heptapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-23. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Enzymatic stability motivates the extra three residues at the carboxyl end. Native tuftsin is cleaved quickly by circulating aminopeptidases and carboxypeptidases, which limits its duration of action and its usefulness as a tool compound. Extending the chain with proline-rich segments is a common design tactic because proline constrains the backbone and slows proteolysis. The same Pro-Gly-Pro motif appears in other Russian-developed peptides of the era. Whether the full seven-residue chain is required for activity, or whether it acts mainly as a prodrug releasing tuftsin, remains unresolved.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its four N-terminal residues reproduce tuftsin, a tetrapeptide fragment of the immunoglobulin heavy chain, while the C-terminal Pro-Gly-Pro extension is a synthetic addition. The peptide has a molecular mass near 752 daltons and carries a net positive charge at physiological pH because of the arginine and lysine side chains. Published indexes list it under the name Selank and the sequence abbreviation TKPRPGP. Solid-phase peptide synthesis is the standard production route for research quantities.
Development took place at the Institute of Molecular Genetics of the Russian Academy of Sciences, where a series of short peptides were designed in the 1980s and 1990s. Selank was selected from variants of tuftsin that showed resistance to plasma peptidases. Russian regulatory approval covers it as an anxiolytic agent given intranasally. Outside that market the compound is normally handled as a research chemical rather than a medicine, and no widely recognised international pharmacopoeial monograph exists. The name Selank is a coined trade designation rather than a systematic chemical name.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Stabilized analog of tuftsin |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro | Single-letter form: TKPRPGP |
| Molecular formula | C33H57N11O9 | Monoisotopic mass about 751.9 Da |
| Appearance | White to off-white powder | Typically supplied as lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in common polar solvents |
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.
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.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
== Early political career (1959–1970) == After World War II ended and the Japanese withdrew, the British grouped the Malay states and the Straits Settlements into the Malayan Union, and granted citizenship to non-Malays. This caused major backlash from Malays and a wave of Malay nationalism swept across the country. Mahathir became politically activated by these changes, joining protests and activism against the new citizenship policies. Mahathir later argued for affirmative action for Malays at medical college. While at college, he contributed to The Straits Times under the pseudonym "C.H.E. Det" and a student journal, in which he fiercely promoted Malay rights, such as calling for the restoration of Malay as an official language. While practising as a physician in Alor Setar, Mahathir became active in UMNO. His earliest political involvement was in the Kampung Charok Kudong Umno branch, where he made his debut in politics. By the time of the first general election for the independent state of Malaya in 1959, he was the chairman of the party in Kedah. Despite his prominence in UMNO, Mahathir was not a candidate in the 1959 election, ruling himself out following a disagreement with then Prime Minister Tunku Abdul Rahman. Their relationship had been strained since Mahathir had criticised Tunku's agreement to retain British and Commonwealth forces in Malaya after independence. Tunku opposed Mahathir's plans to introduce minimum educational qualifications for UMNO candidates.
The perianth is undifferentiated (perigonium) and biseriate (two whorled), formed from six tepals arranged into two separate whorls of three parts (trimerous) each, although Scoliopus has only three petals, free from the other parts, but overlapping. The tepals are usually petaloid (petal like) and apotepalous (free) with lines (striate) or marks in other colors or shades. The perianth is either homochlamydeous (all tepals equal, e.g. Fritillaria) or dichlamydeous (two separate and different whorls, e.g. Calochortus) and may be united into a tube. Nectar is produced in perigonal nectaries at the base of the tepals. The androecium consists of six stamens in two trimerous whorls, with free filaments, usually epiphyllous (fused to tepals) and diplostemonous (outer whorl of stamens opposite outer tepals and the inner whorl opposite inner tepals), although Scoliopus has three stamens opposite the outer tepals. The attachment of the anthers to the filaments may be either peltate (to the surface) or pseudo-basifixed (surrounding the filament tip, but not adnate, that is not fused) and dehisce longitudinally and are extrorse (dehiscing away from center). The pollen is usually monosulcate (single groove), but may be inaperturate (lacking aperture: Clintonia, some Tulipa spp.) or operculate (lidded: Fritillaria, some Tulipa spp.), and reticulate (net patterned: Erythronium, Fritillaria, Gagea, Lilium, Tulipa).
