This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
Reversed-phase high-performance liquid chromatography is the standard technique for estimating peptide purity. The result is a peak-area percentage, which describes how much of the detected material elutes as the main peak in one run. Mass spectrometry confirms the molecular mass and can reveal truncated, adducted, or otherwise modified species. Amino acid analysis or tandem mass spectrometry can address sequence fidelity when identity is in doubt. None of these measurements, taken alone, establishes that a sample is fit for any specific purpose.
Lyophilized selank is normally supplied as a dry powder and is considered stable for extended periods when kept cold and dry. Moisture uptake is the main practical threat, because absorbed water promotes both hydrolysis and aggregation in the solid state. Vials are usually warmed to room temperature before opening so that condensation does not form on the powder. Supplier documentation commonly specifies -20 °C for routine storage, with -80 °C used for material intended to be archived for years.
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.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | 95 percent or higher by RP-HPLC | Area percentage of the main peak |
| Identity confirmation | Electrospray ionization mass spectrometry | Observed mass compared with the theoretical value near 751.9 Da |
| Recommended dry storage | -20 °C, desiccated | -80 °C for multi-year archival material |
| Solution handling | Prepare fresh; avoid long storage | Sterile filtration reduces microbial load |
| Common synonyms | TKPRPGP; TP-7 | Sequence code and laboratory designation used interchangeably |
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.
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
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.
Low-certainty evidence indicates that it mitigates worsening of peripheral neuropathy and disability from disease progression. Inotersen blocks gene expression of both wild-type and mutant TTR, reducing amyloid precursor. Moderate-certainty evidence suggests that it mitigates worsening of peripheral neuropathy. Long-term efficacy and safety of inotersen use in people with mutant TTR-related amyloidosis is still be evaluated in a phase-III clinical trial as of 2021. Both diflunisal and inotersen may also mitigate declines in quality-of-life, though the evidence for this effect is unclear. For people with cardiac ATTR the effect of inotersen use is inconclusive and requires further investigation. In 2018, inotersen was approved by the European Medicines Agency to treat polyneuropathy in adults with hereditary transthyretin amyloidosis. It has since been approved for use in Canada, the European Union and in the USA. Patisiran functions similarly to inotersen. Moderate-certainty evidence suggests that patisiran mitigates worsening of peripheral neuropathy and disability from disease progression. Additionally, low-certainty evidence suggests that patisiran mitigates decreases in quality-of-life and slightly reduces the rate of adverse events versus placebo. There is no evidence of an effect on mortality rate. A review of early data from use of patisiran in people with variant cardiac ATTR suggests that it may reduce mortality and hospitalization, however this is still being investigated and requires further investigation.
== Composition == The characteristic substances inside the extracellular matrix of soft tissue are the collagen, elastin and ground substance. Normally the soft tissue is very hydrated because of the ground substance. The fibroblasts are the most common cell responsible for the production of soft tissues' fibers and ground substance. Variations of fibroblasts, like chondroblasts, may also produce these substances.
Infants can be infected during passage through the birth canal; nevertheless, newborns who acquire GBS through this route may only become colonized, and these colonized infants typically do not develop EOD. Roughly 50% of newborns to GBS colonized mothers are also GBS colonized, and (without prevention measures) 1–2% of these newborns will develop EOD. In the past, the incidence of EOD ranged from 0.7 to 3.7 per thousand live births in the US and from 0.2 to 3.25 per thousand in Europe.Multistate surveillance 2006-2015 shows a decline in EOD from 0.37 to 0.23 per 1000 live births in the US, but LOD remains steady at 0.31 per 1000 live births. In 2021 had been estimated a total of 1970 deaths (0.59/100,000 population) in the US were estimated to be caused by GBS neonatal infections. It was estimated that 226 infants (49 per 100,000) in the United States had a clinically significant GBS infection, and that approximately 11 (2.4%) of those cases resulted in death. The widespread use of intrapartum antibiotic prophylaxis (IAP) has resulted in a decline in the incidence of early neonatal GBS infection in the United States of more than 85%, from 1.8‰ of cases in live births in the 1990s to 0.23‰ in 2015, and to 0.18‰ in 2023.
