The short version of aliquot fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-24 and is reviewed periodically as new material appears.
Epitalon is a synthetic tetrapeptide with the sequence alanine-glutamate-aspartate-glycine, commonly abbreviated AEDG. It was designed at the St. Petersburg Institute of Bioregulation and Gerontology as a short, chemically defined analogue of epithalamin, a fraction obtained from bovine pineal tissue. Small peptide bioregulators of this type formed a long-running line of work there from the 1980s onward. Because the molecule is produced by solid-phase synthesis rather than extraction, its composition is exact and its purity can be measured directly.
The most frequently cited proposed action is induction of telomerase, the enzyme that adds repeat sequences to chromosome ends. Cell-culture work from the originating group reported higher telomerase reverse transcriptase expression and measurable telomere elongation in human somatic cells after exposure. How a four-residue peptide would reach nuclear gene regulation is not established, and no cell-surface receptor or uptake route has been identified. Additional reports describe changes in melatonin secretion, antioxidant enzyme activity and lipid peroxidation in aged animals, but these findings remain mechanistically unconnected to the telomerase observation.
Published evidence comes mainly from Russian-language journals and from a single research group, with small sample sizes and limited independent replication. A few laboratories outside that group have examined related peptides and reported weaker or absent telomerase effects, so the central claim is best described as contested rather than settled. Rodent studies report modest changes in some ageing markers and in survival, but designs vary and control conditions are often sparse. No large randomised trial in humans has been published, and long-term safety data in healthy populations are correspondingly thin.
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.
Short peptides such as AEDG are normally supplied as a freeze-dried solid and are kept dry, cold, and shielded from light. Holding at minus twenty degrees Celsius is common for the long term, while a refrigerator suffices for brief periods before use. The material takes up moisture to some degree, so containers should stay sealed and be allowed to reach room temperature before opening, which limits condensation on the contents. Repeated warming and cooling of a single container is discouraged because it admits water and can lower the amount of intact peptide.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C14H22N4O9 | Calculated from the four residues with three water losses |
| Molecular mass | About 390.35 g/mol | Monoisotopic mass near 390.14, used for mass-spectrometric identification |
| Peptide sequence | Ala-Glu-Asp-Gly | Single-letter form AEDG; no disulfide bonds or modified residues |
| Appearance | White to off-white solid | Supplied as a dried powder |
| Isoelectric point | Around 4 | Estimated from aspartate and glutamate side-chain pKa values |
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.
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.
Lyophilised epitalon is generally held at minus twenty degrees Celsius in a sealed container kept dry and dark. Cooler conditions are sometimes recommended for long-term archives. The solid takes up moisture readily enough that repeated opening of a vial introduces water, so dividing a batch into smaller portions before storage lowers degradation risk. Aqueous solutions are less durable than the dry powder and are usually prepared shortly before use, then kept cold and shielded from light to slow hydrolysis and oxidation.
Verification of research-grade material involves comparing a supplier chromatogram against an in-house reference, checking the observed mass against the calculated value, and where possible confirming residue order by tandem mass spectrometry or enzymatic peptide mapping. Purity claims should be read alongside the method used to obtain them, because detection wavelength and integration settings alter the result. Batch-specific data, rather than a generic grade statement, is the informative part of a certificate.
He was succeeded by Kazuo Ito as president. In April 2002, Ajinomoto reorganized itself into food, amino acid, and medicine divisions, and owned subsidiaries for frozen foods, fats, and oils. In February 2003, Ajinomoto and Unilever completed a joint venture agreement in six countries and regions of Asia. Because of this, Ajinomoto launched the brand VONO to replace its use of the Knorr brand, and in the process established its own brand identity. In July 2003, Ajinomoto bought the French company Orsan from the UK-based Tate and Lyle Group, renaming Orsan to AJI-NO-MOTO Foods, Europe. In November 2005, AJI-NO-MOTO Pharmaceuticals USA, Inc. was liquidated, and its assets and functions were merged into AJI-NO-MOTO Pharmaceuticals, Europe. In January 2006, Ajinomoto bought the cooking sauce and condiments manufacturer Amoy Food from the French dairy company Groupe Danone. In 2009, the company released "Ajinomoto" to commemorate the 100th anniversary of its foundation.
