Everything below concerns reversed-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
In its supplied form epitalon is a white to off-white powder, usually lyophilized and often hygroscopic. It dissolves readily in water and in aqueous buffers, and it is commonly handled as the acetate or trifluoroacetate salt to improve stability during purification and drying. The amide backbone is labile in aqueous media, so solutions are less durable than the dry solid. Handling notes in the chemical literature therefore emphasize keeping the powder dry, cool and shielded from light until it is dissolved.
Epitalon is a synthetic tetrapeptide whose sequence is alanine-glutamate-aspartate-glycine, written in single-letter code as AEDG. The four residues are joined by three peptide bonds, giving a linear backbone with no branching and no disulfide bridges. Its calculated molecular mass for the free form is approximately 390.3 daltons, a figure that rises when the compound is supplied as an acetate or trifluoroacetate salt. Because the chain is short, the molecule is defined entirely by its residue order rather than by any folded three-dimensional structure.
The compound is described in the literature as a derivative of epithalamin, a preparation obtained from bovine pineal tissue. Work on this peptide family was carried out mainly by a research group in Saint Petersburg beginning in the 1980s, and the substance was later registered for clinical use in Russia under the name Epitalon. Outside that region it is generally treated as a research chemical rather than an approved medicine. Statements about its biological activity rest on a relatively small number of studies, and independent replication remains limited.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic tetrapeptide | Four residues, linear chain |
| Residue sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG |
| Calculated mass | 390.3 daltons | Value for the free, uncharged form |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility | Freely soluble in water | Often handled as a salt form |
Laboratory-grade epitalon is typically supplied as a lyophilized powder. Purity is commonly assessed with reverse-phase high-performance liquid chromatography, often paired with mass spectrometry to confirm molecular identity. Amino acid analysis and peptide mapping can provide additional confirmation of sequence. Certificates of analysis for research materials frequently report purity above 95 percent, although the methods behind such figures vary between suppliers. The absence of a pharmacopeial monograph means that no single standardized assay defines the compound, so reported results depend on the analytical protocol chosen.
Storage recommendations center on limiting moisture, heat, and light. The dry powder is generally kept at minus 20 degrees Celsius, and some suppliers recommend minus 80 degrees for long-term archival. Once dissolved, solutions are usually aliquoted and frozen to avoid repeated freeze-thaw cycles, which can promote aggregation or degradation. Aqueous stability depends on pH and concentration, and buffered saline is often preferred over plain water for biological work. Stability data specific to epitalon remain limited, so general peptide-handling practices are applied by analogy rather than from product-specific validation.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and its calculated monoisotopic mass is approximately 390.35 daltons. The compound does not occur naturally as a free peptide; it is produced by solid-phase peptide synthesis. Because it contains two acidic residues and no basic residues, the neutral form carries a net negative charge at physiological pH. This charge profile influences how the peptide behaves in solution and during chromatographic analysis.
Purity assessment of peptide reagents normally relies on reversed-phase high-performance liquid chromatography. A gradient of acetonitrile in water with trifluoroacetic acid, paired with a C18 stationary phase, separates the target tetrapeptide from truncated sequences and deletion analogues. Detection at 214 nanometres exploits absorbance of the peptide backbone, since the molecule contains no aromatic residue. Results are expressed as a percentage of total peak area. Values above ninety-five percent are typical for research-grade material, although reporting conventions vary between suppliers.
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Acroosteolysis is resorption of the distal bony phalanges. Acroosteolysis has two patterns of resorption in adults: diffuse and bandlike. The diffuse pattern of resorption has a widely diverse differential diagnosis which includes: pyknodysostosis, collagen vascular disease and vasculitis, Raynaud's neuropathy, trauma, epidermolysis bullosa, psoriasis, frostbite, sarcoidosis, hypertrophic osteoarthropathy, acromegaly, and advanced leprosy. The bandlike pattern of resorption may be seen with polyvinyl chloride exposure and Hadju-Cheney syndrome. A mnemonic commonly used for acro-osteolysis is PINCHFO. Pyknodysostosis, Psoriasis, Injury (thermal burn, frostbite), Neuropathy (diabetes), Collagen vascular disease (scleroderma, Raynaud's), Hyperparathyroidism, Familial (Hadju-Cheney, progeria), Occupational (polyvinyl exposure), Acroosteolysis may be associated with minimal skin changes or with ischemic skin lesions that may result in digital necrosis.
The activation of the endogenous opioids is for an analgesic effect using the gate control theory of pain. In addition, deep dry may also decrease pain, increase range of motion, and minimize myofascial trigger point irritability. In regards to the factor of pain reduction, relief occurs at four central levels: local pain, spinal pain through nerves, brain stem pain, and higher brain center pain. The relief of myofascial trigger points has been more highly researched than the relief of connective tissues, muscle fascia, muscle tension, and scar tissue; however, the American Physical Therapy Association claims that there potentially may be some benefits of dry needling on these ailments according to some available evidence. The APTA also claims that dry needling should not be used as a standalone procedure, but should be used in conjunction with other treatment methods, including manual soft tissue mobilization, neuromuscular re-education, functional retraining, and therapeutic exercises. Once the needle is inserted, one can manually or electrically stimulate the filiform needle depending for the desired effect of treatment.
