A practical reference on Pineal gland: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-04-11. Anything still debated is marked as such rather than presented as settled.
Reversed-phase high-performance liquid chromatography is the standard approach for assessing purity, usually with ultraviolet detection near 214 nm, where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the molecular mass and helps reveal truncation or deletion byproducts. Amino acid analysis can verify composition, and counterion content is sometimes measured because peptides purified with trifluoroacetic acid retain variable amounts of that salt. Purity figures reported without a stated method and detection wavelength are difficult to interpret.
Material sold for research use varies widely in documented quality. A useful verification package includes a certificate of analysis that states peptide content rather than only net weight, the chromatographic method and column used, and a mass spectrum consistent with the expected mass. Independent testing by a third-party laboratory is occasionally reported. Statements of identity resting only on a supplier label provide little assurance, and the gap between nominal mass and actual peptide content can be substantial once counterions and residual water are counted.
Peptides of this size are generally stable as dry solids but degrade in solution over time. The principal routes are hydrolysis of the peptide backbone and oxidation, with hydrolysis favoured by elevated temperature and extreme pH. Aqueous solutions held at room temperature can show measurable loss of purity within days, while frozen aliquots are considerably more durable. Because the sequence contains neither cysteine nor methionine, oxidation is less of a concern than for many other peptides, but pH control during handling still matters.
Proposed mechanisms centre on cell-culture observations rather than a defined receptor interaction. Several reports describe increased expression of the telomerase catalytic subunit after exposure of cultured human cells, and the authors attributed the effect to short peptide fragments entering the nucleus and influencing gene transcription. No receptor for the tetrapeptide has been identified, and the free peptide is expected to be degraded rapidly by plasma peptidases. Whether any measurable fraction reaches intact tissues after administration remains an unresolved question rather than an established finding.
The published literature is dominated by a small number of research groups, much of it in Russian-language journals, and independent replication outside those groups is limited. Studies are typically small, use cultured cells or rodent models, and report endpoints that differ between papers, which makes comparison difficult. Large randomised human trials have not appeared in the indexed literature. Questions about absorption, distribution and clearance are therefore still treated as open in reviews that mention the compound.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also dissolves in polar organic solvents |
| Typical storage temperature | −20 °C or below | Sealed, desiccated, protected from light |
| Primary purity assay | Reversed-phase HPLC | Ultraviolet detection near 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray ionization commonly used |
Epitalon emerged from research conducted in Saint Petersburg by Vladimir Khavinson and colleagues, who studied short peptides as potential regulators of aging. The work built on epithalamin, a pineal gland extract reported to influence neuroendocrine function. Epitalon was designed as a synthetic counterpart with a defined sequence, allowing reproducible experiments that extracts could not support. Early publications described effects on melatonin rhythms and lifespan in animal models. These findings circulated mainly in Russian-language journals during the 1990s, which limited their visibility among English-speaking researchers.
The most widely cited claim is that epitalon activates telomerase and thereby extends telomere length. Supporting evidence comes largely from cultured human cells, where treatment was associated with increased telomerase activity and delayed replicative senescence. Telomerase activation is a biologically consequential effect, since the enzyme is largely silenced in most somatic cells. However, the route by which a short peptide would reach and act on the enzyme's regulatory machinery has not been established. Independent replication in human trials is scarce, so the link between cell-culture observations and whole-body aging remains an open question.
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.
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Coral Reefs The Ocean Portal by the Smithsonian Institution NOAA – Coral Reef Conservation Program NOAA CoRIS – Coral Reef Biology NOAA Office for Coastal Management – Fast Facts – Coral Reefs NOAA Ocean Service Education – Corals "What is a coral?". Stanford microdocs project. Archived from the original on 2014-01-06. Retrieved 2017-02-04.
=== Chemical === Two materials may form a compound at the joint. The strongest joints are where atoms of the two materials share or swap electrons (known respectively as covalent bonding or ionic bonding). A weaker bond is formed if a hydrogen atom in one molecule is attracted to an atom of nitrogen, oxygen, or fluorine in another molecule, a phenomenon called hydrogen bonding. Chemical adhesion occurs when the surface atoms of two separate surfaces form ionic, covalent, or hydrogen bonds. The engineering principle behind chemical adhesion in this sense is fairly straightforward: if surface molecules can bond, then the surfaces will be bonded together by a network of these bonds. It bears mentioning that these attractive ionic and covalent forces are effective over only very small distances – less than a nanometer. This means in general not only that surfaces with the potential for chemical bonding need to be brought very close together, but also that these bonds are fairly brittle, since the surfaces then need to be kept close together.
== Personal life == Carlisle grew up in Craigieburn, a northern suburb of Melbourne. He is the second youngest of five children and has four sisters. He attended Willmott Park Primary School in Craigieburn before going to Niddrie Secondary College. Carlisle has several tattoos. He has an ambigram tattoo of "mother" and "Darlene" on his arm, "Carlisle" on the right side of his back and his sisters' names on his ribs.
Sources: en.wikipedia.org
The two substrates of this enzyme are (S,S)-butane-2,3-diol and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are (S)-acetoin, reduced NADH, and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (S,S)-butane-2,3-diol:NAD+ oxidoreductase. Other names in common use include L-butanediol dehydrogenase, L-BDH, and L(+)-2,3-butanediol dehydrogenase (L-acetoin forming). This enzyme participates in butanoic acid metabolism.
