Tuftsin analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-08-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Peptide bonds are vulnerable to protease attack, and Selank is no exception. Measured half-life in serum is short, on the order of minutes in several reports, which explains why intranasal administration is the common route described in the literature. Absorption across the nasal mucosa partially bypasses first-pass hepatic metabolism. Quantitative data on human bioavailability remain limited and are difficult to compare across studies.
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.
| Property | Value | Notes |
|---|---|---|
| Dry storage temperature | -20 C or below | Sealed, desiccated, protected from light |
| Solution stability | Hours to days at 2-8 C | Depends on buffer and microbial load |
| Preferred pH range | Near neutral to slightly acidic | Alkaline pH accelerates hydrolysis |
| Main degradation routes | Hydrolysis and deamidation | No cysteine or methionine in sequence |
| Identity confirmation | Electrospray mass spectrometry | Observed mass compared with 751.9 Da |
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.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
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.
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.
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.
The PRs are expressed widely throughout the body, including in the uterus, cervix, vagina, fallopian tubes, breasts, fat, skin, pituitary gland, hypothalamus, and elsewhere throughout the brain. Through activation of the PRs (as well as the mPRs), progesterone has many effects, including the following:
Chloé Zhao's Nomadland wins three awards, including Best Picture, Best Director and Frances McDormand for Best Actress. David Fincher's Mank leads the nominations with ten, while Anthony Hopkins wins Best Actor for The Father (becoming the oldest winner in an acting category), Daniel Kaluuya Best Supporting Actor for Judas and the Black Messiah and Youn Yuh-jung Best Supporting Actress for Minari. Keeping in line with other award ceremonies reporting viewership declines, the telecast garners 10.4 million viewers according to Nielsen estimates, down 56% from the previous year and making the broadcast by far the lowest-rated in Oscar history. April 26 – COVID-19 pandemic – The CDC says that fully vaccinated Americans can go outside without wearing a mask unless they are in large crowds. April 27 – COVID-19 pandemic – Colorado surpasses 500,000 cases of COVID-19. April 28 2021 Joe Biden speech to a joint session of Congress: On the eve of his 100th day in office, President Biden gives his first address to a joint session of Congress encouraging them to pass $4 trillion worth of spending bills, including the American Jobs Plan and the American Families Plan, both part of his Build Back Better Plan. The South Dakota Supreme Court hears oral arguments on an appeal of a ruling which struck down South Dakota Amendment A, which would have legalized recreational cannabis in the state on July 1, 2021. April 30 COVID-19 pandemic Travel restrictions related to the COVID-19 pandemic – The White House announces the U.S.
The eluting strength of the mobile phase is reflected by analyte retention times, as the high eluting strength speeds up the elution (resulting in shortening of retention times). For example, a typical gradient profile in reversed phase chromatography might start at 5% acetonitrile (in water or aqueous buffer) and progress linearly to 95% acetonitrile over 5–25 minutes. Periods of constant mobile phase composition (plateau) may be also part of a gradient profile. For example, the mobile phase composition may be kept constant at 5% acetonitrile for 1–3 min, followed by a linear change up to 95% acetonitrile. The chosen composition of the mobile phase depends on the intensity of interactions between various sample components ("analytes") and stationary phase (e.g., hydrophobic interactions in reversed-phase HPLC). Depending on their affinity for the stationary and mobile phases, analytes partition between the two during the separation process taking place in the column. This partitioning process is similar to that which occurs during a liquid–liquid extraction but is continuous, not step-wise. In the example using a water/acetonitrile gradient, the more hydrophobic components will elute (come off the column) later, then, once the mobile phase gets richer in acetonitrile (i.e., in a mobile phase becomes higher eluting solution), their elution speeds up. The choice of mobile phase components, additives (such as salts or acids) and gradient conditions depends on the nature of the column and sample components.
==== Molecular interaction of AAS with androgen receptors ==== Anabolic steroids interact with ARs across various tissues, including muscle, bone, and reproductive systems. Upon binding to the AR, anabolic steroids trigger a translocation of the hormone-receptor complex to the cell nucleus, where they either alter gene expression or activate cellular signaling pathways; this results in increased protein synthesis, enhanced muscle growth, and reduced muscle catabolism. Anabolic steroids influence cellular differentiation while favoring the development of muscle cells over fat-storage cells. Research in this field has shown that structural modifications in anabolic steroids are critical in determining their binding affinity to ARs and their resulting anabolic and androgenic activities. These modifications affect a steroid's ability to influence gene expression and cellular processes, highlighting the complex biophysical interactions of anabolic steroids at the cellular level.
Sources: en.wikipedia.org
The average 70 kg (150 lb) adult human body contains approximately 7×1027 atoms and contains at least detectable traces of 60 chemical elements. About 29 of these elements are thought to play an active positive role in life and health in humans. The relative amounts of each element vary by individual, mainly due to differences in the proportion of fat, muscle and bone in their body. Persons with more fat will have a higher proportion of carbon and a lower proportion of most other elements (the proportion of hydrogen will be about the same). The numbers in the table are averages of different numbers reported by different references. The adult human body averages ~53% water. This varies substantially by age, sex, and adiposity. In a large sample of adults of all ages and both sexes, the figure for water fraction by weight was found to be 48 ±6% for females and 58 ±8% water for males. Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. Because of water content, the human body contains more oxygen by mass than any other element, but more hydrogen by atom-fraction than any other element.
Venlafaxine, sold under the brand name Effexor among others, is an antidepressant medication of the serotonin–norepinephrine reuptake inhibitor (SNRI) class. It is used to treat major depressive disorder, generalized anxiety disorder, panic disorder, and social anxiety disorder. Studies have shown that venlafaxine improves post-traumatic stress disorder (PTSD) as a recommended first-line treatment. It may also be used for chronic neuropathic pain. It is taken orally (swallowed by mouth). It is also available as the salt venlafaxine besylate (venlafaxine benzenesulfonate monohydrate) in an extended-release formulation (Venbysi XR). Common side effects include loss of appetite, constipation, dry mouth, dizziness, sweating, insomnia, drowsiness and sexual problems. In some patients, sexual dysfunction may persist even after the drug is discontinued, a condition known as post-SSRI sexual dysfunction. Severe side effects include an increased risk of suicide, mania, and serotonin syndrome. Antidepressant withdrawal syndrome may occur if stopped. A meta-analysis of randomized trials in depression found an increased rate of serious adverse events, particularly sexual dysfunction and anorexia, and several non-serious adverse effects, including nervousness, asthenia, and tremor. There are concerns that use during the later part of pregnancy can harm the baby. Venlafaxine's mechanism of action is not entirely clear, but it seems to be related to the potentiation of the activity of some neurotransmitters in the brain.
=== Non-regional === In addition to the regional senses, a spatula can be used in both British and American English to refer to a tool with a flat, blunt blade used for mixing and spreading things as opposed to one used for lifting and flipping food, an example of which is the rubber scraper shown on the right.
Sources: en.wikipedia.org
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.
Hydrolysis of peptide bonds and deamidation of arginine and proline residues are the main degradation routes. Alkaline pH and higher temperatures accelerate both processes. Buffered, near-neutral solutions stored cold generally degrade more slowly than unbuffered ones.
Reverse-phase chromatography gives the clearest single view of related impurities and truncated sequences. Mass spectrometry then confirms that the main peak carries the expected mass. Neither test detects enantiomeric impurities, which require a separate chiral assay.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.