== Selected publications == Dendrosome: Dendrosomes: a novel family of vehicles for transfection and therapy. Journal of Chemical Technology & Biotechnology. Volume 75 Issue 10, Pages 919 - 922 (2000) Dendrosomes as novel gene porters-III. Journal of Chemical Technology & Biotechnology Volume 83 Issue 6, Pages 912 - 920 (2008) Structural biology: Functional and structural characterization of a novel member of the natriuretic family of peptides from the venom of Pseudocerastes persicus. FEBS Letters Volume 557 Issue 1-3, Pages 104-108 (2004) Solution structure of long neurotoxin NTX-1 from the venom of Naja naja oxiana by 2D-NMR spectroscopy. European Journal of Biochemistry Volume 271 Issue 23-24 Pages 4950-4957 (2004) Biomaterials: Synthesis and thermal behavior of triblock copolymers from L-lactide and ethylene glycol with long center PEG block. Journal of Applied Polymer Science Volume 68 Issue 12 Pages 1949-1954 (1998) Synthesis and characterization of novel biodegradable triblock copolymers from L-lactide, glycolide, and PPG. Journal of Applied Polymer Science Volume 73 Issue 5 Pages 633-637 (1999) Synthesis and characterization of ABA triblock and novel multiblock copolymers from ethylene glycol, L-lactide, and epsilon-caprolactone. Journal of Applied Polymer Science Volume 83 Issue 10 Pages 2072-2081 (2002) Mass preparation and characterization of alginate microspheres. Process Biochemistry Volume 35 Issue 9 Pages 885-888 (2000) Membranes: A simple method for preparation of immuno-magnetic liposomes.
President Bill Clinton's administration Greg Burke (1982), former Fox News correspondent and director the Holy See Press Office Claire Shipman (1986), ABC News correspondent Elizabeth Cohen (1987), CNN's senior medical correspondent Alexandra Wallace (1988), executive producer of NBC Nightly News Soterios Johnson (1990), host of Morning Edition on National Public Radio Alexis Glick (1994), anchorwoman for the Fox Business Network Suzy Shuster (1994), Emmy Award-winning sportscaster with ABC Sports Max Kellerman (1998), boxing commentator and host of HBO World Championship Boxing Gideon Yago (2000), MTV News correspondent Jonathan Lemire (2001), journalist and host of MSNBC's Way Too Early Charlotte MacInnis (2002), China Central Television anchor known by the stage name Ai Hua; host of Growing up with Chinese Buzzy Cohen (2007), Jeopardy! guest host and contestant, co-host of The Chase Meghan McCain (2007), former co-host of The View, blogger and daughter of Arizona senator John McCain
The IUPAC Color Books are a collection of books produced by the International Union of Pure and Applied Chemistry (IUPAC), containing its complete list of definitions. Although the colors are not the formal names of these books, they are commonly referred to simply by color by chemists. The set consists of eight volumes: Green, Red, Blue, Purple, Orange, Silver, White, and Gold.
Sources: en.wikipedia.org
== Chemistry == Atenolol is a substituted phenethylamine derivative. It is specifically β-phenylethylamine with an α-keto substitution and a 4- substitution on the phenyl ring. The experimental log P of atenolol is 0.16 and its predicted log P ranges from −0.03 to 0.57. Atenolol showed the lowest predicted lipophilicity of 30 clinically relevant beta blockers.
This organism produces no gas or obvious taste and remains undetected by taste or smell. Its toxin is denatured by cooking, however. Cooked mushrooms, when handled poorly and then canned, can support the growth of Staphylococcus aureus, which produces a toxin that is not destroyed by canning or subsequent reheating.
=== Spray drying === Spray-dried instant coffee is cheaper to produce and is preferred to freeze-drying in some cases because it allows larger scale economic production, shorter drying times, and produces fine, round, dust-sized particles. The particles as produced are too fine to use directly; they must first be steam-fused either in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size. The process produces spherical particles about 300 micrometres (0.012 in) in size with a density of 0.22 g/cm3 through a nozzle atomizer. Various ways of nozzle atomization can be used, each having advantages and disadvantages. Wheels rotating at rapid speeds of about 20,000 rpm can process up to 6,000 pounds (2,700 kg) of solution per hour. The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls. This process can be completed in 5 to 30 seconds, depending on factors such as temperature, size of particle, and diameter of chamber, and can reduce moisture content by over 70%.
== In human culture == The third island on Kunming Lake at Beijing's Summer Palace is called Zaojian Tang Dao (藻鑒堂島). The name comes from the classical Chinese character 藻, meaning both "algae" and "literary talent." As a result the islands name can be translated to either "Island of the Algae-Viewing Hall" or "Island of the Hall for Reflecting on Literary Talent."
Sources: en.wikipedia.org
The peptide contains four residues in the order alanine, glutamate, aspartate and glycine, abbreviated AEDG. The chain is linear and held together by three peptide bonds. Its calculated mass for the uncharged free form is about 390.3 daltons.
Epithalamin refers to a crude preparation derived from bovine pineal tissue, which contains many components. Epitalon is a single synthetic tetrapeptide identified from that material and produced by chemical synthesis. The two names are sometimes confused because early reports treated the synthetic peptide as an active fragment of the extract.
It has been registered for clinical use in Russia, where it is associated with a small family of short peptides. In most other jurisdictions it is not an approved medicine and is traded as a research chemical. Regulatory status varies by country and changes over time.
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.