== Biography == He is a member of the editorial board of the journal Intelligence. His PhD was completed in 1994 at the University of Auckland (New Zealand) and integrated the Eysenckian dimensional model of psychosis with the categorical model of schizotypy proposed by Paul E. Meehl, using measures of personality, creativity, evoked potentials, and smooth pursuit eye movement dysfunction. The title of his doctoral thesis was Psychometric & psychophysiological measures for schizotypy, creativity & psychoticism. Subsequent academic publications include demonstrating the existence of two separate forms of dyslexia, underpinned by distinct genes, and, subsequently, demonstrating that the genes associated with dyslexia are also linked to normal variation in reading ability. This work lead to searches for specific genes involved in reading and language. In positive psychology, he showed (along with Alexander Weiss and Michelle Luciano) that the genes for happiness are genes for personality, suggesting that a general factor of genetic well-being and specific genetic influences from the five factor model traits of Extraversion, Neuroticism/Stability, and Conscientiousness completely explain the heritable component of differences in happiness. With Caroline Rae, Bates showed that creatine supports cognitive function – finding that creatine supplements in vegans substantially increased their cognitive ability and working memory by comparison with placebo. This supported a literal 'mental energy' model of intelligence, first postulated by Charles Spearman.
1993/1789) Criminal Justice Act 1988 (Designated Countries and Territories) (Amendment) Order 1993 (S.I. 1993/1790) Criminal Justice (International Co-operation) Act 1990 (Enforcement of Overseas Forfeiture Orders) (Amendment) Order 1993 (S.I. 1993/1791) Drug Trafficking Offences Act 1986 (Designated Countries and Territories) (Amendment) Order 1993 (S.I. 1993/1792) Haiti (United Nations Sanctions) (Channel Islands) Order 1993 (S.I. 1993/1793) Haiti (United Nations Sanctions)(Isle of Man) Order 1993 (S.I. 1993/1794) Hong Kong (British Nationality) (Amendment) Order 1993 (S.I. 1993/1795) Immigration (Guernsey) Order 1993 (S.I. 1993/1796) Immigration (Jersey) Order 1993 (S.I. 1993/1797) Iraq (United Nations) (Sequestration of Assets) (Guernsey) Order 1993 (S.I. 1993/1798) Iraq (United Nations) (Sequestration of Assets) (Jersey) Order 1993 (S.I. 1993/1799)
The chemical and thermal dynamics in hydrothermal vents makes such environments highly suitable thermodynamically for chemical evolution processes to take place. Therefore, thermal energy flux is a permanent agent and is hypothesized to have contributed to the evolution of the planet, including prebiotic chemistry. Günter Wächtershäuser proposed the iron-sulfur world theory and suggested that life might have originated at hydrothermal vents. Wächtershäuser proposed that an early form of metabolism predated genetics. By metabolism he meant a cycle of chemical reactions that release energy in a form that can be harnessed by other processes. It has been proposed that amino acid synthesis could have occurred deep in the Earth's crust and that these amino acids were subsequently shot up along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals would have fostered the formation of peptides and protocells. This is an attractive hypothesis because of the abundance of CH4 (methane) and NH3 (ammonia) present in hydrothermal vent regions, a condition that was not provided by the Earth's primitive atmosphere. A major limitation to this hypothesis is the lack of stability of organic molecules at high temperatures, but some have suggested that life would have originated outside of the zones of highest temperature. There are numerous species of extremophiles and other organisms currently living immediately around deep-sea vents, suggesting that this is indeed a possible scenario.
