Pineal peptide 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.
Last reviewed on 2026-05-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
Material supplied for laboratory use is normally a lyophilised white to off-white powder that dissolves readily in water and in isotonic saline. Lyophilised cakes are hygroscopic and should be equilibrated to room temperature before opening to limit condensation on the solid. Solutions are typically prepared at milligram-per-millilitre concentrations and divided into single-use aliquots, because repeated freeze–thaw cycles degrade short peptides. Aqueous solutions are far less stable than the dry powder, and identity is usually verified by mass spectrometry alongside purity estimation from reversed-phase high-performance liquid chromatography.
Epitalon is a synthetic linear tetrapeptide with the sequence alanine–glutamate–aspartate–glycine, abbreviated AEDG. Its molecular formula is C14H22N4O9 and the calculated mass is approximately 390.35 g/mol. The compound is made by solid-phase peptide synthesis rather than extracted from tissue, although early work described it as a short fragment of a peptide fraction obtained from bovine pineal extract. In the research literature the spelling epitalon and the variant epithalone both appear, while AEDG is the standard code used in peptide nomenclature.
Several names circulate for the same molecule, including epitalon, epithalone, epithalamin tetrapeptide, and the sequence code AEDG. A CAS registry number, 307297-39-8, is commonly cited for it, though catalogue entries should be checked against supplier documentation because mislabelled records occur. In its usual form the peptide carries free amino and carboxyl termini and is neither glycosylated nor lipidated. Researchers distinguish the defined tetrapeptide from epithalamin itself, a crude pineal preparation containing many peptides that is not chemically characterised.
| 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 |
The peptide is a synthetic analogue of epithalamin, a preparation extracted from bovine pineal glands. Investigators sought a short, chemically defined molecule that would reproduce some of the endocrine and gerontological observations attributed to the glandular extract. Proposed mechanisms centre on induction of telomerase activity, an effect reported in cultured human somatic cells in the early 2000s, together with influences on melatonin secretion and neuroendocrine regulation. Those mechanisms remain incompletely characterised, and the reported telomerase response has not been consistently reproduced by independent groups working in comparable systems.
Published work on this compound consists mainly of in vitro experiments, animal studies, and small clinical investigations, a substantial share of which appeared in Russian-language journals. Sample sizes are generally small, control conditions differ between studies, and several endpoints rely on markers whose clinical meaning is itself debated. Reviews of the longevity field treat the peptide as an early example of telomerase-directed research rather than an established intervention. Regulatory treatment varies by country: some jurisdictions place it under prescription controls, others treat it as a laboratory material, and importation may be restricted regardless of local status.
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.
Some drugs have the capacity to bind with certain types of proteins that are carried in blood plasma. This is important as only drugs that are present in the plasma in their free form can be transported to the tissues. Drugs that are bound to plasma proteins therefore act as a reservoir of the drug within the organism and this binding reduces the drug's final concentration in the tissues. The binding between a drug and plasma protein is rarely specific and is usually labile and reversible. The binding generally involves ionic bonds, hydrogen bonds, Van der Waals forces and, less often, covalent bonds. This means that the bond between a drug and a protein can be broken and the drug can be replaced by another substance (or another drug) and that, regardless of this, the protein binding is subject to saturation. An equilibrium also exists between the free drug in the blood plasma and that bound to proteins, meaning that the proportion of the drug bound to plasma proteins will be stable, independent of its total concentration in the plasma. In vitro studies carried out under optimum conditions have shown that the equilibrium between a drug's plasmatic concentration and its tissue concentration is only significantly altered at binding rates to plasma proteins of greater than 90%. Above these levels the drug is "sequestered", which decreases its presence in tissues by up to 50%.
Copernicium has no stable or naturally occurring isotopes. Several radioactive isotopes have been synthesized in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Eight different isotopes have been reported with mass numbers 277 and 280–286, and one unconfirmed metastable isomer in 285Cn has been reported. Most of these decay predominantly through alpha decay, but some undergo spontaneous fission, and copernicium-283 may have an electron capture branch. The isotope copernicium-283 was instrumental in the confirmation of the discoveries of the elements flerovium and livermorium.
