The short version of Semax fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-28 and is reviewed periodically as new material appears.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
==== Hair bleaching and coloring ==== Diluted H2O2 (between 1.9% and 12%) mixed into a solution with aqueous ammonia, aniline (color molecule) and a coupler, has been used to color human hair. It can also be mixed with powder or cream bleach compounds, most notably potassium chloride. Bleaching hair follicles does not destroy or remove color molecule or melanocytes. Bleaching compounds work to drive wedges between color molecules or melanocytes, allowing more visible light to pass through the hair shaft. The chemical's bleaching property lends its name to the phrase "peroxide blonde". Hydrogen peroxide is also used for tooth whitening. It may be found in most whitening toothpastes. Hydrogen peroxide has shown positive results involving teeth lightness and chroma shade parameters. It works by oxidizing colored pigments onto the enamel where the shade of the tooth may become lighter. Hydrogen peroxide may be mixed with baking soda and salt to make a homemade toothpaste.
== Advantages and Disadvantages == Advantages: The MS2-BioTRAP method is fast, flexible, and easy to set up; it scales well and allows the study of the physiological conditions of the protein-RNA interactions. The MS2 tag is also effective for small molecules when an MS2 coat protein is used to isolate a variety of ribonucleoprotein particles (RNPs). Disadvantages: One caveat of MS2 tagging is that many copies of the MS2 stem-loop inside the RNA need to be added to produce enough signal to view and track one RNA molecule in the nucleus. When tracking more than one RNA sequence in the nucleus of cultured cells, more than one target sequence is needed. This could be affected by the MS2 protein, which has a classical basic nuclear localization signal (NLS), so it could affect the location of the RNA complex, and the nucleus would have most of the GFP-MS2 (Robert Singer’s lab). The accumulation of GFP-MS2 in the nucleus will result in strong nuclear fluorescence signals, which will delay or prevent the analysis of RNA nuclear localization because it will hinder the analysis of splicing, RNA editing, the nuclear export of RNA, and RNA translation. Moreover, due to the addition of the tag, the RNA secondary structure may introduce an artifact. Additionally, the small noncoding RNA (sRNA) expression levels and regulatory properties will be influenced by MS2 tag. Also, by using MS2 as an affinity tag to purify a protein in E. coli bacteria, scientists expressed MS2-MBP, which is an MS2 coat protein carrying mutations fused with maltose-binding proteins.
== Contribution to science and evidence base of insulin therapy == As of January 2024, Kalra has more than 23,000 citations of his publications, with an h-index of 68 and an i10-index of 439. His primary area of focus has been insulin therapy.
== Emerging trends == A number of emerging concepts have the potential to improve the current features of proteomics. Obtaining absolute quantification of proteins and monitoring post-translational modifications are the two tasks that impact the understanding of protein function in healthy and diseased cells. Further, the throughput and sensitivity of proteomic assays, often measured as samples analyzed per day and depth of proteome coverage, respectively, have driven development of cutting-edge instrumentation and methodologies. For many cellular events, the protein concentrations do not change; rather, their function is modulated by post-translational modifications (PTM). Methods of monitoring PTM are an underdeveloped area in proteomics. Selecting a particular subset of protein for analysis substantially reduces protein complexity, making it advantageous for diagnostic purposes where blood is the starting material. Another important aspect of proteomics, yet not addressed, is that proteomics methods should focus on studying proteins in the context of the environment. The increasing use of chemical cross-linkers, introduced into living cells to fix protein-protein, protein-DNA and other interactions, may ameliorate this problem partially. The challenge is to identify suitable methods of preserving relevant interactions. Another goal for studying proteins is development of more sophisticated methods to image proteins and other molecules in living cells and real-time.
Sources: en.wikipedia.org
Standard peptides synthesized from amino acids labeled with stable isotope atoms serve as internal standards for serial dilutions of a sample. These allow for later absolute quantification of proteins and post-translational modifications by mass spectrometry. This technique has been adapted to absolute quantification of proteases, deciphering both activity states and total amounts in biological samples. This is thanks to trypsin treatment for mass spectrometry generating peptides specific to inactive zymogen precursors, active proteases, or common to both forms. PSPs is one form of standard peptide for absolute quantification and Standard of the Expressed Protease (STEP) is the other. The major difference between the two is PSP sequences are designed to mimic tryptic peptides that contain sequences spanning the zymogen's pro-domain and the protease's final form, whereas STEP sequences match tryptic peptide sequences found in both forms of the protease. This capitalizes on protease activation, where the zymogen's pro-domain is cleaved off and the final form lacks that domain. Experiments using iTRAQ labeling and LC-MS/MS with STEP and PSP peptide internal standards have successfully quantified total and active protease levels in biological samples. One major drawback for this approach is the inability to account for inhibitor bound enzymes. It is also difficult to ensure standard peptides can be generated for this method for each and every protease for study.