Sources: en.wikipedia.org
There are two known receptors for the vasoactive intestinal peptide (VIP) termed VPAC1 and VPAC2. These receptors bind both VIP and pituitary adenylate cyclase-activating polypeptide (PACAP) to some degree. Both receptors are members of the 7 transmembrane G protein-coupled receptor family. VPAC1 is distributed widely in the CNS, liver, lung, intestine and T-lymphocytes. VPAC2 is found in the CNS, pancreas, skeletal muscle, heart, kidney, adipose tissue, testis, and stomach. Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) receptors are activated by the endogenous peptides VIP, PACAP-38, PACAP-27, peptide histidine isoleucineamide (PHI), peptide histidine methionineamide (PHM) and peptide histidine valine (PHV). “PACAP type II receptors” (VPAC1 and VPAC2 receptors) display comparable affinity for PACAP and VIP, whereas PACAP-27 and PACAP-38 are >100 fold more potent than VIP as agonists of most isoforms of the PAC1 receptor.
=== Lymphatic drainage === Approximately 75% of the lymph from the breast travels to the axillary lymph nodes on the same side of the body, while 25% of the lymph travels to the parasternal nodes (beside the sternum bone). A small amount of remaining lymph travels to the other breast and to the abdominal lymph nodes. The subareolar region has a lymphatic plexus known as the "subareolar plexus of Sappey". The axillary lymph nodes include the pectoral (chest), subscapular (under the scapula), and humeral (humerus-bone area) lymph-node groups, which drain to the central axillary lymph nodes and to the apical axillary lymph nodes. The lymphatic drainage of the breasts is especially relevant to oncology because breast cancer is common to the mammary gland, and cancer cells can metastasize (break away) from a tumor and be dispersed to other parts of the body by means of the lymphatic system.
The use of MDMA in Texas clubs declined rapidly after criminalization, but by 1991, the drug became popular among young middle-class whites and in nightclubs. In 1985, MDMA use became associated with acid house on the Spanish island of Ibiza. Thereafter, in the late 1980s, the drug spread alongside rave culture to the United Kingdom and then to other European and American cities. Illicit MDMA use became increasingly widespread among young adults in universities and later, in high schools. Since the mid-1990s, MDMA has become the most widely used amphetamine-type drug by college students and teenagers. MDMA became one of the four most widely used illicit drugs in the US, along with cocaine, heroin, and cannabis. According to some estimates as of 2004, only marijuana attracts more first time users in the United States. After MDMA was criminalized, most medical use stopped, although some therapists continued to prescribe the drug illegally. Later, Charles Grob initiated an ascending-dose safety study in healthy volunteers. Subsequent FDA-approved MDMA studies in humans have taken place in the United States in Detroit (Wayne State University), Chicago (University of Chicago), San Francisco (UCSF and California Pacific Medical Center), Baltimore (NIDA–NIH Intramural Program), and South Carolina. Studies have also been conducted in Switzerland (University Hospital of Psychiatry, Zürich), the Netherlands (Maastricht University), and Spain (Universitat Autònoma de Barcelona). "Molly", short for 'molecule', was recognized as a slang term for crystalline or powder MDMA in the 2000s.
The filmmakers decided that Dredd should appear lean and fast like a boxer rather than bulky like "someone who spends hours sort of steroiding himself up." His Judge uniform was altered from the comic version; an extruded eagle statuette was removed from his shoulder pad to emphasise the outfit's functionality and give it a sense of realism. Garland said: "If you did a very faithful adaptation of the uniform you'd have someone who if he got stabbed in the stomach he'd be in big trouble. Dredd is out there on the frontline so he needed protection." Remaining faithful to the comic, Dredd's face, except for his mouth, is never shown and his helmet is not removed throughout the film. Urban said: "He is supposed to be the faceless representative of the law and I think that is part of his enigma ... You wouldn't get to the end of a Sergio Leone Western and go, 'God, I didn't even know the character's name!' It's irrelevant." Dredd's signature weapon, the "Lawgiver" was developed as a fully operational weapon based on a 9mm firing system, capable of firing ammunition and being changed from automatic to semi-auto fire. His motorcycle "Lawmaster" was a modified 500cc motorcycle. A large fairing was added over the motorcycle with machine guns, an extended wheel base and the largest functional tyres possible. The vehicle was also operational and Urban insisted on riding it himself rather than relying on green-screen visual effects.
