The short version of Lyophilized powder fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-02-25. Anything still debated is marked as such rather than presented as settled.
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.
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.
Reference material is normally supplied as a lyophilised powder in a sealed vial. Product literature typically recommends storage at minus twenty degrees Celsius or colder, protected from light and moisture. Freeze-thaw cycling is usually avoided because repeated condensation can introduce water into the vial. Working solutions are commonly prepared fresh, aliquoted, and kept cold for short periods rather than stored at ambient temperature. Labelling the date of opening helps track how long a vial has been in use.
Solubility is high in water, phosphate-buffered saline and normal saline, a pattern that follows from the two acidic residues in the chain. The peptide dissolves poorly in non-polar solvents such as hexane or chloroform. Stock solutions are often prepared in water first and then diluted into the buffer of interest. Because the molecule is small and hydrophilic, filtration through a low-protein-binding membrane is usually straightforward, and visible particulates are uncommon in freshly made solutions.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Free acid form of the tetrapeptide |
| Molecular mass | About 390.35 Da | Calculated monoisotopic value |
| Appearance | White to off-white powder | Typical lyophilized presentation |
| Solubility | Soluble in water | Also dissolves in buffered saline |
| Storage temperature | Minus 20 degrees Celsius | Dry, dark conditions; avoid repeated thawing |
The four residues give epitalon a molecular formula of C14H22N4O9 and a molecular weight near 390.35 daltons. The presence of two acidic residues, glutamate and aspartate, makes the free peptide strongly acidic, while the alanine and glycine ends provide neutral, nonpolar character. This combination produces a molecule with substantial water solubility. Because there are no cysteine, methionine, or tryptophan residues, the peptide lacks the most common oxidation-sensitive side chains, which simplifies handling compared with many longer peptides.
The proposed relationship between epitalon and pineal function is a central part of its background. Khavinson's group reported that short peptides corresponding to regions of larger pineal proteins could influence gene expression in cells. Epitalon was framed as a synthetic analogue of an active fragment rather than a direct isolation product. Whether the tetrapeptide reproduces the effects of the parent extract is an open question, because comparative studies are limited and the parent extract itself is not a single defined substance.
The molecule is a short, linear, hydrophilic peptide that dissolves readily in water or aqueous buffer. Its principal chemical liabilities are hydrolytic rather than oxidative, since it contains no cysteine, methionine, or tryptophan residues. The aspartate–glycine step is a recognised site for aspartimide formation under mildly acidic or basic conditions, generating isoaspartate and succinimide-related products over time. Desiccated lyophilised powder held at −20 °C is comparatively stable, whereas dilute solutions degrade faster and are best frozen as single-use aliquots rather than thawed repeatedly.
No pharmacopoeial monograph exists for this peptide, so quality rests on the supplier's internal specifications and on whatever independent testing a purchaser arranges. Certificates of analysis differ widely in which tests they report and in the limits applied. The counter-ion introduced during purification, commonly acetate or trifluoroacetate, changes the net peptide content of a given mass of powder, so two samples of equal weight may not contain equal amounts of the active sequence. Third-party laboratories can verify purity, identity, residual solvents, and counter-ion content for a fee, which makes documentation more informative than labelling.
Published studies on epitalon are dominated by a small number of research groups, and independent replication in other laboratories remains limited. Proposed mechanisms include activation of telomerase and modulation of melatonin rhythms, but the evidence for either rests mainly on cell cultures and animal models. Whether the peptide produces comparable effects in humans is an open question, and the absence of large controlled trials means the literature is best read as exploratory rather than settled.
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. Its molecular formula is C14H22N4O9, and its calculated molar mass is approximately 390.35 grams per mole. The compound is a short fragment related to a peptide fraction isolated from bovine pineal gland extracts, and it is normally supplied as a lyophilised powder intended for laboratory research. It is not a registered pharmaceutical product in most countries.
The peptide emerged from research carried out in Saint Petersburg from the late 1980s onward, where investigators searched for shorter active fragments of a pineal preparation known as epithalamin. The name epitalon was chosen to reflect that parent extract. Early reports described effects on neuroendocrine markers and on the lifespan of laboratory animals. Much of that work appeared in Russian-language journals, with English translations following later, which affects how readily the original protocols can be assessed by outside groups.
