The short version of tuftsin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-08-18. Anything still debated is marked as such rather than presented as settled.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
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.
| 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 |
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
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.
Mycophenolate mofetil is the morpholino ethyl ester of mycophenolic acid; the ester masks the carboxyl group. Mycophenolate mofetil is reported to have a pKa values of 5.6 for the morpholino moiety and 8.5 for the phenolic group.
== Cytosolic Fatty Acid Synthesis == While essential fatty acids (i.e., linoleic acid) are obtained exclusively through diet, all non-essential fatty acids must be synthesized de novo. Acetyl-CoA is the precursor used for fatty acid synthesis in the cytosol; therefore, fatty acid synthesis requires those reactions which produce acetyl-CoA—namely, glycolysis or amino acid metabolism. Regardless of the metabolic source of the product, all de novo lipogenesis relies on the production and availability of cytosolic acetyl-CoA, and thereafter on its conversion into malonyl-CoA.
=== Subacute === Studies in rats showed decreased weight, and gastric, intestinal, and renal function changes, while repetitive doses lead to neurotoxicity. Reproductive toxicity in males was also reported. A NOAEL in rodents was observed at 43 μg/kg body weight.
On March 2, 2009, Skittles launched a web-based marketing campaign where the official website became a small overlay with options to view different social media sites in the main area, including its official YouTube channel, a Facebook profile, and a Twitter account. The move was debated by people interested in social media. In 2009, the production of Skittles ceased using animal-derived gelatin, making them suitable for vegetarians, vegans, and certain religious groups. Skittles were involved in two political incidents in the 2010s. In the aftermath of the killing of Trayvon Martin, protestors used Skittles, which Martin had reportedly been carrying along with Arizona watermelon fruit-flavored juice drink, as a symbol during rallies. Though Mars' brief statement of condolences was criticized by some outlets, such as Adweek, for being too subdued, Mars' response in 2016 to a Skittles-based image macro (which was posted by Donald Trump Jr. on his Twitter feed as an analogy for immigration) was praised for its tact and directness. MWWPR said Mars' responses could influence public relations best practices. In 2016, Skittles faced controversy over temporarily changing the color of the candies from the signature rainbow appearance to white in support of Pride month, LGBT rights and London Pride. The Wrigley Company, a separate representing party of the Skittles brand, mass-produced the limited-edition colorless candies. Skittles' rainbow themed packaging had also been altered temporarily to complement the achromatic confectionery within.
Sources: en.wikipedia.org
Systemic administration of AAV-based AONs to Mybpc3-targeted knock-in newborn mice prevented both systolic dysfunction and left ventricular hypertrophy, at least for the duration of the investigated period. For the human MYBPC3 gene, skipping of 6 single exons or 5 double exons with specific AONs would result in shortened in-frame cMyBP-Cs, allowing the preservation of the functionally important phosphorylation and protein interaction sites. With this approach, about half of missense or exonic/intronic truncating mutations could be removed, including 35 mutations in exon 25. The other strategy targeting the mutant pre-mRNA is SMaRT. Hereby, two independently transcribed molecules, the mutant pre-mRNA and the therapeutic pre-trans-splicing molecule carrying the wild-type sequence are spliced together to give rise to a repaired full-length mRNA. Recently, the feasibility of this method was shown both in isolated cardiac myocytes and in vivo in the heart of homozygous Mybpc3-targeted knock-in mice, although the efficiency of the process was low and the amount of repaired protein was not sufficient to prevent the development of the cardiac disease phenotype. In principle, however, this SmART strategy is superior to exon skipping or CRISPR/Cas9 genome editing and still attractive, because only two pre-trans-splicing molecules, targeting the 5' and the 3' of MYBPC3 pre-mRNA would be sufficient to bypass all MYBPC3 mutations associated with cardiomyopathies and therefore repair the mRNA.
