The short version of Heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-18 and is reviewed periodically as new material appears.
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.
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 | Modeled on tuftsin |
| Amino acid sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Seven residues |
| Approximate molecular mass | Around 750 Da | Depends on counter-ion and hydration |
| Common forms | Lyophilized powder | Also described as aqueous solution |
| Primary origin of research | Russian laboratories | Mid-1990s onward |
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.
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.
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.
=== Evolutionary biology === By combining microfluidics with landscape ecology and nanofluidics, a nano/micro fabricated fluidic landscape can be constructed by building local patches of bacterial habitat and connecting them by dispersal corridors. The resulting landscapes can be used as physical implementations of an adaptive landscape, by generating a spatial mosaic of patches of opportunity distributed in space and time. The patchy nature of these fluidic landscapes allows for the study of adapting bacterial cells in a metapopulation system. The evolutionary ecology of these bacterial systems in these synthetic ecosystems allows for using biophysics to address questions in evolutionary biology.
The membership of the PSC was reduced from nine to seven, with Xi and Li Keqiang retaining their seats; the other five members were new. In December 2012, Xi visited Guangdong in his first trip outside Beijing since taking the general secretaryship. The overarching theme of the trip was to call for further economic reform and a strengthened military. Xi was elected president on 14 March 2013, in a confirmation vote during the first session of the 12th National People's Congress in Beijing. He received 2,952 for, one vote against, and three abstentions. He replaced Hu Jintao, who retired after serving two terms. Xi was also elected as the chairman of the state CMC. He subsequently nominated Li Keqiang to be the premier, who was then appointed by the NPC.
=== Metabolic panel === A Metabolic Panel (MP) is a routine group of blood tests commonly used for health screenings, disease detection, and monitoring vital signs of hospitalized patients with specific medical conditions. MP panel analyzes common analytes in the blood to assess the functions of the kidneys and liver, as well as electrolyte and acid-base balances. There are two types of MPs - Basic Metabolic Panel (BMP) or Comprehensive Metabolic Panel (CMP).
== Data analysis == Data analysis is generally challenging for DIA methods as the resulting fragment ion spectra are highly multiplexed. In DIA spectra therefore the direct relation between a precursor ion and its fragment ions is lost since the fragment ions in DIA spectra may potentially result from multiple precursor ions (any precursor ion present in the m/z range from which the DIA spectrum was derived). One approach to DIA data analysis attempts to use database-based search engines used in data-dependent acquisition to search the produced multiplexed spectra. This approach can be improved by assigning individual fragment ion to precursor ions observed in precursor ion scans, using the elution profile of the fragment ions and the precursor ions, and then searching the resulting "pseudo-spectra". A second approach to DIA data analysis is based on a targeted analysis, also known as SWATH-MS (Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra). This approach uses targeted extraction of fragment ion traces directly for identification and quantification without an explicit attempt to de-multiplex the DIA fragment ion spectra.
Sources: en.wikipedia.org
=== Feminist collages === In February 2019, she began posting collages which featured brief feminist slogans in public spaces across France, particularly in Paris and Marseille. Her collages are composed of black letters painted one by one on white sheets. Her first slogan was "Since I was 13, men have commented on my physical appearance in the street."
=== Theobromine and oxalate === Chocolate may be a factor for heartburn in some people because one of its constituents, theobromine, may affect the esophageal sphincter muscle in a way that permits stomach acids to enter the esophagus. Theobromine poisoning is an overdosage reaction to the bitter alkaloid, which happens more frequently in domestic animals than humans. However, daily intake of 50–100 g cocoa (0.8–1.5 g theobromine) by humans has been associated with sweating, trembling, and severe headache. Chocolate and cocoa contain moderate to high amounts of oxalate, which may increase the risk of kidney stones.
