If you have been reading about peptidase cleavage 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 2025-12-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
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.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
==== Fruits ==== With conventional dehydration, berries can degrade in quality as their structure is delicate and contains high levels of moisture. Strawberries were found to have the highest quality when freeze dried; retaining color, flavor, and ability to be re-hydrated.
== Evolution == Pyridoxal-5-phosphate (vitamin B6)-dependent enzymes have multiple evolutionary origins. The overall B6 enzymes diverged into four independent evolutionary lines: α family (i.e. aspartate aminotransferase), β family (serine dehydratase), D-alanine aminotransferase family and the alanine racemase family. An example of the evolutionary similarity in the Beta family is seen in the mechanism. The β enzymes are all lyases and catalyze reactions where Cα and Cβ participate. Overall, in the PLP-dependent enzymes, the PLP in every case is covalently attached via an imine bond to the amino group in the active site.
This characterization had already been proved five years earlier by Vaynshtejn. In the solution to his problem, a similar characterization was given by Vasilyev and Senderov. If h1, h2, h3, and h4 denote the altitudes in the same four triangles (from the diagonal intersection to the sides of the quadrilateral), then the quadrilateral is tangential if and only if
Metabotropic receptors, are slow response receptors in postsynaptic cells. Typically these slow responses are characterized by more elaborate intracellular changes in biochemistry. Responses of neurotransmitter uptake by metabotropic receptors can result in the activation of intracellualar enzymes and cascades involving second messengers, as is the case with G protein-linked receptors. Various metabotropic receptors can include certain glutamate receptors, muscarinic ACh receptors, GABAB receptors, and receptor tyrosine kinases.
Sources: en.wikipedia.org
== Origins == The exact origins of Cossacks remain unclear. In the modern view, Don Cossacks descend from Slavic people connected with Russian lands like the Povolzhye, the Novgorod Republic, and the Principality of Ryazan, and Ukrainian lands like the Dnieper. As well as nomadic Turkic tribes inhabiting the Steppes. Gotho-Alans could also have played a role in forming Don Cossack culture, which originated in the western part of the North Caucasus.
); rather, it depends on the orchestrated activity of SOM components. The distinct spatial distribution of these proteins—observed both on coral skeletons and in coral cell cultures—underscores their specific and diverse roles in directing crystal nucleation, growth, and overall skeletal architecture.
Surface energy is conventionally defined as the work that is required to build an area of a particular surface. Another way to view the surface energy is to relate it to the work required to cleave a bulk sample, creating two surfaces. If the new surfaces are identical, the surface energy γ of each surface is equal to half the work of cleavage, W: γ = (1/2)W11. If the surfaces are unequal, the Young-Dupré equation applies: W12 = γ1 + γ2 – γ12, where γ1 and γ2 are the surface energies of the two new surfaces, and γ12 is the interfacial energy. This methodology can also be used to discuss cleavage that happens in another medium: γ12 = (1/2)W121 = (1/2)W212. These two energy quantities refer to the energy that is needed to cleave one species into two pieces while it is contained in a medium of the other species. Likewise for a three species system: γ13 + γ23 – γ12 = W12 + W33 – W13 – W23 = W132, where W132 is the energy of cleaving species 1 from species 2 in a medium of species 3. A basic understanding of the terminology of cleavage energy, surface energy, and surface tension is very helpful for understanding the physical state and the events that happen at a given surface, but as discussed below, the theory of these variables also yields some interesting effects that concern the practicality of adhesive surfaces in relation to their surroundings.
