A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-20 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
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.
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.
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.
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.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
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.
Characterization of Selank in a laboratory setting relies on standard peptide methods. Reverse-phase high-performance liquid chromatography separates the target from related impurities and provides a purity figure, commonly reported as 95 percent or higher. Mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, confirms the molecular mass and helps detect truncation or modification. Amino acid analysis can verify composition when a sequence-level check is needed. These techniques together establish identity and purity for a given lot.
Food and Drug Administration showed that targeting the GLP-1 receptor was a viable strategy and inspired other pharmaceutical companies to focus on that receptor. In 2011, Lilly and Amylin dissolved their partnership, with Amylin keeping the rights to exenatide. Lilly continued to develop drugs of the same class. The 2024 American Diabetes Association conference included presentations on at least 27 GLP-1 receptor agonists then in development. By July 2024, Novo Nordisk's semaglutide and Eli Lilly's tirzepatide were ranked among the world's most popular and lucrative drugs. Novo Nordisk's rollout of semaglutide turned it into the most valuable company in Europe in 2024. Its market capitalization of $570 billion was larger than the entire economy of its home country of Denmark; its $2.3 billion income tax bill for 2023 made it the country's largest taxpayer; and its rapid growth represented nearly all of Denmark's economic growth. By October 2024, tirzepatide had turned Eli Lilly into the world's most valuable drug company.
Research has focused on changing the mixture of keratins produced in the skin. There are 54 known keratin genes—of which 28 belong to the type I intermediate filament genes and 26 to type II—which work as heterodimers. Many of these genes share substantial structural and functional similarity, but they are specialized to cell type and/or conditions under which they are normally produced. If the balance of production could be shifted away from the mutated, dysfunctional keratin gene toward an intact keratin gene, symptoms could be reduced. For example, sulforaphane, a compound found in broccoli sprouts and few other vegetables, was found to reduce blistering in a mouse model to the point where affected pups could not be identified visually, when injected into pregnant mice (5 μmol/day = 0.9 mg) and applied topically to newborns (1 μmol/day = 0.2 mg in jojoba oil). As of 2008, clinical research at the University of Minnesota has explored allogeneic bone marrow transplantation for RD and junctional EB, treating a two-year-old child who is one of two brothers with EB. A second transplant has also been performed on the child's older brother. A Missouri boy has also successfully undergone the transplant, as well as a 5 year old boy from Alabama. So far there have been 12 successful transplants. Another transplant is scheduled for a California baby. A clinical trial is planned for 30 subjects. However, the immune suppression that bone marrow transplantation requires causes a risk of serious infections with large scale blisters and skin erosion.
There is some medical evidence of various malformations (for example, cardiac or facial deformations when used in early pregnancy); however, the data is not conclusive. The data are also inconclusive on whether benzodiazepines such as clonazepam cause developmental deficits or decreases in IQ in the developing fetus when taken by the mother during pregnancy. Clonazepam, when used late in pregnancy, may result in the development of a severe benzodiazepine withdrawal syndrome in the neonate. Withdrawal symptoms from benzodiazepines in the neonate may include hypotonia, apnoeic spells, cyanosis, and impaired metabolic responses to cold stress. The safety profile of clonazepam during pregnancy is less clear than that of other benzodiazepines, and if benzodiazepines are indicated during pregnancy, chlordiazepoxide and diazepam may be a safer choice. The use of clonazepam during pregnancy should only occur if the clinical benefits are believed to outweigh the clinical risks to the fetus. Caution is also required if clonazepam is used during breastfeeding. Possible adverse effects of use of benzodiazepines such as clonazepam during pregnancy include: miscarriage, malformation, intrauterine growth retardation, functional deficits, carcinogenesis, and mutagenesis.
Born: Vyacheslav Gryaznov, Russian classical pianist; in Yuzhno-Sakhalinsk, Sakhalin, Russian SFSR, Soviet Union Filip Karadordević, U.S.-born Serbian businessman and heir to the throne of the abolished monarchy of Serbia and Yugoslavia as the eldest son of the former Crown Prince Alexander Karadordević, who was the only child of King Peter II of Yugoslavia; in Vienna, Virginia Died: Red Smith, 76, American sportswriter and columnist, died four days after he had published a column, which he headlined "Writing Less— and Better?" where he announced that he would be writing only three columns per week rather than four.
