The short version of Backbone hydrolysis fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-25 and is reviewed periodically as new material appears.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography with ultraviolet detection, frequently near 214 nanometers where the peptide bond absorbs. Mass spectrometry, most often with electrospray ionization, confirms the observed molecular mass and helps separate the intact peptide from truncated or modified forms. Amino acid analysis or tandem mass spectrometry can establish residue order. Purity is commonly quoted as an area percentage, yet such values are method-dependent, and comparisons between laboratories require matching column, gradient and detection wavelength.
Laboratory handling begins with dissolution of the lyophilized powder in water or a suitable aqueous buffer. The dry solid is the more stable form, so stock solutions are generally prepared only when required and kept cold afterwards. Repeated freezing and thawing of a solution is avoided because it encourages aggregation and gradual loss of the intact chain. Diluents and containers are selected to limit adsorption of a short peptide onto plastic surfaces and to reduce microbial growth in aqueous preparations.
Stability depends strongly on pH, temperature and the presence of oxygen and trace metals. Cleavage of the backbone proceeds faster under neutral to alkaline conditions, whereas acidic solutions tend to slow that reaction. The aspartate and glutamate side chains can undergo deamidation or imide formation over time, generating closely related impurities. Published stability data specific to epitalon are sparse, so the usable life of a given solution is best regarded as an open question that depends on buffer composition, concentration and storage temperature.
| Property | Value | Notes |
|---|---|---|
| Peptide sequence | Ala-Glu-Asp-Gly | Often abbreviated AEDG in research literature |
| Common synonyms | Epithalon, epitalon, AEDG | Spelling variants refer to the same tetrapeptide |
| Molecular formula | C14H22N4O9 | Theoretical monoisotopic mass near 390.35 Da |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Freely soluble in water | Hydrophilic peptide; dissolves in aqueous buffer |
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.
Because epitalon has no pharmacopoeial monograph, quality assessment depends on supplier documentation and independent testing. Certificates of analysis typically report a purity figure from a single chromatographic run, a measured mass and sometimes an appearance description, but methods and acceptance criteria are not harmonised across vendors. Third-party laboratories can repeat identity and purity measurements, and mismatches between labelled and measured peptide content have been described for research peptides generally. What constitutes adequate identity confirmation for a molecule of this size stays an open question, since mass agreement alone does not separate closely related sequences.
Identity testing for epitalon relies on reversed-phase high-performance liquid chromatography for purity and mass spectrometry for mass confirmation. Because the sequence contains no tryptophan or tyrosine, ultraviolet detection at 280 nanometres is insensitive, so chromatographic methods usually monitor absorbance near 214 nanometres, where the peptide backbone absorbs. Electrospray ionisation or matrix-assisted laser desorption/ionisation then checks the intact mass against the expected value near 390 daltons. Peptide mapping or amino acid analysis after acid hydrolysis can supplement these measurements, although such confirmatory work is seldom reported on commercial certificates of analysis.
== Career == Chen began her career at the Institute of Chemistry of Academia Sinica as assistant research fellow in 1999. She was the Director of the Institute of Chemistry from 2013 to 2019, and is currently a Distinguished Research Fellow. She is also an adjunct professor at National Taiwan University, National Chiayi University, National Taiwan Ocean University, and National Chung Hsing University. She conducts research in mass spectrometry-based bioinformatics, in relation to understanding diseases such as cancer. Since 2016, Chen has participated in the US Cancer Moonshot Initiative, providing proteogenomics expertise as representative of Academia Sinica. She is the project investigator for the Taiwan Cancer Moonshot Project, which analyzes multiomic data related to gastric cancer. She participates in the Chromosome-centric Human Proteome Project, and is the group lead of chromosome 4. Chen served as president for the Human Proteome Organization (2021-2022), the Taiwan Proteomics Society, and the Taiwan Society for Mass Spectrometry (2012-2015). She has been a council member of the Asia Oceania Human Proteome Organization since 2019. She current serves as executive director of the Taiwan Proteomics Society (2021-2023), and the Taiwan Society for Mass Spectrometry. She served on editorial boards of European Journal of Mass Spectrometry, Journal of Proteome Research, and Frontiers in Analytical Chemistry, and currently serves on the Executive Advisory Board of Proteomics.