stomach antrum distension vagal stimulation (mediated by the neurocrine bombesin, or GRP in humans) the presence of partially digested proteins, especially amino acids, in the stomach. Aromatic amino acids are particularly powerful stimuli for gastrin release. hypercalcemia (via calcium-sensing receptors) Gastrin release is inhibited by:
=== Phase 2 === Acetylcysteine lysinate (L-lysine-N-acetyl-L-cysteinate; N-acetylcysteine lysinate; Nacystelyn) – antioxidant Aminolevulinic acid (ALA; BF-200 ALA) – photosensitizer Cannabidiol topical (CBD; BTX-1204; BTX-1308; BTX-1503; BTX-1702; BTX-1801; PBX-1308) – cannabinoid Dimethylcurcumin (ASCJ-9; AJ-101; ASC-J9) – androgen receptor degradation enhancer Imsidolimab (ANB-019) – monoclonal antibody against the interleukin-36 receptor Ivermectin topical (CD-5024; Soolantra) – non-mammalian chloride channel opener LYS-006 – leukotriene A4 hydrolase (LTA4H) inhibitor Methyl aminolevulinate (MAL; CD06809-41; Luxerm; MAL-PDT; Metvix; Metvixia; P-1202; Visonac) – photosensitizer NAI Acne (BI-Acne; BI-K-0376; CB-06-01; CB-06-04; NAI-003; NAI-Acne; VIC-acne) – peptide elongation factor Tu inhibitor Omiganan (CLS-001; CPI-226; MBI-226; MBI-594AN; MX-226; MX-594AN; Omigard) – antiseptic/antibacterial Pyrilutamide (EX-A5504; HY-145451; KX–826) – antiandrogen (androgen receptor antagonist) Tretinoin topical – retinoid (retinoic acid receptor agonist) VB-1953 – antibiotic and toll-like receptor antagonist
Sources: en.wikipedia.org
CD38 (cluster of differentiation 38), also known as cyclic ADP ribose hydrolase, is a glycoprotein found on the surface of many immune cells (white blood cells), including CD4+, CD8+, B lymphocytes and natural killer cells. CD38 also functions in cell adhesion, signal transduction and calcium signaling. In humans, the CD38 protein is encoded by the CD38 gene which is located on chromosome 4. CD38 is a paralog of CD157, which is also located on chromosome 4 (4p15) in humans.
=== Tourism === Located between the North Sea and the Baltic Sea, Schleswig-Holstein is also a popular tourist destination in Germany. Its islands, beaches, and cities attract millions of tourists every year. It has the second highest tourism intensity per local among the German states, after Mecklenburg-Vorpommern, but in absolute value it is rank 6th and only 1/3 of top destination Bavaria. According to a ruling by the Federal Administrative Court, everyone has the right to free access to the beach. Nevertheless, most of the seaside resorts kept cashing in (2-€3 /day/person).
Channel-switching is the action of consumers switching from one type of channel intermediary to a different type of intermediary for their purchases. Examples include switching from brick-and-mortar stores to online catalogues and e-commerce providers; switching from grocery stores to convenience stores or switching from top tier department stores to mass market discount outlets. A number of factors have led to an increase in channel switching behaviour; the growth of e-commerce, the globalization of markets, the advent of category killers (such as Officeworks and Kids 'R Us) as well as changes in the legal or statutory environment. For instance, in Australia and New Zealand, following a relaxation of laws prohibiting supermarkets from selling therapeutic goods, consumers have gradually switched away from pharmacies and toward supermarkets for the purchase of minor analgesics, cough and cold preparations and complementary medicines such as vitamins and herbal remedies. For the consumer, channel switching offers a more diverse shopping experience, which may concern some sellers by its potential to erode market share. Evidence of channel switching can suggest that disruptive forces are at play, and that consumer behaviour is undergoing fundamental changes. A consumer may be prompted to switch channels when the product or service can be found at cheaper prices, when superior models become available, when a wider range is offered, or simply because it is more convenient to shop through a different channel (e.g. online or one-stop shopping).
Dextromethorphan is a cough suppressant used in many cough and cold medicines. In 2022, the US Food and Drug Administration (FDA) approved the combination dextromethorphan/bupropion to serve as a rapid-acting antidepressant in people with major depressive disorder. It is in the morphinan class of medications with dissociative and stimulant properties (at lower doses). Dextromethorphan does not have a significant affinity for the mu-opioid receptor activity typical of morphinan compounds and exerts its therapeutic effects through several other receptors. In its pure form, dextromethorphan occurs as a white powder. When exceeding approved dosages, dextromethorphan acts as a dissociative hallucinogen. It has multiple mechanisms of action, including actions as a nonselective serotonin–norepinephrine reuptake inhibitor and a sigma-1 receptor agonist. Dextromethorphan and its major metabolite dextrorphan also block the NMDA receptor at high doses, producing effects similar to those of other dissociative anesthetics such as ketamine, nitrous oxide, and phencyclidine. It was patented in 1949 and approved for medical use in 1953. In 2023, the combination with promethazine was the 252nd most commonly prescribed medication in the United States, with more than 1 million prescriptions; and the combination with brompheniramine and pseudoephedrine was the 281st most commonly prescribed medication in the United States, with more than 700,000 prescriptions.
== Medical significance == High levels of glucagon secretion has been implicated in both Type I and Type II diabetes. In fact, high levels of plasma glucagon is considered an early sign of the development of both Type I and Type II diabetes.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.