peptidase cleavage 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.
Updated 2025-08-19. Numbers and descriptions here follow the published literature rather than marketing material.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
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.
9 February – The New Zealand Government announces plans to revise the Active Investor Plus visa to attract more wealthy investors. 10 February: Driven by "pollution, degraded waterways, and over-allocation of water", Ngāi Tahu begins proceedings in the High Court against the Crown. The tribe argues that it has never lost rangatiratanga (sovereignty, or the right to exercise authority) over freshwater, but control has been encumbered by the Crown. The Crown's argument is that it has the right to control freshwater through the Resource Management Act 1991 and other acts. The lawsuit has been given the name "Tau v AG", with historian Te Maire Tau as the lead plaintiff, and the Attorney-General (currently Judith Collins) representing the Crown. ACT leader David Seymour drives a Land Rover up the New Zealand Parliament's steps as part of a fundraiser for a heart valve development programme at the University of Auckland. The Director of the Public Health Agency Nicholas Jones resigns. 11 February – The Australian company Millari Group announces plans to acquire and reopen Juken's former Gisborne saw mill, which closed in late 2023. 12 February: The Whangārei District Council led by Mayor Vince Cocurullo reiterates its refusal to comply with an order by Director-General of Health Diana Sarfati to fluoridate its water supply. The Salvation Army releases its annual State of the Nation report, which identifies food insecurity, unaffordable housing and domestic violence against children as major issues facing New Zealand in 2025.
== E == EEG (Electroencephalography) A non-invasive method of recording electrical activity in the brain using electrodes placed on the scalp. It is commonly used to study sleep, epilepsy, and cognitive processes. Effector A muscle, gland, or organ that performs an action in response to a neural signal, typically from the motor neuron. Efferent nerve fiber An axon that carries motor signals away from the central nervous system to muscles or glands. Opposite of afferent nerve fiber. Electroconvulsive therapy (ECT) A psychiatric treatment in which seizures are electrically induced in anesthetized patients for therapeutic effect, often used for treatment-resistant depression. Electrode A conductor used to detect or deliver electrical signals in neural recording or stimulation. Electrodes can be surface (non-invasive), intracranial, or implanted. Electromyography (EMG) A technique for recording the electrical activity produced by skeletal muscles, often used in neuromuscular diagnostics and motor control studies. Electrophysiology The study of the electrical properties of biological cells and tissues. In neuroscience, it often involves measuring voltage changes or currents in neurons. Endocannabinoid system A neuromodulatory system composed of endocannabinoids, receptors (e.g., CB1), and enzymes. It regulates processes such as appetite, pain, mood, and memory. Endocrine system A collection of glands that secrete hormones directly into the bloodstream. It interacts with the nervous system to regulate metabolism, stress, and growth.
==== Stunted growth ==== Untreated OSA in children can also lead to stunted growth. When sleep is disrupted in children who are still growing, there can be significant consequences. Human growth hormone (HGH) is secreted during the night, especially during deep, non-REM sleep. If this is disrupted, growth hormone secretion may be compromised; thus, growth may not occur normally, and children may become shorter than their peers.
== Physical properties == Ciprofol is an optically active 2,6-disubstituted alkylphenol with a cyclopropylethyl group incorporated at the second carbon atom. This cyclopropyl group increases the steric effects and introduces stereoselective effects over its anesthetic properties. These properties appear to increase the anesthetic potency of ciprofol, when compared with propofol.
Leuprorelin, also known as leuprolide, is a manufactured version of a hormone used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids, for early puberty, as part of transgender hormone therapy, or to perform chemical castration of violent sex offenders. It is given by injection into a muscle or under the skin. Leuprorelin is in the gonadotropin-releasing hormone (GnRH) analogue family of medications. It works by decreasing gonadotropins, thereby decreasing testosterone and estradiol. Common side effects include hot flashes, unstable mood, trouble sleeping, headaches, and pain at the site of injection. Other side effects may include high blood sugar, allergic reactions, and problems with the pituitary gland. Use during pregnancy may harm foetal development. Leuprorelin was patented in 1973 and approved for medical use in the United States in 1985. It is on the World Health Organization's List of Essential Medicines. It is sold under the brand name Lupron, among others.
Sources: en.wikipedia.org
More research is needed to determine the precise effects of HMB on muscle strength and function in various populations. In severe cases of muscular atrophy, the use of an anabolic steroid such as methandrostenolone may be administered to patients as a potential treatment although use is limited by side effects. A novel class of drugs, called selective androgen receptor modulators, is being investigated with promising results. They would have fewer side effects, while still promoting muscle and bone tissue growth and regeneration. These effects have yet to be confirmed in larger clinical trials.
==== 2600–2699 ==== Greater Manchester Ambulance Service National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2600) Lancashire Ambulance Service National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2601) Tameside and Glossop Acute Services National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2602) Darlington Memorial Hospital National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2603) Bolton Hospitals National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2604) Priority Healthcare Wearside National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2605) Community Health Care Service (North Derbyshire) National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2606) Wirral Community Healthcare National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2607) North Lakeland Healthcare National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2608) North Downs Community Health National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2609) South Durham Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2610) Salford Community Health Care National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2611) Community Health Care: North Durham National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2612) Kingston and District Community National Health Service Trust (Establishment) Order 1993 (S.I. 1993/2613) North Durham Acute Hospitals National Health Service Trust (Establishment) Order 1993 (S.I.