Stenting, as well as the insertion of coils by means of angiography, may be performed if there is an aneurysm and/or extension of the dissection into the V4 section of the artery. Surgery carries a high risk of complications, and is typically only offered in case of inexorable deterioration or contraindications to any of the other treatments. Various arterial repair procedures have been described.
=== Withdrawal === On abrupt or overly rapid discontinuation of lorazepam, anxiety, and signs of physical withdrawal have been observed, similar to those seen on withdrawal from alcohol and barbiturates. Lorazepam, as with other benzodiazepine drugs, can cause physical dependence, addiction, and benzodiazepine withdrawal syndrome. The higher the dose and the longer the drug is taken, the greater the risk of experiencing unpleasant withdrawal symptoms. Withdrawal symptoms can also occur from standard dosages and after short-term use. Benzodiazepine treatment is recommended to be discontinued as soon as possible via a slow and gradual dose reduction regimen. Rebound effects often resemble the condition being treated, but typically at a more intense level and may be difficult to diagnose. Withdrawal symptoms can range from mild anxiety and insomnia to more severe symptoms such as seizures and psychosis. The risk and severity of withdrawal are increased with long-term use, use of high doses, abrupt or over-rapid reduction, among other factors. Short-acting benzodiazepines, such as lorazepam, are more likely to cause a more severe withdrawal syndrome compared to longer-acting benzodiazepines. Withdrawal symptoms can occur after taking therapeutic doses of lorazepam for as little as one week.
An essential amino acid is an amino acid that is required by an organism but cannot be synthesized de novo by it, and therefore must be supplied in its diet. Out of the twenty standard protein-producing amino acids, nine cannot be endogenously synthesized by humans: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
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At community gatherings, target shooting was a major sport; they practised shooting at targets, such as hens' eggs perched on posts 100 metres (110 yd) away. They made expert mounted infantry, using cover, from which they could pour in a destructive fire using modern, smokeless, Mauser rifles. In preparation for hostilities, the Boers had acquired around 100 of the latest Krupp field guns, all horse-drawn and dispersed among the Kommando groups and several Le Creusot "Long Tom" siege guns. The Boers' skill in adapting themselves to become first-rate artillerymen shows that they were a versatile adversary. The Transvaal had an intelligence service that stretched across South Africa, and of whose extent and efficiency the British were as yet unaware.
Vaccines typically contain attenuated, inactivated or dead organisms or purified products derived from them. There are several types of vaccines in use. These represent different strategies used to try to reduce the risk of illness while retaining the ability to induce a beneficial immune response.
Melamine is used to manufacture melamine-formaldehyde resin, a type of plastic known for its flame-retardant properties and commonly employed in countertops, dry-erase boards, etc. It has also been employed as a non-protein nitrogen, appearing in soy meal, corn gluten meal and cottonseed meal used in cattle feed. Melamine is known to cause kidney failure and kidney stones in humans and animals when it reacts with cyanuric acid inside the body. The use of melamine in food production is not approved by the World Health Organization (WHO) or national authorities. Melamine is nitrogen-rich, so it is sometimes illegally added to food products to increase their apparent protein content. The Kjeldahl and Dumas methods used to test for protein levels fail to distinguish between nitrogen in melamine and naturally occurring nitrogen in amino acids, allowing the protein levels to be falsified. Introduced into milk, it can help conceal fraudulent dilution with water. Melamine adulteration of food products also made headlines when pet food was recalled in Europe and the U.S. in 2007.
Neurosteroids such as dehydroepiandrosterone (DHEA) and allopregnanolone, which modulate neurotransmitter receptors in the brain. Bile acids such as taurocholic acid, which aid in lipid digestion and absorption in the intestine. Aminosteroid neuromuscular blocking agents (synthetic), such as pancuronium bromide, used in anesthesia to induce muscle relaxation. Steroidal antiandrogens (synthetic), such as cyproterone acetate, which block androgen receptors in hormone therapy. Steroidogenesis inhibitors (exogenous), such as alfatradiol, which suppress steroid synthesis for therapeutic purposes. Membrane sterols such as cholesterol (essential for cell membrane fluidity), ergosterol (a fungal membrane component), and various phytosterols (plant-derived sterols with cholesterol-lowering effects). Toxins such as steroidal saponins (plant defense compounds) and cardenolides/cardiac glycosides (which affect heart function). Steroids with an open-ring structure, known as secosteroids, include:
Sources: en.wikipedia.org
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one type of infectious protein called prion. A medical microbiologist studies the characteristics of pathogens, their modes of transmission, mechanisms of infection and growth. The academic qualification as a clinical/Medical Microbiologist in a hospital or medical research centre generally requires a Bachelors degree while in some countries a Masters in Microbiology along with Ph.D. in any of the life-sciences (Biochem, Micro, Biotech, Genetics, etc.). Medical microbiologists often serve as consultants for physicians, providing identification of pathogens and suggesting treatment options. Using this information, a treatment can be devised. Other tasks may include the identification of potential health risks to the community or monitoring the evolution of potentially virulent or resistant strains of microbes, educating the community and assisting in the design of health practices. They may also assist in preventing or controlling epidemics and outbreaks of disease.
