A practical reference on lyophilized powder: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-14. Anything still debated is marked as such rather than presented as settled.
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
| 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 |
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
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.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
=== Comparisons between eukaryotes and prokaryotes === Protein phosphorylation is a reversible post-translational modification of proteins. In eukaryotes, protein phosphorylation functions in cell signaling, gene expression, and differentiation. It is also involved in DNA replication during the cell cycle, and the mechanisms that cope with stress-induced replication blocks. Compared to eukaryotes, prokaryotes use Hanks-type kinases and phosphatases for signal transduction. Whether or not the phosphorylation of proteins in bacteria can also regulate processes like DNA repair or replication still remains unclear. Compared to the protein phosphorylation of prokaryotes, studies of protein phosphorylation in eukaryotes from yeast to human cells have been rather extensive. It is known that eukaryotes rely on the phosphorylation of the hydroxyl group on the side chains of serine, threonine, and tyrosine for cell signaling. These are the main regulatory post-translational modifications in eukaryotic cells but the protein phosphorylation of prokaryotes are less intensely studied. While serine, threonine, and tyrosine are phosphorylated in eukaryotes, histidine and aspartate is phosphorylated in prokaryotes and eukaryotes. In bacteria, histidine phosphorylation occurs in the phosphoenolpyruvate-dependent phosphotransferase systems (PTSs), which are involved in the process of internalization as well as the phosphorylation of sugars. Protein phosphorylation by protein kinase was first shown in E.
Modern genetics started with Mendel's studies of the nature of inheritance in plants. In his paper "Versuche über Pflanzenhybriden" ("Experiments on Plant Hybridization"), presented in 1865 to the Naturforschender Verein (Society for Research in Nature) in Brno, Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically. Although this pattern of inheritance could only be observed for a few traits, Mendel's work suggested that heredity was particulate, not acquired, and that the inheritance patterns of many traits could be explained through simple rules and ratios. The importance of Mendel's work did not gain wide understanding until 1900, after his death, when Hugo de Vries and other scientists rediscovered his research. William Bateson, a proponent of Mendel's work, coined the word genetics in 1905. The adjective genetic, derived from the Greek word genesis—γένεσις, "origin", predates the noun and was first used in a biological sense in 1860. Bateson both acted as a mentor and was aided significantly by the work of other scientists from Newnham College at Cambridge, specifically the work of Becky Saunders, Nora Darwin Barlow, and Muriel Wheldale Onslow. Bateson popularized the usage of the word genetics to describe the study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in London in 1906. After the rediscovery of Mendel's work, scientists tried to determine which molecules in the cell were responsible for inheritance. In 1900, Nettie Stevens began studying the mealworm.
Chiral inversion is the process of conversion of one enantiomer of a chiral molecule to its mirror-image version with no other change in the molecule. Chiral inversion happens depending on various factors (viz. biological-, solvent-, light-, temperature- induced, etc.) and the energy barrier associated with the stereogenic element present in the chiral molecule. 2-Arylpropionic acid nonsteroidal anti-inflammatory drugs (NSAIDs) provide one of the best pharmaceutical examples of chiral inversion. Chirality is attributed to a molecule due to the presence of a stereogenic element (viz. center, planar, helical, or axis). Many pharmaceutical drugs are chiral and have a labile (configurationally unstable) stereogenic element. Chiral compounds with stereogenic center are found to have high energy barriers for inversion and generally undergo biologically mediated chiral inversion. While compounds with helical or planar chirality have low energy barriers and chiral inversions are often caused by solvent, light, temperature. When this happens, the configuration of the chiral molecule may rapidly change reversibly or irreversibly depending on the conditions. The chiral inversion has been intensively studied in the context of the pharmacological and toxicological consequences. Other than NSAIDs, chiral drugs with different chemical structures can also show this effect. Chiral drugs have different effects on the body depending on whether one enantiomer or both enantiomers act on different biological targets.
== Function == Pancreatic polypeptide regulates pancreatic secretion activities by both endocrine and exocrine tissues. It also affects hepatic glycogen levels and gastrointestinal secretions. Its secretion in humans is increased after a protein meal, fasting, exercise, and acute hypoglycaemia, and is decreased by somatostatin and intravenous glucose. Plasma pancreatic polypeptide has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa. In addition, peripheral administration of polypeptide has been shown to decrease food intake in rodents. Pancreatic polypeptide inhibits pancreatic secretion of fluid, bicarbonate, and digestive enzymes. It also stimulates gastric acid secretion. It is the antagonist of cholecystokinin and opposes pancreatic secretion stimulated by cholecystokinin. It may stimulate the migrating motor complex, synergistic with motilin. On fasting, pancreatic polypeptide concentration is 80 pg/ml; after the meal, it rises up from 8 to 10 times more; glucose and fats also induce PP's level increase, but on parenteral introduction of those substances, the level of hormones doesn't change. The administration of atropine, the vagotomy, blocks pancreatic polypeptide secretion after meals. The excitation of the vagus nerve, the administration of gastrin, secretin or cholecystokinin induce PP secretion.
Sources: en.wikipedia.org
One of the journal studies found that a childhood vaccination strategy will be much cheaper than reacting to future epidemics with disruptive and costly case management and mass vaccination campaigns.
