Everything below concerns reverse-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
| Property | Value | Notes |
|---|---|---|
| Principal proposed target | GABA-A receptor complex | Hypothesis derived mainly from animal pharmacology |
| Common behavioral assay | Elevated plus maze | Rodent test for anxiety-like behavior |
| Reported molecular marker | Hippocampal BDNF expression | Measured by immunoassay or mRNA quantification |
| Typical dosing route | Intranasal | Chosen to reduce first-pass metabolism |
| Reported plasma half-life | Minutes | Based on limited peptide stability data |
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
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.
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.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Selank is a synthetic heptapeptide developed in Russia as a structural analogue of tuftsin, a naturally occurring immunomodulatory tetrapeptide. Its sequence, Thr-Lys-Pro-Arg-Pro-Gly-Pro, keeps the tuftsin core at the N-terminus and appends a Pro-Gly-Pro tail. Researchers at the Institute of Molecular Genetics in Moscow synthesized the compound during the 1990s while searching for peptides with combined anxiolytic and immunomodulatory activity. The added tail was intended to resist enzymatic cleavage and prolong the molecule's presence in circulation.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Anaerobic cellular respiration and fermentation generate ATP in very different ways, and the terms should not be treated as synonyms. Cellular respiration (both aerobic and anaerobic) uses highly reduced chemical compounds such as NADH and FADH2 (for example produced during glycolysis and the citric acid cycle) to establish an electrochemical gradient (often a proton gradient) across a membrane. This results in an electrical potential or ion concentration difference across the membrane. The reduced chemical compounds are oxidized by a series of respiratory integral membrane proteins with sequentially increasing reduction potentials, with the final electron acceptor being oxygen (in aerobic respiration) or another chemical substance (in anaerobic respiration). A proton motive force drives protons down the gradient (across the membrane) through the proton channel of ATP synthase. The resulting current drives ATP synthesis from ADP and inorganic phosphate. Fermentation, in contrast, does not use an electrochemical gradient but instead uses only substrate-level phosphorylation to produce ATP. The electron acceptor NAD+ is regenerated from NADH formed in oxidative steps of the fermentation pathway by the reduction of oxidized compounds. These oxidized compounds are often formed during the fermentation pathway itself, but may also be external. For example, in homofermentative lactic acid bacteria, NADH formed during the oxidation of glyceraldehyde-3-phosphate is oxidized back to NAD+ by the reduction of pyruvate to lactic acid at a later stage in the pathway.
On 25 February, Gnassingbé was nominated by delegates of the ruling party, the Rally for the Togolese People, as the party's presidential candidate. He was also chosen as head of the party. Shortly afterwards, under mounting domestic and international pressure, Gnassingbé announced that he would step down as president during the interim period and Bonfoh Abass was appointed by the National Assembly to replace him as acting president until the election on 24 April. Bonfoh was considered by some to be a puppet of the military elite and the Gnassingbé family. Gnassingbé competed with the main opposition candidate, Emmanuel Bob-Akitani, a retired engineer of the state-owned mining company and the second most important person in the opposition coalition after Gilchrist Olympio. Olympio could not take part in the election, since the constitution required that any candidate must have lived for at least 12 months in Togo, and Olympio had been in self-imposed exile for fear that he would be murdered by the Eyadema clan like his father. In the election, Gnassingbé received slightly more than 60% of the votes, according to official results. The RPT refused to allow oversight during the counting of the ballots. The EU and the Carter Center deemed the elections to be fraudulent. Mass protests by the coalition of opposition parties led to the killing of over 1,000 citizens by security forces. 40,000 refugees fled to neighboring Benin and Ghana.
== Medical uses == Fosfomycin is used to treat bladder infections as well as urinary tract infections (UTIs), where it is usually given as a single dose by mouth. Oral fosfomycin is not recommended for children under 12 years old. Additional uses have been proposed. The global problem of advancing antimicrobial resistance has led to a renewed interest in its use more recently. Fosfomycin can be used as an efficacious treatment for both UTIs and complicated UTIs including acute pyelonephritis. The standard regimen for complicated UTIs is an oral 3 g dose administered once every 48 or 72 hours for a total of 3 doses or a 6 g dose every 8 hours for 7–14 days when fosfomycin is given in IV form. Intravenous fosfomycin is being increasingly used for treating infections caused by multidrug-resistant bacteria, mostly as a partner drug in order to avoid the occurrence of resistances and to take advantage of its synergistic activity with several other antimicrobials. In real-life settings, intravenous fosfomycin is most commonly used to treat pneumonia (34%), bloodstream infections (22%), and urinary tract infections (21%). In the majority of cases, it is administered in combination with a beta-lactam antibiotic, and in approximately half of the cases, it is employed as empirical therapy. Daily adult dose usually ranges from 12 to 24 grams. When administered in continuous infusion, a loading dose of fosfomycin 8 g followed by a daily dose of 16 g or 24 g. Continuous infusion is suggested in patients with normal renal function.
