Tuftsin analogue 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 2026-01-27 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.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
| 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 |
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.
Solubility behavior is a practical concern for handling. Selank dissolves readily in water and in common aqueous buffers, which simplifies preparation of working solutions. The choice of solvent, ionic strength, and pH can influence aggregation over time, particularly at higher concentrations. Aqueous solutions are typically sterile-filtered before use. Because stability depends on several variables, storage and handling notes should be treated as general guidance rather than fixed rules, and specific values are best confirmed against a certificate of analysis for each batch.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
== Causes == Few urethral diverticula are present at birth; the vast majority are acquired. Acquired urethral diverticula can be caused by trauma and/or infection. When the peri-urethral ducts become infected repeatedly, they can become blocked and eventually cause a diverticulum. They are usually found in the middle of the urethra or the end farthest from the bladder. Congenital urethral diverticula can arise from several embryological sources. These include defects in the primordial folds and remnants of Gartner's duct.
==== Hoyer's mounting medium ==== Chloral hydrate is also an ingredient used for Hoyer's solution, a mounting medium for microscopic observation of diverse plant types such as bryophytes, ferns, seeds, and small arthropods (especially mites). Other ingredients may include gum arabic and glycerol. An advantage of this medium includes a high refractive index and clearing (macerating) properties of small specimens (especially advantageous if specimens require observation with differential interference contrast microscopy). Because of its status as a regulated substance, chloral hydrate can be difficult to obtain. This has led to chloral hydrate being replaced by alternative reagents in microscopy procedures.
=== Chemical === Meitnerium is the seventh member of the 6d series of transition metals, and should be much like the platinum group metals. Calculations on its ionization potentials and atomic and ionic radii are similar to that of its lighter homolog iridium; implying that meitnerium's basic properties will resemble those of the other group 9 elements: cobalt, rhodium, and iridium. Prediction of the chemical properties of meitnerium has not received much attention recently. Meitnerium is expected to be a noble metal. The standard electrode potential for the Mt3+/Mt couple is expected to be 0.8 V. Based on the most stable oxidation states of the lighter group 9 elements, the most stable oxidation states of meitnerium are predicted to be +6, +3, and +1, with the +3 state being the most stable in aqueous solutions. Rhodium and iridium show a maximum oxidation state of +6; the most stable states are +4 and +3 for iridium and +3 for rhodium. The oxidation state +9, represented only by iridium in IrO4+, might be possible for meitnerium nonafluoride MtF9 and the MtO4+ cation, though IrO4+ is expected to be more stable than these meitnerium compounds. The meitnerium tetrahalides have also been predicted to have similar stabilities to those of iridium, thus also allowing a stable +4 state. It is further expected that the maximum oxidation states of elements from bohrium (element 107) to darmstadtium (110) may be stable in the gas phase but not in aqueous solution.
In early 1936, Thomas met Caitlin Macnamara (1913–1994), a 22-year-old dancer of Irish and French Quaker descent. She had run away from home, intent on making a career in dance, and aged 18 joined the chorus line at the London Palladium. Introduced by Augustus John, Caitlin's lover, they met in The Wheatsheaf pub on Rathbone Place in London's West End. Laying his head in her lap, a drunken Thomas proposed. Thomas liked to assert that he and Caitlin were in bed together ten minutes after they first met. Although Caitlin initially continued her relationship with John, she and Thomas began a correspondence, and in the second half of 1936 were courting. They married at the register office in Penzance, Cornwall, on 11 July 1937. For the first months of their relationship and marriage the couple lived at the Macnamara family home in Blashford, Hampshire. In May 1938 they moved to Wales, to the village of Laugharne, Carmarthenshire where they rented a cottage in Gosport Street before moving into 'Sea View', a larger property, a couple of months later. They left Laugharne in July 1940 and then led a peripatetic lifestyle over the next few years, returning to Blashford and subsequently living at Marshfield (1940), Bishopston (1940–41), Chelsea, in London (1942–43), Talsarn (1942–44), East Knoyle, Beaconsfield (1944), Bosham, Sussex (1944), Blaencwm (Llansteffan) (1944 and 1945), New Quay (1944–45), and in premises arranged by Margaret Taylor, one of Dylan's benefactors (the wife of the historian A. J. P.
