RP-HPLC 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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | RP-HPLC | Reported as percent area, often ≥95% |
| Identity confirmation | Mass spectrometry | Observed mass compared with ~390 Da |
| Typical storage temperature | -20 °C or below | Lyophilized powder, desiccated |
| Reconstitution solvent | Sterile water or buffer | Acidic residues aid dissolution |
| Common synonyms | AEDG; epithalon | Spelling varies in literature |
The most frequently cited laboratory finding is that AEDG increased telomerase activity and extended telomere length in cultured human somatic cells. That work used fetal fibroblast strains and reported changes in enzyme activity alongside altered division counts. Replication by unrelated groups has been limited, and the published record is largely a single-laboratory series rather than a multi-centre programme. The result supports a hypothesis about peptide influence on gene expression in cell culture; it does not by itself establish an effect on telomere length in living animals or in people.
Animal and clinical reports appear mainly in Russian-language journals from the 1990s and 2000s, covering endpoints such as melatonin rhythm, lifespan in aged rodents, and retinal function. Many of these papers involve small groups, lack blinding or placebo comparison, and are difficult to retrieve through indexed databases. Review articles published in English generally summarise the claims without reanalysing the underlying data. Because no large randomised trial exists, the clinical importance of these reported effects stays unresolved and is properly described as an open question.
No national medicines regulator has approved epitalon as a therapeutic product. It is generally distributed as a research chemical, and in some jurisdictions selling peptides for human consumption without approval is restricted or prohibited. Certificates of analysis accompanying commercial material vary in which tests are performed, and independent verification of identity and purity is uncommon. Statements about anti-ageing or disease-prevention benefits on vendor pages are marketing claims rather than regulatory findings, a distinction that shapes how the compound is discussed in scientific and popular sources alike.
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.
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.
== History == 1919 F.D. Edwards establishes Edwards Equipment and Services in London, England. 1939 F.D. Edwards begins manufacturing vacuum equipment. 1955 The company acquires Alto Vuoto SpA, a freeze drying manufacturer in Italy. 1968 The company is acquired by BOC, after staying in private hands through the post-war period and until the 1960s when it went public. 1977 BOC Edwards acquire Kniese Apparatbau GmbH, a freeze drying manufacturer in Germany. 1992 Restructuring of Freeze Drying business resource centralised in Tonawanda (US). 1994 The company’s product portfolio is expanded with the acquisition of pharmaceutical filling systems from Calumatic in The Netherlands. 1995 The company’s portfolio is further expanded with loading systems introduced from the Dongen manufacturing site in The Netherlands. 2004 A joint venture is established with Tianli Cryogenic Company, a pharmaceutical freeze dryer manufacturer in Beijing, China. 2006 The BOC Group is acquired by Linde AG and together form The Linde Group. Linde sells the vacuum division of BOC Edwards. BOC Edwards Pharmaceutical Systems remains part of the Linde Group, as an independent division. 2008 IMA, Italy acquires the BOC Edwards Pharmaceutical Systems group creating IMA Edwards – a part of IMA Life division of the IMA group. 2010 Today the whole group has been renamed under the brand IMA LIFE - Aseptic Processing and Freeze Drying Solutions.
Seymour Benzer in the late 1950s had developed an assay using phage mutations which provided the first detailed linearly structured map of a genetic region. Crick felt he could use mutagenesis and genetic recombination phage to further delineate the nature of the genetic code. In the Crick, Brenner et al. experiment, using these phages, the triplet nature of the genetic code was confirmed. They used frameshift mutations and a process called reversions, to add and delete various numbers of nucleotides. When a nucleotide triplet was added or deleted to the DNA sequence the encoded protein was minimally affected. Thus, they concluded that the genetic code is a triplet code because it did not cause a frameshift in the reading frame. They correctly concluded that the code is degenerate (multiple triplets can correspond to a single amino acid) and that each nucleotide sequence is read from a specific starting point.
The above table reflects the hybrid nature of metalloids. The properties of form, appearance, and behaviour when mixed with metals are more like metals. Elasticity and general chemical behaviour are more like nonmetals. Electrical conductivity, band structure, ionization energy, electronegativity, and oxides are intermediate between the two.
=== Longevity === Giant tortoises are among the longest-lived vertebrate animals (over 100 years by some estimates) and have been used as a model for studying longevity. DNA analysis of the genomes of Lonesome George, the iconic last member of Chelonoidis abingdonii, and the Aldabra giant tortoise Aldabrachelys gigantea led to the detection of lineage-specific variants affecting DNA repair genes that might contribute to our understanding of increased lifespan.