Sources: en.wikipedia.org
== Recent developments == TurboID-based proximity labeling has been used to identify regulators of a receptor involved in the innate immune response, a NOD-like receptor. BioID-based proximity labeling has been used to identify the molecular composition of breast cancer cell invadopodia, which are important for metastasis. Biotin-based proximity labeling studies demonstrate increased protein tagging of intrinsically disordered regions, suggesting that biotin-based proximity labeling can be used to study the roles of IDRs. A photosensitizer nucleus-targeted small molecule has also been developed for photoactivatable proximity labeling.
In the context of nutritional science, red meat is defined as meat obtained from mammals, including beef, pork, lamb, mutton, veal, venison, and goat. Some sources also specify that the meat must be muscle meat, as opposed to organ meat. Red meat does not necessarily appear red in color. In culinary contexts, the term red meat is used more loosely to refer to meat that is red when raw. The term is used to refer to adult or "gamey" mammals, while that from young mammals (rabbit, veal, lamb) is white. Most poultry is white. Game is sometimes put in a separate category altogether (French: viandes noires 'dark meats'). The redness of meat comes from its myoglobin content. Some cuts of pork are considered white under the gastronomic definition, but all pork is considered red meat in nutritional studies. The National Pork Board has positioned it as "the other white meat", profiting from the ambiguity to suggest that pork has the nutritional properties of white meat, which is considered more healthful. Ostrich, emu, and rhea meat are sometimes referred to as types of red meat or "alternatives to red meat" . However, their nutritional characteristics differ significantly from the characteristics of other types of red meat.
The Oxford team analysed the chemical properties of the cephalosporin ring system, opening the door to the production of semisynthetic cephalosporins created through replacing side chains, as had been done with penicillin to create semisynthetic penicillins. "Everybody I have questioned who was involved in the development of cephalosporin C," science writer David Wilson reported, "when asked if one man was responsible for keeping the project going, replied: 'Florey'." Controversy over British firms having to pay royalties to American ones for the use of the deep submergence techniques developed in the United States to produce penicillin when penicillin was seen as a British innovation led to the establishment of the National Research Development Corporation (NRDC) in June 1948. The Oxford team patented their work on cephalosporins and assigned the patents to the NRDC. By 1978, the annual world sales of cephalosporins were worth over £600,000 (equivalent to £3,279,000 in 2025) and the NRDC was reaping £100,000 (equivalent to £546,000 in 2025) a year in royalties. Florey received a 0.5 per cent share in the last two years of his life.
John J. Abel Award Julius Axelrod Award Pharmacia-ASPET Award in Experimental Therapeutics Robert R. Ruffolo Career Achievement Award Travel Award for Pharmacology Educators Bernard B. Brodie Award in Drug Metabolism P.B. Dews Lifetime Achievement Award for Research in Behavioral Pharmacology Drug Metabolism Early Career Achievement Award Goodman and Gilman Award in Receptor Pharmacology Benedict R. Lucchesi Distinguished Lectureship in Cardiac Pharmacology Torald Sollmann Award in Pharmacology Paul M. Vanhoutte Distinguished Lectureship in Cardiovascular Pharmacology Travel awards to participate in its meetings are also given to students and postdocs. Chemotherapy Clinical pharmacology Drug metabolism Neuropharmacology Pharmacology Toxicology Official website Molecular Interventions magazine
Sources: en.wikipedia.org
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.
Behavioral endpoints include time spent in open arms of the elevated plus maze and avoidance latencies. Biochemical endpoints include BDNF concentration, cytokine levels, and monoamine metabolite ratios in brain tissue.
Most published studies are small, originate from a limited number of laboratories, and lack independent replication. Dose-response relationships, measured brain exposure, and long-term outcomes are not well characterized.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.