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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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.
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.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
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.
SISCAPA’s use of proteolytic digestion as a first step eliminates the protein:protein complexes (including complexes of a target protein with auto-antibodies) that cause “interferences” in protein capture assays, including conventional immunoassays (e.g., ELISA assays). Elimination of such autoantibody interferences drove the adoption of SISCAPA as an alternative to immunoassays for clinical measurement of thyroglobulin as a marker of thyroid cancer recurrence in patients who exhibit anti-thyroglobulin autoantibodies. A limitation of the specific peptide capture approach is the requirement for a specially developed antibody against the selected peptide. To date several hundred anti-peptide antibody reagents have been developed for enrichment of tryptic peptides from sample digests, mainly for established clinical biomarkers (,) and cancer research targets, but these do not yet cover a majority of protein targets of interest in non-cancer research or clinical contexts. A variety of MS instrument types have been used for quantitation of the enriched peptides, including most frequently triple quadrupole mass spectrometers implementing the “multiple reaction monitoring” (MRM) method (a format sometimes referred to as “immuno-MRM”), and MALDI-ToF (a format sometimes referred to as iMALDI).
== Diagnosis == It is often possible to diagnose myxedema on clinical grounds alone. Characteristic symptoms are weakness, cold intolerance, mental and physical slowness, dry skin, typical facies, and hoarse voice. Results of the total serum thyroxine and free thyroxine index tests usually will confirm the diagnosis.
==== Anabolic/androgenic steroid use ==== This period also saw the rise of anabolic steroids in bodybuilding and many other sports. More significant use began with Arnold Schwarzenegger, Sergio Oliva, and Lou Ferrigno in the late 1960s and early 1970s, and continuing through the 1980s with Lee Haney, the 1990s with Dorian Yates, Ronnie Coleman, and Markus Rühl, and up to the present day. Bodybuilders such as Greg Kovacs attained mass and size never seen previously but were not successful at the pro level. Others were renowned for their spectacular development of a particular body part, like Tom Platz or Paul Demayo for their leg muscles. At the time of shooting Pumping Iron, Schwarzenegger, while never admitting to steroid use until long after his retirement, said, "You have to do anything you can to get the advantage in competition". He would later say that he did not regret using steroids. To combat anabolic steroid use and in the hopes of becoming a member of the IOC, the IFBB introduced doping tests for both steroids and other banned substances. Although doping tests occurred, the majority of professional bodybuilders still used anabolic steroids for competition. During the 1970s, the use of anabolic steroids was openly discussed, partly due to the fact they were legal. In the Anabolic Steroids Control Act of 1990, the U.S. Congress placed anabolic steroids into Schedule III of the Controlled Substances Act (CSA). In Canada, steroids are listed under Schedule IV of the Controlled Drugs and Substances Act, enacted by the federal Parliament in 1996.
Sources: en.wikipedia.org
The drug testing policy hampered the quality of the 1992 championship, while attempts to increase interest by hiring WCW wrestler Lex Luger as a figurehead (hosting a WBF television program on USA Network, and planning to make a guest pose during the 1992 championship before being injured in a motorcycle accident) and attempting to sign Lou Ferrigno (who left the organization shortly after the drug testing policy was announced) did not come to fruition. The second PPV received a minuscule audience, and the WBF dissolved only one month later in July 1992.
Simmons has said the band intended to use the name only for a few early performances until they came up with something better, but they never did. The Doobie Brothers improved their playing by performing live all over Northern California in 1970. They attracted a particularly strong following among local chapters of the Hells Angels and got a recurring gig at one of the bikers' favorite venues, the Chateau Liberté in the Santa Cruz mountains, playing there through the summer of 1975 (although some of these concerts did not include all band members and were of an impromptu nature). A set of demos, which showcased fuzz-toned dual lead electric guitars, three-part harmonies and Hartman's drumming, caught the ear of Warner Brothers' staff A & R representative and former member of '60s pop band Harpers Bizarre, Ted Templeman who eventually earned the group a contract at Warner Bros. Records before the year (1970) was out. The band's image originally reflected that of their biggest fans—leather jackets and motorcycles. Released in April 1971, their self-titled debut album departed significantly from that image and their live sound of the period. Produced at Pacific Recorders in San Mateo, the album, which failed to chart, emphasized acoustic guitars and reflected country influences. The leadoff song "Nobody", the band's first single, has surfaced in their live set several times over the ensuing decades. Most recently, this song was re-recorded and added to their 2010 album World Gone Crazy.
While no correlation between race and the level of neuromelanin in the substantia nigra has been reported, the significantly lower incidence of Parkinson's in blacks than in whites has "prompt[ed] some to suggest that cutaneous melanin might somehow serve to protect the neuromelanin in substantia nigra from external toxins." In addition to melanin deficiency, the molecular weight of the melanin polymer may be decreased by various factors such as oxidative stress, exposure to light, perturbation in its association with melanosomal matrix proteins, changes in pH, or in local concentrations of metal ions. A decreased molecular weight or a decrease in the degree of polymerization of ocular melanin has been proposed to turn the normally anti-oxidant polymer into a pro-oxidant. In its pro-oxidant state, melanin has been suggested to be involved in the causation and progression of macular degeneration and melanoma. Rasagiline, an important monotherapy drug in Parkinson's disease, has melanin binding properties, and melanoma tumor reducing properties. Higher eumelanin levels also can be a disadvantage, however, beyond a higher disposition toward vitamin D deficiency. Dark skin is a complicating factor in the laser removal of port-wine stains. Effective in treating white skin, in general, lasers are less successful in removing port-wine stains in people of Asian or African descent. Higher concentrations of melanin in darker-skinned individuals simply diffuse and absorb the laser radiation, inhibiting light absorption by the targeted tissue.
