The short version of Tuftsin fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-23 and is reviewed periodically as new material appears.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
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.
coli for animals and humans Kentucky Bioprocessing took over Large Scale Biology's facilities in Owensboro, Kentucky, and offers contract biomanufacturing services in tobacco plants, grown in greenhouses or in open fields. Medicago Inc. – Pre-clinical trials of Influenza vaccine made in transiently infected Nicotiana benthamiana (relative of tobacco) plants in greenhouses. Medicago grew virus-like particles in the Australian weed Nicotiana benthamiana, for development of a candidate vaccine against the COVID-19 virus, initiating a Phase I clinical trial in July 2020. PharmaPraxis – Developing biosimilars in collaboration with PlantForm (see below) and Fraunhofer. Pharming – C1 inhibitor, human collagen 1, fibrinogen (with American Red Cross), and lactoferrin in cow milk The intellectual property behind the fibrinogen project was acquired from PPL Therapeutics when PPL went bankrupt in 2004. Phyton Biotech uses plant cell culture systems to manufacture active pharmaceutical ingredients based on taxanes, including paclitaxel and docetaxel Planet Biotechnology – antibodies against Streptococcus mutans, antibodies against doxorubicin, and ICAM 1 receptor in tobacco PlantForm Corporation – biosimilar trastuzumab in tobacco – It is developing biosimilars in collaboration with PharmaPraxis (see above) and Fraunhofer. ProdiGene – was developing several proteins, including aprotinin, trypsin and a veterinary TGE vaccine in corn. Was in process of launching trypsin product in 2002 when later that year its field test crops contaminated conventional crops.
These adverse effects were reversed when the regimen stopped, but it was fatal in some patients with protracted vomiting. Milk-alkali syndrome declined in men after effective treatments for peptic ulcer disease arose. Since the 1990s it has been most frequently reported in women taking calcium supplements above the recommended range of 1.2 to 1.5 grams daily, for prevention and treatment of osteoporosis, and is exacerbated by dehydration. Calcium has been added to over-the-counter products, which contributes to inadvertent excessive intake. Excessive calcium intake can lead to hypercalcemia, complications of which include vomiting, abdominal pain and altered mental status. As a food additive it is designated E170, and it has an INS number of 170. Used as an acidity regulator, anticaking agent, stabilizer or color it is approved for usage in the EU, US and Australia and New Zealand. It is "added by law to all UK milled bread flour except wholemeal". It is used in some soy milk and almond milk products as a source of dietary calcium; at least one study suggests that calcium carbonate might be as bioavailable as the calcium in cow's milk. Calcium carbonate is also used as a firming agent in many canned and bottled vegetable products. Several calcium supplement formulations have been documented to contain the chemical element lead, posing a public health concern. Lead is commonly found in natural sources of calcium.
==== Angiopoietins ==== The angiopoietins, Ang1 and Ang2, are required for the formation of mature blood vessels, as demonstrated by mouse knock out studies. Ang1 and Ang2 are protein growth factors which act by binding their receptors, Tie-1 and Tie-2; while this is somewhat controversial, it seems that cell signals are transmitted mostly by Tie-2; though some papers show physiologic signaling via Tie-1 as well. These receptors are tyrosine kinases. Thus, they can initiate cell signaling when ligand binding causes a dimerization that initiates phosphorylation on key tyrosines.
However, fatty acids are also important components of the phospholipids that form the phospholipid bilayers out of which all the membranes of the cell are constructed (the cell wall, and the membranes that enclose all the organelles within the cells, such as the nucleus, the mitochondria, endoplasmic reticulum, and the Golgi apparatus). The "uncombined fatty acids" or "free fatty acids" found in the circulation of animals come from the breakdown (or lipolysis) of stored triglycerides. Because they are insoluble in water, these fatty acids are transported bound to plasma albumin. The levels of "free fatty acids" in the blood are limited by the availability of albumin binding sites. They can be taken up from the blood by all cells that have mitochondria (with the exception of the cells of the central nervous system). Fatty acids can only be broken down in mitochondria, by means of beta-oxidation followed by further combustion in the citric acid cycle to CO2 and water. Cells in the central nervous system, although they possess mitochondria, cannot take free fatty acids up from the blood, as the blood–brain barrier is impervious to most free fatty acids, excluding short-chain fatty acids and medium-chain fatty acids. These cells have to manufacture their own fatty acids from carbohydrates, as described above, in order to produce and maintain the phospholipids of their cell membranes, and those of their organelles.
=== Sale in Japan === The alcoholic beverage industry in Japan is large. For example, in fiscal year 2013, Suntory, one of the country's largest beverage companies, recorded sales of 570.7 billion yen (about US$4.7 billion) in alcoholic beverages, excluding wine. Currently, the sales revenue from powdered alcohol has been too small to affect the sales of liquid-alcohol companies. Additionally, powdered alcohol's market share is currently too small to be considered as a statistical item in Japanese tax reports. Powdered alcohol is found in some mass production foods, used in small amounts (as are other additives).
