This is a working overview of lyophilised powder, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-21 and is reviewed periodically as new material appears.
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
(2026) present new information on growth and development of teeth of Anchitherium, based on the study of their histology. Evidence from the study of tooth enamel of Miocene Anchitherium, indicative of similar life histories of specimens from Germany and Spain ranging from the MN5 to the MN7/8 interval, is presented by Calderón et al. (2026). Sanz-Pérez et al. (2026) report evidence from the study of isotopic composition of tooth enamel of Hipparion from Miocene (Vallesian) localities in Duero and Madrid basins (Spain) indicative of intensification of seasonality in central Iberian Peninsula by MN 10 interval, as well as indicative of consumption of C3 vegetation by the studied equids and their ecological flexibility. Dağ et al. (2026) study the composition of the hipparion assemblage from the Miocene strata from the Yamula Reservoir localities (Turkey), and interpret the studied assemblage as consistent with presence of regionally variable mosaic habitats. Becker et al. (2026) describe hipparion fossil material from the late Pliocene Jradzor section (Armenia) and transfer "Hipparion" longipes and "H." fissurae to the genus Cremohipparion. Evidence indicating that occlusal enamel patterns in cheek teeth of Pleistocene equids from Alaska and Yukon cannot be used to reliably differentiate among tooth morphotypes is presented by Landry et al. (2026). Song et al.
== Clinical significance == Myositis may cause thickening of the muscle fascicles. This may be detected with ultrasound scans. Muscle fascicle structure is a useful diagnostic tool for dermatomyositis. Myocytes towards the edges of the muscle fascicle are typically narrower, while those at the centre of the muscle fascicle are a normal thickness. Muscle fascicles may be involved in myokymia, although commonly only individual myocytes are involved.
are the respective mole fractions and viscosities of the component liquids. Since blending is an important process in the lubricating and oil industries, a variety of empirical and proprietary equations exist for predicting the viscosity of a blend.
Unlike most amino acids, which are primarily oxidized in the liver, BCAAs are predominantly metabolized in skeletal muscle and other peripheral tissues. Degradation of branched-chain amino acids involves the branched-chain alpha-keto acid dehydrogenase complex (BCKDH). A deficiency of this complex leads to a buildup of the branched-chain amino acids (leucine, isoleucine, and valine) and their toxic by-products in the blood and urine, giving the condition the name maple syrup urine disease. On the other hand, unchecked activity of this complex causes branched-chain keto acid dehydrogenase kinase deficiency. The BCKDH complex converts branched-chain amino acids into acyl-CoA derivatives, which after subsequent reactions are converted either into acetyl-CoA or succinyl-CoA that enter the citric acid cycle. Enzymes involved are branched chain aminotransferase and 3-methyl-2-oxobutanoate dehydrogenase.
Sources: en.wikipedia.org
Methenamine, also known as hexamine or hexamethylenetetramine and sold under the brand names Hiprex, Urex, and Urotropin among others, is a urinary tract antiseptic and antibacterial medication which is used in the prevention of recurrent urinary tract infections (UTIs). It is not an antibiotic, and unlike antibiotics, has no risk of bacterial resistance. Methenamine can reduce the risk of UTIs by 44 to 86% and has been found to be non-inferior to low-dose prophylactic antibiotics. It is taken by mouth. The drug is available both by prescription and at lower doses over the counter. Besides for UTI prevention, methenamine is also available in a topical form to treat hyperhidrosis. Side effects of methenamine are generally minor and include upset stomach, nausea, and headache, among others. Methenamine is a prodrug of formaldehyde in acidic urine. Formaldehyde is a non-specific antiseptic and bactericide which works via denaturation of bacterial proteins and nucleic acids. Conversion of methenamine into formaldehyde only occurs in acidic environments and hence its actions show selectivity for tissues like the bladder and stomach. Chemically, methenamine is a simple cyclized hydrocarbon and is similar in structure to adamantane. Methenamine was discovered in 1859 and was first introduced for medical use as a urinary antiseptic in 1895. It was formally approved for medical use in the United States in 1967.
== Palace restoration == Princess Esra is credited with the restoration of Chowmahalla Palace and Falaknuma Palace. The former was opened to the public while the latter was leased as a luxury hotel to the Taj Group. She appointed architect Rahul Mehrotra to restore the Chowmahalla Palace. She initiated a project for the royal palaces in August 2000. The restoration project for Chowmahalla Palace involved tasks ranging from stabilising the existing structural components to reconstitution of collapsed and dilapidated sections of the complex, restoration of external and internal spaces and decorative elements and finishes.
