Tuftsin analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-07-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
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.
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.
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.
The Helvetic Republic was set up by France when it invaded Switzerland in 1798. France had withdrawn its troops, but violent strife broke out against the government, which many Swiss saw as overly centralised. Bonaparte reoccupied the country in October 1802 and imposed a compromise settlement. This caused widespread outrage in Britain, which protested that this was a violation of the Treaty of Lunéville. Although continental powers were unprepared to act, the British decided to send an agent to help the Swiss obtain supplies, and also sent secret orders to the Cape Colony to prevent a Dutch takeover. Swiss resistance collapsed before anything could be accomplished, and, after a month, Britain countermanded the orders to not restore Cape Colony. At the same time, Russia finally joined the guarantee regarding Malta. Concerned that there would be hostilities when Bonaparte found out that Cape Colony had been retained, the British began to procrastinate on the evacuation of Malta. In January 1803, a government paper in France published a report from a commercial agent which noted the ease with which Egypt could be conquered. The British seized on this to demand satisfaction and security before evacuating Malta, which was a convenient stepping stone to Egypt. France disclaimed any desire to seize Egypt and asked what sort of satisfaction was required, but the British were unable to give a response. There was still no thought of going to war; Prime Minister Henry Addington publicly affirmed that Britain was in a state of peace.
==== MeSH D06.472.317 – gastrointestinal hormones ==== MeSH D06.472.317.152 – cholecystokinin MeSH D06.472.317.152.700 – sincalide MeSH D06.472.317.350 – epidermal growth factor MeSH D06.472.317.400 – gastric inhibitory polypeptide MeSH D06.472.317.410 – gastrin-releasing peptide MeSH D06.472.317.413 – gastrins MeSH D06.472.317.413.593 – pentagastrin MeSH D06.472.317.413.800 – tetragastrin MeSH D06.472.317.469 – glucagon precursors MeSH D06.472.317.469.500 – enteroglucagons MeSH D06.472.317.469.500.500 – glucagon-like peptide 1 MeSH D06.472.317.525 – motilin MeSH D06.472.317.662 – peptide yy MeSH D06.472.317.800 – secretin MeSH D06.472.317.950 – vasoactive intestinal peptide
== Pharmacokinetics == Synthetic cannabinoids are delivered by smoking. In a human study, after 50 μg/kg smoked JWH-018 are delivered, one male and a female have their serum concentration of 8.1 and 10.2 μg/L respectively after 5 minutes, down to 4.6 and 6.1 μg/L after 15 minutes, suggesting the biological half-life of JWH-018 is short. 13 phase 1 metabolites are identified. Monohydroxylated and dihydrodiol metabolites are most prevalent metabolites of synthetic cannabinoids. UGT1A1, UGT1A3, UGT1A9, UGT1A10 and UGT2B7 isoenzymes were primarily responsible for JWH-018 and JWH-073 metabolites' conjugation and had high affinity for hydroxylated metabolites (Km=12–18 mmol/L). Generation of JWH-018-N-4- and 5-hydroxypentyl (JWH-018 metabolites) was primarily mediated by CYP2C9 followed by CYP1A2 and CYP2C19. CYP3A4 catalyzed JWH-018-N-4-hydroxypentyl production but with lower activity than CYP1A2 and CP2C19. The drugs are mainly excreted as urine. Phenethylamines are first-order kinetics with half life of 5 to 10 minutes which are absorbed by ingestion. The drugs have low concentration in the brain due to low biological half-life. It is difficult to measure the plasma concentration due to low stability of Phenethylamine. There are two possible metabolism pathways. The first possible pathway is metabolism by MAO-B (an intracellular enzyme mainly in the brain and tightly bound to the outer membrane of mitochondria which deaminates free primary and secondary amines) to form phenylacetic acid due to MAO-B selectivity on non-polar aromatic amines.
