If you have been reading about Heptapeptide 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.
Updated 2025-08-18. Numbers and descriptions here follow the published literature rather than marketing material.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
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.
| Property | Value | Notes |
|---|---|---|
| Common route | Intranasal | Also injected in some animal work |
| Solubility class | Freely soluble in water | Solid form is hygroscopic |
| Typical storage | About -20 degrees Celsius | Keep desiccated and dark |
| Purity method | Reverse-phase HPLC | Reported as area percent |
| Confirmatory method | Mass spectrometry | Verifies expected molecular mass |
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
The 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.
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.
In 2017, the US Food and Drug Administration (FDA) approved pembrolizumab for any unresectable or metastatic solid tumor with certain genetic anomalies (mismatch repair deficiency or microsatellite instability). This was the first time the FDA approved a cancer drug based on tumor genetics rather than tissue type or tumor site; therefore, pembrolizumab is a so-called tissue-agnostic drug. In the European Union, pembrolizumab is indicated for:
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==== Interwar period and World War II (1918–1945) ==== During the interwar period, medical organizations and doctors in mainland Europe experimented with the idea of routine circumcision for prophylactic reasons as well, alongside developments in the Anglophonic world. In France, the medical profession went so far as to recommend universal routine circumcision. However, prevalence in France and mainland Europe remained low. There is a lack of consensus in the academic literature on why this occurred.
The cars (outfitted with state-of-the-art fiberglass insulation and axle-driven fans for internal air circulation) traveled throughout the Southern Pacific and Union Pacific systems, where they were displayed to promote PFE's post-World War II modernization. Though both units remained in service over 15 years (#45698 was destroyed in a wreck in May 1962, while #44739 was scrapped in 1966), no additional aluminum reefers were constructed. Fruit Growers Express number 38374 was equipped with an experimental aluminum body in the Indiana Harbor, Indiana shops.
Farmers of wakame must obtain permission from Biosecurity New Zealand to access approval of Sections 52 and 53 from the Biosecurity Act 1993, which deal with exceptions to the possession of pests and unwanted creatures. Furthermore, any farmed wakame must only be naturally settled in pre-existing marine farms; mussel farms are a commonly infested area for wakame. As an exceptional case of permitted farming purely as pest control, profitting from wakame is not permitted, with exception of Ngāi Tahu, in which the iwi's revenue from catching wakame is funded for further pest control.
Sources: en.wikipedia.org
Over the next few decades, various competing hypotheses arose as to where and how the "posterior lobe hormones" were produced, transported, and stored. Finally in 1954, Berta and Ernst Scharrer concluded that the hormones were produced by the nuclei of cells in the hypothalamus.
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== Types == Alkaptonuria Aspartylglucosaminuria Branched-chain keto acid dehydrogenase kinase deficiency Methylmalonic acidemia Maple syrup urine disease Homocystinuria Tyrosinemia Trimethylaminuria Hartnup disease Biotinidase deficiency Ornithine carbamoyltransferase deficiency Carbamoyl-phosphate synthase I deficiency disease Citrullinemia Hyperargininemia Hyperhomocysteinemia Hypermethioninemia Hyperlysinemias Nonketotic hyperglycinemia Propionic acidemia Hyperprolinemia
== Connective tissue cells == Connective tissue cells are typically divided into two types, fixed cells and wandering cells. Fibrocytes, or fibroblasts and fat cells(adipocytes) are fixed cells, where as macrophages, monocytes, lymphocytes, plasma cells, eosinophils and mast cells are wandering cells. Fibrocytes are the most common cell type in connective tissues. If fibrocytes are stimulated by damage to the surrounding tissue, the fibrocyte is altered into a fibroblast. The fibroblasts contain organelles that are necessary for the synthesis and excretion of proteins needed to repair the tissue damage. Fibrocytes usually do not leave the connective tissue. Reticular cells are usually larger than fibrocytes. Reticular cells are the fibrocytes of reticular connective tissue and form a network of reticular fibers. Adipocytes are fat cells that are fixed cells in loose connective tissue. Their main function is the storage of lipid. Macrophages arise from monocytes. Monocytes originate in the bone marrow upon which they are released into the blood stream. They are mobile and leave the blood stream to enter connective tissues where they differentiate into macrophages. The fibroblasts are the most important in the connective tissue. Fibroblasts manufacture and maintain the extracellular material. They migrate throughout the extracellular matrix to wherever they are needed. Adipocytes are cells that are very efficient at storing energy in the form of triglycerides.
== Chemical composition == The flavonol miquelianin, as well as the alkaloids (+)-(1R)-coclaurine and (−)-(1S)-norcoclaurine, can be found in the leaves of N. nucifera. The plant also contains nuciferine, neferine, and many other benzylisoquinoline alkaloids with medicinal properties.
Sources: en.wikipedia.org
1 March to 8 May The 4th Marine Regiment launched Operation Purple Martin against three PAVN regiments operating near the Vietnamese Demilitarized Zone (DMZ). The operation results in 347 PAVN killed and approximately 100 Marines killed.
== Professional membership == American Association of Clinical Chemistry (AACC) Academy Fellow of AACC American Society of Clinical Pathology (ASCP) International Society on Thrombosis and Haemostasis (ISTH) Korean Society for Biochemistry and Molecular Biology
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In the United States, shipments larger than about 7,000 kg (15,432 lb) are typically classified as truckload (TL) freight. This is because it is more efficient and economical for a large shipment to have exclusive use of one larger trailer rather than share space on a smaller LTL trailer. By the Federal Bridge Gross Weight Formula the total weight of a loaded truck (tractor and trailer, 5-axle rig) cannot exceed 80,000 lb (36,287 kg) in the United States. In ordinary circumstances, long-haul equipment will weigh about 15,000 kg (33,069 lb), leaving about 20,000 kg (44,092 lb) of freight capacity. Similarly a load is limited to the space available in the trailer, normally 48 ft (14.63 m) or 53 ft (16.15 m) long, 2.6 m (102+3⁄8 in) wide, 9 ft 0 in (2.74 m) high and 13 ft 6 in or 4.11 m high overall. While express, parcel and LTL shipments are always intermingled with other shipments on a single piece of equipment and are typically reloaded across multiple pieces of equipment during their transport, TL shipments usually travel as the only shipment on a trailer. In fact, TL shipments usually deliver on exactly the same trailer as they are picked up on.
Sources: en.wikipedia.org
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.
Reported human trials are few, brief and originate mainly from one country. They describe effects on anxiety-related measures, but sample sizes are small and reporting is limited. The results are widely regarded as preliminary rather than confirmed.
Reverse-phase liquid chromatography is used to assess purity and separation of related impurities. Mass spectrometry confirms that the observed molecular mass matches the expected peptide. A certificate of analysis from the supplier is the usual document of record.
Dry powder is normally held at -20 degrees Celsius or below in a sealed, light-protected container with desiccant. Brief room-temperature handling during weighing is generally tolerated. Storage instructions vary between suppliers, so the accompanying certificate of analysis should be followed.