Everything below concerns counterion. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-10-09. Numbers and descriptions here follow the published literature rather than marketing material.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | 95% or higher | By reversed-phase HPLC area |
| Identity method | Electrospray mass spectrometry | Confirms molecular mass |
| Purity method | Reversed-phase HPLC | Detection near 214 nm |
| Primary degradation | Methionine oxidation | Sulfoxide product, +16 Da |
| Solution storage | 2-8 °C, short term | Aliquot to avoid freeze-thaw |
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
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.
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.
The fruits are eaten fresh or made into jams, fools, juices, or pies. In France and Italy, they are used as a base for liqueurs and are a popular flavoring for sorbets and other desserts. In Brittany, they are often used as a flavoring for crêpes. In the Vosges and the Massif Central, bilberry tart (tarte aux myrtilles) is a traditional dessert. In Romania, they are used as a base for a liqueur called afinată – the name of the fruit in Romanian is afină. In Nordic countries, they are eaten fresh or made into jams and other dishes, including bilberry pie (Finnish mustikkapiirakka, Swedish blåbärspaj) and blåbärssoppa, a bilberry soup served hot or cold. In Iceland, they are eaten with skyr (a cultured dairy product similar to yoghurt). In Poland, they are eaten fresh (often mixed with sugar), as a filling in a sweet yeast-leavened bun known as jagodzianka, in jams, and with śmietana.
GABAA receptor: positive allosteric modulator (primarily of δ subunit-containing receptors) NMDA receptor: negative allosteric modulator AMPA receptor: negative allosteric modulator Kainate receptor: negative allosteric modulator Glycine receptor: positive allosteric modulator Serotonin 5-HT3 receptor: positive allosteric modulator Opioid receptor: endogenous positive allosteric modulator Muscarinic acetylcholine receptor: positive allosteric modulator. Nicotinic acetylcholine receptor: positive allosteric modulator Glycine reuptake inhibitor Adenosine reuptake inhibitor L-type calcium channel: channel blocker GIRK: channel opener Voltage-gated calcium channel Dihydropyridine-sensitive L-type Ca2+ channels BK channel modulation G-protein-activated inwardly rectifying K+ channels Brain medulla: Decreased levels of nitric oxide Mesolimbic pathway: Increased levels of dopamine and endogenous opioids, secondary to other actions Many of these actions have been found to occur only at very high concentrations that may not be pharmacologically significant at recreational doses of ethanol, and it is unclear how or to what extent each of the individual actions is involved in the effects of ethanol. Some of the actions of ethanol on ligand-gated ion channels, specifically the nicotinic acetylcholine receptors and the glycine receptor, are dose-dependent, with potentiation or inhibition occurring dependent on ethanol concentration. This seems to be because the effects of ethanol on these channels are a summation of positive and negative allosteric modulatory actions.
Polymers display varying degrees of crystallinity, and many are completely non-crystalline. Glass, some ceramics, and many natural materials are amorphous, not possessing any long-range order in their atomic arrangements. The study of polymers combines elements of chemical and statistical thermodynamics to give thermodynamic and mechanical descriptions of physical properties.
Rather than absolute concentrations of either two, it is the ratio of MMP and TIMP that maintains the proteolytic balance, and this ratio is found to be disturbed in diabetic ulcers. Despite these findings, the exact mechanism responsible for increased MMP activity in diabetes is not known yet. One possible line of thought considers Transforming growth factor beta (TGF-β) as an active player. Most MMP genes have TGF-β inhibitory element in their promoter regions and thus TGF–β regulates the expression of both MMP and their inhibitor TIMP. In addition to the importance of cell-cell and cell-matrix interactions, all phases of wound healing are controlled by a wide variety of different growth factors and cytokines. To mention precisely, growth factors promote switching of the early inflammatory phase to the granulation tissue formation. A decrease in growth factors responsible for tissue repair, such as TGF-β, is documented in diabetic wounds. Thus, reduced levels of TGFβ in diabetes cases lower the effect of inhibitory regulatory effect on MMP genes and thus cause MMPs to overexpress.
Abciximab, a glycoprotein IIb/IIIa receptor antagonist antibody manufactured by Janssen Biologics BV and distributed by Eli Lilly under the trade name ReoPro, is a platelet aggregation inhibitor mainly used during and after coronary artery procedures like angioplasty to prevent platelets from sticking together and causing thrombus (blood clot) formation within the coronary artery. It is a glycoprotein IIb/IIIa inhibitor. While abciximab has a short plasma half-life, due to its strong affinity for its receptor on the platelets, it may occupy some receptors for weeks. In practice, platelet aggregation gradually returns to normal about 96 to 120 hours after discontinuation of the drug. Abciximab is made from the Fab fragments of an immunoglobulin that targets the glycoprotein IIb/IIIa receptor on the platelet membrane.
Sources: en.wikipedia.org
=== Associated defects/diseases === There are thousands of deaths a year of infants, either during or shortly after birth, and the leading cause of these deaths are congenital birth defects (CBDs), which are defined as abnormalities of the chromosomes. In the year 2004, CBDs had been the cause of over 139,000 hospitalizations in the U.S. and had cost the community $2.6 billion in healthcare and medical supplies. While some CBDs can be easily fixed by simple surgery or medication, such as cleft lip, there are still life threatening diseases that are caused by mutations to the Grhl family members or genetic pathways that they are associated with. In developing countries, where there is a large percentage of the population in poverty, families struggle to receive the necessary treatment to combat CBDs and the extent at which the quality of life is affected is continually worsening. Members of the Grhl3 family are closely related to endodermal tissues and the issues that can arise from a mutation in one of the Grhl family members can include respiratory problems, loss of hearing, spina bifida and much more. Grhl3 has been shown to be a downstream target of genes such as Fgf8 and Irf6, of which the associated pathways are involved in the aetiology of Van der Woude syndrome.
