If you have been reading about Certificate of analysis and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-01-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Tuftsin analogue |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Calculated for the free peptide |
| Molecular weight | About 751.9 g/mol | Derived from the sequence |
| Appearance | White to off-white powder | Typical lyophilised form |
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.
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.
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.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
== Distribution and habitat == Calliphora vomitoria can be found throughout the world, including most of Europe, Alaska, Greenland, the south of Mexico, United States, and southern Africa. It prefers higher elevations relative to other Calliphoridae species, such as Lucilia sericata and Chrysomya albiceps. They are among the most abundant flies found in these regions. Temperature has a significant effect on distribution. As is the case with most flies, C. vomitoria are found most abundantly during spring and summer, and least abundant during fall and winter. The preferred habitat of C. vomitoria varies depending on the season. During winter and summer, they can be found mostly in rural areas (and riparian areas to a lesser extent). During spring and fall, they are found in riparian areas.
=== Increasing huntingtin clearance === Another strategy to reduce the level of mutant huntingtin is to increase the rate at which cells are able to clear it. As mHTT (and many other protein aggregates) may be degraded by autophagy, increasing the rate of autophagy has the potential to reduce levels of mHTT and thereby ameliorate disease. Pharmacological and genetic inducers of autophagy have been tested in a variety of HD models; many have been shown to reduce mHtt levels and decrease toxicity in mice.
Subdural fluid collections Enhancement of the meninges Engorgement of venous structures Pituitary swelling Sagging of the brain For suspected spinal CSF leaks, spine imaging can be used to guide treatment.
=== Pregnancy and lactation === Use of tramadol during pregnancy is generally avoided, as it may cause some reversible withdrawal effects in the newborn. A small prospective study in France found, while an increased risk of miscarriages existed, no major malformations were reported in the newborn. Its use during lactation is also generally advised against, but a small trial found that infants breastfed by mothers taking tramadol were exposed to about 2.88% of the dose the mothers were taking. No evidence of this dose harming the newborn was seen.
Sources: en.wikipedia.org
The ELISA template, commonly used for performing immunoassays and other enzyme-based biochemical assays, has been adapted for use with the DMF platform for the detection of analytes such as IgE and IgG. In one example, a series of bioassays were conducted to establish the quantification capabilities of DMF devices, including an ELISA-based immunoassay for the detection of IgE. Superparamagnetic nanoparticles were immobilized with anti-IgE antibodies and fluorescently labeled aptamers to quantify IgE using an ELISA template. Similarly, for the detection of IgG, IgG can be immobilized onto a DMF chip, conjugated with horseradish-peroxidase (HRP)-labeled IgG, and then quantified through measurement of the color change associated with product formation of the reaction between HRP and tetramethylbenzidine. To further expand the capabilities and applications of DMF immunoassays beyond colorimetric detection (i.e., ELISA, magnetic bead-based assays), electrochemical detection tools (e.g., microelectrodes) have been incorporated into DMF chips for the detection of analytes such as TSH and rubella virus. For example, Rackus et al. integrated microelectrodes onto a DMF chip surface and substituted a previously reported chemiluminescent IgG immunoassay with an electroactive species, enabling detection of rubella virus. They coated magnetic beads with rubella virus, anti-rubella IgG, and anti-human IgG coupled with alkaline phosphatase, which in turn catalyzed an electron transfer reaction that was detected by the on-chip microelectrodes.
In this model an infection does not leave any immunity thus individuals that have recovered return to being susceptible, moving back into the S(t) compartment. The following differential equations describe this model:
Lori stated that he would be taking a sabbatical from the program until he recovers. She blamed the stroke on Bakker's hard work on his show and wrote that he had described the criticism against him as "the most vicious attack that he has ever experienced". Bakker returned to his program for the first time following his stroke on July 8, 2020. On June 23, 2021, Missouri Attorney General Eric Schmitt announced the settlement of the state's lawsuit against Bakker. Bakker and Morningside Church would be prohibited from saying silver solution could "diagnose, prevent, mitigate, treat, or cure any disease or illness". Restitution of about $157,000 would also be paid to those who bought silver solution between February 12, 2020, and March 10, 2020.
=== Coup trap === The accumulation of previous coups is a strong predictor of future coups, a phenomenon called the coup trap. A 2014 study of 18 Latin American countries found that the establishment of open political competition helps bring countries out of the coup trap and reduces cycles of political instability.