GSK completed the acquisition of New Jersey–based Block Drug in 2001, for US$1.24 billion. In 2006, GSK acquired the US-based consumer healthcare company CNS Inc., whose products included Breathe Right nasal strips and FiberChoice dietary supplements, for US$566 million in cash. Chris Gent, previously CEO of Vodafone, was appointed chairman of the board in 2005. GSK opened its first R&D centre in China in 2007, in Shanghai, initially focused on neurodegenerative diseases. Andrew Witty became the chief executive officer in 2008. Witty joined Glaxo in 1985, and had been president of GSK's Pharmaceuticals Europe since 2003. In 2009, GSK acquired Stiefel Laboratories, then the world's largest independent dermatology drug company, for US$3.6 billion. In November 2009, the FDA approved GSK's vaccine for 2009 H1N1 influenza protection, manufactured by the company's ID Biomedical Corp in Canada. Also in November 2009, GSK formed a joint venture with Pfizer to create ViiV Healthcare, which specializes in HIV research. In 2010, the company acquired Laboratorios Phoenix, an Argentine pharmaceutical company, for US$253m, and the UK-based sports nutrition company Maxinutrition for £162 million (US$256 million).
== Further reading == Arthur, Joyce (1996). "Creationism: Bad Science or Immoral Pseudoscience?". Skeptic. 4 (4): 88–93. Archived from the original on March 7, 2012. Montagu, M. F. Ashley, ed. (1984-01-12). Science and Creationism (Kindle ed.). USA: Oxford University Press. ASIN B000QXDJIG. Nelkin, Dorothy (2000) [1986]. The Creation Controversy: Science or Scripture in the Schools. toExcel. ISBN 0-595-00194-7. Numbers, Ronald L. (2006). The Creationists: From Scientific Creationism to Intelligent Design (expanded ed.). Harvard. ISBN 978-0-674-02339-0.
Other protein assay like BCA and Lowry are ineffective because molecules like reducing agents interfere with the assay. Using Bradford can be advantageous against these molecules because they are compatible to each other and will not interfere. The linear graph acquired from the assay (absorbance versus protein concentration in μg/mL) can be easily extrapolated to determine the concentration of proteins by using the slope of the line. It is a sensitive technique. It is also very simple: measuring the OD at 595 nm after 5 minutes of incubation. This method can also make use of a Vis spectrophotometer or a mobile smartphone camera (RGBradford method).
Sources: en.wikipedia.org
=== TikTok Notes === In April 2024, TikTok users started receiving notifications that their current and future picture posts would be shown on a new app called TikTok Notes. The app was not released yet; however, TikTok confirmed it was being worked on. TikTok Notes was a direct competitor to Instagram for photo sharing. Jasmine Enberg, a principal social media analyst at eMarketer, observes that launching Notes as a separate app, instead of as a new feature in TikTok, may have been done in response to regulatory and consumer scrutiny. On 18 April 2024, Notes first released to users in Canada and Australia for limited testing. On 1 April 2025, it was announced that Notes would be shut down on 8 May. It went defunct on 8 May 2025.
=== Birth control === A progesterone vaginal ring is available for birth control when breastfeeding in a number of areas of the world. An intrauterine device containing progesterone has also been marketed under the brand name Progestasert for birth control, including previously in the United States.
English-language newspapers include The Moscow Times. Until its closure in 2014, The Moscow News was the oldest English-language weekly newspaper in Russia. Kommersant, Vedomosti, and Novaya Gazeta are Russian-language newspapers headquartered in Moscow. Kommersant and Vedomosti are among the country's oldest Russian-language business newspapers.
Sources: en.wikipedia.org
== Research == Experiments using cultured cells have demonstrated that humanin has both neuroprotective as well as cytoprotective effects and experiments in rodents have found that it has protective effects in Alzheimer's disease models, Huntington's disease models and stroke models. Humanin is proposed to have myriad neuroprotective and cytoprotective effects. Studies in both cells and rodents have found that administration of humanin or humanin derivatives increases survival and/or physiological parameters in Alzheimer's disease models. In addition to Alzheimer's disease, humanin has other neuroprotective effects against models of Huntington's disease, prion disease, and stroke. Beyond the possible neuroprotective effects, humanin protects against oxidative stress, atherosclerotic plaque formation, and heart attack. Humanin activates chaperone-mediated autophagy in a dose-dependent manner. Humanin decreases production of inflammatory cytokines, which is part of its anti-apoptotic effect. Metabolic effects have also been demonstrated and humanin helps improve survival of pancreatic beta-cells, which may help with type 1 diabetes, and increases insulin sensitivity, which may help with type 2 diabetes. In rats, the humanin analog appears to normalize glucose levels and reduce diabetes symptoms. Rattin shows the same ability as humanin to defend neurons from the toxicity of beta-amyloid, associated with the degeneration in Alzheimer's disease.
