The short version of certificate of analysis fits in a sentence. The long version — which is the one that helps — is below.
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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.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue with a C-terminal Pro-Gly-Pro tail |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Abbreviated TKPRPGP in most catalogues |
| Molecular mass | About 752 Da | Value for the free peptide |
| Solubility | Freely soluble in water | Aqueous solutions are kept cold and used promptly |
| Typical storage | -20 °C, dry, protected from light | Applies to the lyophilised powder before reconstitution |
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
Regulatory treatment varies by jurisdiction. In Russia the compound is a registered prescription product, while in the European Union and the United States it is generally handled as a research chemical without a marketing authorization. Suppliers therefore operate outside pharmaceutical oversight, and buyers rely on supplier documentation for purity and identity claims. Chain of custody and third-party testing are the main verification tools. Analysts note that the absence of a pharmacopoeial monograph for research-grade material limits standardization across vendors.
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.
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.
=== Pregnancy === Control of metabolism is vital during pregnancy of women with MSUD. To prevent detrimental abnormalities in the development of the embryo or fetus, dietary adjustments should be made and plasma amino acid concentrations of the mother should be observed carefully and frequently. Amino acid deficiency can be detected through fetal growth, making it essential to monitor development closely. BCAA levels should be monitored strictly with the goal of maintaining normal levels in individuals with MSUD who are pregnant. Often times there was an increase in leucine levels about the target range through the whole course of the pregnancy. Pregnant individuals with MSUD can have healthy newborns which tells us that MSUD metabolites are unlikely to have teratogenic outcomes that lead to birth defects, developmental delays, or miscarriages.
Small, medium, and large veins The small veins merge to feed as tributaries into medium-sized veins. The medium veins feed into the large veins which include the internal jugular, and renal veins, and the venae cavae that carry the blood directly into the heart. The venae cavae enter the right atrium of the heart from above and below. From above, the superior vena cava carries blood from the arms, head, and chest to the right atrium of the heart, and from below, the inferior vena cava carries blood from the legs and abdomen to the right atrium. The inferior vena cava is the larger of the two. The inferior vena cava is retroperitoneal and runs to the right and roughly parallel to the abdominal aorta along the spine.
Adaptogens are plants that support health through nonspecific effects, neutralize various environmental and physical stressors while being relatively safe and free of side effects. As of 2008, the position of the European Medicines Agency was that "The principle of an adaptogenic action needs further clarification and studies in the pre-clinical and clinical area." As such, the term is not accepted in pharmacological and clinical terminology that is commonly used in the EU."
== Academic career == In 1974, Candace Pert earned a Ph.D. in pharmacology from Johns Hopkins University School of Medicine, where she worked in the laboratory of Solomon Snyder and discovered the brain's opiate receptor. Pert conducted a National Institutes of Health Postdoctoral Fellowship with the Department of Pharmacology at the Johns Hopkins University School of Medicine from 1974 to 1975. She conducted research at the National Institute of Mental Health from 1975 to 1987. In 1983, she became the Chief of the Section on Brain Biochemistry of the Clinical Neuroscience Branch, the only female chief at NIMH. She left to found and direct a private biotech laboratory in 1987. Pert was a research professor in the department of physiology and biophysics at Georgetown University School of Medicine in Washington, D.C. In her latter years, she was with RAPID Pharmaceuticals. In 1997 she published her book Molecules of Emotion. She appeared as one of the experts in Bill Moyers 1993 PBS video production, "Healing and the Mind", and in the 2004 film What the #$*! Do We Know!?. She died on September 12, 2013, in Potomac, Maryland.
== Epidemiology == Scleroderma most commonly first presents between the ages of 20 and 50 years, although any age group can be affected. Women are four to nine times more likely to develop scleroderma than men. This disease is found worldwide. In the United States, prevalence is estimated at 240 per million, and the annual incidence of scleroderma is 19 per million people. Likewise, in the United States, it is slightly more common in African Americans than in their white counterparts. Choctaw Native Americans are more likely than Americans of European descent to develop the type of scleroderma that affects internal organs. In Germany, the prevalence is between 10 and 150 per million people, and the annual incidence is between three and 28 per million people. In South Australia, the annual incidence is 23 per million people, and the prevalence 233 per million people.
Sources: en.wikipedia.org
: equilibrium In order to meet the thermodynamic condition for equilibrium, the Gibbs energy must be stationary, meaning that the derivative of G with respect to the extent of reaction, ξ, must be zero. It can be shown that in this case, the sum of chemical potentials times the stoichiometric coefficients of the products is equal to the sum of those corresponding to the reactants. Therefore, the sum of the Gibbs energies of the reactants must be the equal to the sum of the Gibbs energies of the products.
25 April Elements of the PAVN 271st Regiment attacked Patrol Base Frontier City southeast of Tây Ninh. The attack was countered with intensive fire from fixed wing and helicopter gunships and the PAVN lost 214 killed and six captured for no U.S. losses.