Yet the symbiosis raised a century-long puzzle: if multiple fungi adopted algal partners independently, the "lichen condition" might be polyphyletic. This question of how many times lichenization evolved remained speculative until the advent of molecular phylogenetics. Early lichenologists such as Walter Watson warned that symbiosis can so remodel a fungus that its ancestry becomes hard to trace. Modern molecular studies confirm the problem: convergent thallus forms have evolved repeatedly and even been lost again, making ancestry hard to infer.
6-carboxytetrahydropterin synthase (EC 4.1.2.50, CPH4 synthase, queD (gene), ToyB, ykvK (gene)) is an enzyme with systematic name 7,8-dihydroneopterin 3'-triphosphate acetaldehyde-lyase (6-carboxy-5,6,7,8-tetrahydropterin and triphosphate-forming). This enzyme catalyses the following reversible chemical reaction. 7,8-dihydroneopterin 3′-triphosphate + H2O ⇌ 6-carboxy-5,6,7,8-tetrahydropterin + acetaldehyde + triphosphate This enzyme binds Zn2+. It is isolated from the bacteria Bacillus subtilis and Escherichia coli. The stimulation is part of the biosynthesis pathway of queuosine. The enzyme from Escherichia coli can also convert 6-pyruvoyl-5,6,7,8-tetrahydropterin and sepiapterin to 6-carboxy-5,6,7,8-tetrahydropterin. Media related to 6-carboxytetrahydropterin synthase at Wikimedia Commons 6-carboxytetrahydropterin+synthase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
The variation in the 14C/12C ratio in different parts of the carbon exchange reservoir means that a straightforward calculation of the age of a sample based on the amount of 14C it contains will often give an incorrect result. There are several other possible sources of error that need to be considered. The errors are of four general types:
Several degradation processes occur, some during cycling, some during storage, and some all the time: Degradation is strongly temperature-dependent: degradation at room temperature is minimal but increases for batteries stored or used in high temperature (usually > 35 °C) or low temperature (usually < 5 °C) environments. Also, battery life in room temperature is maximal. High charge levels also hasten capacity loss. Frequent charge to > 90% and discharge to < 10% may also hasten capacity loss. Keeping the li-ion battery status to about 60% to 80% can reduce the capacity loss. In a study, scientists provided 3D imaging and model analysis to reveal main causes, mechanics, and potential mitigations of the problematic degradation of the batteries over charge cycles. They found "[p]article cracking increases and contact loss between particles and carbon-binder domain are observed to correlate with the cell degradation" and indicates that "the reaction heterogeneity within the thick cathode caused by the unbalanced electron conduction is the main cause of the battery degradation over cycling". The most common degradation mechanisms include:
Sources: en.wikipedia.org
(131.5 kg) Ladd, the tallest player in professional football, was All-AFL three times (1961, 1964-65) and an AFL All-Star from 1962 to 1965. Nery and Hudson played with Faison and Ladd in 1961 and 1962, Hudson being named an All-Star in 1961, and Nery selected All-AFL in 1962. Faison and Ladd were later joined by right defensive end Bob Petrich (1963-65), defensive tackle George Gross (1963-65), and Henry Schmidt who had been a reserve lineman and then had starter roles at tackle and end (1961-65). At the time Gross and Ladd were two of the largest and strongest men in professional football. From 1961 to 1965, the Chargers played in four of the five AFL Championship games, winning the 1963 AFL Championship Game, 51–10, over the Boston Patriots.
Sandra Jill James is a retired American biochemist and autism researcher who studied metabolic autism biomarkers. She worked at Arkansas Children's Hospital Research Institute, where she was the director of the Metabolic Genomics Laboratory, as well as the University of Arkansas for Medical Sciences' department of pediatrics, where she began working in 2002. She was also a member of the Autism Speaks Treatment Advisory Board. James' research focused on the role of epigenetics in autism, as well as the effectiveness of supplements as a treatment for autism and the potential existence of abnormal metabolism in autistic children. This research was previously funded by a 5-year grant from the National Institutes of Health entitled "Metabolic biomarkers of autism: predictive potential and genetic susceptibility", as well as by a grant from Autism Speaks. James has falsely speculated that the thiomersal used as a preservative in some vaccines is potentially harmful to the human brain and that prophylactic supplements may protect against such harm preceding vaccination.