Sources: en.wikipedia.org
This is a list of investigational panic disorder drugs, or drugs that are currently under development for clinical use for the treatment of panic disorder (PD) but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses. The format of list items is "Name (Synonyms) – Mechanism of Action [Reference]". This list was last comprehensively updated in September 2025. It is likely to become outdated with time.
Cooling preserves food by slowing down the growth and reproduction of microorganisms and the action of enzymes that causes the food to rot. The introduction of commercial and domestic refrigerators drastically improved the diets of many in the Western world by allowing food such as fresh fruit, salads and dairy products to be stored safely for longer periods, particularly during warm weather. Before the era of mechanical refrigeration, cooling for food storage occurred in the forms of root cellars and iceboxes. Rural people often did their own ice cutting, whereas town and city dwellers often relied on the ice trade. Today, root cellaring remains popular among people who value various goals, including local food, heirloom crops, traditional home cooking techniques, family farming, frugality, self-sufficiency, organic farming, and others.
In 1999, the High Court ruled in favor of three transgender women in the case North West Lancashire Health Authority v A, D and G. The transgender women sued the North West Lancashire Health Authority after being denied gender reassignment surgery from 1996 to 1997. The judgement was the first time that transgender surgical operations had been tested in an open court in the United Kingdom and was described by Stephen Lodge (the solicitor representing the three women) as a "landmark in the continuing struggle for legal recognition" of transgender rights in Britain. The ruling means that it is illegal for any health authority in England or Wales to put a blanket ban on gender-affirming surgery relating to transgender people. A 2013 survey of gender identity clinic services provided by the UK National Health Service (NHS) found that 94% of transgender people using the gender identity clinics were satisfied with their care and would recommend the clinics to a friend or family member. This study focused on transgender people using the NHS clinics and so was prone to survivorship bias, as those unhappy with the NHS service are less likely to use it. Despite this positive response, however, other National Health Service programs are lacking; almost a third of respondents reported inadequate psychiatric care in their local area. The options available from the National Health Service also vary with location; slightly differing protocols are used in England, Scotland, Wales and Northern Ireland. Protocols and available options differ widely outside of the UK.
== Arms == The skin of the arms, and specifically the softer skin of the inner arms and across the creased mid-arm bend covering the ventral side of the elbow, are highly sensitive to manual or oral stimulation. Caressing with fingers or tongue, more vigorous kneading, and butterfly kissing can initiate arousal and, in some cases, induce clitoral/vaginal orgasm or penile ejaculation without direct contact with the latter areas. The mid-arm bend is especially sensitive due to the thinner skin found there, which makes nerve endings more accessible. Arm sensitivity may be reduced or concentrated to a more narrow range by excessive muscularity or obesity on the one hand, or transformed to uncomfortable tenderness by excessive thinness on the other.
=== Biological role === Nicotinamide occurs as a component of a variety of biological systems, including within the vitamin B family and specifically the vitamin B3 complex. It is also a critically important part of the structures of NADH and NAD+, where the N-substituted aromatic ring in the oxidised NAD+ form undergoes reduction with hydride attack to form NADH. The NADPH/NADP+ structures have the same ring, and are involved in similar biochemical reactions. Nicotinamide can be methylated in the liver to biologically inactive 1-methylnicotinamide when there are sufficient methyl donors.
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide designed as a stabilized analog of the natural tetrapeptide tuftsin. It has been investigated mainly for anxiolytic and cognitive effects. It is not an approved pharmaceutical in most countries.
It was developed in Russia, at the Institute of Molecular Genetics of the Russian Academy of Sciences, during the 1990s. Most published research originates from Russian institutions. Independent international replication remains limited.
Tuftsin is a natural tetrapeptide with the sequence Thr-Lys-Pro-Arg that participates in immune signaling. Selank extends that sequence with Pro-Gly-Pro at the C-terminus. The added residues are linked to greater resistance to enzymatic breakdown.
Selank is a seven-amino-acid peptide built from the tuftsin sequence plus a Pro-Gly-Pro tail. It is produced by chemical synthesis rather than extracted from a natural source. The free peptide is usually supplied as a lyophilised powder or in an aqueous formulation.