Sources: en.wikipedia.org
== Epidemiology == The first cases of yellow fever occurred in early September, but the first blood samples for confirmation were not sent to the Institut Pasteur reference laboratory in Dakar, Senegal until 30 October. On 9 November, WHO Sudan reported 266 suspected cases and 85 deaths for a case fatality rate of 32%. Most cases were in Central Dafur state (51.5 percent, reported in March 2013), but the outbreak later expanded to the four other states of North Darfur (21 percent), West Darfur (17.4 percent) and South Darfur (9.5 percent), including refugee camps related to the ongoing war in Darfur. Laboratory confirmation of yellow fever came on 13 November. Most of the cases were among nomads, which contributed to the rapid spread. According to newspaper reports, about 10 000 workers from the gold mines of Jebel Amer fled to Nyala, the capital of South Darfur, after more than 60 deaths in the gold mining area. One newspaper reported: "The spread of the disease in South Darfur is a disaster and the epidemic requires organizations and the international community to address the disease and provide enough vaccines to vaccinate all citizens of the state." Hundreds of patients had accumulated at the Nyala Teaching Hospital, some sleeping outside, and there was a shortage of medical personnel and supplies. By early December the number of deaths had reached 164. Health authorities in China began scanning travelers and Chinese citizens returning from Sudan. As many as a million Chinese workers are employed in oil, mining and construction in Africa.
== Origin == GHRH is released from neurosecretory nerve terminals of these arcuate neurons, and is carried by the hypothalamo-hypophyseal portal system to the anterior pituitary gland, where it stimulates growth hormone (GH) secretion by stimulating the growth hormone-releasing hormone receptor. GHRH is released in a pulsatile manner, stimulating similar pulsatile release of GH. In addition, GHRH promotes slow-wave sleep directly. Growth hormone is required for normal postnatal growth, bone growth, regulatory effects on protein, carbohydrate, and lipid metabolism.
The biosynthesis of tacrolimus is hybrid synthesis of both type 1 polyketide synthases (PKS 1) and nonribosomal peptide syntheses (NRPS). The research shows the hybrid synthesis consists of ten modules of type 1 polyketide synthase and one module of nonribosomal peptide synthase. The synthetic enzymes for tacrolimus are found in 19 gene clusters named fkb. The 19 genes are fkbQ, fkbN, fkbM, fkbD, fkbA, fkbP, fkbO, fkbB, fkbC, fkbL, fkbK, fkbJ, fkbI, fkbH, fkbG, allD, allR, allK and allA. There are several possible ways of biosynthesis of tacrolimus. The fundamental units for biosynthesis are following: one molecule of 4,5-dihydroxycyclohex-1-enecarboxylic acid (DHCHC) as a starter unit, four molecules of malonyl-CoA, five molecules of methylmalonyl-CoA, one molecule of allylmalonyl-CoA as elongation units. However, two molecules of malonyl-CoA are able to be replaced by two molecules of methoxymalonyl CoA. Once two malonyl-CoA molecules are replaced, post-synthase tailoring steps are no longer required where two methoxymalonyl CoA molecules are substituted. The biosynthesis of methoxymalonyl CoA to Acyl Carrier protein is proceeded by five enzymes (fkbG, fkbH, fkbI, fkbJ, and fkbK). Allylmalonyl-CoA is also able to be replaced by propionylmalonyl-CoA. The starter unit, DHCHC from the chorismic acid is formed by fkbO enzyme and loaded onto CoA-ligase domain (CoL). Then, it proceeds to NADPH dependent reduction(ER). Three enzymes, fkbA,B,C enforce processes from the loading module to the module 10, the last step of PKS 1.
=== Stand-up === Hart's first stand-up performance took place at The Laff House in his native Philadelphia under the name of Lil Kev, which did not go well. His career suffered a slow start and he was booed offstage several times, once even having a piece of chicken thrown at him. After those initial unsuccessful shows, he began entering comedy competitions throughout Massachusetts, with audience receptions eventually improving. It took time for Hart to develop a unique comedic style. After an early period of attempting to imitate comedians like Chris Tucker, he found his own rhythm by delving into his insecurities and life experiences. He said: "Because of what I do, it has to be an open book. But right now, this is a book that is being written." Hart's comedy tours began in 2009 with his act titled I'm a Grown Little Man, followed by Seriously Funny in 2010, Laugh at My Pain in 2011, and Let Me Explain in 2013, the last two of which were also released as features in theaters. Hart grossed over $15 million from "Laugh at My Pain", making it one of the year's top-selling comedy tours. Hart also has a game app available through iTunes called "Little Jumpman". His Facebook page, Twitter account, and YouTube channel are all connected to and accessible through this app. Most overseas fans of Hart discovered him on YouTube, as well. On April 9, 2015, Hart embarked on a comedy world tour titled the What Now? Tour at the AT&T Center in San Antonio, which concluded on August 7, 2016, at the Columbus Civic Center in Columbus, Georgia.
Sources: en.wikipedia.org
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.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.