== Professional membership == American Association of Clinical Chemistry (AACC) Academy Fellow of AACC American Society of Clinical Pathology (ASCP) International Society on Thrombosis and Haemostasis (ISTH) Korean Society for Biochemistry and Molecular Biology
==== Encoded combinatorial libraries ==== When dealing with a non-peptide organic libraries library, it is not as simple to determine the identity of the content of a bead as in the case of a peptide one. In order to circumvent this difficulty, methods have been developed to attach molecules that encode the structure of the compound formed in the bead to the beads, in parallel with the synthesis of the library. Ohlmeyer and his colleagues published a binary encoding method. They used mixtures of 18 tagging molecules that, after cleaving them from the beads, could be identified by Electron Capture Gas Chromatography. Sarkar et al. describe chiral oligomers of pentenoic amides (COPAs) that can be used to construct mass encoded OBOC libraries. Kerr et al. introduced an innovative encoding method. An orthogonally protected removable bifunctional linker was attached to the beads. One end of the linker was used to attach the non-natural building blocks of the library, while encoding amino acid triplets were linked to the other end. The building blocks were non-natural amino acids and the series of their encoding amino acid triplets could be determined by Edman degradation. The important aspect of this kind of encoding was the possibility to cleave down from the beads the library members together with their attached encoding tags forming a soluble library. The same approach was used by Nikolajev et al. for encoding with peptides. In 1992, Brenner and Lerner introduced DNA sequences to encode the beads of the solid support that proved to be the most successful encoding method.
Sources: en.wikipedia.org
Peukert wrote: "Eclectic as regards ideas, but up to date in its attitude to technology, National Socialism laid claims to offer a "conclusive" new answer to the challenges and discomforts of the modern age". Peukert wrote that: "The much heralded Volksgemeinschaft of the National Socialists in no way abolished the real contradictions of a modern industrial society; rather these were inadvertently aggravated by the use of highly modern industrial and propaganda techniques for achieving war readiness. In fact, the long-term characteristics of a modern industrial society, which had been interrupted by the world economic crisis, continued to run their course". Reflecting the influence of functionalist historians like Martin Broszat and Hans Mommsen, Peukert wrote the inability to achieve the idealized volksgemeinschaft of their dreams left the National Socialists increasingly frustrated and led them to lash out against groups considered to be enemies of the volksgemeinschaft as a way of compensation. Peukert argued that for the National Socialists "it was more important to travel hopefully than to arrive", as for the Nazis had no solutions to the problems of classical modernity other than a creating a sense of movement towards the vague goal of the utopian society that was to be the volksgemeinschaft. Peukert wrote the "violent answers" of the Nazis to the "contradictions of modernity" were not the basis of a successful social order, and as such the dynamism of the Nazi movement was primarily negative and the "movement" had a strong self-destructive streak.
After independence, the government began a deliberate process of crafting a uniquely Singaporean identity and culture. Singapore has a reputation as a nanny state. The government also places a heavy emphasis on meritocracy, where one is judged based on one's ability. The national flower of Singapore is the hybrid orchid, Vanda Miss Joaquim, named in memory of Agnes Joaquim, who crossbred the flower in her garden at Tanjong Pagar in 1893. Singapore is known as the Lion City and many national symbols such as the coat of arms and the lion head symbol make use of a lion. Major religious festivals are public holidays. UNESCO recognises Singapore as a "Design City."
=== Central hematopoietic and antigen-responsive organ === Bone marrow is a priming site for T-cell responses to blood-borne antigens, as first described in 2003. Mature circulating naïve T cells travel to bone marrow sinuses after they have passed through arteries and arterioles. They transmigrate sinus endothelium and enter the parenchyma which contains dendritic cells (DCs). These have a capacity of antigen uptake, processing, and presentation. Cognate interactions between antigen-specific T cells and antigen-presenting DCs (APCs) in parenchyma lead to rapid T-APC cluster formation followed by T cell activation, T cell proliferation and T cell re-circulation to blood. These findings were corroborated and extended in 2013 by in situ two-photon dynamic imaging of mice skulls.
This material comprises coordinatively saturated Zn4O nodes and fully complexed BDC struts (see above for abbreviation); yet it apparently catalyzes the Friedel–Crafts tert-butylation of both toluene and biphenyl. Furthermore, para alkylation is strongly favored over ortho alkylation, a behavior thought to reflect the encapsulation of reactants by the MOF.
He explained the importance of O'Higgins and his horse walking over the corpse of a dead enemy tyrant's soldier. The Cuban Army General Staff Band played El Mambi and La Bayamesa. The delegation from the Dominican Republic reminded the room that Máximo Gómez had been born in their country, and had died in Cuba. After a prayer to the Great Architect of the Universe, the Conference conducted its normal business.
Sources: en.wikipedia.org
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.
Tuftsin is a natural tetrapeptide derived from the Fc portion of immunoglobulin G. Selank retains that tetrapeptide at its N-terminus and adds three residues to improve resistance to enzymatic breakdown. The relationship is structural, and the two molecules are not interchangeable in experimental work.
It holds a product registration in Russia for intranasal use as an anxiolytic. Registrations of that kind are not automatically accepted by regulators elsewhere. In most other countries it is treated as an unapproved substance or a research material.
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.