Microfluidic liquid-liquid extraction has shown to be advantageous in numerous applications such as pharmacokinetic drug studies where only small cell numbers are needed, and in additional studies where smaller reagent volumes are required. Droplet-based microfluidics can also be used for chemical phase transfer reactions. An early example was the synthesis of azo dyes in nanoliter fluid segments using a double injector chip device.
Negrin opened wide, fascinating vistas to my imagination, not only through his lectures and laboratory teaching, but through his advice, encouragement, and stimulation to read scientific monographs and textbooks in languages other than Spanish. Negrín encouraged Ochoa and another student, José Valdecasas, to isolate creatinine from urine. The two students succeeded and also developed a method to measure small levels of muscle creatinine. Ochoa spent the summer of 1927 at University of Glasgow working with D. Noel Paton on creatine metabolism and improving his English skills. He also refined the assay procedure further and upon returning to Spain he and Valdecasas submitted a paper describing the work to the Journal of Biological Chemistry, where it was rapidly accepted, marking the beginning of Ochoa's biochemistry career. Ochoa completed his undergraduate medical degree in the summer of 1929 and decide to go abroad again to gain further research experience. His creatine and creatinine work led to an invitation to join Otto Meyerhof's laboratory at the Kaiser Wilhelm Institute for Biology in Berlin-Dahlem in 1929. At that time the institute was a "hot bed" of the rapidly evolving discipline of biochemistry, and thus Ochoa had the experience of meeting and interacting with scientists such as Otto Heinrich Warburg, Carl Neuberg, Einar Lundsgaard, and Fritz Lipmann in addition to Meyerhof who had received the Nobel Prize in Physiology and Medicine less than a decade earlier.
== External links == ABCC1+protein,+ human at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Human ABCC1 genome location and ABCC1 gene details page in the UCSC Genome Browser. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
== Side effects == The most common adverse effects are blurred vision, tearing and other kinds of eye discomfort. Eye pain, eye oedema, headache, increased intraocular pressure and other side effects are seen in less than 1% of patients.
Sources: en.wikipedia.org
=== Withdrawal === The magnitude and speed of dose reduction in corticosteroid withdrawal should be determined on a case-by-case basis, taking into consideration the underlying condition being treated, and individual patient factors such as the likelihood of relapse and the duration of corticosteroid treatment. Gradual withdrawal of systemic corticosteroids should be considered in those whose disease is unlikely to relapse and have:
The city currently has a large number of rail and road work sites. Although this activity has increased as a result of the 2006 Winter Olympics, parts of it had long been planned. Some of the work sites deal with general roadworks to improve traffic flow, such as underpasses and flyovers, but two projects are of major importance and will radically change the shape of the city. One is the Spina Centrale ('Central Spine') project which includes the doubling of a major railway crossing the city, the Turin-Milan railway locally known as Passante Ferroviario di Torino ('Turin Railway Bypass'). The railroad previously ran in a trench, which will now be covered by a major boulevard running from north to south of Turin, in a central position along the city. Porta Susa, on this section, will become Turin's main station to substitute the terminus of Porta Nuova with a through station. Other important stations are Stura, Rebaudengo, Lingotto and Madonna di Campagna railway stations, though not all of them belong to the layout of the Spina Centrale.
=== 13 February === Thomas Bach, head of the IOC, stood by the offer of allowing Russian and Belarusian athletes to participate under a white or neutral flag for the 2024 Paris Olympics, saying that national governments should not decide who can participate in sports competitions. It was reported that Pakistan had sent some 10,000 Grad rockets to Ukraine in February.
Also, ZEB1 is capable of conferring stem cell-like properties, thus strengthening the relationship between EMT and stemness. Thus, EMT may present increased danger to cancer patients, as EMT not only enables the carcinoma cells to enter the bloodstream, but also endows them with properties of stemness which increases tumorigenic and proliferative potential. However, recent studies have further shifted the primary effects of EMT away from invasion and metastasis, toward resistance to chemotherapeutic agents. Research on breast cancer and pancreatic cancer both demonstrated no difference in cells' metastatic potential upon acquisition of EMT. These are in agreement with another study showing that the EMT transcription factor TWIST actually requires intact adherens junctions in order to mediate local invasion in breast cancer. The effects of EMT and its relationship to invasion and metastasis may therefore be highly context specific. In urothelial carcinoma cell lines overexpression of HDAC5 inhibits long-term proliferation but can promote epithelial-to-mesenchymal transition (EMT).
Sources: en.wikipedia.org
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.
In solution, hydrolysis of peptide bonds and oxidation of the methionine residue are the principal concerns. Oxidation converts methionine to its sulfoxide form, shifting the mass by sixteen daltons. Both processes are slowed by cold storage and by avoiding alkaline conditions.
A certificate documents what the supplier measured on a specific lot, not how a laboratory will use the material. Independent verification of identity and purity is common practice. Acceptance criteria should be defined before a batch is ordered.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.