=== No development reported === 4-Chlorokynurenine (4-CL-KYN; 7-CL-KYNA; AV-101) – ionotropic glutamate NMDA receptor antagonist and 3-hydroxyanthranilate oxidase inhibitor [146] α-Synuclein picobody (a-syn-pico) – positron-emission tomography (PET) enhancer – diagnosis [147] A-86929 – dopamine D1 receptor agonist [148] AB-4166 – microbiome modulator [149] ACI-12589 – positron-emission tomography (PET) enhancer – diagnosis [150] Affitope-PD03 (PD03; PD03A) – α-synuclein inhibitor and immunostimulant [151] ANPD-002 (ANPD002) – dopaminergic cell replacement [152] AP-472 – metabotropic glutamate mGlu4 receptor positive allosteric modulator [153] Aplindore (DAB-452; palindore; SLS-006; WAY-DAB 452) – dopamine D2 receptor agonist [154] Armesocarb (MLR-1019) – atypical dopamine reuptake inhibitor (DRI) [155] Atuzaginstat (COR-388) – peptide hydrolase inhibitor [156] ATV:aSyn (ATV:α-synuclein; ATV:αSyn) – α-synuclein inhibitor [157] Autologous adipose derived mesenchymal stem cells - Hope Biosciences – cell replacement [158] AZ-001 – undefined mechanism of action [159] Beperminogene perplasmid (AMG-0001; Collategene; hepatocyte growth factor gene therapy) – gene transference and hepatocyte growth factor (HGF) expression stimulant [160] BTRX-246040 (LY-2940094) – nociceptin receptor (NOP) antagonist [161] Cannabidiol/tetrahydrocannabinol (CBD/THC; CanChew; MedChew; THC/CBD) – cannabinoid CB1 and CB2 receptor agonist and other actions [162] Carbidopa/levodopa (WD-1603) – combination of carbidopa (aromatic L-amino acid decarboxylase (AAAD) inhibitor) and levodopa (dopamine precursor) [163] Carbidopa/levodopa oral solution (EXN-32) – combination of carbidopa (aromatic L-amino acid decarboxylase (AAAD) inhibitor) and levodopa (dopamine precursor) [164] Ciforadenant (CPI-444, V-81444) – adenosine A2A receptor antagonist CM-4612 (CM-ADHD; CM-AT; CM-PK) – enzyme replacement and modulator [165] Crisdesalazine (AAD-2004) – microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitor [166] CTx-GBA1 – gene transference [167] Cu(II)ATSM (copper(II)-ATSM; Cu-ATSM) – neuron modulator [168] Debamestrocel (autologous bone marrow derived mesenchymal stem cell therapy; NurOwn) – dopaminergic cell replacement [169] DNL-201 – leucine-rich repeat kinase 2 (LRRK2) inhibitor [170] Dopamine intranasal – non-selective dopamine receptor agonist [171] DX-0308 (DX-308) – retinoic acid metabolism modulator [172] Emrusolmin (anle-138b; TEV-56286) – α-synuclein inhibitor and protein aggregation inhibitor [173] ESB-1609 – sphingosine-1-phosphate (S1P) receptor agonist [174] ESB-5070 – leucine-rich repeat kinase 2 (LRRK2) inhibitor [175] F-14413 – α2-adrenergic receptor inverse agonist [176] FB-101 (1ST-102) – Bcr-Abl tyrosine kinase inhibitor [177] Fibroblast growth factor 1 (FGF-1) – fibroblast growth factor stimulant and angiogenesis-inducing agent [178] GO-101 – gene transference [179] GT-02329 – β-glucocerebrosidase (GCase) activator and/or chaperone [180] ISC-hpNSC (human parthenogenetic neural stem cells) – dopaminergic cell replacement [181] Itanapraced (CHF-5074; CSP-1103) – γ-secretase modulator and non-steroidal anti-inflammatory drug (NSAID) derivative lacking cyclooxygenase (COX) inhibition [182] Levodopa deuterated (deuterium-containing levodopa; SD-1077) – dopamine precursor and indirect non-selective dopamine receptor agonist [183] Liatermin (BVF-014; GDNF; glial-derived neutrotrophic factor; r-metHuGDNF) – neuron stimulant [184] Lu-AE-04621 (Lu-AE04621) – dopamine receptor agonist (prodrug of Lu-AA40326) [185] Masupirdine (SUVN-502; SUVN502) – serotonin 5-HT6 receptor antagonist [186] Mesocarb (MLR-1017) – atypical dopamine reuptake inhibitor (DRI) [187] MTK-458 – protein-serine-threonine kinase stimulant [188] NPT-200-11 (NPT200-11; UCB-1332) – α-synuclein inhibitor [189] NPT-520-34 (NPT520-34) – 1-phosphatidylinositol 3 kinase modulator and other actions [190] ODM-104 – catechol O-methyltransferase (COMT) inhibitor [191] OP-101 (dendrimer N-acetylcysteine) – various actions [192] OP-501 – catechol O-methyltransferase (COMT) inhibitor [193] Ordopidine (ACR-325) – low-affinity dopamine D2 receptor antagonist and dopaminergic stabilizer [194] PD-04 (a-Syn-PD-04; Affitope PD-04; PD04) – peptide vaccine against α-synuclein [195] Rasagiline – monoamine oxidase B (MAO-B) inhibitor [196] Rasagiline transdermal patch (TPU-002RA) – monoamine oxidase B (MAO-B) inhibitor [197] Research programme: adenosine A2A/A1 selective antagonists - Domain Therapeutics/CleveXel Pharma (CVXL-0069; DT-1133; DT0926; FP-0692; FP-1133) – adenosine A1 receptor