If you have been reading about lyophilised powder and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Regulatory status varies by country and is not harmonized. Epitalon is not an approved drug in major Western jurisdictions. In some countries it is sold as a research chemical, and in others it has appeared in products marketed for other categories. This inconsistent status means that purity, labeling accuracy, and documentation differ widely between suppliers, and verification of identity and purity through independent analysis is the usual way buyers assess a given lot.
Epitalon appears in the literature primarily through a small number of research groups, most of them associated with the St. Petersburg Institute of Bioregulation and Gerontology. Publications describe cell culture experiments, animal studies, and a limited number of small human studies. Independent replication outside this network is sparse. As a result, reviews of the topic usually separate descriptive reports of observed effects from the question of whether those effects generalize, and they note the difficulty of comparing studies that use different preparations and endpoints.
Analytical characterization of epitalon relies on standard peptide methods. Reverse-phase high-performance liquid chromatography is used to assess purity, and mass spectrometry confirms identity by checking the observed mass against the expected value near 390 daltons. Amino acid analysis can verify composition. Because the peptide is short and hydrophilic, it elutes early on many reverse-phase columns, so method development often requires ion-pairing reagents to achieve adequate retention and resolution from related impurities.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised and often hygroscopic |
| Solubility class | Freely soluble in water | Poor solubility in non-polar solvents |
| Typical storage temperature | -20 degrees Celsius or colder | Sealed, desiccated, protected from light |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Establishes purity and confirms mass |
| Common salt form | Trifluoroacetate or acetate | Counterion reported alongside purity values |
Identity confirmation uses mass spectrometry, usually electrospray ionisation in positive mode or matrix-assisted laser desorption. The protonated free peptide produces a signal near three hundred and ninety-one daltons, while salt adducts shift that value slightly. Tandem mass spectrometry or amino acid analysis supplies sequence-level confirmation, which a single mass measurement cannot. Peptides containing aspartate can cyclise into succinimide intermediates that hydrolyse to isoaspartate isomers of identical mass. Because those isomers are difficult to separate chromatographically, identity and purity results carry more weight when interpreted together.
Storage practice centres on limiting moisture, oxygen, and repeated temperature cycling. Freeze-dried powder is generally held desiccated at minus twenty degrees Celsius or colder and protected from light. Reconstituted solutions are markedly less stable, and the aspartate-glycine junction is prone to succinimide formation at neutral to mildly alkaline pH. Portioning material into single-use aliquots reduces degradation compared with repeated freeze-thaw cycles. Stability data specific to this tetrapeptide remain scarce, so most handling guidance is extrapolated from general peptide chemistry rather than measured directly.
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.
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.
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.
Human data are limited to small studies, often without the randomization, blinding, or control groups expected in contemporary clinical research. Reported outcomes have included changes in melatonin levels, immune markers, and subjective measures, but sample sizes were generally too small to support firm conclusions. Some reviews treat the peptide as promising while noting methodological weaknesses; others question whether the observed effects are specific. The compound is frequently discussed in longevity-focused communities, where enthusiasm often outpaces the published evidence. Separating established findings from speculation is therefore important when reading summaries of this research.
Dissolution is usually performed in water or a suitable aqueous buffer, and the resulting liquid is divided into single-use portions before freezing. Freeze-thaw cycling is a recognised source of loss for short peptides, since each cycle can encourage aggregation or adsorption onto container walls. Working solutions are generally kept cold and used within a short window, although published stability data specific to epitalon are thin. Containers should be marked with concentration and date, and solutions examined for cloudiness before use.
Identity is normally established by reversed-phase high-performance liquid chromatography combined with mass spectrometry, a pairing that separates components and confirms molecular mass at once. Purity is quoted as a percentage from the chromatogram, and figures above ninety-five percent are a frequent commercial specification. Amino acid analysis or sequencing supplies further confirmation when required. Because many short peptides behave similarly under chromatography, retention time alone does not establish sequence; the mass measurement is what separates one tetrapeptide from another, and certificates should report both.
==== MODAL ==== The MODAL strategy defines overlap sequences known as "linkers" to reduce the amount of customisation that needs to be done with each DNA fragment. The linkers were designed using the R2oDNA Designer software and the overlap regions were designed to be 45 bp long to be compatible with Gibson assembly and other overlap assembly methods. To attach these linkers to the parts to be assembled, PCR is carried using part-specific primers containing 15 bp prefix and suffix adaptor sequences. The linkers are then attached to the adaptor sequences via a second PCR reaction. To position the DNA fragments, the same linker will be attached to the suffix of the desired upstream fragment and the prefix of the desired downstream fragments. Once the linkers are attached, Gibson assembly, CPEC, or the other overlap assembly methods can all be used to assemble the DNA fragments in the desired order.
Different bat species have different diets, including insects, nectar, pollen, fruit and even vertebrates. Megabats are mostly fruit, nectar and pollen eaters. Due to their small size, high metabolism and rapid burning of energy through flight, bats must consume large amounts of food for their size. Insectivorous bats may eat over 120 percent of their body weight per day, while frugivorous bats may eat over twice their weight. They can travel significant distances each night, exceptionally as much as 38.5 km (24 mi) in the spotted bat (Euderma maculatum), in search of food. Bats may acquire water from the food they eat or drink from sources like lakes and streams, flying over the surface and dipping their tongues into the water. Bats as a group appear to be losing vitamin C synthesis. Such a loss was recorded in 34 bat species from six major families, both insect- and fruit-eating, with the cause being a single mutation inherited from a common ancestor. Vitamin C synthesis has been recorded in at least two species of bat, Leschenault's rousette (Rousettus leschenaultii) and the great roundleaf bat (Hipposideros armiger).