=== Mentor === Hodgkin's mentor Professor John Desmond Bernal greatly influenced her life: scientifically, politically, and personally. Bernal was a key scientific adviser to the UK government during the Second World War. He was also an open and vocal member of the Communist Party and a faithful supporter of the Soviet regime until its invasion of Hungary in 1956. He was a chemist who believed in equal opportunity for women. In his laboratory, Hodgkin extended work that he began on biological molecules including sterols. She helped him to make the first X-ray diffraction studies of pepsin and crystalline protein. Hodgkin always referred to him as "Sage". They were lovers before she met Thomas Hodgkin. The marriages of both Dorothy and Bernal were unconventional by the standards of the present and of those days.
the Division Artillery consisted of: Battery A, 319th Artillery Battery B, 319th Artillery Battery C, 319th Artillery (Battery C, 320th Artillery after 1960; C-319th accompanied the 2d ABG, 503d Infantry on its assignment to the 25th Infantry Division) Battery D, 320th Artillery Battery E, 320th Artillery Battery B, 377th Artillery additional division elements consisted of: 82nd Medical Company 82nd Signal Battalion 82nd Aviation Company Troop A, 17th Cavalry 307th Airborne Engineer Battalion 407th Supply and Transportation Battalion (The 82nd Quartermaster Parachute Supply and Maintenance Company [activated 1 March 1945] was reorganized and redesignated as Company B, 407th S&T Battalion.) 782nd Maintenance Battalion The pentomic organization was unsuccessful. In 1964, the division reorganized into three brigades of three battalions, the Reorganization Objective Army Division (ROAD) organization.
=== Environmental rehabilitation === When the factory was closed in 1986, pipes, drums and tanks were sold. The MIC and the Sevin plants are still there, as are storages of different residues. Isolation material is falling down and spreading. The area around the plant was used as a dumping area for hazardous chemicals. In 1982, tube wells in the vicinity of the UCIL factory had to be abandoned and tests in 1989 performed by UCC's laboratory revealed that soil and water samples collected near the factory and inside the plant were toxic to fish. Several other studies had also shown polluted soil and groundwater in the area. Reported polluting compounds include 1-naphthol, naphthalene, Sevin, tarry residue, toxic organochlorines, volatile organochlorine compounds, mercury, chromium, copper, nickel, lead, hexachloroethane, hexachlorobutadiene, and the pesticide HCH (Hexachlorocyclohexane). In order to provide safe drinking water to the population around the UCIL factory, the government of Madhya Pradesh proposed a water-supply improvement scheme. In December 2008, the Madhya Pradesh High Court decided that the toxic waste should be incinerated at Ankleshwar in Gujarat, which was met by protests from activists all over India. On 8 June 2012, the centre for incineration of toxic Bhopal waste agreed to pay ₹250 million (US$2.6 million) to dispose of UCIL chemical plants' waste in Germany. On 9 August 2012, Supreme court directed the Union and Madhya Pradesh Governments to take immediate steps for disposal of toxic waste lying around and inside the factory within six months.
A torsion angle, found in stereochemistry, is a particular example of a dihedral angle describing the geometric relation of two parts of a molecule joined by a chemical bond. Every set of three non-colinear atoms of a molecule defines a half-plane. As explained above, when two such half-planes intersect (i.e., a set of four consecutively-bonded atoms), the angle between them is a dihedral angle. Dihedral angles are used to specify the molecular conformation. Stereochemical arrangements corresponding to angles between 0° and ±90° are called syn (s), those corresponding to angles between ±90° and 180° anti (a). Similarly, arrangements corresponding to angles between 30° and 150° or between −30° and −150° are called clinal (c) and those between 0° and ±30° or ±150° and 180° are called periplanar (p). The two types of terms can be combined so as to define four ranges of angle; 0° to ±30° synperiplanar (sp); 30° to 90° and −30° to −90° synclinal (sc); 90° to 150° and −90° to −150° anticlinal (ac); ±150° to 180° antiperiplanar (ap). The synperiplanar conformation is also known as the syn- or cis-conformation; antiperiplanar as anti or trans; and synclinal as gauche or skew. For example, with n-butane two planes can be specified in terms of the two central carbon atoms and either of the methyl carbon atoms. The syn-conformation shown above, with a dihedral angle of 60° is less stable than the anti-conformation with a dihedral angle of 180°. For macromolecular usage the symbols T, C, G+, G−, A+ and A− are recommended (ap, sp, +sc, −sc, +ac and −ac respectively).
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.
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.