Sources: en.wikipedia.org
=== Bactericides === A main way to combat the growth of bacterial cells on a surface is to prevent the initial adhesion of the cells to that surface. Some coatings which accomplish this include chlorhexidine incorporated hydroxyapatite coatings, chlorhexidine-containing polylactide coatings on an anodized surface, and polymer and calcium phosphate coatings with chlorhexidine. Antibiotic coatings provide another way of preventing the growth of bacteria. Gentamicin is an antibiotic that has a relatively broad antibacterial spectrum. Also, gentamicin is one of the rare kinds of thermo-stable antibiotics, so it is one of the most widely used antibiotics for coating titanium implants. Other antibiotics with broad antibacterial spectra are cephalothin, carbenicillin, amoxicillin, cefamandole, tobramycin, and vancomycin. Copper and copper alloy surfaces are effective means for preventing the growth of bacteria. Extensive U.S. EPA-supervised antimicrobial efficacy tests on Staphylococcus aureus, Enterobacter aerogenes, Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli 0157:H7, and Pseudomonas aeruginosa have determined that when cleaned regularly, some 355 different EPA-registered antimicrobial copper alloy surfaces:
Non-road engines (or non-road mobile machinery in the European Union) are internal combustion engines that are used for other purposes than a motor vehicle that is used on a public roadway. The term is commonly used by regulators to classify the engines in order to control their emissions. Non-road engines are used in a wide range of applications which may include machinery and non-road vehicles. In many jurisdictions, the term non-road engine is assumed to refer to the engines that have mobility or portability, which is separated from the term stationary engine. The definition of non-road engine may explicitly exclude certain non-road vehicles such as aircraft, locomotives, and ocean-going marine vessels.
is the standard entropy change. Since the enthalpy should be approximately the same for the two reactions, the difference between the two stability constants is due to the effects of entropy. In equation (1) there are two particles on the left and one on the right, whereas in equation (2) there are three particles on the left and one on the right. This difference means that less entropy of disorder is lost when the chelate complex is formed with bidentate ligand than when the complex with monodentate ligands is formed. This is one of the factors contributing to the entropy difference. Other factors include solvation changes and ring formation. Some experimental data to illustrate the effect are shown in the following table.
Sources: en.wikipedia.org
== Anything Drug Conjugates == As the antibody–drug conjugate field has matured, a more accurate definition of ADC is now Anything-Drug Conjugate. Alternatives for the antibody targeting component now include multiple smaller antibody fragments like diabodies, Fab, scFv, and bicyclic peptides.
Several fluorescent bases have also been made, such as the 2-amino-6-(2-thienyl)purine and pyrrole-2-carbaldehyde base pair. Metal-coordinated bases, such as pairing between a pyridine-2,6-dicarboxylate (tridentate ligand) and a pyridine (monodentate ligand) through square planar coordination to a central copper ion. Universal bases may pair indiscriminately with any other base, but, in general, lower the melting temperature of the sequence considerably; examples include 2'-deoxyinosine (hypoxanthine deoxynucleotide) derivatives, nitroazole analogues, and hydrophobic aromatic non-hydrogen-bonding bases (strong stacking effects). These are used as proof of concept and, in general, are not utilized in degenerate primers (which are a mixture of primers). The numbers of possible base pairs is doubled when xDNA is considered. xDNA contains expanded bases, in which a benzene ring has been added, which may pair with canonical bases, resulting in four additional possible base-pairs (xA-T, xT-A, xC-G, xG-C) with eight bases (or 16 bases if the unused arrangements are used). Another form of benzene added bases is yDNA, in which the base is widened by the benzene.
While the pharmacokinetic profile of pregabalin results in few direct drug-drug interactions, the pharmacodynamic risk of additive CNS and respiratory depression with other depressant substances represents the primary clinical concern in its use alongside other medications.
Sources: en.wikipedia.org
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.
The powder is generally kept refrigerated or frozen, protected from light and moisture. Vials should reach room temperature before opening to prevent condensation. Reconstituted solutions are usually stored cold and used within a limited window because dilute solutions can degrade or support microbial growth.
Epitalon is not an approved drug in major Western regulatory jurisdictions. Its legal status differs between countries, and it is often distributed as a research chemical. This means product documentation and purity vary considerably between suppliers.
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.