Everything below concerns freeze-thaw. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Identity confirmation | Reversed-phase HPLC retention time versus reference standard | Retention depends on column, gradient, and ion-pairing agent |
| Mass confirmation | Electrospray or MALDI mass spectrometry | Doubly protonated ion near m/z 377 is consistent with about 752 Da |
| Typical purity specification | 95 percent or higher by chromatographic peak area | Lower values suggest truncated or modified peptide species |
| Storage of lyophilized powder | -20 °C, desiccated, protected from light | Powder tolerates long storage better than solution |
| Storage of solution | 2-8 °C for short periods | Freeze-thaw cycling promotes aggregation and surface adsorption |
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
Nevertheless, alpha-synuclein aggregates to form insoluble fibrils in pathological conditions characterized by Lewy bodies, such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. These disorders are known as synucleinopathies. In vitro models of synucleinopathies revealed that aggregation of alpha-synuclein may lead to various cellular disorders including microtubule impairment, synaptic and mitochondrial dysfunctions, oxidative stress as well as dysregulation of Calcium signaling, proteasomal and lysosomal pathway. Alpha-synuclein is the primary structural component of Lewy body fibrils. Occasionally, Lewy bodies contain tau protein; however, alpha-synuclein and tau constitute two distinctive subsets of filaments in the same inclusion bodies. Alpha-synuclein pathology is also found in both sporadic and familial cases with Alzheimer's disease. The alpha-synuclein seed amplification assay (SAA) using cerebrospinal fluid demonstrated high diagnostic performance in distinguishing synucleinopathies with Lewy bodies from control subjects. Additionally, SAA kinetics are associated with cognitive impairment and predict the development of dementia. The aggregation mechanism of alpha-synuclein is uncertain. There is evidence of a structured intermediate rich in beta structure that can be the precursor of aggregation and, ultimately, Lewy bodies. A single molecule study in 2008 suggests alpha-synuclein exists as a mix of unstructured, alpha-helix, and beta-sheet-rich conformers in equilibrium.
1,8-Cineole 2-exo-monooxygenase (EC 1.14.14.56, CYP3A4) is an enzyme with systematic name 1,8-cineole,NADPH:oxygen oxidoreductase (2-exo-hydroxylating). This enzyme catalyses the following chemical reaction
Many fast food chains stopped use of the product after the controversy arose, or stated that they had not used the product before. In April 2012, the Concord Monitor reported increased business in some small neighborhood markets where the product's use was less likely, due to consumer concerns about the additive. In March 2012, 70% of ground beef in the U.S. contained lean finely textured beef, and a year later, in March 2013, the amount was estimated by meat industry officials to be at approximately 5%. This significant reduction is due in part to the extensive media coverage that began in March 2012 about the additive. Kroger Co. and Supervalu Inc. stopped using the additive. On March 25, 2012, BPI announced it would suspend operations at three of its four plants, being in "crisis planning". The three plants produced a total of about 900,000 pounds of the product per day. BPI said it lost contracts with 72 customers, many over the course of one weekend, and production decreased from 5 million pounds of LFTB per week to below one million pounds a week at the nadir (lowest point of production). Effective May 25, 2012, BPI closed three of its four plants, including one in Garden City, Kansas, lost more than $400 million in sales, and laid off 700 workers. Production decreased to less than 2 million pounds in 2013. Cargill also significantly cut production of finely textured beef and in April 2012 "warned [that] the public's resistance to the filler could lead to higher hamburger prices this barbecue season".
== Controversies == In December 2015, a settlement was reached that applies to protein shakes and beverages that include MuscleTech. In June 2016, MuscleTech's parent Iovate was sued by rival Hi-Tech Pharmaceuticals over Racketeer Influenced and Corrupt Organizations and protein spiking allegations. In September 2019, MuscleTech was sued by a consumer claiming that a MuscleTech dietary supplement (Platinum 100% BCAA 8:1:1) decreased muscle protein synthesis. In May 2020, a MuscleTech product made in the U.S. was linked to a death in Spain. In April 2022, a lawsuit was filed alleging containers of MuscleTech powder supplements were sold half empty. In June 2025, Malaysian bodybuilding supplement retailer Muscle Mania Club claimed that there are only 9.9g of protein in Nitro-Tech, well below the 30g of protein claimed on the bottle, after they sent a sample for a third party lab testing done in Malaysia. Iovate responded by producing its own test results done by Eurofins that showed protein content meeting the 30g label claim and added that Muscle Mania Club is not an authorized MuscleTech reseller.
