batch purity raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-07-04 and is reviewed periodically as new material appears.
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.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
After the resignations of Kissinger's aides, Nixon took away the authority to tap phones, which he had given Kissinger in May 1969, and gave it to the attorney general, John Mitchell. Unknown to Kissinger, Mitchell had been illegally tapping his phone since the fall of 1969. Adding to the tension, on 2 May 1970, U.S. aircraft bombed North Vietnam for the first time since 1968, causing Senator Fulbright to say, "Good God", when he heard the news. Senate Majority Leader Mike Mansfield said he had trouble believing that Nixon and Kissinger were so reckless. To Nixon, Kissinger accused Laird and/or Rogers of leaking the news of the bombing raid on North Vietnam and asked for the FBI to tap their phones. Without informing Nixon, on 4 May 1970, Laird announced the end of the bombing raids on North Vietnam. On the night of 8 May 1970, Nixon, who had been rattled by the protests, stayed up all night, drinking heavily and randomly phoning people he knew. Between 11:00 pm–2:00 am, Nixon made forty calls, with Kissinger receiving eight of the calls. The Cambodian "incursion" saw American and South Vietnamese troops take the areas of eastern Cambodia that American commanders called the Fish Hook and Parrot's Beak and capture an impressive haul of arms originating from China and the Soviet Union. However, the majority of Vietnamese Communist forces had withdrawn deeper into Cambodia before the invasion, with only a small number left behind to wage a fighting retreat to avoid charges of cowardice.
=== Legal recognition of denturists === The 1919 Tasmanian Dental Act made a clear distinction between the role of a Dentist and the practice of denture making. For a patient that required dentures, a consultation by referral from a Dentist became normal procedure. Denturism – that is the field of dentures - was not recognised until more recent times. The Health Amendment Act (1933) was the first legal document that gave rise to the practice of Denturism in Canada. The Dental Mechanics Act of Alberta (1961) was the future update to this legislation allowing Denturists to begin work in the field. They were also known as "Dental Mechanics" or "Denture Therapists." This gave rise for the need for legal recognition of denturists in other countries. In the United States, the first legally recognised Denturists were found in Oregon, 1971. In 1974, denturists were first legally recognised and in 1978, Denture Therapists began practicing. The increasing rate of ill-fitting, misaligned, unstable and unsupportive dentures motivated three Denturists in 1956 to pursue international recognition. Rolf Pfenniger, Hannes Stiebler and Stephan Grabert formed the Internationale Arbeitsgemeinschaft der Zahnprothetiker. In English, this is the International Federation of Denturists. Denturists have campaigned for the right to practice independently in many states, with the argument that they can provide greater access and lower-cost prosthetic services. This argument has been disproved by examining other jurisdictions in the world which have both dentists and denturists.
=== Moffatt oxidation === In combination with dimethyl sulfoxide (DMSO), DCC affects the Pfitzner–Moffatt oxidation. This procedure is used for the oxidation of alcohols to aldehydes and ketones. Unlike metal-mediated oxidations, such as the Jones oxidation, the reaction conditions are sufficiently mild to avoid over-oxidation of aldehydes to carboxylic acids. Generally, three equivalents of DCC and 0.5 equivalents of proton source in DMSO are allowed to react overnight at room temperature. The reaction is quenched with acid.
The intercalated discs run perpendicular to the direction of muscle fibers. Under electron microscopy, an intercalated disc's path appears more complex. At low magnification, this may appear as a convoluted electron dense structure overlying the location of the obscured Z-line. At high magnification, the intercalated disc's path appears even more convoluted, with both longitudinal and transverse areas appearing in longitudinal section.
== Medical uses == Hydroxyzine is used in the treatment of itchiness, anxiety, and nausea due to motion sickness. A systematic review concluded that hydroxyzine outperforms placebo in treating generalized anxiety disorder. Insufficient data were available to compare the drug with benzodiazepines and buspirone. Hydroxyzine can also be used for the treatment of allergic conditions, such as chronic urticaria, atopic or contact dermatoses, and histamine-mediated pruritus. These have also been confirmed in both recent and past studies to have no adverse effects on the liver, blood, nervous system, or urinary tract. Use of hydroxyzine for premedication as a sedative has no effects on tropane alkaloids, such as atropine, but may, following general anesthesia, potentiate meperidine and barbiturates, and use in pre-anesthetic adjunctive therapy should be modified depending upon the state of the individual. Doses of hydroxyzine hydrochloride used for sleep range from 25 to 100 mg. As with other antihistamine sleep aids, hydroxyzine is usually only prescribed for short term or "as-needed" use since tolerance to the central nervous system (CNS) effects of hydroxyzine can develop in as little as a few days. A major systematic review and network meta-analysis of medications for the treatment of insomnia published in 2022 found little evidence to inform the use of hydroxyzine for insomnia. A 2023 meta-review concludes that hydroxyzine is effective for inducing sleep onset but less effective for maintaining sleep for eight hours.