== Relative isotopic mass == Relative isotopic mass (a property of a single atom) is not to be confused with the averaged quantity atomic weight (see above), that is an average of values for many atoms in a given sample of a chemical element. While atomic mass is an absolute mass, relative isotopic mass is a dimensionless number with no units. This loss of units results from the use of a scaling ratio with respect to a carbon-12 standard, and the word "relative" in the term "relative isotopic mass" refers to this scaling relative to carbon-12. The relative isotopic mass, then, is the mass of a given isotope (specifically, any single nuclide), when this value is scaled by the mass of carbon-12, where the latter has to be determined experimentally. Equivalently, the relative isotopic mass of an isotope or nuclide is the mass of the isotope relative to +1/12 of the mass of a carbon-12 atom. For example, the relative isotopic mass of a carbon-12 atom is exactly 12. For comparison, the atomic mass of a carbon-12 atom is exactly 12 daltons. Alternately, the atomic mass of a carbon-12 atom may be expressed in any other mass units: for example, the atomic mass of a carbon-12 atom is 1.99264688270(62)×10−26 kg. As is the case for the related atomic mass when expressed in daltons, the relative isotopic mass numbers of nuclides other than carbon-12 are not whole numbers, but are always close to whole numbers. This is discussed fully below.
Sources: en.wikipedia.org
August 14, 2009: Hong Kong After shrinking 4.3% during January–March, Hong Kong's GDP grew 3.3% between April and June, improving its GDP forecasts, which went from negative growth between 5.5 and 6.5% to negative growth between 4.5 and 5.5%. Still, comparing the second quarter of 2009 to the second quarter of 2008, Hong Kong's GDP shrank 3.8% in the former.
=== Variants and subgroups === Regulators and clinical trials often use additional subgroups based on how active the disease is, even if there is no firm agreement on their definition. Examples are 'active MS', 'highly active MS' and 'rapidly evolving severe MS'. One definition of highly active MS is having an unchanged or increased number of relapses even after starting disease-modifying treatment. In addition, the term 'relapsing MS' is often used to denote people with relapsing-remitting MS as well as the subset of individuals with secondary progressive MS who still experience some relapses. The terms "benign MS" is sometimes used for people who have had MS for a long time (15 years or so) with few attacks and little disability. As people may still get worse, the term is discouraged. On the other hand, the term aggressive multiple sclerosis (previously known as "malignant multiple sclerosis") is used to describe people with MS having reached a significant level of disability in a short period. Atypical variants of MS have been described; these include tumefactive multiple sclerosis, Balo concentric sclerosis, and Marburg multiple sclerosis.
== Accurate mass == The accurate mass (more appropriately, the measured accurate mass) is an experimentally determined mass that allows the elemental composition to be determined. For molecules with mass below 200 Da, 5 ppm accuracy is often sufficient to uniquely determine the elemental composition.
== Further reading == Sitruk-Ware R, Bricaire C, De Lignieres B, Yaneva H, Mauvais-Jarvis P (October 1987). "Oral micronized progesterone. Bioavailability pharmacokinetics, pharmacological and therapeutic implications--a review". Contraception. 36 (4): 373–402. doi:10.1016/0010-7824(87)90088-6. PMID 3327648. Simon JA (December 1995). "Micronized progesterone: vaginal and oral uses". Clinical Obstetrics and Gynecology. 38 (4): 902–14. doi:10.1097/00003081-199538040-00024. PMID 8616985. Ruan X, Mueck AO (November 2014). "Systemic progesterone therapy--oral, vaginal, injections and even transdermal?". Maturitas. 79 (3): 248–55. doi:10.1016/j.maturitas.2014.07.009. PMID 25113944.
Amikacin Amoxicillin Amoxicillin/clavulanic acid (amoxicillin + clavulanic acid) Ampicillin Benzathine benzylpenicillin Benzylpenicillin Cefalexin Cefazolin Chloramphenicol Clindamycin Cloxacillin Doxycycline Gentamicin Metronidazole Nitrofurantoin Phenoxymethylpenicillin (penicillin V) Procaine benzylpenicillin Spectinomycin Sulfamethoxazole/trimethoprim (sulfamethoxazole + trimethoprim) Trimethoprim
Sources: en.wikipedia.org
Dry powder is best kept sealed, protected from light, and held at minus 20 degrees Celsius or below. Desiccant packaging helps limit moisture uptake because the material is hygroscopic. A sealed vial should be allowed to equilibrate to room temperature before opening to reduce condensation.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
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.