In June 1973, Gaddafi created a political ideology as a basis for the Popular Revolution: Third International Theory. This approach regarded both the US and the Soviet Union as imperialist and thus rejected Western capitalism as well as Marxist–Leninist atheism. In this respect, it was similar to the Three Worlds Theory developed by China's political leader Mao Zedong. As part of this theory, Gaddafi praised nationalism as a progressive force and advocated the creation of a pan-Arab state which would lead the Islamic and Third Worlds against imperialism. Gaddafi saw Islam as having a key role in this ideology, calling for an Islamic revival that returned to the origins of the Qur'an, rejecting scholarly interpretations and the Hadith; in doing so, he angered many Libyan clerics. During 1973 and 1974, his government deepened the legal reliance on sharia, for instance by introducing flogging as punishment for those convicted of adultery or homosexual activity. Gaddafi summarized Third International Theory in three short volumes published between 1975 and 1979, collectively known as The Green Book. Volume one was devoted to the issue of democracy, outlining the flaws of representative systems in favour of direct, participatory GPCs. The second dealt with Gaddafi's beliefs regarding socialism, while the third explored social issues regarding the family and the tribe. While the first two volumes advocated radical reform, the third adopted a socially conservative stance, proclaiming that while men and women were equal, they were biologically designed for different roles in life.
the damage to Mr. Banki's life brought about by his lengthy incarceration, occasioned by his confinement, cannot be measured only by the 22 months in which he lost his liberty and which he cannot get back".
It is indeed simultaneously realized that the TLC methods used thus far in almost all published studies on INMT and DMT biosynthesis are incapable to resolve DMT from those tetrahydro-β-carbolines. These findings are a blow for all previous claims of evidence of INMT activity and DMT biosynthesis in avian and mammalian brain, including in vivo, as they all relied upon use of the problematic TLC methods: their validity is doubted in replication studies that make use of improved TLC methods, and fail to evidence DMT-producing INMT activity in rat and human brain tissues. Published in 1978, the last study attempting to evidence in vivo INMT activity and DMT production in brain (rat) with TLC methods finds biotransformation of radiolabeled tryptamine into DMT to be real but "insignificant". Capability of the method used in this latter study to resolve DMT from tetrahydro-β-carbolines is questioned later. To localize INMT, a qualitative leap is accomplished with use of modern techniques of molecular biology, and of immunohistochemistry. In humans, a gene encoding INMT is determined to be located on chromosome 7. Northern blot analyses reveal INMT messenger RNA (mRNA) to be highly expressed in rabbit lung, and in human thyroid, adrenal gland, and lung. Intermediate levels of expression are found in human heart, skeletal muscle, trachea, stomach, small intestine, pancreas, testis, prostate, placenta, lymph node, and spinal cord. Low to very low levels of expression are noted in rabbit brain, and human thymus, liver, spleen, kidney, colon, ovary, and bone marrow.
Sources: en.wikipedia.org
Though technically distinct from the alkanes, this class of hydrocarbons is referred to by some as the "cyclic alkanes." As their description implies, they contain one or more rings. Simple cycloalkanes have a prefix "cyclo-" to distinguish them from alkanes. Cycloalkanes are named as per their acyclic counterparts with respect to the number of carbon atoms in their backbones, e.g., cyclopentane (C5H10) is a cycloalkane with 5 carbon atoms just like pentane (C5H12), but they are joined up in a five-membered ring. In a similar manner, propane and cyclopropane, butane and cyclobutane, etc. Substituted cycloalkanes are named similarly to substituted alkanes – the cycloalkane ring is stated, and the substituents are according to their position on the ring, with the numbering decided by the Cahn–Ingold–Prelog priority rules.
Roller chain is ordinarily hooked up using a master link (also known as a "connecting link"), which typically has one pin held by a horseshoe clip rather than friction fit, allowing it to be inserted or removed with simple tools. Chain with a removable link or pin is also known as "cottered chain", which allows the length of the chain to be adjusted. Half links (also known as "offsets") are available and are used to increase the length of the chain by a single roller. Riveted roller chain has the master link (also known as a "connecting link") "riveted" or mashed on the ends. These pins are made to be durable and are not removable.
Brettanomyces (Teleomorph Dekkera) Candida (Teleomorphs for different species from several genera including Pichia, Metschnikowia, Issatchenkia, Torulaspora and Kluyveromyces) Kloeckera (Teleomorph Hanseniaspora), usually the most common "wild yeast" found in the vineyard. Some species are known as "killer yeast" that produce inhibitory levels of ethyl acetate and acetic acid that can kill off sensitive strains of Saccharomyces cerevisiae Saccharomycodes Schizosaccharomyces, the only wine yeast that reproduced by fission whereas most wine yeast reproduce by budding. Zygosaccharomyces, very alcohol-tolerant and can grow in wines up to 18% v/v. Additionally this yeast can survive in extremely high sugar levels (as much as 60% w/w or 60 Brix) and is very resistant to sulfur dioxide. Aureobasidium, particularly the "black yeast" species of Aureobasidium pullulans found in moist cellars that can contaminate aging wine in barrels.