== Science == Analytic network process, a mathematical decision making technique similar to Analytic Hierarchy Process Atrial natriuretic peptide, a peptide hormone Acyclic nucleoside phosphonate, a group of antiviral drugs Acidic leucine-rich nuclear phosphoprotein 32 family member A ANP32B ANP32C ANP32D ANP32E
=== April === 2 April – The Birmingham Walkathon returns to the city for the first time since 2013. The event, originally organised by Birmingham radio station BRMB, is organised for its 2023 staging by former BRMB director David Bagley and charity Help Harry Help Others. 3 April – NHS England launches its spring booster campaign, which will see around five million people, including those aged over 75 or classed as clinically vulnerable, receive a COVID-19 booster vaccine. The National Education Union announces two further strike dates in England on 27 April and 2 May, stating that the offer from the pay UK government is unacceptable, not fully funded, and does not address a shortage of teachers. Environment Minister Therese Coffey confirms government plans to ban wet wipes containing plastic in England as a means of helping to tackle water pollution. The new England women's national football team kit is unveiled, and it is confirmed they will wear blue shorts at the 2023 World Cup. The change has been made amid period concerns. 4 April – Members of the Association of School and College Leaders overwhelmingly reject the UK government's 4.3% pay offer for teachers in England. 5 April – Twenty one people are convicted over the largest child sex abuse case ever investigated by West Midlands Police. The National Association of Head Teachers becomes the third teaching union to reject the UK government's 4.3% pay offer for teachers in England.
Ang has the same general catalytic properties as RNase A, it cleaves preferentially on the 3' side of pyrimidines and follows a transphosphorylation/hydrolysis mechanism. Although angiogenin contains many of the same catalytic residues as RNase A, it cleaves standard RNA substrates 105–106 times less efficiently than RNase A. The reason for this inefficiency is due to the 117 residue consisting of a glutamine, which blocks the catalytic site. Removal of this residue through mutation increases the ribonuclease activity between 11 and 30 fold. Despite this apparent weakness, the enzymatic activity of Ang appears to be essential for biological activity: replacements of important catalytic site residues (histidine-13 and histidine-114) invariably diminish both the ribonuclease activity toward tRNA by 10,000 fold and almost abolishes angiogenesis activities completely.
A physical examination, sometimes combined with a psychological examination, can determine whether the onset of the disease has begun. Excessive unintentional movements of any part of the body are often the reason for seeking medical consultation. If these are abrupt and have random timing and distribution, they suggest a diagnosis of HD. Cognitive or behavioral symptoms are rarely the first symptoms diagnosed; they are usually only recognized in hindsight or when they develop further. How far the disease has progressed can be measured using the unified Huntington's disease rating scale, which provides an overall rating system based on motor, behavioral, cognitive, and functional assessments. Medical imaging, such as a CT scan or MRI scan, can show atrophy of the caudate nuclei early in the disease, as seen in the illustration to the right, but these changes are not, by themselves, diagnostic of HD. Cerebral atrophy can be seen in the advanced stages of the disease. Functional neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), can show changes in brain activity before the onset of physical symptoms, but they are experimental tools and are not used clinically.
Sources: en.wikipedia.org
== Plot == Bree goes for a swim at the Ketea Aquatic Center and is joined in the Olympic-sized pool by her sister, Jonna, a recovering drug addict who is three months clean. When the pool manager, McGradey, catches the janitor, Clara, who is an ex-convict on parole, attempting to steal from the lost and found, he fires her and tells her to clean up. He then asks the customers to leave as the pool is closing for the holiday. While packing up, Bree notices her engagement ring is missing. Jonna sees the ring, stuck in the metal grille at the bottom of the pool and both dive in to retrieve it. McGradey, unaware the women are in the deep end, engages the fiberglass pool cover and leaves. Terrified, the siblings attempt to push the pool cover up or break through it, unsuccessfully. They find only one small hole. Jonna confesses she threw the ring into the pool because she is envious of Bree's successful lifestyle and recent engagement. Bree is angry at first, but then opens up about their abusive, alcoholic, drug-addicted father and the fire that led to his death. She reveals she is diabetic and requires insulin or she may fall into a diabetic coma. Clara, preparing to leave, sees the sisters. She steals Bree's cash, smartphone and credit card and says she will release them if Bree reveals her phone password and credit card PIN. Bree does so, but Clara turns the water heater off and leaves the sisters trapped for the whole night. Next morning, Clara returns to taunt them again.
Larry Robert Bigbie (born November 4, 1977) is an American former professional baseball first baseman and outfielder. He played in Major League Baseball from 2001 through 2006 for the Baltimore Orioles, Colorado Rockies, and St. Louis Cardinals.
Released in May 2016, Battleborn was a cooperative first-person shooter video game with multiplayer online battle arena (MOBA) elements. Battleborn takes place in a space fantasy setting where multiple races contest possession of the universe's last star. Players select one of multiple pre-defined heroes, customized with passive abilities gained through end-of-mission loot, to complete both player-vs-player and player-vs-environment events. During such events, characters are leveled up through their "Helix tree", granting one of two abilities at each level. It was released within a month of Blizzard Entertainment's Overwatch, a hero shooter with similar concepts, and which quickly overshadowed Battleborn. The title went free-to-play in June 2017 and was shut down in January 2021.
Deep gas-phase reactor oxidation of ethylene oxide at 800–1,000 K (527–727 °C; 980–1,340 °F) and a pressure of 0.1–1 MPa (15–145 psi) yields a complex mixture of products containing O2, H2, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H6, C3H8, and CH3CHO.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.