Meropenem solutions should not be frozen. Somewhat paradoxically, while meropenem is designed to resist bacterial enzymes, it can still be broken down by water. Specifically, the amide bond in the β-lactam ring of meropenem makes it resistant to many β-lactamases (penicillinases), which are bacterial enzymes that can break down penicillin and related antibiotics such as meropenem. Meropenem’s resistance is due to the stability of the β-lactam ring, which is less susceptible to hydrolysis by these enzymes. However, meropenem can undergo hydrolysis in aqueous solutions, which can reduce its effectiveness. Hence meropenem requires prolonged slow administration, or frequent re-administration, to continually replace what has been hydrolyzed by the water component of blood. Meropenem is administered every 8 hours. Dosing must be adjusted for altered kidney function and for haemofiltration. Studies describe application of meropenem therapeutic drug monitoring (measurements of drug levels in the bloodstream at specific intervals) for optimal application. As with other β-lactams antibiotics, the effectiveness of treatment depends on the amount of time during the dosing interval that the meropenem concentration is above the minimum inhibitory concentration for the bacteria causing the infection. For β-lactams, including meropenem, prolonged intravenous administration is associated with lower mortality compared to bolus intravenous infusion, especially in severe infections or those caused by less sensitive bacteria, such as Pseudomonas aeruginosa.
Richard G. Hiskey (May 21, 1929 – July 28, 2016) was an American chemist and Alumni Distinguished Professor of Chemistry at University of North Carolina at Chapel Hill. Hiskey joined the department of chemistry of the University of North Carolina at Chapel Hill in 1958. He served in various capacities within the university, including director of graduate studies (1965-1970) and chairman of the department (1970-1975), (elected) chairman of the division of natural sciences from 1975 to 1981, and faculty representative to the Atlantic Coast Conference and National Association of Intercollegiate Athletics (1985-1995).
Sources: en.wikipedia.org
=== Depression === A comparative meta-analysis of 21 major antidepressants found that venlafaxine, agomelatine, amitriptyline, escitalopram, mirtazapine, paroxetine, and vortioxetine were more effective than other antidepressants, although the quality of many comparisons was assessed as low or very low. Open-label evidence also suggests potential benefit in treatment-resistant cases: in a multicenter Canadian study of adults with inadequate response to prior antidepressants (n=159), 58% achieved response and 28% remission after 8 weeks of venlafaxine (mean 260 mg/day); tolerability was generally acceptable. Venlafaxine was similar in efficacy to the atypical antidepressant bupropion; however, the remission rate was lower for venlafaxine. In a double-blind study, patients who did not respond to an SSRI were switched to either venlafaxine or another SSRI (citalopram); similar improvement was observed in both groups. Studies have not established its efficacy for use in pediatric populations. In children and adolescents with depression, venlafaxine increases the risk of suicidal thoughts or attempts. Higher doses (e.g., 225 mg and 375 mg per day) of venlafaxine are more effective than lower doses (e.g., 75 mg per day) but also cause more side effects. Studies have shown that the extended-release is superior to the immediate-release form of venlafaxine. A 2017 meta-analysis has shown that the efficacy of venlafaxine is not correlated with baseline severity of depression.
During the early phase of the COVID-19 pandemic, Duterte downplayed the severity of the outbreak and urged the public to avoid anti-Chinese sentiment. In a February 2020 press briefing, he assured citizens that "everything is well" and stated that the public should refrain from discriminating against Chinese nationals. The first reported COVID-19 case in the Philippines was on January 30, 2020, prompting Duterte to issue bans on the entry of Chinese nationals from China and calling for calm. Duterte changed his tune in March, during which he placed the Philippines under a State of National Calamity and ordered a lockdown in Luzon. His administration opted to use what it described as "draconian measures" to control the contagion, and Duterte employed the military and police to enforce the public's strict adherence to quarantine and health protocols. As countries were scrambling in securing COVID-19 vaccines for their own citizens, Duterte called for patience amid criticism. To expedite vaccine procurement, Duterte rejected creating a committee and designated Carlito Galvez Jr. as "vaccine czar", who had the gargantuan task of acquiring vaccines from other countries. Additionally, Duterte personally requested vaccines from world leaders, notably Chinese president Xi Jinping and Russian President Vladimir Putin. China and Russia responded favorably, and the Duterte administration started its vaccination program on March 1, 2021, a day after receiving 600,000 CoronaVac vaccines sent by the Chinese government.
