presented in easily viewed tables. In particular, VADAR's output is presented in a vertical, tabular format with most of the sequence data, residue numbering and any other calculated property or feature presented from top to bottom, rather than from left to right.
The cover of Private Eye announced "A Legend Lives" and one major newspaper ended an editorial by proclaiming that the "balance of probability" was that Heseltine would be prime minister before the end of the year – this being at a time when John Major's leadership had lost much credibility after the scandals following the "Back to Basics" campaign the previous autumn. Heseltine also acted to enforce a squeaky clean image at this time, by announcing an inquiry in July 1994, into allegations of insider dealing by Jeffrey Archer (there was insufficient evidence to prosecute), and by personally (rather than in writing) announcing an inquiry into whether a weapons manufacturing company called BMARC had broken government guidelines on trading with Iraq in the late 1980s. Heseltine launched a White Paper on Competitiveness in 1994. He was active in leading British trade delegations to South Africa, South America, India and Russia, but despite his enthusiasm for European Unity was seen to display little interest in the nuts and bolts of trade negotiations with the continent. In 1994 Heseltine planned to privatise 40% of the Post Office, a move which the Conservatives had previously shied away from. He was seen as imperious and intolerant by backbench opponents concerned at the threat to local postal services ("he seemed to have lost touch" one commented after a meeting), and the plan was abandoned by the Cabinet as unlikely to pass the House of Commons, as the Major government's majority had dropped to 14 by then.
Indoor air quality (IAQ) is the air quality within buildings and structures. Poor indoor air quality due to indoor air pollution is known to affect the health, comfort, and well-being of building occupants. It has also been linked to sick building syndrome, respiratory issues, reduced productivity, and impaired learning in schools. Common pollutants of indoor air include secondhand tobacco smoke, air pollutants from indoor combustion, radon, molds and other allergens, carbon monoxide, volatile organic compounds, legionella and other bacteria, asbestos fibers, carbon dioxide, ozone and particulates. Source control, filtration, and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality. Although ventilation is an integral component of maintaining good indoor air quality, it may not be satisfactory alone. In scenarios where outdoor pollution would deteriorate indoor air quality, other treatment devices such as filtration may also be necessary. IAQ is evaluated through collection of air samples, monitoring human exposure to pollutants, analysis of building surfaces, and computer modeling of air flow inside buildings. IAQ is part of indoor environmental quality (IEQ), along with other factors that exert an influence on physical and psychological aspects of life indoors (e.g., lighting, visual quality, acoustics, and thermal comfort). Indoor air pollution is a major health hazard in developing countries and is commonly referred to as "household air pollution" in that context.
In July 2010, Xinhua reported that authorities had seized 64 tonnes of dairy product contaminated with melamine from Dongyuan Dairy Factory, in Minhe County, in Qinghai, after authorities in Gansu discovered the contaminated powdered milk. Approximately 38 tonnes of raw materials had been purchased from Hebei, raising the possibility that traders had bought tainted milk that was supposed to have been destroyed after the 2008 scandal. Police have detained the owner and production director of the factory. Powdered milk produced in the plant was mainly sold in Zhejiang and Jiangsu, with only a small amount sold in Qinghai. Also, in Jilin, authorities were testing samples of suspect powdered milk produced in Heilongjiang. At the end of June 2010, Beijing lowered the minimum protein level for raw milk, from 2.955 to 2.8%, to discourage dairy farmers from attempting to falsify the passing of protein tests. Wu Heping, secretary general of the Heilongjiang Dairy Industry Association noted that between 75% and 90% of raw milk in some provinces had failed to reach the old protein level standard (in place since 1986) in 2007 and 2008. He said that the new standard reflected "the reality of the domestic dairy farm industry". However, Guangzhou dairy industry association president Wang Dingmian stated that this alone would not remove the incentive for adulteration, because milk price still depends on protein content.
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.
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.