This is a working overview of lyophilized powder, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-15 and is reviewed periodically as new material appears.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
== Chemistry == Suvorexant is a small-molecule compound. The chemical name of suvorexant is [(7R)-4-(5-chloro-2-benzoxazolyl)hexahydro-7-methyl-1H-1,4-diazepin-1-yl][5-methyl-2-(2H-1,2,3-triazol-2-yl)phenyl]methanone. Its molecular formula is C23H23N6O2Cl and its molecular weight is 450.92 g/mol. Suvorexant is a white to off-white powder and is lipophilic and insoluble in water. It is structurally related to other orexin receptor antagonists like lemborexant, daridorexant, and seltorexant.
== Geography == Enewetak Atoll formed atop a seamount. The seamount was formed in the late Cretaceous. This seamount is now about 1,400 meters (4,600 ft) below sea level. It is made of basalt, and its depth is due to a general subsidence of the entire region and not because of erosion. Enewetak has a mean elevation above sea level of 3 meters (9.8 ft).
Aminoacyl tRNA synthetases catalyze the aminoacylation of tRNA by their cognate amino acid. Because of their central role in linking amino acids with nucleotide triplets contained in tRNAs, aminoacyl-tRNA synthetases are thought to be among the first proteins that appeared in evolution. Threonyl-tRNA synthetase belongs to the class-II aminoacyl-tRNA synthetase family.
=== Iodine-124 === Iodine-124 is a proton-rich isotope of iodine with a half-life of 4.1760 days, decaying to 124Te by 77.3% electron capture and 22.7% positron emission. Iodine-124 can be made by numerous nuclear reactions in a cyclotron. The most common starting material used is 124Te. Iodine-124 as the iodide salt can be used to directly image the thyroid using positron emission tomography (PET). Iodine-124 can also be used as a PET radiotracer with a usefully longer half-life compared with fluorine-18. In this use, the nuclide is chemically bonded to a pharmaceutical to form a positron-emitting radiopharmaceutical, and injected into the body, where again it is imaged by PET scan.
Sources: en.wikipedia.org
If a lich's corporeal body is destroyed, the portion of its soul that remained in the body does not pass on to the afterlife; rather, it persists in a non-corporeal form capable of being reconstituted or resurrected. However, if all of a lich's soul-artifacts are destroyed, its only remaining anchor to the material world becomes its corporeal body—meaning that its destruction would result in permanent death.
A common parasite of bowfin is the anchor worm (Lernaea species). These small crustaceans infest the skin and bases of fins, with consequences ranging from slowed growth to death. The mollusk Megalonaias gigantea lays eggs in the bowfin gills that are then externally fertilized by sperm passing in the water flow. The small glochidia larvae then hatch and develop in the gill tubes. Bowfin with liver cancer or fatal leukemia have been reported.
== Structure and action == Brilacidin, a non-peptide chemical mimic, is an aryl amide foldamer designed to replicate the amphiphilic properties of antimicrobial peptides while solving the problems encountered by peptide-based antimicrobials. Brilacidin, a broad-spectrum antibiotic, has potent Gram positive activity and Gram negative coverage, and is highly effective in treating the 'superbug' methicillin-resistant Staphylococcus aureus (MRSA). Brilacidin has low cytotoxicity against mammalian cells while selectively targeting bacteria, directly and rapidly disrupting their membranes, resulting in the bacteria's death. Due to this unique mechanism of action (mimicking the host's natural immune response, proven to be successful in fighting off infections over millions of years of evolution), bacterial antibiotic resistance is less likely to develop.
Through the activation of agonist muscle, which produces most of the force and control of an action, movement occurs. Antagonist muscles are the muscles that produce an opposing joint torque to the agonist muscles. Synergist muscles, also called fixators or neutralisers, act around a joint to help, counter, or neutralise the action of an agonist muscle. Generally, as one muscle contracts, the other muscle relaxes in a process known as reciprocal inhibition. Muscle contraction may be concentric (i.e. shortening), eccentric (i.e. lengthening), or isometric (i.e. involving no change in length). Muscle groups (e.g. elbow flexors) are sometimes named based on the joint action they produce during concentric contraction. During muscle contraction, the insertion of a muscle is the structure that is moved and is typically a bone that is distal and lighter than the origin; the origin is the bone, typically proximal, that remains more stable during contraction; the head of a muscle is the end part of the muscle that attaches to its origin.
