The short version of Khavinson fits in a sentence. The long version — which is the one that helps — is below.
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Identity and purity of epitalon samples are normally established by reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, combined with mass spectrometry. The mass spectrum confirms the expected molecular ion and can reveal truncated or oxidised by-products. Amino acid analysis after acid hydrolysis verifies that the four residues are present in the expected ratio. Certificates typically report a purity figure taken from chromatographic peak area, expressed as a percentage of total integrated signal.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
The parent extract epithalamin was characterised as a low-molecular-weight fraction of pineal tissue rather than a single defined chemical entity. Researchers fractionated it and tested successive fragments for activity, a screening approach typical of peptide discovery work in that era. Epitalon emerged from that process as one of the shorter sequences of interest. Because the original extract was never fully resolved into individual components, claims about which constituent drives a given effect rest on inference. This distinction matters when reading older reports that attribute extract observations to the tetrapeptide itself.
Epitalon is a synthetic tetrapeptide with the residue sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its monoisotopic mass is approximately 390.35 daltons, and it is usually supplied as a lyophilised trifluoroacetate or acetate salt. The compound was derived from a pineal gland extract called epithalamin, a heterogeneous preparation investigated in the former Soviet Union. Researchers associated with the Saint Petersburg Institute of Bioregulation and Gerontology described the tetrapeptide as a constituent fragment of that extract. Commercial material is offered as a laboratory reagent rather than as a finished pharmaceutical product.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by HPLC area | Higher grades are also offered |
| Primary analytical method | Reversed-phase HPLC, UV detection | Frequently paired with mass spectrometry |
| Confirmatory technique | Electrospray mass spectrometry | Observed mass compared with theory |
| Storage temperature | Minus 20 degrees Celsius, dry powder | Sealed, desiccated, protected from light |
| Solution handling | Prepare fresh before use | Hydrolysis proceeds in aqueous media |
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.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
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.
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.
Proteomics is the large-scale study of proteins. The proteome is the entire set of proteins produced or modified by an organism or system. Proteomics is an interdisciplinary field that covers the exploration of proteomes from the overall level of protein composition, structure, and activity. While the scale and complexity of the proteome is formidable, recent technological progress has substantially expanded the sensitivity and scope of proteome analysis. Proteomics generally denotes the large-scale experimental analysis of proteins and proteomes, but often refers specifically to protein purification and mass spectrometry. Indeed, mass spectrometry is the most powerful method for analysis of proteomes, both in large samples composed of millions of cells, and in single cells. Proteins are vital macromolecules of all living organisms, with many functions such as the formation of structural fibers of muscle tissue, enzymatic digestion of food, or synthesis and replication of DNA. In addition, other kinds of proteins include antibodies that protect an organism from infection, and hormones that send important signals throughout the body. Proteomics enables the identification of ever-increasing numbers of proteins. This varies with time and distinct requirements, or stresses, that a cell or organism undergoes.
=== Neurotransmitter === Aspartate (the conjugate base of aspartic acid) stimulates NMDA receptors, though not as strongly as the amino acid neurotransmitter L-glutamate does. Aspartate is the "A" in NMDA (N-methyl-D-aspartate receptor).
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ribonucleic acid (RNA) A polymeric nucleic acid molecule composed of a series of ribonucleotides which incorporate a set of four nucleobases: adenine (A), guanine (G), cytosine (C), and uracil (U). Unlike DNA, RNA is more often found as a single strand folded onto itself, rather than a paired double strand. Various types of RNA molecules serve in a wide variety of essential biological roles, including coding, decoding, regulating, and expressing genes, as well as functioning as signaling molecules and, in certain viral genomes, as the primary genetic material itself.
Sources: en.wikipedia.org
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For psoriasis, UVB phototherapy has been shown to be effective. A feature of psoriasis is localized inflammation mediated by the immune system. Ultraviolet radiation is known to suppress the immune system and reduce inflammatory responses. Light therapy for skin conditions like psoriasis usually use 313 nanometer UVB though it may use UVA (315–400 nm wavelength) or a broader spectrum UVB (280–315 nm wavelength). UVA combined with psoralen, a drug taken orally, is known as PUVA treatment. In UVB phototherapy the exposure time is very short, seconds to minutes depending on intensity of lamps and the person's skin pigment and sensitivity.
Rudyard Griffiths, director of The Dominion Institute, wrote in the Toronto Star in July 2006 that the ascension of the chain to the status of a cultural icon was a "worrying sign" for Canadian nationalism, adding, "Surely Canada can come up with a better moniker than the Timbit Nation." The recognition of Tim Hortons as a Canadian icon has permeated into American culture as the result of product placement efforts in conjunction with a marketing agency. In the American sitcom How I Met Your Mother, while standing in a Tim Hortons "just around the corner from the Hockey Hall of Fame", Robin, played by Canadian actress Cobie Smulders, called the location the "most Canadian place in the universe". The chain has embraced this comment as an unofficial slogan and has used it in promotional advertisements to emphasize its fixture in modern Canadian culture. The chain has been featured in the TV series Homeland. Another TV show that has Tim Hortons products making an appearance is The Last Ship. Stan Mikita's Donuts from the film Wayne's World is supposed to be a parody of Tim Hortons.
Sources: en.wikipedia.org
The usual approach is reversed-phase HPLC with ultraviolet detection, reported as a percentage of total peak area. Mass spectrometry is used alongside chromatography to confirm identity rather than purity alone.
The dry powder is commonly kept at minus twenty degrees Celsius, desiccated and away from light. Solutions are generally prepared fresh because they break down faster than the solid form.
Tandem mass spectrometry or enzymatic peptide mapping can establish residue order. A single intact mass value indicates composition and molecular weight but not always the precise arrangement of residues.
It is based on epithalamin, a peptide-rich preparation obtained from pineal gland tissue and studied in the former Soviet Union. Researchers later identified the tetrapeptide AEDG as a constituent fragment of that material. Modern supplies are produced by chemical synthesis rather than tissue extraction.