Valproate moderately increases the levels of amitriptyline and nortriptyline through an unclear mechanism. The prescribing information warns that the combination of amitriptyline with monoamine oxidase inhibitors may cause potentially lethal serotonin syndrome; however, this has been disputed. The prescribing information cautions that some patients may experience a large increase in amitriptyline concentration in the presence of topiramate. However, other literature states that there is little or no interaction: in a pharmacokinetic study topiramate only increased the level of amitriptyline by 20% and nortriptyline by 33%. Amitriptyline counteracts the antihypertensive action of guanethidine. When given with amitriptyline, other anticholinergic agents may result in hyperpyrexia or paralytic ileus. Co-administration of amitriptyline and disulfiram is not recommended due to the potential for the development of toxic delirium. Amitriptyline causes an unusual type of interaction with the anticoagulant phenprocoumon during which great fluctuations of the prothrombin time have been observed.
Sources: en.wikipedia.org
== Relevance to human disease == Possible implications of the SARM1 pathway with regard to human health may be found in animal models of neurodegeneration, where loss of SARM1 is neuroprotective in models of traumatic brain injury, chemotherapy-induced neuropathy, diabetic neuropathy, degenerative eye conditions, drug-induced Schwann cell death, Charcot-Marie-Tooth disease, and hereditary spastic paraplegia. Loss-of-function alleles of the SARM1 gene also occur naturally in the human population, potentially altering susceptibility to various neurological conditions. Specific mutations in the human NMNAT2 gene, encoding a key regulator of SARM1 activity, have linked the Wallerian degeneration mechanism to two human neurological diseases - fetal akinesia deformation sequence and childhood-onset polyneuropathy with erythromelalgia. Mutations in the human SARM1 gene that result in SARM1 protein with constitutive NADase activity have been reported in patients with amyotrophic lateral sclerosis (ALS).
transcription start site (TSS) Also transcription initiation site. The specific location within a gene at which RNA polymerase begins transcription, defined by the specific nucleotide or codon corresponding to the first ribonucleotide(s) to be assembled in the nascent transcript (which is not necessarily the same as the first codon to be translated). This site is usually considered the beginning of the coding sequence and is the reference point for numbering the individual nucleotides within a gene. Nucleotides upstream of the start site are assigned negative numbers and those downstream are assigned positive numbers, which are used to indicate the positions of nearby sequences or structures relative to the TSS. For example, the binding site for RNA polymerase might be a short sequence immediately upstream of the TSS, from approximately -80 to -5, whereas an intron within the coding region might be defined as the sequence starting at nucleotide +207 and ending at nucleotide +793.
His method of testing won the Intel International Science and Engineering Fair Gordon E. Moore Award in the spring of 2012. The Boeing Company has patented the use of carbon nanotubes for structural health monitoring of composites used in aircraft structures. This technology is hoped to greatly reduce the risk of an in-flight failure caused by structural degradation of aircraft. Zyvex Technologies has also built a 54' maritime vessel, the Piranha Unmanned Surface Vessel, as a technology demonstrator for what is possible using CNT technology. CNTs help improve the structural performance of the vessel, resulting in a lightweight 8,000 lb boat that can carry a payload of 15,000 lb over a range of 2,500 miles. IMEC is using carbon nanotubes for pellicles in semiconductor lithography. In tissue engineering, carbon nanotubes have been used as scaffolding for bone growth. Carbon nanotubes can serve as additives to various structural materials. For instance, nanotubes form a tiny portion of the material(s) in some (primarily carbon fiber) baseball bats, golf clubs, car parts, or damascus steel. IBM expected carbon nanotube transistors to be used on Integrated Circuits by 2020.
Yuchanyan is an early Neolithic cave site in Dao County (Daoxian), Hunan, China. The site yielded sherds of ceramic vessels and other artifacts which were dated by analysis of charcoal and bone collagen, giving a date range of 17,500 to 18,300 years old for the pottery. The pottery specimens may be the oldest known examples of pottery. The cave yielded fragmentary remains of 2 or more ceramic vessels, in addition to large amounts of ash, a rich animal bone assemblage, cobble and flake artifacts, bone tools, and shell tools. The artifacts indicate that the cave was a Late Paleolithic foragers' camp. Here we report on the radiocarbon ages of the sediments based on analyses of charcoal and bone collagen. The best-preserved charcoal and bone samples were identified by prescreening in the field and laboratory. The dates range from around 21,000 to 13,800 cal BP. The age of the ancient pottery ranges between 18,300 and 15,430 cal BP. Charcoal and bone collagen samples located above and below one of the fragments produced dates of around 18,000. These ceramic potsherds therefore provide some of the earliest evidence for pottery making in China.
Sources: en.wikipedia.org
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.
Reversed-phase HPLC establishes purity and separation from related peptides, and mass spectrometry confirms the molecular mass. Amino acid analysis can verify residue composition. No single method proves identity on its own, so the results are read together.
Yes. Residual trifluoroacetate or acetate from purification adds mass and can shift the value obtained by certain assays. Purity figures are therefore meaningful only when the counterion form is stated. Reporting both peptide content and salt form gives a clearer picture.
Identity is normally confirmed by mass spectrometry, which checks the measured mass against the expected value near 390 daltons. Reverse-phase high-performance liquid chromatography is used alongside it to assess purity. Amino acid analysis can provide additional composition data.