The short version of Epithalamin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-28. Anything still debated is marked as such rather than presented as settled.
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.
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.
| 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 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.
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.
（TG:@pojiaai）Epitalon is a synthetic linear tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, abbreviated AEDG. It emerged from work on epithalamin, a peptide fraction prepared from bovine pineal tissue, and was designed as a short, chemically defined analogue of that extract. Early publications came mainly from Russian laboratories studying pineal peptides and aging-related endpoints. The compound appears in the literature under several spellings, including epithalon and epithalone, which complicates systematic searching. Its small size makes solid-phase assembly and routine analytical characterization straightforward.
Chemically, the molecule consists of four amino acid residues joined by three peptide bonds, with a free N-terminal amino group and a free C-terminal carboxyl group. Its molecular formula is C14H22N4O9, and its monoisotopic mass is approximately 390 daltons. The acidic glutamate and aspartate side chains give the peptide a net negative charge near neutral pH, a property that shapes its chromatographic behaviour and solubility profile. No disulfide bridges or other post-translational modifications are present, so the primary sequence alone defines the structure.
Reported biological findings come mainly from cell culture and rodent experiments. Those studies describe changes in telomerase catalytic subunit expression, melatonin rhythm amplitude, and antioxidant enzyme activity after peptide exposure. Human data are sparse and consist of small trials with limited blinding and inconsistent endpoints. The proposed mechanisms remain hypotheses rather than established facts, and there is no consensus on whether effects observed in animals carry over to people. Independent replication outside the original research groups is limited, which is a recognised gap in the published literature.
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.
== Synthesis and Post-translational Modification == Proinsulin is synthesized on membrane associated ribosomes found on the rough endoplasmic reticulum, where it is folded and its disulfide bonds are oxidized. It is then transported to the Golgi apparatus where it is packaged into secretory vesicles, and where it is processed by a series of proteases to form mature insulin. Mature insulin has 35 fewer amino acids; 4 are removed altogether, and the remaining 31 form the C-peptide. The C-peptide is abstracted from the center of the proinsulin sequence; the two other ends (the B chain and A chain) remain connected by disulfide bonds. The post translational modification of proinsulin to mature insulin only occurs in the beta cells of the pancreatic islets. When proinsulin is transported through the Golgi apparatus the C-peptide is cleaved. This cleavage occurs with the aid of two endoproteases. Type I endoproteases, PC1 and PC3, disrupt the C peptide-B chain connection. PC2, a type II endoprotease, cleaves the C peptide-A chain bond. The resulting molecule, now mature insulin, is stored as a hexamer in secretory vesicles and is stabilized with
=== Blood oxygen content === The kidneys measure the oxygen content rather than the partial pressure of oxygen in the arterial blood. When the oxygen content of the blood is chronically low, oxygen-sensitive cells secrete erythropoietin (EPO) into the blood. The effector tissue is the red bone marrow which produces red blood cells (RBCs, also called erythrocytes). The increase in RBCs leads to an increased hematocrit in the blood, and a subsequent increase in hemoglobin that increases the oxygen carrying capacity. This is the mechanism whereby high altitude dwellers have higher hematocrits than sea-level residents, and also why persons with pulmonary insufficiency or right-to-left shunts in the heart (through which venous blood by-passes the lungs and goes directly into the systemic circulation) have similarly high hematocrits. Regardless of the partial pressure of oxygen in the blood, the amount of oxygen that can be carried, depends on the hemoglobin content. The partial pressure of oxygen may be sufficient for example in anemia, but the hemoglobin content will be insufficient and subsequently as will be the oxygen content. Given enough supply of iron, vitamin B12 and folic acid, EPO can stimulate RBC production, and hemoglobin and oxygen content restored to normal.
==== 2010s ==== In 2012, Starbucks had annual Frappuccino sales of over US$2 billion. In August 2012, the largest Starbucks in the US opened at the University of Alabama's Ferguson Centre. On June 25, 2013, Starbucks began to post calorie counts on menus for drinks and pastries in all of its U.S. stores. In July 2013, more than 10% of in-store purchases were made on customers' mobile devices via the Starbucks app. The company once again utilized the mobile platform when it launched the "Tweet-a-Coffee" promotion in October 2013. On this occasion, the promotion also involved Twitter and customers were able to purchase a US$5 gift card for a friend by entering both "@tweetacoffee" and the friend's handle in a tweet. Research firm Keyhole monitored the progress of the campaign; a December 2013 media article reported that 27,000 people had participated and US$180,000 of purchases had been made to date. In January 2014, as part of a change in compact direction, Starbucks management transitioned from a singular brand worldwide to focusing on locally relevant design for each store. In May 2014, Starbucks announced ongoing losses in the Australian market, which resulted in all remaining stores being sold to the Withers Group. In July 2017, Starbucks acquired the remaining 50% stake in its Chinese venture from long-term joint venture partners Uni-President Enterprises Corporation (UPEC) and President Chain Store Corporation (PCSC) for US$1.3 billion.