antagonists and adenosine A2A receptor antagonists [198] Research programme: catalytic antioxidants - Aeolus Pharmaceuticals (AEOL-10113; AEOL-11207) – antioxidants [199] Research programme: central nervous system therapeutics - Delpor – undefined mechanism of action [200] Research programme: cGAS/STING antagonists - IFM Due – nucleotidyltransferase inhibitors [201] Research programme: COMT inhibitors - Avalo Therapeutics (AVTX-406; CERC-425; CERC-406) – catechol O-methyltransferase (COMT) inhibitors [202] Research programme: dopamine D1 receptor agonists - Takeda – dopamine D1 receptor agonists [203] Research programme: exosome therapeutics - ArunA Biomedical – undefined mechanism of action [204] Research programme: GPCR modulators - Nxera Pharma – various actions [205] Research programme: KEAP1 inhibitors - Keapstone Therapeutics – Kelch-like ECH-associated protein 1 (KEAP1) inhibitors [206] Research programme: long-acting neuropsychiatric therapeutics - Teva (NP-201; NP-202; risperidone/ropinirole implants) – various actions [207] Research programme: LRRK2 inhibitor - GlaxoSmithKline – leucine-rich repeat kinase 2 (LRRK2) inhibitors [208] Research programme: LRRK2 inhibitors - Novartis – leucine-rich repeat kinase 2 (LRRK2) inhibitors [209] Research programme: neurodegenerative disorder gene therapies - Denali Therapeutics (AAV-LF2; CNS-directed AAV-based gene therapies) – gene transference [210] Research programme: neurodegenerative disorders therapeutics - BioArctic Neuroscience (AD-0802; AD-1502; AD-2203; AE-1501; BAN-2203; BAN-2502; BAN2401 back-up) – various actions [211] Research programme: neurodegenerative disorder therapeutics - Celgene Corporation/Evotec (BMSxxx) – cell replacements [212] Research programme: neurodegenerative disease therapeutics - ProteoTech (DP-68; DP-74; PD-61-W3; PeptiClere; PTI-19; PTI-51; PTI-51-CH3; Synuclere; TauPro) – various actions [213] Research programme: neurological disorders therapeutics - Gloriana therapeutics (ECB-PD; ECT-PD; Meteorin; Ns-G34; NsG-0301; NsG-33) – glial cell line-derived neurotrophic factor modulators [214] Research programme: Parkinson's disease therapeutics - Alectos Therapeutics – glucocerebrosidase 2 (GBA2) protein inhibitor [215] Research programme: Parkinson's disease therapies - Zymes (co-Q10; coenzyme Q10; ubidecarenone) – antioxidants [216] Research programme: Parkinson's disease therapy - AbbVie – dopamine D2 and D3 receptor agonists [217] Research programme: positive allosteric modulators - Proximagen – various actions [218] Research programme: protective autoimmunity enhancer - Proneuron Biotechnologies (PN-277) – immunomodulators [219] Research programme: protein phosphatase 2A modulators - Signum Biosciences (SIG-1012; SIG-1106) – protein phosphatase 2A (PP2A) modulator [220] Research programme: small molecule therapeutics - Amathus Therapeutics – mitochondrial protein stimulants [221] Research programme: small molecule therapeutics - Aranda Pharma/Tarrex Biopharma (ADA-308; ADA-409; Backup; MDA-308; MDA-409) – androgen receptor antagonists [222] Research programme: transmembrane protein 175 agonists - AbbVie/Caraway Therapeutics – TMEM175 stimulants [223] Rotigotine controlled release (SER-214) – non-selective dopamine receptor agonist and other actions [224] S-32504 – dopamine D2 and D3 receptor agonist [225] SAGE-324 (BIIB-124) – GABAA receptor positive allosteric modulator and neurosteroid [226] Saracatinib (AZD-0530) – Src-family kinase inhibitor [227] Selegiline transdermal (Emsam) – monoamine oxidase B (MAO-B) inhibitor and other actions [228] Seridopidine (ACR343; ACR-343) – dopamine receptor modulator and so-called "dopaminergic stabilizer" [229] SLS-004 (LV-dCas9-DNMT3A) – gene therapy and α-synuclein expression inhibitor [230] Sonlicromanol (KH-176) – prostaglandin-E synthase inhibitor and reactive oxygen species modulator [231] SPN-803 (SPN803) – undefined mechanism of action [232] STEL-101 (AMA-101; STL-101) – undefined mechanism of action [233] UB-312 – immunostimulant [234] YKP-10461 (SKL-PD; YKP10461) – monoamine oxidase B (MAO-B) inhibitor [235] YTX-7739 – stearoyl-CoA desaturase inhibitor [236] Xenon (NBTX-001) – ionotropic glutamate NMDA receptor antagonist [237]
Sources: en.wikipedia.org
This continuous process is highly efficient for producing large volumes of coated materials, which are essential in various industries including printing, packaging, and electronics. The technology allows for consistent high-quality application of the coating material over large surface areas, enhancing productivity and uniformity.