Tourism is a major industry and contributor to the Singaporean economy, attracting 13.6 million international tourists in 2023, more than double Singapore's total population. Tourism contributed directly to about 3% of Singapore's GDP, on average, in the 10 years before 2023, excluding the COVID-19 pandemic years. Altogether, the sector generated approximately 8.6% of Singapore's employment in 2016. Well-known landmarks include the Merlion, the Esplanade, Marina Bay Sands, Gardens by the Bay, Jewel Changi Airport, CHIJMES, National Gallery Singapore, the Singapore Flyer, the Orchard Road shopping belt, the resort island of Sentosa, and the Singapore Botanic Gardens, Singapore's first UNESCO World Heritage Site, all located in southern and eastern Singapore.
Sources: en.wikipedia.org
== Usage == Deltamethrin is a highly effective insecticide. It is used, among other applications, for the production of long-lasting insecticidal nets (LLINs), which, along with indoor residual spraying (IRS), are the main vector control strategies recommended by the World Health Organization (WHO) for the management of malaria. Deltamethrin plays a key role in controlling malaria vectors, and is used in the manufacture of long-lasting insecticidal mosquito nets. It is used as one of a battery of pyrethroid insecticides in control of malarial vectors, particularly Anopheles gambiae, and whilst being the most employed pyrethroid insecticide, can be used in conjunction with, or as an alternative to, permethrin, cypermethrin and organophosphate-based insecticides, such as malathion and fenthion. Resistance to deltamethrin (and its counterparts) is now extremely widespread and threatens the success of worldwide vector control programmes.
=== Genome-scale screening === Genome-scale RNAi research relies on high-throughput screening (HTS) technology. RNAi HTS technology allows genome-wide loss-of-function screening and is broadly used in the identification of genes associated with specific phenotypes. This technology has been hailed as a potential second genomics wave, following the first genomics wave of gene expression microarray and single nucleotide polymorphism discovery platforms. One major advantage of genome-scale RNAi screening is its ability to simultaneously interrogate thousands of genes. With the ability to generate a large amount of data per experiment, genome-scale RNAi screening has led to an explosion of data generation rates. Exploiting such large data sets is a fundamental challenge, requiring suitable statistics/bioinformatics methods. The basic process of cell-based RNAi screening includes the choice of an RNAi library, robust and stable cell types, transfection with RNAi agents, treatment/incubation, signal detection, analysis and identification of important genes or therapeutical targets.
Reprocessing allows the recycling of the uranium and plutonium into fresh fuel (RepU and MOX) and a strong reduction of volume, decay heat and radiotoxicity of the HLW. A measure of the HLW hazard is provided by radiotoxicity coming from the different nature of radionuclides. The SNF radiotoxicity is usually evaluated as a function of time and compared to the natural uranium ore. The spent nuclear fuel without reprocessing has a long-term toxicity that is mainly dominated by transuranic elements. Mainly due to plutonium, SNF without reprocessing reaches the reference radiotoxicity level after about 300,000 years. After uranium and plutonium removal, HLW is less radioactive and it decays to the reference level within 10,000 years. Since minor actinides (MAs) also contribute to the long-term decay heat and radiotoxicity of the spent fuel, an advanced reprocessing could further reduce the radiotoxic inventory with a decay to the reference level of about 300 years.
LiveNation (which already operates music venues at the site) will revamp the Budweiser Stage Amphitheatre into an indoor/outdoor facility with a capacity of up to 20,000 people in the summer and nearly 9,000 in winter. Austrian company Therme Group will develop the west island. A new large facility will cover most of the island. The facility will include indoor and outdoor pools, a spa, waterslides, restaurants, and a botanical garden. Outside of the facility, it will build a 12 acres (4.9 ha) public park and beach. The projected admission price for indoor activities is about $40 per person for full-day admittance. A third company proposed to build a zip-line and adventure park but pulled out of the project. The company and the government could not come to terms on the lease. Private sector investments are expected to be about $500 million. Public sector investment was not disclosed. A review process for environmental, heritage, and public consultation will likely extend into 2023. Construction is scheduled to begin in 2024, with a 2030 completion. In February 2022, Toronto city council voted to adopt a process to create an approvals process for the Province's plan for the redevelopment of Ontario Place. This process generally follows the city's traditional development approvals process, notwithstanding Ontario Place is predominately constructed on Provincially-owned land. Based on this timeline, a rezoning application is expected in late 2022 and a site plan approval process began in 2023. The Cinesphere was closed for renovations.
Sources: en.wikipedia.org
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.
Lyophilized powder is normally stored desiccated at -20 °C, protected from light and moisture. Powder kept under these conditions is generally stable for long periods. Solutions are less stable and are usually prepared immediately before use.
A purity value from one chromatographic method does not capture every possible impurity. Related peptides with similar retention behavior, counterions, and residual solvents may not appear in the same analysis. Independent testing with an orthogonal method provides stronger assurance of identity and content.
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.