tuftsin comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Peptide bonds in selank are susceptible to hydrolysis under strongly acidic or basic conditions, and the terminal proline residues are vulnerable to exopeptidase activity in biological samples. Lyophilized powder stored dry at -20 °C typically remains stable for extended periods, whereas aqueous solutions degrade faster and may lose measurable purity within days to weeks depending on pH, temperature, and microbial load. Repeated freeze-thaw cycles promote aggregation and adsorption to container surfaces. For analytical work, solutions are usually prepared fresh, kept cold, and used within a single working day.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
== Uses == In organic synthesis, HClO converts alkenes to chlorohydrins. In biology, hypochlorous acid is generated in activated neutrophils by myeloperoxidase-mediated peroxidation of chloride ions, and contributes to the destruction of bacteria and other microbes. In medicine, hypochlorous acid water has been used as a disinfectant and sanitiser. In wound care, and as of early 2016, the U.S. Food and Drug Administration has approved products whose main active ingredient is hypochlorous acid for use in treating wounds and various infections in humans and pets. It is also FDA-approved as a preservative for saline solutions. In disinfection, it has been used in the form of liquid spray, wet wipes and aerosolised application. Recent [when?] studies have shown hypochlorous acid water to be suitable for fog and aerosolised application for disinfection chambers and suitable for disinfecting indoor settings, such as offices, hospitals and healthcare clinics. In food service and water distribution, specialized equipment to generate weak solutions of HClO from water and salt is sometimes used to generate adequate quantities of safe (unstable) disinfectant to treat food preparation surfaces and water supplies. It is also commonly used in restaurants due to its non-flammable and nontoxic characteristics. In water treatment, hypochlorous acid is the active sanitizer in hypochlorite-based products (e.g. used in swimming pools).
==== Philippines ==== The Chinese are being blamed after a cybersecurity company, F-Secure Labs, found a malware, NanHaiShu, which targeted the Philippines Department of Justice. It sent information in an infected machine to a server with a Chinese IP address. The malware which is considered particularly sophisticated in nature was introduced by phishing emails that were designed to look like they were coming from an authentic sources. The information sent is believed to be relating to the South China Sea legal case.
Embryonic Hb are expressed as early as four to six weeks of embryogenesis and disappear around the eighth week of gestation as they are replaced by fetal Hb. Embryonic Hbs include: Hb Gower-1, composed of two ζ (zeta) globins and two ε (epsilon) globins, i.e., ζ2ε2 Hb Gower-2, composed of two α globins and two ε globins (α2ε2) Hb Portland, composed of two ζ globins and two γ (gamma) globins (ζ2γ2) Fetal Hb (HbF) is produced from approximately eight weeks of gestation through birth and constitutes approximately 80 percent of Hb in the full-term neonate. It declines during the first few months of life and, in the normal state, constitutes <1 percent of total Hb by early childhood. HbF is composed of two α globins and two γ globins (α2γ2). Adult Hb (HbA) is the predominant Hb in children by six months of age and onward; it constitutes 96-97% of total Hb in individuals without a hemoglobinopathy. It is composed of two α globins and two β globins (α2β2). HbA2 is a minor adult Hb that normally accounts for approximately 2.5–3.5% of total Hb from six months of age onward. It is composed of two α globins and two δ (delta) globins (α2δ2).
Sources: en.wikipedia.org
== Organic heterocycles and polymers == Radical cations figure prominently in the chemistry and properties of conducting polymers. Such polymers are formed by the oxidation of heterocycles to give radical cations, which condense with the parent heterocycle. For example, polypyrrole is prepared by oxidation of pyrrole using ferric chloride in methanol:
In March 2021, Columbia University professor Thomas J. Christensen wrote that the cold war between the US and China "is unlikely" in comparison to the original Cold War, citing China's prominence in the "global production chain" and absence of the authoritarianism vs. liberal democracy dynamic. Christensen further advised those concerned about the tensions between the two nations to research China's role in the global economy and its "foreign policy toward international conflicts and civil wars" between liberal and authoritarian forces. In September 2021, former Portuguese defence and foreign minister Paulo Portas described the announcement of the AUKUS security pact and the ensuing unprecedented diplomatic crisis between the signatories (Australia, the United Kingdom, and the United States) and France (which has several territories in the Indo-Pacific) as a possible formal starting point of a new Cold War. On 7 November 2021, President Biden's national security adviser Jake Sullivan stated that the US does not pursue system change in China anymore, marking a clear break from the China policy pursued by previous US administrations. Sullivan said that the US is not seeking a new Cold War with China, but is looking for a system of peaceful coexistence. In November 2021, Hal Brands and Yale professor John Lewis Gaddis wrote in Foreign Affairs that while it was no longer debatable that the United States and China has been entering into their "own new cold war", it was not clear that the world has also been following suit and entering into a new cold war.
Some consider mosaicism to be a form of chimerism, while others consider it to be distinct. Mosaicism involves a mutation of the genetic material in a cell, giving rise to a subset of cells that are different from the rest. Natural chimerism is the fusion of more than one fertilized zygote in the early stages of prenatal development. It is much rarer than mosaicism. In artificial chimerism, an individual has one cell lineage that was inherited genetically at the time of the formation of the human embryo and the other that was introduced through a procedure, including organ transplantation or blood transfusion. Specific types of transplants that could induce this condition include bone marrow transplants and organ transplants, as the recipient's body essentially works to permanently incorporate the new blood stem cells into it.
== More studies and projects == Brain Age: Environmental influences in prenatal life have a major impact on brain aging and age-associated brain disorders. Aging is considered as a major risk factor of most neurogenerative diseases such as Alzheimer's or Parkinson's disease for example. EuroBATS: Studies that uses both genetic and biological approaches. Study of 8,000 identical twins to identify markers of aging. The use of improving the length of the telomeres will be used in this process. Frailomic: Utility of biomarkers to characterize elderly individuals at risk for frailty, its progression to disability outcomes, and overall health and well-being consequences. The main objective is to prevent and detect frailty before suffering from it.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Identity is confirmed by matching the retention time in reversed-phase chromatography against a reference standard and by measuring the molecular mass with mass spectrometry. Tandem mass spectrometry or amino acid analysis can verify the sequence of the seven residues. Because the peptide contains no aromatic amino acids, detection at 280 nm is not useful.