This is a working overview of Pro-Gly-Pro tail, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-07-26. Anything still debated is marked as such rather than presented as settled.
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.
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.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
The predecessor of the Parliament of South Africa, before the 1910 Union of South Africa, was the bicameral Parliament of the Cape of Good Hope. This was composed of the House of Assembly (the lower house) and the Legislative Council (the upper house). This predecessor dated back to the beginnings of Cape independence in 1853 and was elected according to the multi-racial Cape Qualified Franchise system, whereby suffrage qualifications were applied equally to all males, regardless of race. The buildings of the Cape Parliament went on to house the Parliament of South Africa, after union.
== Exposure to benzene == According to the Agency for Toxic Substances and Disease Registry, benzene is both a synthetically made and naturally occurring chemical from processes that include: volcanic eruptions, wild fires, synthesis of chemicals such as phenol, production of synthetic fibers, and fabrication of rubbers, lubricants, pesticides, medications, and dyes. The major sources of benzene exposure are tobacco smoke, automobile service stations, exhaust from motor vehicles, and industrial emissions; however, ingestion and dermal absorption of benzene can also occur through contact with contaminated water. Among those in the United States who are exposed to benzene, over half of the known exposures occur due to tobacco smoking. Benzene is hepatically metabolized and excreted in the urine. Measurement of air and water levels of benzene is accomplished through collection via activated charcoal tubes, which are then analyzed with a gas chromatograph. The measurement of benzene in humans can be accomplished via urine, blood, and breath tests; however, all of these have their limitations because benzene is rapidly metabolized in the human body. Occupational Safety and Health Administration regulates levels of benzene in the workplace. The maximum allowable amount of benzene in workroom air during an 8-hour workday, 40-hour workweek is 1 ppm.
Meropenem exhibits poor permeability across the gut and low oral bioavailability because of its hydrophilic properties, which inhibit its passive diffusion across the intestinal epithelium. The challenges related to research of oral delivery of meropenem are related to high susceptibility of meropenem to degradation through hydrolysis of the amide bond in the β-lactam ring, even at relatively low temperatures and humidity. This instability can result in the loss of meropenem's antibacterial activity. Besides that, meropenem is unstable in the acidic environment of the stomach, leading to extensive degradation and loss of the drug after oral administration. In addition, intestinal efflux (secretory) transport can pump the drug back into the gut: efflux transporters, particularly P-glycoprotein (P-gp), present in the gastrointestinal tract can actively pump meropenem back into the gut lumen, limiting its absorption and reducing oral bioavailability; in the attempts of oral administration bacteria can develop resistance to meropenem by enhancing the active efflux of the antibiotic through efflux transporters, such as the MexAB-OprM tripartite efflux system in Pseudomonas aeruginosa. That's why meropenem is administered intravenously. There is insufficient data regarding the administration of meropenem during breastfeeding. However, it has been observed that, in general, the concentration of this β-lactam antibiotic in breast milk is relatively low, therefore, β-lactam antibiotics are not anticipated to induce detrimental effects in infants who are breastfed.
where ABCD+ is selected by MS1, dissociates into molecule AB and ion CD+. The ion is selected in the second mass spectrometry stage MS2 then undergoes further fragmentation to form ion D+ which is selected in the third mass spectrometry stage MS3 and detected. Multiple reaction monitoring (MRM) is the application of selected reaction monitoring to multiple product ions from one or more precursor ions, for example
=== In literature === Thorazine was often depicted in Tom Wolfe's The Electric Kool-Aid Acid Test to abort bad trips on LSD. Thorazine is also mentioned in Fear and Loathing in Las Vegas, where it was reported to negate the effects of LSD: "You better hope there's some Thorazine in that bag, because if there's not, you're in bad trouble."
Sources: en.wikipedia.org
11 August – A bioengineered cornea made from pig's skin is shown to restore vision to blind people. It can be mass-produced and stored for up to two years, unlike donated human corneas that are scarce and must be used within two weeks. 12 August — The National Centers for Environmental Information publish a report, where they state an all-time record cold temperature occurred in Australia during the month. On October 7, 2022, Zack Labe, a climate scientist for the NOAA GFDL releases a statement and a climate report from Berkeley Earth denying the all-time record cold temperature occurred saying, "There are still no areas of record cold so far in 2022." Labe's statement also denies the record cold temperatures in Brazil, reported by the National Institute of Meteorology in May 2022, a month before the official start of winter, was also not record cold temperatures. 13 August – Rocket Lab describes its self-funded plans in detail, first announced in early 2020, to send a probe to Venus, likely in 2023, to search for life in the planet's cloud layer, where other scientists reported the potential detection of biosignature-levels of phosphine in late 2020 and thereafter. ~14 August – As record-breaking heatwaves and droughts affect water supplies, rivers (along with shipping and nuclear reactor cooling), ecosystems, various global supply chains, health, and agriculture worldwide, in Europe, Spain domestically restricts e.g.
A protein called divalent metal transporter 1 (DMT1), which can transport several divalent metals across the plasma membrane, then transports iron across the enterocyte's cell membrane into the cell. If the iron is bound to heme, it is instead transported across the apical membrane by heme carrier protein 1 (HCP1). Heme is then catabolized by microsomal heme oxygenase into biliverdin, releasing Fe2+. These intestinal lining cells can then either store the iron as ferritin, which is accomplished by Fe2+ binding to apoferritin (in which case the iron will leave the body when the cell dies and is sloughed off into feces), or the cell can release it into the body via the only known iron exporter in mammals, ferroportin. Hephaestin, a ferroxidase that can oxidize Fe2+ to Fe3+ and is found mainly in the small intestine, helps ferroportin transfer iron across the basolateral end of the intestine cells. Upon release into the bloodstream, Fe3+ binds transferrin and circulates to tissues. In contrast, ferroportin is post-translationally repressed by hepcidin, a 25-amino acid peptide hormone. The body regulates iron levels by regulating each of these steps. For instance, enterocytes synthesize more Dcytb, DMT1 and ferroportin in response to iron deficiency anemia. Iron absorption from diet is enhanced in the presence of vitamin C and diminished by excess calcium, zinc, or manganese.