The New York State Agricultural Experiment Station recipe for the concentrate suggests starting with 80 lb of sulfur, 36 lb of quicklime, and 50 gal of water, equivalent to 19.172 kg of sulfur and 8.627 kg of calcium oxide per 100 liters of water. About 2.2:1 is the ratio (by weight) for compounding sulfur and quicklime; this ratio yields the highest proportion of calcium pentasulfide. If calcium hydroxide (builders' or hydrated lime) is used, an increase of one-third or more (to 115 g/L or more) may be used with the 192 g/L of sulfur. If the quicklime is 85%, 90%, or 95% pure, 101 g/L, 96 g/L, or 91 g/L is used, respectively; if impure hydrated lime is used, its quantity is increased to compensate, though in practice lime with a purity lower than 90% is rarely used. The mixture is then boiled for one hour while being stirred, and small amounts of water are added for evaporation.
=== Therapeutic opportunities === The ribosome is a prominent drug target for antibacterials, which interfere with translation at different stages of the elongation cycle Most clinically relevant translation compounds are inhibitors of bacterial translation, but inhibitors of eukaryotic translation may also hold therapeutic potential for application in cancer or antifungal chemotherapy. Elongation inhibitors show antitumor activity 'in vivo' and 'in vitro'. One toxic inhibitor of eukaryotic translation elongation is the glutarimide antibiotic cycloheximide (CHX), which has been co-crystallized with the eukaryotic 60S subunit and binds in the ribosomal E site. The structural characterization of the eukaryotic ribosome may enable the use of structure-based methods for the design of novel antibacterials, wherein differences between the eukaryotic and bacterial ribosomes can be exploited to improve the selectivity of drugs and therefore reduce adverse effects.
Sources: en.wikipedia.org
=== National advertising === Kellogg began the breakfast cereal marketing and introduced the first in-box prize in the early 1900s. Quaker Oats entered the market with Puffed Rice and Wheat Berries it had introduced at the 1904 World Fair, with raw grains shot with hot compressed air from tubes, popping up to many times their size. They were marketed as a revolution in food science. In the 1920s, national advertising in magazines and radio broadcasts played a key role in the emergence of the fourth big cereal manufacturer, General Mills. In 1921, James Ford Bell, president of a Minneapolis wheat milling firm, began experimenting with rolled wheat flakes. After tempering, steaming, cracking wheat, and processing it with syrup, sugar, and salt, it was prepared in a pressure cooker for rolling and then dried in an electric oven. By 1925, Wheaties had become the "Breakfast of Champions". In 1928, four milling companies consolidated as the General Mills Company in Minneapolis. The new firm expanded packaged food sales with heavy advertising, including sponsorship of radio programs such as "Skippy", "Jack Armstrong, The All-American Boy", and baseball games. Jack Dempsey, Johnny Weissmuller, and others verified the "Breakfast of Champions" slogan. By 1941 Wheaties had won 12% percent of the cereal market. Experiments with the puffing process produced Kix, a puffed corn cereal, and Cheerios, a puffed oats cereal. Further product innovation and diversification brought total General Mills sales to over $500 million annually (18% in packaged foods) by the early 1950s.
=== Polymer chemistry === Although MS-based analyses of polymers have largely been performed using single-stage MS, tandem MS has also been used to characterize polymer components. CID is the most common method of dissociation used, but ETD has been used as a complementary method. Unique bond cleavages resulting from ETD supply valuable diagnostic information.
Sporting leagues in Hong Kong include Hong Kong Premier League, Hong Kong Premiership (rugby union), Hong Kong A1 Division Championship, and the Hong Kong Ice Hockey League. Famous local sporting clubs include Hong Kong Football Club, South China Athletic Association, Kitchee SC, and Hong Kong Eastern. Hong Kong sports have been described as "Club Life". Some clubs have documented their history thoroughly, while others have disappeared along with their past.
During Bukele's presidency, El Salvador has hosted a number of international sporting events and one edition of the Miss Universe beauty pageant. Some experts have described El Salvador's hosting of such events as an attempt at sportswashing. Bukele has promoted surfing as part of El Salvador's tourism market. He designated part of El Salvador's Pacific coastline in the La Libertad Department as "Surf City", where the 2021 and 2023 ISA World Surfing Games were hosted. El Salvador also hosted the 2023 Central American and Caribbean Games. At the tournament's opening ceremony, Bukele rebuked critics by saying that he was "not a dictator" and told them to ask everyday Salvadorans what they thought about his "supposed dictatorship". In January 2023, Bukele announced that El Salvador would host the Miss Universe 2023 pageant; the last time El Salvador had hosted Miss Universe was in 1975. At the pageant, Bukele said that Miss Universe had given El Salvador the opportunity to "show the world what we are capable of". On the day of the pageant, 300 members of the Movement for Victims of the State of Emergency held a protest demanding the release of innocent victims of the country's gang crackdown and wanting "Miss Universe to see that Salvadorans are suffering". Some protestors wore sashes reading "Miss Political Prisoners", "Miss Persecution", and "Miss Mass Trials".
=== Financial markets === Thai equities rallied when trading resumed on 9 February. The SET Index closed at 1,400.89, up 46.88 points or 3.46 per cent, having reacted at the open to unofficial results that pointed to Bhumjaithai leading the next government and easing fears of a political vacuum. Turnover reached 102.1 billion baht, the first hundred-billion-baht session in a year and five months. Foreign investors bought a net 16.5 billion baht and institutions a net 6.2 billion, while domestic retail investors sold a net 24.3 billion. Therdsak Thaveeteeratham of Asia Plus Securities called the rally a surprise, saying the market read the result as improving the odds of a stable government formation and of sustained fund flows back into Thai stocks. Asadej Kongsiri, president of the Stock Exchange of Thailand, said investors expected continuity from the outgoing administration and welcomed policies aimed at domestic demand and living costs. Several analysts warned that profit-taking was likely after so sharp a jump.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.