Radio direction finding (RDF) – this is a general technique, used since the early 1900s, of using specialized radio receivers with directional antennas (RDF receivers) to determine the exact bearing of a radio signal, to determine the location of the transmitter. The location of a terrestrial transmitter can be determined by simple triangulation from bearings taken by two RDF stations separated geographically, as the point where the two bearing lines cross, this is called a "fix". Military forces use RDF to locate enemy forces by their tactical radio transmissions, counterintelligence services use it to locate clandestine transmitters used by espionage agents, and governments use it to locate unlicensed transmitters or interference sources. Older RDF receivers used rotatable loop antennas, the antenna is rotated until the radio signal strength is weakest, indicating the transmitter is in one of the antenna's two nulls. The nulls are used since they are sharper than the antenna's lobes (maxima). More modern receivers use phased array antennas which have a much greater angular resolution. Animal migration tracking – a widely used technique in wildlife biology, conservation biology, and wildlife management in which small battery-powered radio transmitters are attached to wild animals so their movements can be tracked with a directional RDF receiver. Sometimes the transmitter is implanted in the animal. The VHF band is typically used since antennas in this band are fairly compact.
== Further reading == Schroeder, Avi; Honen, Reuma; Turjeman, Keren; Gabizon, Alberto; Kost, Joseph; Barenholz, Yechezkel (2009). "Ultrasound triggered release of cisplatin from liposomes in murine tumors". Journal of Controlled Release. 137 (1): 63–8. doi:10.1016/j.jconrel.2009.03.007. PMID 19303426. Scott, Robert C.; Wang, Bin; Nallamothu, Ramakrishna; Pattillo, Christopher B.; Perez-Liz, Georgina; Issekutz, Andrew; Valle, Luis Del; Wood, George C.; Kiani, Mohammad F. (2007). "Targeted delivery of antibody conjugated liposomal drug carriers to rat myocardial infarction". Biotechnology and Bioengineering. 96 (4): 795–802. doi:10.1002/bit.21233. PMID 17051598. S2CID 30039741. Scott, Robert C; Crabbe, Deborah; Krynska, Barbara; Ansari, Ramin; Kiani, Mohammad F (2008). "Aiming for the heart: targeted delivery of drugs to diseased cardiac tissue". Expert Opinion on Drug Delivery. 5 (4): 459–70. doi:10.1517/17425247.5.4.459. PMID 18426386. S2CID 71338475. Wang, Bin; Rosano, Jenna M; Cheheltani, Rabe'e; Achary, Mohan P; Kiani, Mohammad F (2010). "Towards a targeted multi-drug delivery approach to improve therapeutic efficacy in breast cancer". Expert Opinion on Drug Delivery. 7 (10): 1159–73. doi:10.1517/17425247.2010.513968. PMID 20738211. S2CID 19679654. Wang, Bin; Scott, Robert C.; Pattillo, Christopher B.; Prabhakarpandian, Balabhaskar; Sundaram, Shankar; Kiani, Mohammad F. (2008). "Modeling Oxygenation and Selective Delivery of Drug Carriers Post-Myocardial Infarction". In Kang, Kyung A.; Harrison, David K.; Bruley, Duane F. (eds.). Oxygen Transport to Tissue XXIX.
Sources: en.wikipedia.org
No. Epithalamin is a peptide-containing extract of bovine pineal glands, while epitalon is a single synthetic tetrapeptide. The extract contains many peptides and other tissue components, so its composition varies between batches in ways that a synthesised sequence does not.
It is not recognised as an endogenous peptide hormone. The four-residue sequence can appear inside larger proteins and in digestive fragments of dietary protein, but no dedicated pathway producing it as a signalling molecule has been identified.
Several cell-culture reports describe increased telomerase activity after treatment, measured by enzyme assays or by transcript levels. Results differ between cell types and laboratories, and measured telomere lengthening has been reported in some studies but not in others, which leaves the physiological relevance open.
Reversed-phase high-performance liquid chromatography is run alongside mass spectrometry. The chromatogram separates components and gives a purity figure, while the mass spectrum confirms that the measured molecular mass matches the expected sequence. Neither measurement on its own is treated as sufficient.