== Naming conventions == Amines are named in several ways. Typically, the compound is given the prefix "amino-" or the suffix "-amine". The prefix "N-" shows substitution on the nitrogen atom. An organic compound with multiple amino groups is called a diamine, triamine, tetraamine and so forth. Lower amines are named with the suffix -amine.
Bergamot essential oil has been used in cosmetics, aromatherapy, and as a flavoring in food and beverages. Its citrus scent makes it a natural flavoring and deodorizing agent. The volatile oils of the bergamot orange are described as flavoring agents in the USP Food Chemicals Codex and are generally recognized as safe for human consumption by the US Food and Drug Administration. For example, Earl Grey tea is a type of black tea that may contain bergamot essential oil as a flavoring agent. Historically, bergamot essential oil was an ingredient in Eau de Cologne, a perfume originally concocted by Johann Maria Farina at the beginning of the 18th century. The first record of bergamot oil used as a fragrance in perfume is from 1714, found in the Farina Archive in Cologne.
C-type natriuretic peptide (CNP) primarily interacts with NPR-B, which triggers an increase in the concentration of cGMP in the cell. This process can lead to several physiological effects, such as tissue remodeling, reduction of pulmonary hypertension and fibrosis, and stimulation of long bone growth. CNP is highly concentrated in vascular endothelial cells and plays a crucial role in regulating vascular tone through its vasodilatory action. Furthermore, CNP has been shown to have anti proliferative effects on vascular smooth muscle and an inhibitory effect on the migration of human coronary artery smooth muscle cells.
==== Crackdown on crack ==== As the media focused on the emergence of crack cocaine in the early 1980s, the Reagan administration shored up negative public opinion, encouraging the DEA to emphasize the harmful effects of the drug. Stories of "crack whores" and "crack babies" became commonplace. In mid-1986, crack dominated the news. Time declared crack the issue of the year. Newsweek compared the magnitude of the crack story to Vietnam and Watergate. The cocaine overdose deaths of rising basketball star Len Bias, and young NFL football player Don Rogers, both in June, received wide coverage. Riding the wave of public fervor, that October Reagan signed into law much harsher sentencing for crack through the Anti-Drug Abuse Act, commonly known as the Len Bias law. According to historian Elizabeth Hinton, "[Reagan] led Congress in criminalizing drug users, especially African American drug users, by concentrating and stiffening penalties for the possession of the crystalline rock form of cocaine, known as 'crack', rather than the crystallized methamphetamine that White House officials recognized was as much of a problem among low-income white Americans". The Anti-Drug Abuse Act appropriated an additional $1.7 billion to drug war funding, and established 29 new mandatory minimum sentences for drug offenses (until then, the American legal system had seen 55 minimum sentences in total). Of particular note, the act made sentences for larger amounts of cocaine 100 times more severe for crack than for the powder form.
Sources: en.wikipedia.org
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.
Selank is a synthetic analogue built on the tuftsin tetrapeptide Thr-Lys-Pro-Arg. Extra proline residues were added to the C-terminus during design work. That modification is intended to make the peptide less vulnerable to rapid enzymatic degradation.
Transliteration from Russian produces variant spellings such as Selanc. Many suppliers avoid the trade-style name entirely and list the peptide sequence. Comparing sequences rather than names is the reliable way to confirm two entries describe the same molecule.
Reverse-phase HPLC is the usual method and gives a percentage purity value. Mass spectrometry then confirms the molecular mass. Together they provide a basic identity and purity profile for a lot.