=== Antimalarial === Doxycycline is active against the erythrocytic stages of Plasmodium falciparum, a protozoan parasite that causes malaria, but it is not active against the gametocytes of P. falciparum. As such, doxycycline is used to prevent malaria, but not recommended alone for initial treatment of malaria, even when the parasite is doxycycline-sensitive, because the antimalarial effect of doxycycline is delayed by 48 to 96 hours owing to a "delayed death" mechanism in which parasites complete their current replication cycle before dying in the next cycle. For this reason, doxycycline prophylaxis must be continued for four weeks after leaving a malarious area, compared with only seven days for atovaquone/proguanil. Doxycycline blocks protein production in the apicoplast (an organelle) of P. falciparum. This disrupts the parasite's ability to produce fatty acids, which are essential for its growth, and impairs the production of heme, a cofactor. These effects occur late in the parasite's life cycle during the blood stage (the erythrocytic cycle, when the parasite replicates inside human red blood cells). By blocking important processes in the parasite, doxycycline both inhibits the growth and prevents the replication of P. falciparum. Doxycycline does not directly kill living P. falciparum, but creates conditions that prevent their growth and replication. The World Health Organization (WHO) guidelines state that the combination of doxycycline with either artesunate or quinine may be used for the treatment of uncomplicated malaria due to P.
Apart from diagnosing hyperprolactinemia and hypopituitarism, prolactin levels are often checked by physicians in those who have had a seizure, when there is a need to differentiate between epileptic seizure or a non-epileptic seizure. Shortly after epileptic seizures, prolactin levels often rise, whereas they are normal in non-epileptic seizures.
=== Class I: Cys-based PTPs === Class I PTPs constitute the largest family. They contain the well-known classical receptor (a) and non-receptor PTPs (b), which are strictly tyrosine-specific, and the DSPs (c) which target Ser/Thr as well as Tyr and are the most diverse in terms of substrate specificity.
Sources: en.wikipedia.org
A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the periodic table's d-block), are coordination complexes. Coordination complexes can have a wide variety of coordination numbers and molecular geometries, with some complexes exhibiting Jahn–Teller distortions. Additionally, most coordination complexes are colored, due to visible light absorption due to d-d transitions or charge-transfer. The two main models explaining the properties (such as electronic structure, magnetism, and color) of complexes are crystal field theory and ligand field theory.
Multi-substrate analogue inhibitors are high affinity selective inhibitors that can be prepared for enzymes that catalyse reactions with more than one substrate by capturing the binding energy of each of those substrate into one molecule. For example, in the formyl transfer reactions of purine biosynthesis, a potent Multi-substrate Adduct Inhibitor (MAI) to glycinamide ribonucleotide (GAR) TFase was prepared synthetically by linking analogues of the GAR substrate and the N-10-formyl tetrahydrofolate cofactor together to produce thioglycinamide ribonucleotide dideazafolate (TGDDF), or enzymatically from the natural GAR substrate to yield GDDF. Here the subnanomolar dissociation constant (KD) of TGDDF was greater than predicted presumably due to entropic advantages gained and/or positive interactions acquired through the atoms linking the components. MAIs have also been observed to be produced in cells by reactions of pro-drugs such as isoniazid or enzyme inhibitor ligands (for example, PTC124) with cellular cofactors such as nicotinamide adenine dinucleotide (NADH) and adenosine triphosphate (ATP) respectively.
== History == Both Adolf Jarisch, an Austrian dermatologist, and Karl Herxheimer, a German dermatologist, are credited with the discovery of the Jarisch–Herxheimer reaction. Both Jarisch and Herxheimer observed reactions in patients with syphilis treated with mercury. The reaction was first seen following treatment in early and later stages of syphilis treated with Salvarsan, mercury, or antibiotics. Jarisch thought that the reaction was caused by a toxin released from the dying spirochetes.
== Dextran microspheres == Dextran microspheres are 1 to 250 micrometer sized polymeric particles that can encapsulate drugs. Microspheres composed of dextran have several advantages as a drug delivery system including controlled drug release, localized drug concentration, and reduced adverse reactions. Controlled drug release by these dextran microparticles is achieved by degradation, which is the breakdown of chemical bonds in the molecular structure of the polymeric network. Dextran microspheres are formulated in many forms including native dextran, dextran as a cross-linker, dextran conjugates, and chemically modified dextran.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.