=== Scientific assessment === On 11 August 2020, a World Health Organization (WHO) spokesperson said "prequalification of any vaccine includes the rigorous review and assessment of all required safety and efficacy data". A WHO assistant director said, "You cannot use a vaccine or drugs or medicines without following through all of these stages, having complied with all of these stages". Francois Balloux, a geneticist at University College London, called the Russian government's approval of Gam-COVID-Vac a "reckless and foolish decision". Professor Paul Offit, the director of the Vaccine Education Center at Children's Hospital of Philadelphia, characterized the announcement as a "political stunt", and stated that the untested vaccine could be harmful. Stephen Griffin, Associate Professor in the School of Medicine, University of Leeds, said "we can be cautiously optimistic that SARS-CoV2 vaccines targeting the spike protein are effective". Moreover, as the Sputnik antigen is delivered via a different modality, namely using a disabled Adenovirus rather than formulated RNA, this provides flexibility in terms of perhaps one or other method providing better responses in certain age-groups, ethnicities, etc., plus the storage of this vaccine ought to be more straightforward. "There is a huge risk that confidence in vaccines would be damaged by a vaccine that received approval and was then shown to be harmful", said immunologist Peter Openshaw.
Used in biological sequence analysis: Genbank, UniProt Used in structure analysis: Protein Data Bank (PDB) Used in finding Protein Families and Motif Finding: InterPro, Pfam Used for Next Generation Sequencing: Sequence Read Archive Used in Network Analysis: Metabolic Pathway Databases (KEGG, BioCyc), Interaction Analysis Databases, Functional Networks Used in design of synthetic genetic circuits: GenoCAD
Sources: en.wikipedia.org
=== Chilled caramel topping === Another example of non-Newtonian fluid flow is chilled caramel ice cream topping (so long as it incorporates hydrocolloids such as carrageenan and gellan gum). The sudden application of force—by stabbing the surface with a finger, for example, or rapidly inverting the container holding it—causes the fluid to behave like a solid rather than a liquid. This is the "shear thickening" property of this non-Newtonian fluid. Gentler treatment, such as slowly inserting a spoon, will leave it in its liquid state. Trying to jerk the spoon back out again, however, will trigger the return of the temporary solid state.
Andrew Welsh has served as President of the board since September 2025, with Vice-President Anthony Di Pietro serving since March 2026. Essendon's board members are Andrew Welsh, Tim Roberts, David Wills, Dorothy Hisgrove, Andrew Muir, Kate O'Sullivan, Anthony Howard AM KC, and Catriona Larritt.
=== Hypodermis === Beneath these layers lies the hypodermis, which is composed of adipose tissue, fascia, as well as larger lymphatic and blood vessels. For joint and muscle disease treatment, topically applied drugs such as non-steroidal anti-inflammatory drugs (NSAIDs) can penetrate the subcutaneous tissue or even deeper tissues in the hypodermis. Drugs are primarily delivered into the underlying muscle by direct penetration without prior entry into the systemic circulation to prevent unintended side effects.
== Identification == Fossil dinosaur eggshell fragments can be recognized based on three important traits. Their thickness should be roughly uniform, they are usually slightly curved, and their surface is covered in tiny pores. Less frequently, the concave underside of the eggshell fragment will preserve bumps known as mammillae. Sometimes the embryo had absorbed so much of the calcium that the mammillae need a magnifying glass or microscope to be seen. However, there are many kinds of naturally occurring objects which can resemble fossil eggs. These can fool even professional paleontologists.
The Sino-Soviet split was one of the key events of the Cold War, equal in importance to the construction of the Berlin Wall, the Cuban Missile Crisis, the Second Vietnam War, and Sino-American rapprochement. The split helped to determine the framework for the Cold War period 1979–1985 in general, and influenced the course of the Second Vietnam War in particular.
Sources: en.wikipedia.org
As of 2018, some retailers had begun experimenting with the use of blue light bulbs in bathrooms in order to deter addicts from using such spaces to inject opiates. Blue lights are said to make finding veins to inject more difficult. However, a 2013 study has found that the use of blue lights are unlikely to deter drugs users from injecting in public washrooms and may increase drug use-related harm.
Minimally invasive procedures were pioneered by interventional radiologists who had first introduced angioplasty and the catheter-delivered stent. Many other minimally invasive procedures have followed where images of all parts of the body can be obtained and used to direct interventional instruments by way of catheters (needles and fine tubes), so that many conditions once requiring open surgery can now be treated non-surgically. A minimally invasive procedure typically involves the use of arthroscopic (for joints and the spine) or laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or large scale display panel, and is carried out through the skin or through a body cavity or anatomical opening. Interventional radiology now offers many techniques that avoid the need for surgery. By use of a minimally invasive procedure, a patient may require only an adhesive bandage on the incision, rather than multiple stitches or staples to close a large incision. This usually results in less infection, a quicker recovery time and shorter hospital stays, or allow outpatient treatment. However, the safety and effectiveness of each procedure must be demonstrated with randomized controlled trials. The term was coined by John E. A. Wickham in 1984, who wrote of it in British Medical Journal in 1987.