As of 2025, the reasons for the higher mortality in men are unknown. It has been speculated that men have different dementia risk factors than women, like traumatic brain injury. Aspiration pneumonia is the most frequent immediate cause of death brought by AD. While the reasons behind the lower prevalence of cancer in AD patients remain unclear, some researchers hypothesize that biological mechanisms shared by both diseases might play a role. However, this requires further investigation.
pseudomallei in 99% of cases, as does the automated Vitek 1 system, but the automated Vitek 2 system only identifies 19% of isolates. The pattern of resistance to antimicrobials is distinctive, and helps to differentiate the organism from P. aeruginosa. The majority of B. pseudomallei isolates are intrinsically resistant to all aminoglycosides (via an efflux pump mechanism), but sensitive to co-amoxiclav: this pattern of resistance almost never occurs in P. aeruginosa and is helpful in identification. Unfortunately, the majority of strains in Sarawak, Borneo, are susceptible to aminoglycosides and macrolides, which means the conventional recommendations for isolation and identification do not apply there. Molecular methods (PCR) of diagnosis are possible, but not routinely available for clinical diagnosis. Fluorescence in situ hybridisation has also been described, but has not been clinically validated, and it is not commercially available. In Thailand, a latex agglutination assay is widely used, while a rapid immunofluorescence technique is also available in a small number of centres.
Sources: en.wikipedia.org
The network concept was made up of acu-tracts, such as a line down the arms, where it said acupoints were located. Some of the sites acupuncturists use needles at today still have the same names as those given to them by the Yellow Emperor's Classic. Numerous additional documents were published over the centuries introducing new acupoints. By the 4th century AD, most of the acupuncture sites in use today had been named and identified.
== Research == Limited clinical studies have provided weak evidence for the use of frankincense resin in certain disease conditions, but the inconsistent, low quality of research remains inconclusive for determining any effect.
== Types and examples == The most important progestogen in the body is progesterone (P4). Other endogenous progestogens, with varying degrees of progestogenic activity, include 16α-hydroxyprogesterone (16α-OHP), 17α-hydroxyprogesterone (17α-OHP) (very weak), 20α-dihydroprogesterone (20α-DHP), 20β-dihydroprogesterone (20β-DHP), 5α-dihydroprogesterone (5α-DHP), 5β-dihydroprogesterone (5β-DHP) (very weak), 3β-dihydroprogesterone (3β-DHP), 11-deoxycorticosterone (DOC), and 5α-dihydrodeoxycorticosterone (5α-DHDOC). They are all metabolites of progesterone, lying downstream of progesterone in terms of biosynthesis.
== In medicine == In medicine, immunophilins act as receptors for immunosuppressive drugs such as sirolimus (rapamycin), cyclosporin (such as CsA) and tacrolimus (FK506), which inhibit the prolyl isomerase activity of the immunophilins. The drug-immunophilin complexes (CsA-CyP and FK506-FKBP) bind to calcineurin, which inhibits the phosphatase activity of calcineurin and engenders the immunosuppressive effects. CsA and FK506 thus affect the calcium-dependent step of T cell response which prevents release of interleukin-2. Immunophilins also form protein complex with ryanodine and inositol triphosphate (IP3) which impacts the release of calcium. FK506 binds with high affinity to other smaller proteins, such as FKBP-12. FKBP-12 and cyclophilins both share common peptide-prolyl isomerase activity. While the majority of the Peptide bonds within proteins exist in trans (planar) conformation because of the partial double-bond nature of the peptide bond, a small fraction occurs in cis. Unlike regular peptide bonds, the X-Pro peptide bond does not adopt the intended trans conformation spontaneously, thus, cis-trans isomerization can be the rate-limiting (slowest) step in the process of protein folding. Immunophilins, with their prolyl isomerase activity, thus function as protein-folding chaperones.
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 built from alanine, glutamate, aspartate and glycine. The four residues are joined by standard peptide bonds, giving a linear chain rather than a branched structure.