=== Phase 2 === Acetylcysteine lysinate (L-lysine-N-acetyl-L-cysteinate; N-acetylcysteine lysinate; Nacystelyn) – antioxidant Aminolevulinic acid (ALA; BF-200 ALA) – photosensitizer Cannabidiol topical (CBD; BTX-1204; BTX-1308; BTX-1503; BTX-1702; BTX-1801; PBX-1308) – cannabinoid Dimethylcurcumin (ASCJ-9; AJ-101; ASC-J9) – androgen receptor degradation enhancer Imsidolimab (ANB-019) – monoclonal antibody against the interleukin-36 receptor Ivermectin topical (CD-5024; Soolantra) – non-mammalian chloride channel opener LYS-006 – leukotriene A4 hydrolase (LTA4H) inhibitor Methyl aminolevulinate (MAL; CD06809-41; Luxerm; MAL-PDT; Metvix; Metvixia; P-1202; Visonac) – photosensitizer NAI Acne (BI-Acne; BI-K-0376; CB-06-01; CB-06-04; NAI-003; NAI-Acne; VIC-acne) – peptide elongation factor Tu inhibitor Omiganan (CLS-001; CPI-226; MBI-226; MBI-594AN; MX-226; MX-594AN; Omigard) – antiseptic/antibacterial Pyrilutamide (EX-A5504; HY-145451; KX–826) – antiandrogen (androgen receptor antagonist) Tretinoin topical – retinoid (retinoic acid receptor agonist) VB-1953 – antibiotic and toll-like receptor antagonist
Isocitrate dehydrogenase 1 (NADP+), soluble is an enzyme that in humans is encoded by the IDH1 gene on chromosome 2. Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which uses NAD+ as the electron acceptor and the other NADP+. Five isocitrate dehydrogenases have been reported: three NAD+-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP+-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. Each NADP+-dependent isozyme is a homodimer. The protein encoded by this gene is the NADP+-dependent isocitrate dehydrogenase found in the cytoplasm and peroxisomes. It contains the PTS-1 peroxisomal targeting signal sequence. The presence of this enzyme in peroxisomes suggests roles in the regeneration of NADPH for intraperoxisomal reductions, such as the conversion of 2,4-dienoyl-CoAs to 3-enoyl-CoAs, as well as in peroxisomal reactions that consume 2-oxoglutarate, namely the alpha-hydroxylation of phytanic acid. The cytoplasmic enzyme serves a significant role in cytoplasmic NADPH production. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Sep 2013]
== Enzymatic mechanism == The positive charges of RNase A lie mainly in a deep cleft between two lobes. The RNA substrate lies in this cleft and is cleaved by two catalytic histidine residues, His12 and His119, to form a 2',3'-cyclic phosphate intermediate that is stabilized by nearby Lys41.
Sources: en.wikipedia.org
Epitalon is a synthetic tetrapeptide built from four amino acids: alanine, glutamate, aspartate, and glycine. It is not extracted from a natural source but made in the laboratory by chemical synthesis. Its short length makes it relatively straightforward to produce at high purity.
No naturally occurring free form of the peptide has been described. The four-amino-acid sequence can appear as a fragment within larger proteins, but that is not the same as the intact compound being present as a circulating molecule. Materials used in research are synthetic.
Purity is usually checked by reverse-phase high-performance liquid chromatography, which separates the target peptide from related impurities. Mass spectrometry is commonly used alongside it to confirm molecular mass. Some suppliers also provide amino acid analysis for additional sequence confirmation.
Sealed lyophilised powder is normally kept at minus twenty degrees Celsius or below, away from light and moisture. Vials are allowed to reach room temperature before opening to limit condensation. Repeated warming and cooling of the same vial is discouraged.