== Military campaigns in Syria and Jazira == Ubayd Allah fought for Marwan and his tribal allies against the Qaysi tribes led by al-Dahhak ibn Qays al-Fihri, the governor of Damascus, at the Battle of Marj Rahit in August 684. The Qays were routed and al-Dahhak killed. Ubayd Allah was put in command of Marwan's army which, during Marj Rahit, consisted of 6,000 men from a handful of loyalist tribes. According to Kennedy, Ubayd Allah "clearly intended to rebuild the Syrian army which had served Mu'awiya and Yazid I so well". In the aftermath of Marj Rahit, Ubayd Allah oversaw campaigns against rebel Qaysi tribes for Marwan and his son and successor Abd al-Malik (r. 685–705) in the Jazira. However, Marwan's forces were too little to assert Umayyad rule throughout the caliphate. Thus, Ubayd Allah expanded recruitment to include various Qaysi tribes. He placed Husayn ibn Numayr al-Sakuni of Kindah as his second-in-command, and Shurahbil ibn Dhi'l Kala' of Himyar, Adham ibn Muhriz of Bahila, Rabi'a ibn al-Mukhariq of Banu Ghani and Jabala ibn Abd Allah of Khath'am as deputy commanders. Other than Husayn ibn Numayr, all of the commanders were either Qaysi or had earlier supported al-Dahhak against Marwan. In January 685, as Ubayd Allah was in Manbij preparing for the Umayyad reconquest of Iraq, Husayn ibn Numayr defeated the pro-Alid Penitents at the Battle of Ayn al-Warda. Ubayd Allah had been promised by Marwan the governorship over all of the lands he could conquer from the Alids and Ibn al-Zubayr, and he may have been sanctioned to plunder Kufa.
Sources: en.wikipedia.org
bai zhi (Chinese:白芷，Angelica dahurica), cao wu (Chinese:草烏, Aconitum kusnezoffii, Aconitum kusnezoffii, Kusnezoff's monkshood, or wolfsbane root), chuān xiōng (Chinese:川芎，Ligusticum wallichii, or Szechuan lovage), dong quai (Chinese:当归, Angelica sinensis, or "female ginseng"), wu tou (烏頭, Aconitum carmichaelii, rhizome of Aconitum, or "Chinese monkshood"), yang jin hua (洋金花, Flos Daturae metelis, or Datura stramonium, jimson weed, devil's trumpet, thorn apple, locoweed, moonflower), ya pu lu (押不芦, Mandragora officinarum), rhododendron flower, and jasmine root. Others have suggested the potion may have also contained hashish, bhang, shang-luh, or opium. Victor H. Mair wrote that mafei "appears to be a transcription of some Indo-European word related to "morphine"." Some authors believe that Hua Tuo may have discovered surgical analgesia by acupuncture, and that mafeisan either had nothing to do with or was simply an adjunct to his strategy for anesthesia. Many physicians have attempted to re-create the same formulation based on historical records but none have achieved the same clinical efficacy as Hua Tuo's. In any event, Hua Tuo's formula did not appear to be effective for major operations. Other substances used from antiquity for anesthetic purposes include extracts of juniper and coca.
== Mode of action == The molecular mechanism of inhibiting mechanosensitive channels by GsMTx-4 is bilayer-dependent. Rather than directly binding to the gating structures like other ICK peptides do, GsMTx4 makes the mechanosensitive channels less sensitive to mechanical tension of the bilayer membrane. By its tension-dependent insertion into the membrane, GsMTx4 is thought to distort the distribution of tension near mechanosensitive channels, which will make the transfer of force from the bilayer to the channel less efficient. Unlike other ICK peptides, the action of GsMTx-4 is not stereospecific, as both L- and D-GsMTx-4 can block MSCs.
==== Gastrointestinal system ==== The human digestive system, also known as the gastrointestinal system, comprises the gastrointestinal tract and the accessory organs of digestion: the tongue, salivary glands, pancreas, liver, and gallbladder. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase.
Dunnigan-type familial partial lipodystrophy, also known as FPLD Type II and abbreviated as (FPLD2), is a rare monogenic form of insulin resistance characterized by loss of subcutaneous fat from the extremities, trunk, and gluteal region. FPLD recapitulates the main metabolic attributes of the insulin resistance syndrome, including central obesity, hyperinsulinemia, glucose intolerance and diabetes usually type 2, dyslipidemia, hypertension, and early endpoints of atherosclerosis. It can also result in hepatic steatosis. FPLD results from mutations in LMNA gene, which is the gene that encodes nuclear lamins A and C. The condition is named after Scottish doctor Matthew Dunnigan, who pioneered early study into the disorder.
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.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.