Sources: en.wikipedia.org
These devices detect hydrocarbon gas leaks in the transportation of natural gas and crude oil. Infrared spectroscopy is an important analysis method in the recycling process of household waste plastics, and a convenient stand-off method to sort plastic of different polymers (PET, HDPE, ...). Other developments include a miniature IR-spectrometer that's linked to a cloud based database and suitable for personal everyday use, and NIR-spectroscopic chips that can be embedded in smartphones and various gadgets. In catalysis research it is a very useful tool to characterize the catalyst, as well as to detect intermediates. Infrared spectroscopy coupled with machine learning and artificial intelligence also has potential for rapid, accurate and non-invasive sensing of bacteria. The complex chemical composition of bacteria, including nucleic acids, proteins, carbohydrates and fatty acids, results in high-dimensional datasets where the essential features are effectively hidden under the total spectrum. Extraction of the essential features therefore requires advanced statistical methods such as machine learning and deep-neural networks. The potential of this technique for bacteria classification have been demonstrated for differentiation at the genus, species and serotype taxonomic levels, and it has also been shown promising for antimicrobial susceptibility testing, which is important for many clinical settings where faster susceptibility testing would decrease unnecessary blind-treatment with broad-spectrum antibiotics.
Hot dogs are prepared commercially by mixing the ingredients (meats, spices, binders and fillers) in vats where rapidly moving blades grind and mix the ingredients in the same operation. This mixture is forced through tubes into casings for cooking. Most hot dogs sold in the US are "skinless" rather than "natural casing" sausages.
== Structure == Like other amino acids (not as a residue of a protein), cysteine exists as a zwitterion. Cysteine has l chirality in the older d/l notation based on homology to d- and l-glyceraldehyde. In the newer R/S system of designating chirality, based on the atomic numbers of atoms near the asymmetric carbon, cysteine (and selenocysteine) have R chirality, because of the presence of sulfur (or selenium) as a second neighbor to the asymmetric carbon atom. The remaining chiral amino acids, having lighter atoms in that position, have S chirality. Replacing sulfur with selenium gives selenocysteine.
The (3R, 6R, 7R) series 2, 3 showed very good levels of selectivity relative to the vasopressin receptors. However, although all the (3R, 6R, 7R) isomers of the monosubstituted aryl 2,5-DKPs with wide range of different functionality had similarly high levels of potency, they all had low bioavailability in the rat. Optimization of the pharmacokinetic (PK) profile of this template was achieved by property-based design using an estimated of human oral absorption (EHOA) which focused the SAR on 2,5-DKPs with small exocyclic aromatic rings combined with small amides. This resulted in the 2’,4’-difluoro dimethylamide 3 which achieved good oral bioavailability in the rat (53%) and dog (51%) whilst retaining good oxytocin antagonist potency (Ki= 0.63nM) and >1000 fold selectivity relative to the human vasopressin V1A, V2, V1B receptors. The introduction of polar heterocycles to improve the solubility and human cytochrome P450 (Cyp450) enzyme profile of 3 using intrinsic clearance in microsomes to drive the improvements in the later’s pharmacokinetic profile lead to the 2’,6’-dimethyl-3’-pyridyl morpholine amide Epelsiban.
=== Truett's Chick-fil-A === Truett's Chick-fil-A is designed in honor of founder S. Truett Cathy. The restaurant is decorated with family photos and favorite quotes of the restaurant founder. The restaurant offers drive-thru, counter, and sit-down service for breakfast, lunch, and dinner. There are four locations including Newnan, Rome, Stockbridge, Loganville and Woodstock, Georgia.
Sources: en.wikipedia.org
It insured the lives of its members for $1,000 and that of members' wives for half that amount. Sick benefits were administered by the subordinate lodges and death benefits by the Supreme Lodge. The ritual was based on the covenant between God, Noah, Abraham, and Moses. The emblem was the All Seeing Eye above three pillars with the tablets of the Ten Commandments between them. Independent Order of B'rith Abraham - Founded in 1887 as a split from the Order of Brith Abraham, whose leadership they felt was incompetent. Some sources give the name as the Improved Order of B'rith Abraham. Admitted women and was smoothly run. Added social membership option to what was already essentially an insurance society in 1924. Had a peak membership of 206,000 in 1917. In 1923 it had 585 lodges and a benefit membership of 142,812. Had 58,000 immediately before World War II. Changed name to simply B'rith Abraham in 1968. Merged with B'nai Zion in 1981. Headquarters in 1923 at 37 Seventh Street New York City. New York was still the headquarters in 1979. The Order's stated objectives in 1969 were to "foster fraternity in the context of Jewish ideals, tradition, and welfare", provide fraternal benefits to its members, and support programs for underprivileged children and seniors. It also promoted Zionism. Independent Order of American Israelites - Founded in 1894 in New York City by a group of men, some or all of whom had been members of the Independent Order, Free Sons of Israel, and the Sons of Benjamin. Order paid a $1,000 death benefit for male members and $500 for female members.