Sources: en.wikipedia.org
=== Clearance in CNS === In comparison to Schwann cells, oligodendrocytes require axon signals to survive. In their developmental stages, oligodendrocytes that fail to make contact to axon and receive axon signals undergo apoptosis. Experiments in Wallerian degeneration have shown that upon injury oligodendrocytes either undergo programmed cell death or enter a state of rest. Therefore, unlike Schwann cells, oligodendrocytes fail to clean up the myelin sheaths and their debris. In experiments conducted on rats, myelin sheaths were found for up to 22 months. Therefore, CNS rates of myelin sheath clearance are very slow and could possibly be the cause for hindrance in the regeneration capabilities of the CNS axons as no growth factors are available to attract the proximal axons. Another feature that results eventually is glial scar formation. This further hinders chances for regeneration and reinnervation. Oligodendrocytes fail to recruit macrophages for debris removal. Macrophage entry in general into CNS site of injury is very slow. In contrast to PNS, microglia play a vital role in CNS Wallerian degeneration. However, their recruitment is slower in comparison to macrophage recruitment in PNS by approximately 3 days. Further, microglia might be activated but hypertrophy, and fail to transform into fully phagocytic cells. Those microglia that do transform, clear out the debris effectively. Differentiating phagocytic microglia can be accomplished by testing for expression of major histocompatibility complex (MHC) class I and II during Wallerian degeneration.
=== Personality === The modifiable personality traits which might cause greater well-being have yet to be critically synthesised. However, there is evidence that certain traits are beneficial for individual happiness or performance: locus of control, curiosity, religiousness, spirituality, spiritual striving, sense of urgency, self-compassion, authenticity, growth mindset, positive mental attitudes, grit, goal orientation with a meta-analysis concluding that approach rather than avoidance goals are superior for performance; as well as prosocial rather than zero-sum goals. Researchers who have reported on the character traits of people with high and low life satisfaction found that character strengths which predict life satisfaction are zest, curiosity, hope, and humour. Character strengths that do not predict life satisfaction include appreciation of beauty and excellence, creativity, kindness, love of learning, and perspective. Meanwhile, research on character strengths that is separated by gender indicates the character strengths that predict life satisfaction in men are humour, fairness, perspective, and creativity, while the character strengths that predict life satisfaction in women are zest, gratitude, hope, appreciation of beauty, and love. Certain traits are specifically beneficial to those with certain health issues. Believing in yourself (high self efficacy) matters for eating disorders, immune response, stress management, pain management and healthy living.
== Selected publications == Yang, Yee Hwa; Speed, Terry (2002), "Design issues for cDNA microarray experiments", Nature Reviews Genetics, 3 (8): 579–588, doi:10.1038/nrg863, PMID 12154381, S2CID 260480 Dudoit, Sandrine; Yang, Yee Hwa; Callow, Matthew J.; Speed, Terence P. (2002), "Statistical methods for identifying differentially expressed genes in replicated cDNA microarray experiments", Statistica Sinica, 12 (1): 111–139, JSTOR 24307038, MR 1894191 Yang, Yee Hwa; Dudoit, Sandrine; Luu, Percy; Lin, David M.; Peng, Vivian; Ngai, John; Speed, Terence P. (2002), "Normalization for cDNA microarray data: a robust composite method addressing single and multiple slide systematic variation", Nucleic Acids Research, 30 (4): e15, doi:10.1093/nar/30.4.e15, PMC 100354, PMID 11842121 Gentleman, Robert C.; Carey, Vincent J.; Bates, Douglas M.; Bolstad, Ben; Dettling, Marcel; Dudoit, Sandrine; Ellis, Byron; Gautier, Laurent; Ge, Yongchao; Gentry, Jeff; Hornik, Kurt; Hothorn, Torsten; Huber, Wolfgang; Iacus, Stefano; Irizarry, Rafael; Leisch, Friedrich; Li, Cheng; Maechler, Martin; Rossini, Anthony J.; Sawitzki, Gunther; Smith, Colin; Smyth, Gordon; Tierney, Luke; Yang, Jean Y. H.; Zhang, Jianhua (2004), "Bioconductor: open software development for computational biology and bioinformatics", Genome Biology, 5 (10): R80, doi:10.1186/gb-2004-5-10-r80, PMC 545600, PMID 15461798
The success of the Half-Life series has spurred the creation of several spin-off games for Half-Life 2. Codename Gordon (sometimes called Codename: Gordon) is a two-dimensional Flash sidescroller shooter developed by NuclearVision, and was released over Valve's Steam online delivery system on May 18, 2004, as a promotional game for the then-upcoming Half-Life 2. Characters from Half-Life have appeared in other games. Peggle Extreme, a special edition of Peggle bundled with the PC version of The Orange Box features levels based on Half-Life 2, Team Fortress 2 and Portal. The headcrab is also an unlockable character in Super Meat Boy when bought on Steam. The Headcrab also appeared in an April Fools event in the MMO Vindictus as an event item along with the Crowbar, possibly due to the game being created on the Source Engine as well. In the game Magicka there is a playable character (after the addition of a DLC), which closely resembles the original zombie from the Half-Life universe, equipped with a crowbar. Gordon also appears in Renegade Ops and the headcrab is available as a pet in Torchlight 2. Half-Life has also inspired a number of fan-made mods, some which have gained recognition on their own. Garry's Mod started as a sandbox mode using Half-Life 2 assets but since has become a commercial product and given users the ability to incorporate other assets. Among notable fan-made campaigns is Minerva, which was designed to extend the story from Half-Life 2.
=== Medications === There are many drugs that can affect calcium level in the blood, and therefore PTH secretion. For example, many individuals may take a calcium carbonate supplement, which increases the calcium level in the blood. PTH is decreased. Many medications may also increase urination, furthering loss of calcium.
Sources: en.wikipedia.org
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.