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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.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
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.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
=== Other forms === The anamorphic form of P. semilanceata is an asexual stage in the fungus's life cycle involved in the development of mitotic diaspores (conidia). In culture, grown in a petri dish, the fungus forms a white to pale orange cottony or felt-like mat of mycelia. The conidia formed are straight to curved, measuring 2.0–8.0 by 1.1–2.0 μm, and may contain one to several small intracellular droplets. Although little is known of the anamorphic stage of P. semilanceata beyond the confines of laboratory culture, in general, the morphology of the asexual structures may be used as classical characters in phylogenetic analyses to help understand the evolutionary relationships between related groups of fungi. Scottish mycologist Roy Watling described sequestrate (truffle-like) or secotioid versions of P. semilanceata he found growing in association with regular fruit bodies. These versions had elongated caps, 20–22 cm (7.9–8.7 in) long and 0.8–1 cm (0.3–0.4 in) wide at the base, with the inward curved margins closely hugging the stipe from the development of membranous flanges. Their gills were narrow, closely crowded together, and anastomosed (fused together in a vein-like network). The color of the gills was sepia with a brownish vinaceous (red wine-colored) cast, and a white margin. The stipes of the fruit bodies were 5–6 cm (2.0–2.4 in) long by 0.1–0.3 cm (0.04–0.12 in) thick, with about 2 cm (0.8 in) of stipe length covered by the extended cap. The thick-walled ellipsoid spores were 12.5–13.5 by 6.5–7 μm.
== Evolutionary background == LepA has a highly conserved sequence. LepA orthologs have been found in bacteria and almost all eukaryotes. The conservation in LepA has been shown to cover the entire protein. More specifically, the amino acid identity of LepA among bacterial orthologs ranges from 55%-68%. Two forms of LepA have been observed; one form of LepA branches with mitochondrial LepA sequences, while the second form branches with cyanobacterial orthologs. These findings demonstrate that LepA is significant for bacteria, mitochondria, and plastids. LepA is absent from archaea.
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== Contraindications == The safety of methenamine in people with renal impairment is unknown and it is considered to be contraindicated in this context. Other contraindications include severe liver disease or hepatic impairment, known hypersensitivity to methenamine or the drug formulation's components, severe dehydration, hyperphosphatemia, and use of sulfonamides. Caution is also advised in people with gout. Its safety during pregnancy is unclear and it is known to enter the placenta, amniotic fluid, and breast milk. As such, discontinuation of methenamine is recommended during breastfeeding. No teratogenic effects with methenamine in animals have been observed. Although the preceding contraindications of methenamine have been specified, they are not well-defined and may not be absolute contraindications in all cases.
Sources: en.wikipedia.org
2-carboxy-D-arabinitol + phosphate This enzyme belongs to the family of hydrolases, to be specific, those acting on phosphoric monoester bonds. The systematic name is 2-carboxy-D-arabinitol-1-phosphate 1-phosphohydrolase.
An analgesic, also called an antalgic, painkiller, or pain reliever, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in some instances eliminate, sensation, although analgesia and anesthesia are neurophysiologically overlapping and thus various drugs have both analgesic and anesthetic effects. Analgesic choice is also determined by the type of pain: For neuropathic pain, recent research has suggested that classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants may be considered as an alternative. Various analgesics, such as many NSAIDs, are available over the counter in most countries, whereas various others are prescription drugs owing to the substantial risks and high chances of overdose, misuse, and addiction in the absence of medical supervision.
=== Reservoir effects === Libby's original exchange reservoir hypothesis assumed that the 14C/12C ratio in the exchange reservoir is constant all over the world, but it has since been discovered that there are several causes of variation in the ratio across the reservoir.
Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.