If you have been reading about lyophilised powder and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-04-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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 |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
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.
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.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Recent evidence has shown that smoking tobacco increases the release of dopamine in the brain, specifically in the mesolimbic pathway, the same neuro-reward circuit activated by addictive substances such as heroin and cocaine. This suggests nicotine use has a pleasurable effect that triggers positive reinforcement. One study found that smokers exhibit better reaction-time and memory performance compared to non-smokers, which is consistent with increased activation of dopamine receptors. Neurologically, rodent studies have found that nicotine self-administration causes lowering of reward thresholds—a finding opposite that of most other addictive substances (e.g., cocaine and heroin). The carcinogenity of tobacco smoke is not explained by nicotine per se, which is not carcinogenic or mutagenic, although it is a metabolic precursor for several compounds which are. In addition, it inhibits apoptosis, therefore accelerating existing cancers. Also, NNK, a nicotine derivative converted from nicotine, can be carcinogenic. The addictive potential of nicotine is increased after co-administration of a MAOI, which specifically causes sensitization of the locomotor response in rats, a measure of addictive potential.
Ketone bodies can be used as fuels, yielding 22 ATP and 2 GTP molecules per acetoacetate molecule when oxidized in the mitochondria. Ketone bodies are transported from the liver to other tissues, where acetoacetate and beta-hydroxybutyrate can be reconverted to acetyl-CoA to produce reducing equivalents (NADH and FADH2), via the citric acid cycle. Ketone bodies cannot be used as fuel by the liver, because the liver lacks the enzyme β-ketoacyl-CoA transferase, also called thiolase. Acetoacetate in low concentrations is taken up by the liver and undergoes detoxification through the methylglyoxal pathway which ends with lactate. Acetoacetate in high concentrations is absorbed by cells other than those in the liver and enters a different pathway via 1,2-propanediol. Though the pathway follows a different series of steps requiring ATP, 1,2-propanediol can be turned into pyruvate.
The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. In the case of a closed system, the principle says that the total amount of energy within the system can only be changed through energy entering or leaving the system. Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite. Classically, the conservation of energy was distinct from the conservation of mass. However, special relativity shows that mass is related to energy and vice versa by
Sources: en.wikipedia.org
=== Other uses === In developing countries, moringa has the potential to improve nutrition, boost food security, foster rural development, and support sustainable landcare. It may be used as forage for livestock, a micronutrient liquid, a natural anthelmintic, and possible adjuvant. Moringa trees have been used to combat malnutrition, especially among infants and nursing mothers. Since moringa thrives in arid and semiarid environments, it may provide a versatile, nutritious food source throughout the year in various geographic regions. Some 140 organizations worldwide have initiated moringa cultivation programs to lessen malnutrition, purify water, and produce oils for cooking. Moringa oleifera leaf powder was as effective as soap for hand washing when wetted in advance to enable antiseptic and detergent properties from phytochemicals in the leaves. Moringa oleifera seeds and press cake have been implemented as wastewater conditioners for dewatering and drying fecal sludge. Moringa seed cake, obtained as a byproduct of pressing seeds to obtain oil, is used to filter water using flocculation to produce potable water for animals or humans. Moringa seeds contain dimeric cationic proteins, which absorb and neutralize colloidal charges in turbid water, causing the colloidal particles to clump together, making the suspended particles easier to remove as sludge by either settling or filtration. Combination of moringa seed protein, biochar, and sand removes toxicants in water, including E. coli, making the treated drinking water safe by international water quality criteria.
Ion exchange is a reversible interchange of one species of ion present in an insoluble solid with another of like charge present in a solution surrounding the solid. Ion exchange is used in softening or demineralizing of water, purification of chemicals, and separation of substances. Ion exchange usually describes a process of purification of aqueous solutions using solid polymeric ion-exchange resin. More precisely, the term encompasses a large variety of processes where ions are exchanged between two electrolytes. Aside from its use to purify drinking water, the technique is widely applied for purification and separation of a variety of industrially and medicinally important chemicals. Although the term usually refers to applications of synthetic (human-made) resins, it can include many other materials such as soil. Typical ion exchangers are ion-exchange resins (functionalized porous or gel polymer), zeolites, montmorillonite, clay, and soil humus. Ion exchangers are either cation exchangers, which exchange positively charged ions (cations), or anion exchangers, which exchange negatively charged ions (anions). There are also amphoteric exchangers that are able to exchange both cations and anions simultaneously. However, the simultaneous exchange of cations and anions is often performed in mixed beds, which contain a mixture of anion- and cation-exchange resins, or passing the solution through several different ion-exchange materials.
== Biological role == Substrate proteins attached to cell walls by sortases include enzymes, pilins, and adhesion-mediating large surface glycoproteins. These proteins often play important roles in virulence, infection, and colonization by pathogens. Surface proteins not only promote interaction between the invading pathogen and animal tissues, but also provide ingenious strategies for bacterial escape from the host's immune response. In the case of S. aureus protein A, immunoglobulins are captured on the microbial surface and camouflage bacteria during the invasion of host tissues. S. aureus mutants lacking the srtA gene fail to anchor and display some surface proteins and are impaired in the ability to cause animal infections. Sortase acts on surface proteins that are initiated into the secretion (Sec) pathway and have their signal peptide removed by signal peptidase. The S. aureus genome encodes two sets of sortase and secretion genes. It is conceivable that S. aureus has evolved more than one pathway for the transport of 20 surface proteins to the cell wall envelope. Note that exosortase and archaeosortase are functionally analogous, while not in any way homologous to sortase.
Sources: en.wikipedia.org
=== Neodymium === The rare earth element Neodymium is extracted by di(2-ethyl-hexyl)phosphoric acid into hexane by an ion exchange mechanism. Neodymium can also be separated from dysprosium through selective precipitation of dysprosium with Cyanex 272 when the HNO3 concentration was 0.001 mol/L.
Mitchell had designed an excellent seaplane for the 1931 Schneider Trophy, but the British government would not fund this excellent design - the Supermarine S.6B, leaving Lucy, Lady Houston, married to Sir Robert Houston, 1st Baronet, to fund the project entirely herself, from a request of the Royal Aero Club; the 230 mph Type 224 led to the 265 mph Type 425, with a 650 hp Goshawk engine; R-R proposed a 27-litre engine, derived from their R engine, in 1934; this new engine led R.J. Mitchell to propose the 350 mph Type 300 with the 1000 hp Merlin engine, and a £10,000 contract was offered for this aircraft to be ready by October 1935; the Hawker Hurricane was a monoplane Hawker Fury; 310 Spitfires were ordered; military historian Corelli Barnett and how later versions of the Spitfire took three times the man hours of the Bf 109; Sir Peter Masefield; 19 Squadron, led by Iliffe Cozens, converted from the Gloster Gauntlet to the Spitfire in August 1938; in the Battle of Britain, thirty Spitfires had the 20mm cannon fitted; the second movement - Fortune plango vulnera of Carmina Burana and the Messerschmitt Bf 109 at RAF Boscombe Down; Spitfire pilot Laddie Lucas; around 350 Spitfires entered US service.
== Metabolite Quantification and Analysis == In order to identify and quantify metabolites produced by the body, various detection methods have been employed. Most often, these involve the use of nuclear magnetic resonance (NMR) spectroscopy or mass spectrometry (MS), providing universal detection, identification and quantification of metabolites in individual patient samples. Although both processes are used in pharmacometabolomic analyses, there are advantages and disadvantages for using either nuclear magnetic resonance (NMR) spectroscopy- or mass spectrometry (MS)-based platforms in this application.
Sources: en.wikipedia.org
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.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
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.