This problem can be avoided by fusing an affinity tag to self-cleavable inteins in a controlled environment. The first generation of expression vectors of this kind used modified Saccharomyces cerevisiae VMA (Sce VMA) intein. Chong et al. used a chitin binding domain (CBD) from Bacillus circulans as an affinity tag, and fused this tag with a modified Sce VMA intein. The modified intein undergoes a self-cleavage reaction at its N-terminal peptide linkage with 1,4-dithiothreitol (DTT), β-mercaptoethanol (β-ME), or cystine at low temperatures over a broad pH range. After expressing the recombinant protein, the cell homogenate is passed through the column containing chitin. This allows the CBD of the chimeric protein to bind to the column. Furthermore, when the temperature is lowered and the molecules described above pass through the column, the chimeric protein undergoes self-splicing and only the target protein is eluted. This novel technique eliminates the need for a proteolysis step, and modified Sce VMA stays in column attached to chitin through CBD. Recently inteins have been used to purify proteins based on self aggregating peptides. Elastin-like polypeptides (ELPs) are a useful tool in biotechnology. Fused with target protein, they tend to form aggregates inside the cells. This eliminates the chromatographic step needed in protein purification.
The instrumentation needed to perform capillary electrophoresis is relatively simple. A basic schematic of a capillary electrophoresis system is shown in figure 1. The system's main components are a sample vial, source and destination vials, a capillary, electrodes, a high-voltage power supply, a detector, and a data output and handling device. The source vial, destination vial and capillary are filled with an electrolyte such as an aqueous buffer solution. To introduce the sample, the capillary inlet is placed into a vial containing the sample. Sample is introduced into the capillary via capillary action, pressure, siphoning, or electrokinetically, and the capillary is then returned to the source vial. The migration of the analytes is initiated by an electric field that is applied between the source and destination vials and is supplied to the electrodes by the high-voltage power supply. In the most common mode of CE, all ions, positive or negative, are pulled through the capillary in the same direction by electroosmotic flow. The analytes separate as they migrate due to their electrophoretic mobility, and are detected near the outlet end of the capillary. The output of the detector is sent to a data output and handling device such as an integrator or computer. The data is then displayed as an electropherogram, which reports detector response as a function of time. Separated chemical compounds appear as peaks with different migration times in an electropherogram. The technique is often attributed to James W.
Sources: en.wikipedia.org
The same survey stated that about 30% of adults reported they consumed a vitamin C dietary supplement or a multi-vitamin/mineral supplement that included vitamin C, and that for these people total consumption was between 300 and 400 mg/d.
Topical beta-adrenergic receptor antagonists, such as timolol, levobunolol, and betaxolol, decrease aqueous humor production by the epithelium of the ciliary body. Alpha2-adrenergic agonists, such as brimonidine and apraclonidine, work by a dual mechanism, decreasing aqueous humor production and increasing uveoscleral outflow. Less-selective alpha agonists, such as epinephrine, decrease aqueous humor production through vasoconstriction of ciliary body blood vessels, useful only in open-angle glaucoma. Epinephrine's mydriatic effect, however, renders it unsuitable for closed-angle glaucoma due to further narrowing of the uveoscleral outflow (i.e., further closure of the trabecular meshwork, which is responsible for the absorption of aqueous humor). Miotic agents (parasympathomimetics), such as pilocarpine, work by contraction of the ciliary muscle, opening the trabecular meshwork and allowing increased outflow of the aqueous humor. Echothiophate, an acetylcholinesterase inhibitor, is used in chronic glaucoma. Carbonic anhydrase inhibitors, such as dorzolamide, brinzolamide, and acetazolamide, lower secretion of aqueous humor by inhibiting carbonic anhydrase in the ciliary body. Each of these medicines may have local and systemic side effects. Wiping the eye with an absorbent pad after the administration of eye drops may result in fewer adverse effects. Initially, glaucoma drops may reasonably be started in either one or in both eyes.
A 2020 review in The Journal of Bone and Joint Surgery (JB&JS) found it remains broadly popular: ≈2⁄3 of people with OI types III and IV (severe OI) have undergone some form of rodding surgery in their lives, at a mean age of 4+1⁄10 and 7+1⁄2 years respectively; one possible explanation for a tendency towards earlier intervention in type III is that one half of affected children could not walk at all without the surgery, as their limbs were more bowed, so surgery was sought sooner. In those with type III OI who had undergone rodding surgery, 79.5% had the femurs and tibias of both legs rodded. The most common form of rods used are intramedullary (IM) rods, some of which, such as the Fassier–Duval IM rod, are telescoping, meaning that they are designed to grow as the child grows, in an attempt to avoid the necessity of revision surgeries. Telescoping IM rods are widely used, and the common Fassier–Duval IM rod is designed to be used to rod the femur, tibia, and humerus. The surgery involves breaking the long bones in between one and three (or more) places, then fixing the rod alongside the bone to keep it straight. While telescoping IM rods are intended to grow along with both the femur and tibia in developing children; surgeons have a preference to use non-telescoping IM rods, such as Rush rods, in the tibia, which grows less comparatively—the JB&JS review found that while 69.7% of femurs were treated with telescoping IM rods, only 36.9% of tibiae were.
Sources: en.wikipedia.org
The powder is normally kept at −20 °C or below in a sealed, moisture-protected container. Letting the vial reach room temperature before opening helps prevent condensation on the contents.
Reversed-phase HPLC with ultraviolet detection is the usual approach, often paired with mass spectrometry. Together the two methods address both chromatographic purity and molecular identity.
Differences arise from the analytical method, the detection wavelength, and whether the number refers to the peptide or to total powder mass. Counterion and water content can lower the actual peptide fraction considerably.
No. Epithalamin is a heterogeneous peptide fraction obtained from pineal gland extract and contains many components. Epitalon is a single synthetic tetrapeptide with the sequence Ala-Glu-Asp-Gly. Researchers synthesised the shorter peptide while attempting to identify active sequences within the extract.