Only two divisions (43rd and 53rd), two armoured brigades, and a parachute brigade were to remain allocated for NATO and the defence of Western Europe; the other eight divisions were placed on a lower establishment for home defence only. The territorial units of the Royal Armoured Corps were also reduced in number to nine armoured regiments and eleven reconnaissance regiments. This was effected by the amalgamation of pairs of regiments, and the conversion of four RAC units to an infantry role. The new parachute brigade group become the 44th Independent Parachute Brigade Group. British forces contracted dramatically as the end of conscription in 1960 came in sight as announced in the 1957 Defence White Paper. On 20 July 1960, a reorganisation of the TA was announced in the House of Commons. The territorials were to be reduced from 266 fighting units to 195. There was to be a reduction of 46 regiments of the Royal Artillery, 18 battalions of infantry, 12 regiments of the Royal Engineers and two regiments of the Royal Corps of Signals. The reductions were carried out in 1961, mainly by amalgamating units. Thus, on 1 May 1961, the TA divisional headquarters were merged with regular army districts, which were matched with Civil Defence Regions to aid mobilisation for war. The Army Reserve Act of April 1962 made provision for a new TA Emergency Reserve (TAER), within existing TA units, who could be called out without Royal Proclamation as individuals to reinforce regular units around the world, for up to six months in every twelve.
Sources: en.wikipedia.org
The 1946 elections saw the Muslim League secure 90 percent of the Muslim seats, supported by the landowners of Sindh and Punjab. This forced the Indian National Congress, initially skeptical of the League's representation of Indian Muslims, to acknowledge its significance. Jinnah's emergence as the voice of the Indian Muslims, compelled the British to consider their stance, despite their reluctance to partition India. In a final attempt to prevent partition, they proposed the Cabinet Mission Plan. As the Cabinet Mission failed, the British announced their intention to end rule by June 1948. Following rigorous discussions involving Viceroy of India, Lord Mountbatten of Burma, Muhammad Ali Jinnah of the All-India Muslim League, and Jawaharlal Nehru of Congress, the formal declaration to partition British India into two independent dominions—namely Pakistan and India—was issued by Mountbatten on the evening of 3 June 1947. In Mountbatten's oval office, the prime ministers of around a dozen major princely states gathered to receive their copies of the plan before its worldwide broadcast. At 7:00 P.M., All India Radio transmitted the public announcement, starting with the viceroy's address, followed by individual speeches from Nehru, and Jinnah. The founder of Pakistan Muhammad Ali Jinnah concluded his address with the slogan Pakistan Zindabad (Long Live Pakistan).
Flunitrazepam is a drug that is frequently involved in drug intoxication, including overdose. Overdose of flunitrazepam may result in excessive sedation, or impairment of balance or speech. This may progress in severe overdoses to respiratory depression or coma and possibly death. The risk of overdose is increased if flunitrazepam is taken in combination with CNS depressants such as alcohol and opioids. Flunitrazepam overdose responds to the GABAA receptor antagonist flumazenil, which thus can be used as a treatment.
== Research == Researchers have explored the potential of teicoplanin as an antiviral agent against various viruses, including SARS-CoV-2. Laboratory studies indicate that teicoplanin inhibits cathepsin L, a host cell protease utilized by SARS-CoV-2 for cell entry via the endocytic pathway. In vitro experiments have demonstrated teicoplanin's ability to reduce SARS-CoV-2 infection, with reported IC50 values in the low micromolar range. This suggests potential efficacy against various SARS-CoV-2 variants due to conserved cathepsin L cleavage sites on the SARS-CoV-2 spike protein. Animal studies have also shown a protective effect against SARS-CoV-2 infection with teicoplanin pre-treatment.
Sources: en.wikipedia.org
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.
It originates from research in Russia, associated with the Institute of Molecular Genetics of the Russian Academy of Sciences. The first descriptions date to the mid-1990s. Most published studies come from Russian laboratories.
No, Selank itself does not occur naturally. Its backbone is based on tuftsin, which is produced in the body, but the seven-residue version is a synthetic construct. It is supplied as a manufactured peptide.
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.