=== Mitochondrial genetics === Mitochondrial genetics concerns the diagnosis and management of mitochondrial disorders, which have a molecular basis but often result in biochemical abnormalities due to deficient energy production. There exists some overlap between medical genetic diagnostic laboratories and molecular pathology. In the UK, the NHS Highly Specialised Service for Rare Mitochondrial Disorders offers diagnostic testing for patients. Based in laboratories in Newcastle upon Tyne , Oxford and London which are integrated within the NHS Genomic Medicine Service (GMS).
A mass spectrum is a histogram plot of intensity vs. mass-to-charge ratio (m/z) in a chemical sample, usually acquired using an instrument called a mass spectrometer. Not all mass spectra of a given substance are the same; for example, some mass spectrometers break the analyte molecules into fragments; others observe the intact molecular masses with little fragmentation. A mass spectrum can represent many different types of information based on the type of mass spectrometer and the specific experiment applied. Common fragmentation processes for organic molecules are the McLafferty rearrangement and alpha cleavage. Straight chain alkanes and alkyl groups produce a typical series of peaks: 29 (CH3CH2+), 43 (CH3CH2CH2+), 57 (CH3CH2CH2CH2+), 71 (CH3CH2CH2CH2CH2+) etc.
General xenobiochemistry, including in vitro studies concerned with the metabolism, disposition and excretion of drugs, and other xenobiotics, as well as the structure, function and regulation of associated enzymes Clinical pharmacokinetics and metabolism, covering the pharmacokinetics and absorption, distribution, metabolism and excretion of drugs and other xenobiotics in man. Animal pharmacokinetics and metabolism, covering the pharmacokinetics, and absorption, distribution, metabolism and excretion of drugs and other xenobiotics in animals. Pharmacogenetics, defined as the identification and functional characterisation of polymorphic genes that encode xenobiotic metabolising enzymes and transporters that may result in altered enzymatic, cellular and clinical responses to xenobiotics. Molecular toxicology, concerning the mechanisms of toxicity and the study of toxicology of xenobiotics at the molecular level. Topics in xenobiochemistry, in the form of reviews and commentaries are primarily intended to be a critical analysis of the issue, wherein the author offers opinions on the relevance of data or of a particular experimental approach or methodology. According to the Journal Citation Reports, the journal received a 2014 impact factor of 2.199, ranking it 134th out of 254 journals in the category Pharmacology & Pharmacy and 50th out of 87 journals in the category Toxicology. The editor in chief is Costas Ioannides (University of Surrey).
A survey in 2007 showed 63% of Americans were overweight or obese, with 26% in the obese category (a BMI of 30 or more). "By 2014, 37.7% of adults in the United States were obese, 35% of men and 40.4% of women (BMI over 40) values were 7.7% for men and 9.9% for women." However, according to world statistics, "American Samoans have the highest BMI (75.6) While Egypt has 43% and Iraq has a BMI of 37.4%." According to the WHO (World Health Organization), obesity has tripled since 1975 and research has shown that obesity is linked to health issues, and high cost of medical care. The Pacific Islands dominate the top obese countries and factors contributed to this problem include dietary change, fast foods, and possible genetic predispositions. The least obese countries include Madagascar, Ethiopia, and Japan. Factors involve a more healthy diet, famine and poverty. WHO and GOO research reports that obesity rates vary by country because of lifestyle, diet and also obesity rates depend on its economic status as well. However, the wealthier the country is, the more educated their citizens tend to be. Promoting a healthier lifestyle is encouraged. The United States being one of the wealthiest countries has the 18th highest obesity rate in the world at 42.7% and researchers attribute that to diet, environment and cultural factors.
Sources: en.wikipedia.org
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.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
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.