The short version of Tuftsin analogue fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-24. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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 |
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
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.
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.
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.
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.
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.
Daime members also uses the words Luz ("light") or Santa Luz ("holy light") Some nomenclature are created by the cultural and symbolic signification of ayahuasca, with names like planta professora ("plant teacher"), professor dos professores ("teacher of the teachers"), sagrada medicina ("holy medicine") or la purga ("the purge").
Wakame Seaweed Archived 2016-04-21 at the Wayback Machine at About.com AlgaeBase link Undaria pinnatifida Archived 2019-09-24 at the Wayback Machine at the FAO Undaria pinnatifida at the Joint Nature Conservation Committee, UK Global Invasive species database Archived 2011-06-11 at the Wayback Machine Undaria Management at the Monterey Bay National Marine Sanctuary
Chromatographic methods with fluorescence detection Liquid chromatography with fluorescence detection (LC-FLD) provides a selective, relatively cheap, reproducible method for the qualitative and quantitative analysis of YTX for shellfish and algae samples. This method requires an additional sample preparation step after the analyte extraction procedure has been completed (in this case SPE is preferentially used so common interferences can be removed from the sample). This additional step involves the derivatization of the YTXs with a fluorescent dienophile reagent — dimethoxy-4-methyl-3-oxo-3,4-dihydroquinoxalinyl)ethyl]-1,2,4-triazoline-3,5-dione, which facilitates analyte detection. This additional sample preparation step can make LC-FLD analysis extremely time-consuming and is a major disadvantage of the technique.
Sources: en.wikipedia.org
== Taxonomy == German naturalist Wilhelm Peters described the coastal taipan as Pseudechis scutellatus in 1867, from material collected in Rockhampton, Queensland. Charles Walter De Vis described Pseudechis wilesmithii from Walsh River in north Queensland in 1911. In 1922, scientific bird collector William McLennan killed two snakes near Coen in far north Queensland. Impressed by their size—up to 2.76 m, he sent the skins and skulls to the Australian Museum in Sydney. Australian naturalist Roy Kinghorn established the genus Oxyuranus in 1923, describing a specimen from Coen as O. maclennani after its collector. He noted the distinctness of the palatine bone necessitated the new genus as distinct from all other elapid snakes. In 1930, Kinghorn announced it as the second largest venomous snake in the world, with 3/4 inch fangs. In 1933, Australian zoologist Donald Thomson concluded that Pseudechis scutellatus and Oxyuranus maclennani were the same species; this meant that Peters' specific epithet had priority, as did Kinghorn's genus as the species was highly distinct. Hence, the coastal taipan became Oxyuranus scutellatus. Thomson had spent some years in Cape York peninsula with the indigenous people, who told tales of a giant snake they greatly feared. Australian herpetologist Ken Slater described Oxyuranus scutellatus canni, commonly known as the Papuan taipan, in 1956, on the basis of its distinctive coloration. He named it after George Cann, longtime Snake Man of La Perouse. It is found throughout the southern portion of the island of New Guinea.
Abdul Basit, senior associate fellow at the International Centre for Political Violence and Terrorism Research (ICPVTR), stressed that the concern was not the drones' sophistication, but their presence in Pakistan's capital. Taliban drones forced airspace closures and targeted deep within the country, escalating the threat both horizontally and vertically. Hammad Waleed, a research associate at Pakistan's Strategic Vision Institute, stated that while Pakistan's air defense could counter numbered drone projectiles, it would struggle against drone swarms.
This can be the case, for example, if one kidney has already become a non-functioning shrunken kidney due to urinary retention and the second suddenly swells acutely due to urinary retention (hydronephrosis) and is damaged ("large kidney-small kidney syndrome") or if hyperthyroidism is treated and the glomerular filtration rate is suddenly reduced as a result.
Sources: en.wikipedia.org
== Metabolic diseases == Early studies in the area reported that a liver-derived protein, alpha2-HS Glycoprotein, also known as Fetuin-A, can inhibit insulin tyrosine kinase activation and might play a role in the pathogenesis of metabolic disorders. Results suggest that hepatokine production could remodel metabolic homeostasis. This is exemplified by a number of studies revealing that hepatokines play a pivotal role in metabolism and contribute to the development of obesity, insulin resistance, T2D, NAFL, and NASH (109, 149). So far, ~20 hepatokines have been described to be involved in the regulation of energy and nutrient metabolism by acting directly on the liver or on distal target tissues. Hepatokines can be remodelled depending on the environment, for example, exercise-training can remodel hepatokine secretion. Little work in human hepatokines has been performed, however, using precision-cut liver slicing of human livers with and without MASH over 2000 hepatokines were described with potential roles in either promoting or protecting cardiometabolic disease pathogenesis. Hepatokines are now considered potential targets for the treatment of cardiometabolic disorders.
Jürgen Sundermann (28 May 1991 – 30 June 1993) Bernd Stange (1 July 1993 – 21 February 1994) Jürgen Sundermann (22 February 1994 – 8 April 1994) Damian Halata (9 April 1994 – 30 June 1994) Tony Woodcock (1 July 1994 – 30 October 1994) August "Gustl" Starek (31 October 1994 – 30 May 1996) Damian Halata (1 June 1996 – 30 June 1996) Sigfried "Siggi" Held (1 July 1996 – 7 October 1997) Damian Halata (8 October 1997 – 30 June 1998) Hans-Ulrich "Uli" Thomale (1 July 1998 – 28 March 1999) Dragoslav Stepanović (29 March 1999 – 29 August 1999) Joachim Steffens (30 August 1999 – 22 July 2001) Hans-Jürgen "Dixie" Dörner (23 July 2001 – 26 March 2003) Detlef Schößler (27 March 2003 – 3 June 2003) Hermann Andreev (24 June 2003 – 19 March 2004) Michael Breitkopf and Jörg Engelmann (20 March 2004 – 22 April 2004) Mike Sadlo (23 April 2004 – 30 June 2004) – Player/manager 1. FC Lok Leipzig
The Sumerians are said to have cultivated and harvested the opium poppy (Papaver somniferum) in lower Mesopotamia as early as 3400 BC, though this has been disputed. The most ancient testimony concerning the opium poppy found to date was inscribed in cuneiform script on a small white clay tablet at the end of the third millennium BC. This tablet was discovered in 1954 during excavations at Nippur, and is currently kept at the University of Pennsylvania Museum of Archaeology and Anthropology. Deciphered by Samuel Noah Kramer and Martin Leve, it is considered to be the most ancient pharmacopoeia in existence. Some Sumerian tablets of this era have an ideogram inscribed upon them, "hul gil", which translates to "plant of joy", believed by some authors to refer to opium. The term gil is still used for opium in certain parts of the world. The Sumerian goddess Nidaba is often depicted with poppies growing out of her shoulders. About 2225 BC, the Sumerian territory became a part of the Babylonian empire. Knowledge and use of the opium poppy and its euphoric effects thus passed to the Babylonians, who expanded their empire eastwards to Persia and westwards to Egypt, thereby extending its range to these civilizations. British archaeologist and cuneiformist Reginald Campbell Thompson writes that opium was known to the Assyrians in the 7th century BC. The term "Arat Pa Pa" occurs in the Assyrian Herbal, a collection of inscribed Assyrian tablets dated to c. 650 BC.
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.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.