Sources: en.wikipedia.org
== January 9, 1982 (Saturday) == A frigid blast of Arctic air began in the U.S. Midwest and South, setting records for cold in numerous cities, including a record low in Chicago of 26° below zero F (-32 °C) on the morning of January 10 and a wind chill factor of -100 °F (-73 °C). By January 17, there were 261 deaths attributed to hypothermia form the cold weather. The first World Cup series of cross-country skiing was started by the International Ski Federation, beginning with a meet in West Germany at Reit im Winkl for men and Klingenthal for women. Born: Catherine, Princess of Wales, wife since 2011 of William, Prince of Wales, heir apparent to the British throne; as Catherine Middleton in Reading, Berkshire Anusha Dandekar, Sudanese-born and Australian-raised Indian supermodel, veejay on MTV India, as well as a film actress, known for Juna Furniture (2024) and Baap Manus (2022); in Khartoum
National Food and Nutrition Policy Brazilian Dietary Guidelines (Guia Alimentar para a População Brasileira) National School Feeding Program Physical activity promotion campaigns Food labelling regulations The Brazilian Dietary Guidelines, first published in 2014, received international recognition for emphasising minimally processed foods and warning against excessive consumption of ultra-processed foods. Public health experts continue to debate additional interventions, including taxation of sugar-sweetened beverages, restrictions on food marketing directed at children, and expanded access to obesity treatment services.
== Treatment == Debate is ongoing as to whether NTIS is an adaptive or maladaptive mechanism in response to physiological stress. Some sources indicate that NTIS is beneficial as an acute-phase response, but detrimental during the chronic phase of illness. Several trials have investigated a possible therapy for NTIS, but they yielded inconsistent and partly contradictory results. This may be due to the heterogeneity of investigated populations, and to the lack of a consistent definition of NTIS. Administering exogenous T3 and T4 has variable results, but overall seems to confer no improvements to health outcome. Administering TRH to patients with chronic illness, however, seems to normalize thyroid levels and improve catabolic function. When NTIS is caused by the normal fasting response to illness, early parenteral nutrition has been shown to attenuate alterations in thyroid hormone (TSH, T3, T4, rT3) levels, whereas late parenteral nutrition exacerbates it. Late parenteral nutrition, though, also reduced complications and accelerated recovery in one study.
== Structure == Transpeptidases are members of the penicilloyl-serine transferase superfamily, which has a signature SxxK conserved motif. With "x" denoting a variable amino acid residue, the transpeptidases of this superfamily show a trend in the form of three motifs: SxxK, SxN (or analogue), and KTG (or analogue). These motifs occur at equivalent places, and are roughly equally spaced, along the polypeptide chain. The folded protein brings these motifs close to each other at the catalytic center between an all-α domain and an α/β domain. The structure of the streptomyces K15 DD-transpeptidase has been studied, and consists of a single polypeptide chain organized into two domains. One domain contains mainly α-helices, and the second one is of α/β-type. The center of the catalytic cleft is occupied by the Ser35-Thr36-Thr37-Lys38 tetrad, which includes the nucleophilic Ser35 residue at the amino-terminal end of helix α2. One side of the cavity is defined by the Ser96-Gly97-Cys98 loop connecting helices α4 and α5. The Lys213-Thr214-Gly215 triad lies on strand β3 on the opposite side of the cavity. The backbone NH group of the essential Ser35 residue and that of Ser216 downstream from the motif Lys213-Thr214-Gly215 occupy positions that are compatible with the oxyanion hole function required for catalysis. The enzyme is classified as a DD-transpeptidase because the susceptible peptide bond of the carbonyl donor extends between two carbon atoms with the D-configuration.
==== Campaign coordinator's death ==== On 17 October 2016, during his campaign for the second round, the executive-coordinator of Melo's campaign, Plínio Zalewski, was found dead at the PMDB's base of operations in the Centro Histórico neighborhood. He was one of the campaign's principal spokespersons, and would be eulogized by Melo in the wake of his death. He was buried the following day. The main hypothesis is that he died by suicide with a cold weapon. At the place where he died, a suicide letter was found. The PMDB temporarily suspended the campaign for 24 hours.
