mass spectrometry is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-24. Numbers and descriptions here follow the published literature rather than marketing material.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
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.
Lyophilized Selank, the dry powder form, is generally stored frozen at minus 20 degrees Celsius or colder for long-term keeping. The solid is hygroscopic and should stay sealed, dry, and protected from light. Once dissolved, the peptide is less stable and is usually held refrigerated at 2 to 8 degrees Celsius for short periods. Repeated freezing and thawing is avoided because it can promote aggregation and loss of activity. Buffers and pH choice also affect how long a solution remains usable.
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.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
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.
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.
Brazil: The leaf juice is taken orally to induce vomiting and narcosis. Colombia: Fresh leaf is used as poultice over boils and infected wounds; the leaves are crushed with oil from palms and used as hair treatment to prevent baldness. Cuba: Extract of the leaf is taken orally to treat dysmenorrhea. East Africa: Dried leaves of Nicotiana tabacum and Securinega virosa are mixed into a paste and used externally to destroy worms in sores. Ecuador: Leaf juice is used for indisposition, chills and snake bites and to treat pulmonary ailments. Fiji: Fresh root is taken orally for asthma and indigestion; fresh root is applied ophthalmically as drops for bloodshot eyes and other problems; seed is taken orally for rheumatism and to treat hoarseness. Guatemala: Leaves are applied externally by adults for myiasis, headache and wounds; hot water extract of the dried leaf is applied externally for ring worms, fungal diseases of the n, wounds, ulcers, bruises, sores, mouth lesions, stomatitis and mucosa; leaf is orally taken for kidney diseases. Haiti: Decoction of dried leaf is taken orally for bronchitis and pneumonia. Hong Kong: Fresh leaves are mashed and combined with vegetable oil to create a potion that is applied to injuries for it to heal faster. This practice is also apparent in other places in China. Iran: Infusion of the dried leaf is applied externally as an insect repellent; ointments made from crushed leaves are used for baldness, dermatitis and infectious ulceration and as a pediculicide.
== Research == Later, nelotanserin was repurposed for the treatment of Lewy body dementia (LBD) by Axovant Sciences (now Sio Gene Therapies). In late 2018, the company announced that while nelotanserin was generally well-tolerated by LBD patients in a small Phase 2 clinical trial for the treatment of REM sleep behavior disorder (RBD) and there were positive indications on some secondary trial outcomes such as sleep diaries and some polysomnogram sleep parameters, the drug failed to meet its primary endpoint of reducing the frequency of RBD episodes and would be discontinued.
In a speech to the Scottish Labour Party conference in Edinburgh, Labour leader Sir Keir Starmer rules out a deal with the SNP "under any circumstances", and warns against complacency following the departure of Nicola Sturgeon as SNP leader and First Minister. 20 February – Finance Secretary Kate Forbes announces she is running in the Scottish National Party leadership election. 21 February Kate Forbes insists her campaign to become the next SNP leader has not been derailed after she lost the support of several colleagues following comments about same-sex marriage and having children outside marriage, both of which she is opposed to as a member of the Free Church of Scotland. MSPs vote 68–57 to approve the Scottish Government's budget for the 2023–24 financial year, which includes a tax rise for everyone in Scotland earning more than £43,662. 23 February – Sir Iain Livingstone announces he will retire as Chief Constable of Police Scotland in the summer after five years in the post. 24 February Nominations close for the SNP leadership election, with Kate Forbes, Ash Regan and Humza Yousaf having all reached the threshold of supporters to go forward into the contest. Two crew died after tugboat capsized & sank close to Greenock harbour. 25 February – Members of the Scottish Secondary Teachers' Association (SSTA) vote to accept a new pay offer from the Scottish Government, and announce they have suspended strike action scheduled for the following week. 28 February – Transgender rapist Isla Bryson is sentenced to eight years in prison with a further three years supervision.
Sources: en.wikipedia.org
Bush pursued many educational initiatives, such as increasing the funding for the National Science Foundation and National Institutes of Health in his first years of office and creating education programs to strengthen the grounding in science and mathematics for American high school students. Funding for the NIH was cut in 2006, the first such cut in 36 years, due to rising inflation. One of the administration's early major initiatives was the No Child Left Behind Act, which aimed to measure and close the gap between rich and poor student performance, provide options to parents with students in low-performing schools, and target more federal funding to low-income schools. This landmark education initiative passed with broad bipartisan support, including the support of Senator Ted Kennedy of Massachusetts. It was signed into law by Bush in early 2002. Many contend that the initiative has been successful, as cited by the fact that students in the U.S. have performed significantly better on state reading and math tests since Bush signed "No Child Left Behind" into law. Critics argue that it is underfunded and that NCLBA's focus on "high-stakes testing" and quantitative outcomes is counterproductive. On November 1, 2005, Bush launched a National Strategy for Pandemic Influenza, which culminated in an implementation plan published by the Homeland Security Council in May 2006.
== Research == Studies indicate that benzydamine has notable in vitro antibacterial activity and also shows synergism in combination with other antibiotics, especially tetracyclines, against antibiotic-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa. It also has some cannabinoid activity in rats but has not been tested in humans. It is also hypothesized to act on 5-HT2A receptors due to its structural similarity with serotonin.
== The Saint and the Sinners (1965–1968)| Airborne (1969–1970) == Ron next worked with The Saint and the Sinners (1965–1968) featuring lead singer Tommy Forrest (ex-The Monterays), keyboardist George Day, Si Sifer (drums), Dave Machan (vocals/guitar). The Saint and the Sinners started out as a typical mid 60's garage/dance band before evolving into a soul/horn band, not unlike Wilmer & the Dukes (another regionally popular band). The Saint and the Sinners fought it out with both The Dukes and The Monterays on the local dance circuit. The band could be seen regularly playing the hip clubs and dances of the era. These places include: Hewitt's, The Pin-O-Rama in Oswego, S.U. frat blasts, Carlsys, The Turn On in Downtown Syracuse, and other local high school dances. It was at this time that the Sinners made their first recordings "LIVE" (naturally) at St. Matthews School in East Syracuse. The Saint and the Sinners spent summer 1967 as the "virtual" house band of The Forest Hotel in Sylvan Beach, New York. ""The popularity of the band was established when we played all summer at The Forest Hotel," Ron states. "People of that generation still remember us from performing there. Stop in and ask Captain John at his restaurant in Sylvan Beach as to who was one of the best bands to play at the Forest." Soon after this engagement, the group underwent another split, with George Day leaving (he would later surface in The Monterays.) The Sinners soldiered on, acquiring saxophonist Frank Segroi and organist (and former Campus Walker) Larry Brennan. Ron-"We completely changed our style.
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
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.