Fish is a highly perishable product: the "fishy" smell of dead fish is due to the breakdown of amino acids into biogenic amines and ammonia. Live food fish are often transported in tanks at high expense for an international market that prefers its seafood killed immediately before it is cooked. Delivery of live fish without water is also being explored. While some seafood restaurants keep live fish in aquaria for display purposes or cultural beliefs, the majority of live fish are kept for dining customers. The live food fish trade in Hong Kong, for example, is estimated to have driven imports of live food fish to more than 15,000 tonnes in 2000. Worldwide sales that year were estimated at US$400 million, according to the World Resources Institute. If the cool chain has not been adhered to correctly, food products generally decay and become harmful before the validity date printed on the package. As the potential harm for a consumer when eating rotten fish is much larger than for example with dairy products, the U.S. Food and Drug Administration (FDA) has introduced regulation in the USA requiring the use of a time temperature indicator on certain fresh chilled seafood products. Because fresh fish is highly perishable, it must be eaten promptly or discarded; it can be kept for only a short time. In many countries, fresh fish are filleted and displayed for sale on a bed of crushed ice or refrigerated. Fresh fish is most commonly found near bodies of water, but the advent of refrigerated train and truck transportation has made fresh fish more widely available inland.
==== Evolution stability ==== The genomes of non-segmented negative-stranded RNA viruses (including paramyxoviruses) have a low rate of homologous recombination and evolve comparatively slowly. Multiple reasons for this genomic stability likely exist: (1) the genomes of these viruses are nonsegmented, therefore cannot undergo genetic reassortment, (2) each protein and each amino acid has an important function. Therefore, any new genetic insertion, substitution or deletion would lead to a decrease or total loss of function that would in turn cause the new virus variant to be less viable. (3) Sendai virus belong to viruses that are governed by the "rule of six". SeV genome as genomes of other paramyxoviruses mainly include six genes, which encode for six major proteins. Low rate of homologous RNA recombination in paramyxoviruses probably results from this unusual genomic requirement for polyhexameric length (6n+0). Natural high genomic stability of SeV is a positive feature for it potential use as a vaccine vector or as an oncolytic agent. For any clinical or industrial applications, it is important that SeV genomic and inserted foreign trans genes would be expressed in a stable way. Paramyxoviruses show relatively little genomic or antigenic change over time. They are known to stably express a wide variety of heterologous antigens at relatively high levels in many species of animals.
Anti-cardiolipin antibodies (ACA) are antibodies often directed against cardiolipin and found in several diseases, including syphilis, antiphospholipid syndrome, livedoid vasculitis, vertebrobasilar insufficiency, Behçet's syndrome, idiopathic spontaneous abortion, and systemic lupus erythematosus (SLE). They are a form of anti-mitochondrial antibody. In SLE, anti-DNA antibodies and anti-cardiolipin antibodies may be present individually or together; the two types of antibodies act independently. This is in contrast to rheumatoid arthritis with systemic sclerosis (scleroderma) because anti-cardiolipin antibodies are present in both conditions, and therefore may tie the two conditions together. Anti-cardiolipin antibodies can be classified in two ways:
Sources: en.wikipedia.org
Sealed, desiccated storage at -20 °C or colder is the standard recommendation for research-grade material. Vials should reach room temperature before they are opened, which limits condensation. Repeated temperature cycling is discouraged.
A reported purity value reflects the share of the main peak in one chromatographic run and says nothing about identity. Confirming that the expected sequence is present requires a separate measurement such as mass spectrometry. Purity and identity are distinct questions.
A mass spectrum reports the molecular masses present in a sample and shows whether they match the value expected for selank, near 751.9 Da. It also flags common artifacts such as truncation or adduct formation. It does not establish correct stereochemistry or complete sequence order on its own.
Selank is a synthetic peptide made of seven amino acids. It is modeled on tuftsin, a natural tetrapeptide, with an added three-residue tail. It is not a small-molecule drug.