In the eocyte hypothesis linking the closest known archaeal relatives of eukaryotes (achaean eocytes), the organism at the root of the eocytes lineage may have been a ribocyte from the RNA-world. For cellular DNA and DNA processing systems, an "out of virus" scenario has been proposed. In this model, DNA as the main genetic information material may have first evolved in viruses and was later transferred to ribocytes twice: once transforming them into bacteria and once transforming them into archaea. Similarly in viral eukaryogenesis, a hypothesis theorizing that eukaryotes evolved from a DNA virus, ribocytes may have been an ancient host for a DNA virus. Because ribocytes used RNA to store their genetic information, viruses may initially have used DNA as a way to resist RNA-degrading enzymes present in the host ribocells. The introduction of a DNA-based system may have been as significant for protocells as later additions of chloroplasts or mitochondria through endosymbiosis in evolving eukaryotic cells. In this hypothesis, bacteria, archaea, and eukaryotes each obtained their DNA informational system from a different virus. In the reduction hypothesis, where giant viruses evolved from primordial cells that became parasitic, viruses might have evolved after FUCA but before LUCA.
University of Kentucky plastic surgeon Brian Rinker encountered many women in his practice who attributed their sagging breasts to breastfeeding, which was also the usual belief among medical practitioners. He decided to find out if this was true, and between 1998 and 2006 he and other researchers interviewed 132 women who were seeking breast augmentation or breast lifts. They studied the women's medical history, body mass index (BMI), their number of pregnancies, their breast cup size before pregnancy, and smoking status. The study results were presented at a conference of the American Society of Plastic Surgeons. According to Rinker's research, there are several key factors. A history of cigarette smoking "breaks down a protein in the skin called elastin, which gives youthful skin its elastic appearance and supports the breast." The number of pregnancies was strongly correlated with ptosis, with the effects increasing with each pregnancy. As most women age, breasts naturally yield to gravity and tend to sag and fold over the inframammary crease, the lower attachment point to the chest wall. This is more true for larger-breasted women. The fourth reason was significant weight gain or loss (greater than 50 pounds (23 kg)). Other significant factors were higher body mass index and larger bra cup size. In Rinker's study, 55% of respondents reported an adverse change in breast shape after pregnancy. Many women mistakenly attribute the changes and their sagging breasts to breastfeeding, and as a result some are reluctant to nurse their infants.
Properties also decrease with the age of the fiber. Younger fibers tend to be stronger and more elastic than older ones. Many natural fibers exhibit strain rate sensitivity due to their viscoelastic nature. Bone contains collagen and exhibits strain rate sensitivity in that the stiffness increases with strain rate, also known as strain hardening. Spider silk has hard and elastic regions that together contribute to its strain rate sensitivity, these cause the silk to exhibit strain hardening as well. Properties of natural fibers are also dependent on the moisture content in the fiber.
== Function == The basic function, as already mentioned (see: Translocase § Definition), is to "catalyse the movement of ions or molecules across membranes or their separation within membranes". This form of membrane transport is classified under active membrane transport, an energy-requiring process of pumping molecules and ions across membranes against a concentration gradient. Translocases biological importance relies primarily on their critical function, in the way that they provide movement across the cell's membrane in many cellular processes that are substantial, such as:
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.
It is a synthetic tetrapeptide. Its sequence was derived from research on peptide fractions of bovine pineal extract, and the intact AEDG sequence has not been demonstrated as an abundant free peptide in human tissue.