Ari is first seen among a number of hostages during a siege at the local hospital, which formed the show's season finale. Kipa-Williams likened the filming of the storyline to a feature film. Ari seeks a quieter life and his family soon move to Summer Bay, where initial scenes between them show that Nikau blames Ari for something that happened in their past, while Ari thinks Tane is a bad influence on Nikau. The Paratas feud with Constable Colby Thorne (Tim Franklin), who has their passports blocked when they plan a trip to New Zealand to scatter the ashes of their brother, father and husband, Mikaere. The Parata men honour Mikaere by performing a Haka on the beach. The scenes were a first for Home and Away and involved multiple takes. Kipa-Williams dedicated his performance to a family member and admitted to feeling the weight of responsibility with the storyline. Ari soon establishes a relationship with restaurateur Mackenzie Booth (Emily Weir). A love triangle develops when Mac finds herself attracted to Tane, but she realises that she has serious feelings for Ari, who soon commits to her. Weir believed Ari was the best match for her character, as Tane would likely bring chaos to her life. The relationship ends shortly after the introductions of Ari's stepdaughter Chloe Anderson (Sam Barrett) and her mother Mia Anderson (Anna Samson). Kipa-Williams admitted he was disappointed with Mac and Ari's break-up, as he wanted the characters to become a solid, long term couple.
Rich reported severe side effects from the injections, including emotional blunting and loss of physical sensation. Following a final recommitment order in December 2018, he died by suicide on January 11, 2019, at age 29. His mother, attorney Elizabeth Rich, founded the nonprofit Andrew's V.O.I.C.E. (Victory Over Involuntary Commitment Excesses) to advocate for mental health law reform. His case was documented in a July 2019 investigative article by Robert Whitaker in Mad in America as part of a broader critique of AOT law evidence and practice. A 2023 expert analysis by physician and researcher Peter C. Gøtzsche published in Mad in America documented the case of a Swedish patient, Tuva Andersson, who was forcibly administered paliperidone palmitate depot injections at a forensic psychiatric facility without a confirmed psychotic diagnosis, over her explicit objection. Documented adverse effects included severe muscle stiffness, loss of motor function, and marked cognitive deterioration, which treating clinicians attributed to her underlying condition rather than the medication. An additional medication for Parkinsonism was added rather than the paliperidone being reduced. Andersson died by suicide in 2019, at age 37. A post-mortem assessment by an independent psychiatrist retained by the regional insurance authority concluded that her care had been deficient, that increasing suicide risk had not been met with corresponding interventions, and that her death was likely caused by failures in her treatment.
=== Inflammatory and immune-related diseases === Microbial therapeutics are being studied for the treatment of inflammatory and immune-related diseases, including inflammatory bowel disease (IBD), allergies, and autoimmune disorders. In these conditions, the immune system becomes overactive or poorly regulated, leading to chronic inflammation. Certain microorganisms can help reduce inflammation by promoting immune balance. For example, some gut microbes produce molecules that calm inflammatory immune responses or support immune cells that help prevent excessive inflammation. Researchers are also developing engineered microorganisms that can release anti-inflammatory substances directly at sites of inflammation, which may reduce side effects compared with treatments that affect the entire body.
Sources: en.wikipedia.org
Epitalon is a synthetic four-amino-acid peptide with the sequence alanine–glutamate–aspartate–glycine, also written AEDG. It was developed in Russian gerontology research and is studied for proposed effects on telomerase, melatonin regulation, and neuroendocrine function. It is not an approved pharmaceutical in the United States or the European Union.
No. Epithalamin is a peptide-rich extract prepared from bovine pineal glands, while epitalon is a short synthetic peptide designed as a defined analogue of it. The synthetic version was intended to provide a reproducible molecule with some of the same proposed biological activity.
Telomere elongation and telomerase activation have been reported in cultured human somatic cells, but evidence from living human subjects is limited and has not been independently confirmed at scale. Reported findings come largely from small studies with differing designs, so the question remains open rather than settled.
The dry powder is typically held at -20 degrees Celsius or lower, protected from light and moisture. Allowing a sealed vial to reach room temperature before opening reduces condensation on its contents. Conditions stated on a supplier certificate of analysis take precedence over general guidance.