Sources: en.wikipedia.org
== Komagataella as a model organism == In the last few years, Komagataella was investigated and identified as a good model organism with several advantages. First of all, Komagataella can be grown and used easily in lab. Like other widely used yeast models, it has relatively short life span and fast regeneration time. Moreover, some inexpensive culture media have been designed, so that Komagataella can grow quickly on them, with high cell density. Whole genome sequencing for Komagataella has been performed. The K. phaffii GS115 genome has been sequenced by the Flanders Institute for Biotechnology and Ghent University, and published in Nature Biotechnology. The genome sequence and gene annotation can be browsed through the ORCAE system. The complete genomic data allows scientists to identify homologous proteins and evolutionary relationships between other yeast species and Komagataella. In addition, all seven species were sequenced by 2022. Furthermore, Komagataella are single eukaryotic cells, which means researchers could investigate the proteins inside Komagataella. Then the homologous comparison to other more complicated eukaryotic species can be processed, to obtain their functions and origins. Another advantage of Komagataella is its similarity to the well-studied yeast model — Saccharomyces cerevisiae. As a model organism for biology, S. cerevisiae have been well studied for decades and used by researchers for various purposes throughout history.
Significance of research: All experiments are carried out at 60 °C. Changes in the equilibrium constant (K) are used to determine what type of lipid interactions are occurring within the modeled membrane as well as observe liquid-ordered versus liquid-disorder regions. The value of the equilibrium constant determine the following: 1) if monomers are mixed ideally (K = 4.0) 2) when the monomers are mixed homogenously also referred to as a homo-association (K < 4.0) and 3) if the monomers have interchanged heterogeneously which is referred to as an hetero-association (K > 4.0) A plot of (K) is then created versus the cholesterol mol%. Each plot has similar trends in which the value of the equilibrium constant increased as the mol% increased with and without the presence of ethanol indicating a linear regression. Initially all the model membranes were organized in a liquid order phase but as the addition of cholesterol increase a liquid-disorder phase was observed. The following was determined regarding the liquid-order and liquid-disordered transitions during the addition of cholesterol in the presence of ethanol in each model membrane: 1) 0–15 mol% cholesterol a liquid-disordered phase was present 2) from 15 to 30 mol% there was a co-existence of both phases and 3) above 27 mole% of cholesterol the model membrane completed converted back to the original liquid-order phase within a two-hour time frame. The linear regression maxed out at 30 mol% of cholesterol.
Narrated by Tim Pigott-Smith, produced by Patrick Uden, directed by Sheila Hayman, made by Uden Associates 28 August A Short History of the Future: Spaceship, how space ships were viewed at cinema, and that the US space programme was largely started by Wernher von Braun, when making documentary programmes at Walt Disney; the American public needed to be convinced of the possibilities of space travel - as it would be publicly funded; Jesco Von Puttkamer of NASA; technology historical writer Frederick I. Ordway III; von Braun had first attempted a rocket launch in 1937, but it exploded; on 3 October 1942, his first successful rocket was the first man-made supersonic craft; there were 3,165 V-2 successful launches during the war; much 1950s popular space diagrams were drawn by Chesley Bonestell, which drew the attention of Walt Disney and producer Ward Kimball, who subsequently made the 1955 television episodes Man in Space and Man and the Moon, featuring Wernher von Braun, where von Braun demonstrated his XR-1 craft; health effects of space were demonstrated by former Luftwaffe fighter pilot and physicist Heinz Haber, later a well-known German television presenter; Star Trek: The Original Series was not popular when first shown, but was hugely popular after 1972 when it was repeated; consequently, the first space shuttle was named Enterprise, and when the shuttle was displayed in California on 17 September 1976, it was attended by the full cast of Star Trek, with the theme music also being played; Beverly Thurmond, NASA food scientist; Laura Louviere of NASA.
== Role in cell signaling == Protein quaternary structure also plays an important role in certain cell signaling pathways. The G protein-coupled receptor pathway involves a heterotrimeric protein known as a G protein. G proteins contain three distinct subunits known as the G-alpha, G-beta, and G-gamma subunits. When the G protein is activated, it binds to the G protein-coupled receptor protein and the cell signaling pathway is initiated. Another example is the receptor tyrosine kinase (RTK) pathway, which is initiated by the dimerization of two receptor tyrosine kinase monomers. When the dimer is formed, the two kinases can phosphorylate each other and initiate a cell signaling pathway.
=== Function in pregnancy === During pregnancy, the production of prolactin by the mother increases steadily, starting at 6–8 weeks of gestation and continuing until the end of the pregnancy. Prolactin levels in the human fetal circulation see a gradual increase from around 30 weeks of gestation until birth. Prolactin is released into milk at amounts consistent with the typical circulating concentration. By the twentieth week of gestation, mammary glands have reached a sufficient level of development to generate milk components as a result of stimulation by prolactin. Post-lactational involution refers to the process of breast tissue returning to its normal state after milk production stops due to a decrease in prolactin levels.
Sources: en.wikipedia.org
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, commonly written as TKPRPGP. It shares the first four residues with tuftsin and carries three prolines in the chain. The proline-rich tail is the main structural feature that separates it from the parent tetrapeptide.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.