On January 27, 1967, the same day the US and USSR signed the Outer Space Treaty, the crew of the first crewed Apollo mission, Command Pilot Virgil "Gus" Grissom, Senior Pilot Ed White, and Pilot Roger Chaffee, were killed in a fire that swept through their spacecraft cabin during a ground test, less than a month before the planned February 21 launch. An investigative board determined the fire was probably caused by an electrical spark and quickly grew out of control, fed by the spacecraft's atmosphere of pure oxygen at greater than one standard atmosphere. Crew escape was made impossible by inability to open the plug door hatch cover against the internal pressure. The board also found design and construction flaws in the spacecraft, and procedural failings, including failure to appreciate the hazard of the pure-oxygen atmosphere, as well as inadequate safety procedures. All these flaws had to be corrected over the next twenty-two months until the first piloted flight could be made. Mercury and Gemini veteran Grissom had been a favored choice of Deke Slayton, NASA's Director of Flight Crew Operations, to make the first piloted landing.
However, Karachi-based K-Electric and Water and Power Development Authority (WAPDA) generate much of the electricity used in Pakistan and collect revenue nationwide. In 2023, Pakistan's installed electricity generation capacity was ~45,885 MWt. Pakistan produced 1,135 megawatts of renewable energy for the month of October 2016. Pakistan expects to produce 10,000 megawatts of renewable energy by 2025.
Sources: en.wikipedia.org
=== Degrees === Petechiae – small pinpoint hematomas less than 3 mm in diameter; Purpura (purple) – a bruise about 3–10 mm in diameter, generally round in shape; Ecchymosis – subcutaneous extravasation of blood in a thin layer under the skin, i.e. bruising, over 1 cm in diameter.
=== Degradation === Histidine can be metabolized into glutamate, which is readily metabolized into AKG (alpha-ketoglutarate), making histidine one of the amino acids whose metabolites can become citric acid cycle intermediates. The process requires several steps. In prokaryotes, histidine first undergoes deamination, the removal of its amino group by the emzyme histidase. This step produces ammonia and urocanic acid (urocanate). The enzyme urocanase then converts urocanic acid into imidazolonepropionate (4-imidazolone-5-propionate). The enzyme imidazolonepropionase then converts imidazolonepropionate into formiminoglutamate (FIGLU). The enzyme formimidoyltransferase cyclodeaminase removes the formimino group (which is transferred to tetrahydrofolate), leaving behind a glutamate molecule. Glutamate can then be deaminated by glutamate dehydrogenase or transaminated to form α-ketoglutarate.
The history of carbohydrates, to some extent, is the history of sugar cane, which was first grown in New Guinea. The mass cultivation occurred in India where techniques were developed for the isolation of crystalline sugar. Cane sugar and its cultivation reached Europe around the 13th Century and then expanded to the New World, where industrialization occurred. The chemistry and biochemistry of carbohydrates can be traced to 1811. On that year Constantin Kirchhoff discovered that grape sugar (glucose) forms when starch is boiled with acid. The starch industry started the following year. Henri Braconnot discovered in 1819 that sugar is formed through the action of sulfuric acid on cellulose. William Prout, after chemical analyses of sugar and starch by Joseph Louis Gay-Lussac and Thénard, gave this group of substances the group name "saccharine." The term "carbohydrate" was first proposed by German chemist Carl Schmidt in 1844. In 1856, glycogen, a form of carbohydrate storage in animal livers, was discovered by French physiologist Claude Bernard. Emil Fischer received the 1902 Nobel Prize in Chemistry for his work on sugars and purines. For the discovery of glucose metabolism, Otto Meyerhof received the 1922 Nobel Prize in Physiology or Medicine.
Ubiquitin carboxyl-terminal hydrolase 48 is an enzyme that in humans is encoded by the USP48 gene. This gene encodes a protein containing domains that associate it with the peptidase family C19, also known as family 2 of ubiquitin carboxyl-terminal hydrolases. Family members function as deubiquitinating enzymes, recognizing and hydrolyzing the peptide bond at the C-terminal glycine of ubiquitin. Enzymes in peptidase family C19 are involved in the processing of poly-ubiquitin precursors as well as that of ubiquitinated proteins. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. In melanocytic cells USP48 gene expression may be regulated by MITF.
Bush pursued many educational initiatives, such as increasing the funding for the National Science Foundation and National Institutes of Health in his first years of office and creating education programs to strengthen the grounding in science and mathematics for American high school students. Funding for the NIH was cut in 2006, the first such cut in 36 years, due to rising inflation. One of the administration's early major initiatives was the No Child Left Behind Act, which aimed to measure and close the gap between rich and poor student performance, provide options to parents with students in low-performing schools, and target more federal funding to low-income schools. This landmark education initiative passed with broad bipartisan support, including the support of Senator Ted Kennedy of Massachusetts. It was signed into law by Bush in early 2002. Many contend that the initiative has been successful, as cited by the fact that students in the U.S. have performed significantly better on state reading and math tests since Bush signed "No Child Left Behind" into law. Critics argue that it is underfunded and that NCLBA's focus on "high-stakes testing" and quantitative outcomes is counterproductive. On November 1, 2005, Bush launched a National Strategy for Pandemic Influenza, which culminated in an implementation plan published by the Homeland Security Council in May 2006.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.