Pretreatment produces "purified water" and focuses on removing contaminants with inexpensive methods prior to reverse osmosis or ion exchange during primary treatment. Coagulation (flocculation) and settling are used along with filtration to remove particulate matter that could clog reverse osmosis filters or ion exchange resin beds. Water softening by precipitation may be used for water sources with a relatively high concentrations of dissolved salts to prevent scaling during subsequent steps. The use of coagulation, flocculation, and settling are common in municipal water treatment systems meaning pretreatment may not be necessary depending on locale. For electronics (semiconductor) applications, aluminium salts along with lime-based water softeners are used to remove silica during pre-treatment. Transition metal ions like iron and manganese can be removed through oxidation followed by precipitation/flocculation methods. After bulk chemical treatments, pretreatment may include microfiltration or ultrafiltration to remove solids. Ion-exchange resins are commonly used in the pretreament step to further reduce the amount of scale-forming ions like calcium prior to reverse osmosis treatment as scaling can easily clog reverse osmosis membranes.
Sources: en.wikipedia.org
Melamine manufacturing and the chemical processes in which melamine are used are completely unrelated to the manufacture or processing of food products such as wheat gluten. On 9 April the FDA stated that there is a "distinct possibility" that the food was intentionally contaminated. According to Senator Richard J. Durbin, one theory that investigators are exploring is whether melamine was added to fraudulently increase the measured protein content, which determines the value of the product. Some analysis methods for determining protein content actually measure the amount of nitrogen present, on the assumption that only protein in the sample contributes significantly to its nitrogen content. Melamine contains a very high proportion of nitrogen. According to Liu Laiting, a Chinese professor of animal sciences, melamine is also hard to detect in ordinary tests.
A schematic of the optical systems is shown in Figure 1. The variable UV-Vis absorbance detector's optical bench is showing how the flow cell is positioned after the optical system, including the monochromator, which typically has a physical slit and a moving grating, so it is illuminated by a selected wavelength, reaching a photo-diode. The bench of the diode array detector, however, is configured so that the flow cell is positioned before the optical parts, so that the beam containing the entire spectrum is passing through it. The optical parts consist also with a monochromator and a slit, but with a fixed grating, which disperses the light onto a diode array imaging element.
== Mission parameters == Mass: 3,570 kg (7,870 lb) Perigee (insertion): 165.8 km (103.0 mi; 89.5 nmi) Apogee (insertion): 293.7 km (182.5 mi; 158.6 nmi) Period: 88.94 min Inclination: 32.53° Perigee (last orbit): 150 km (93 mi; 81 nmi) Apogee (last orbit): 232.8 km (144.7 mi; 125.7 nmi)
Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low glucose availability. In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency. Ketoacidosis is most commonly the result of complete insulin deficiency in type 1 diabetes or late-stage type 2 diabetes. Ketone levels can be measured in blood, urine or breath and are generally between 0.5 and 3.0 millimolar (mM) in physiological ketosis, while ketoacidosis may cause blood concentrations greater than 10 mM. Trace levels of ketones are always present in the blood and increase when blood glucose reserves are low and the liver shifts from primarily metabolizing carbohydrates to metabolizing fatty acids. This occurs during states of increased fatty acid oxidation such as fasting, carbohydrate restriction, or prolonged exercise. When the liver rapidly metabolizes fatty acids into acetyl-CoA, some acetyl-CoA molecules can then be converted into ketone bodies: pyruvate, acetoacetate, beta-hydroxybutyrate, and acetone. These ketone bodies can function as an energy source as well as signalling molecules. The liver itself cannot utilize these molecules for energy, so the ketone bodies are released into the blood for use by peripheral tissues including the brain.
== Awards and honours == 2020 Preis der Stadt Wien für Naturwissenschaften 2017 European Research Council (ERC) Advanced Grant 2015 Honorary member of the Swiss Society for Allergology and Immunology 2010 Virchow Medal, Medical Faculty, University of Würzburg 2012 European Research Council (ERC) Advanced Grant 2009 Full member of the Austrian Academy of Sciences 2005 Corresponding member of the Austrian Academy of Sciences 2001 Wittgenstein Award 2000 Member of the Academia Europaea 1990 Member of the European Molecular Biology Organization (EMBO) 1981 Postdoctoral fellowship (Swiss National Science Foundation)
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.