=== Mushroom production === Although DET is a synthetic compound with no known natural sources, it has been used in conjunction with the mycelium of Psilocybe cubensis to biosynthetically produce the chemicals ethocybin (4-PO-DET) and ethocin (4-HO-DET). Isolation of the alkaloids resulted in 3.3% ethocybin and 0.01-0.8% ethocin.
=== Increased MPV === Immune thrombocytopenia Disseminated intravascular coagulation Myeloproliferative disorders Administration of erythropoietin / thrombopoietin Recovery from transient hypoplasia Gray platelet syndrome GATA-1 mutation vWD Type 2B Platelet Type vWD Paris-Trousseau syndrome Mediterranean macrothrombocytopenia Bernard–Soulier syndrome MYH9-related disorders 21q11 deletion syndrome Chronic myelogenous leukemia Post-splenectomy Vasculitis Diabetes mellitus Pre-eclampsia Chronic kidney disease Respiratory diseases Thrombocytopenia secondary to sepsis Hyperthyroidism Hypothyroidism Myocardial infarction Artificial heart valves Massive hemorrhage
=== Macro-TGA === In TGA, the sample is loaded first before the increase of temperature, and the heating rate is low (less than 100 °C min−1). Macro-TGA can use gram-scale samples to investigate the effects of pyrolysis with mass and heat transfer.
Glycyrrhizin (glycyrrhizic acid or glycyrrhizinic acid) is the chief sweet-tasting constituent of Glycyrrhiza glabra (liquorice) root. Structurally, it is a saponin used as an emulsifier and gel-forming agent in foodstuffs and cosmetics. Its aglycone is enoxolone.
Sources: en.wikipedia.org
The media claimed that it was taking advantage of the lack of a nationally recognised framework for safety and quality across online-only telehealth services by advertising prescription-only drugs on social media.
The nature of the organic group on the silanization agent strongly influences the properties of the surface. Simple alkyl-containing silanizing groups confer hydrophobicity. When side chains of the silane compound are amines or thiols, the surfaces assume the properties of those functional groups. These surfaces are susceptible to further reactions characteristic of the appended functional groups. Grafting can be performed, for example.
=== Drug transport === South American cartels and Moroccan crime syndicates have maintained good relationships, and created trafficking networks to transport cargoes that involved thousands of containers through Moroccan ports since the 1980s. Due to the large waves of Moroccan immigration to the Netherlands and Belgium, beginning Moroccan traffickers were able to infiltrate the ports of Rotterdam and Antwerp, and criminal networks were eventually able to grow their influences over these port cities. In the 2000s, drug traffickers in these port-cities have changed the use of their hashish and cannabis routes for the use of cocaine trafficking to gain larger profits. A large part of these traffickers came from the north of Morocco, which explains their ease in expressing themselves in the Spanish language. With the arrival of new communication technologies, it was easier for these organisations to create and maintain new contacts, and networks were eventually established over three continents. The Moroccan mafia in the Netherlands and Belgium dominate the European market for cocaine, cannabis and synthetic drugs, alongside the Irish Mob, and the Italian (’Ndrangheta and Camorra), Serbian, and Albanian mafia. Moroccan gangs in Amsterdam, Utrecht, and Rotterdam have a firm foothold in importing cocaine from South America, particularly from Peru and Colombia, where Colombian cartels trust Dutch- and Belgian-Moroccan drug traffickers in Antwerp to receive and distribute these drugs.
== The Kenner Prize and Awards at University of Liverpool == The George Kenner Prize and Lectureship was established in 1979 with a sum of £12,000 raised by subscription to commemorate the late Professor GW Kenner, Heath Harrison Professor of Organic Chemistry from 1957 to 1976 and Royal Society Professor from 1977 to 1978. The duty of the Lectureship recipient is to deliver lectures on subjects related to the study of Organic Chemistry at the University. The first of these lectures was held on 28 October 1980. Lord Todd introduced the speaker, George Kenner's former research collaborator and lifelong friend Har Gobind Khorana, Nobel prizewinner and Professor at the Massachusetts Institute of Technology. Other famous organic chemists awarded the honour of the George Kenner Lectureship include Gilbert Stork, Ryoji Noyori, Steven V. Ley, Albert Eschenmoser, John George Adami, Duilio Arigoni, and Jean-Marie Lehn. The George W. Kenner Award for graduate students was established at the University of Liverpool in 2006 to commemorate Kenner. The award is annually given to the first-year PhD student in the organic section of the Department of Chemistry who is the best in both academic and research performance.
The finding consists of a single bone fragment about 2 cm long that was unearthed in 2012 by Russian archeologists at the Denisova Cave from layer 12 of the East Gallery. The cave is located in Denisova valley, Altai Mountains in Siberia, Russia. At the time, the origin of the bone fragment remained unknown because it was archived along with thousands of other nondescript bone fragments from the cave. In 2015, Tom Higham and Katerina Douka decided to try and apply new scientific methods to see whether they could be used to find human remains amongst the thousands of unidentified bone samples in the site. With the collaboration of the head excavators of the Denisova site; Michael Shunkov and Anatoly Derevianko, they took several bags containing thousands of unidentified bone fragments back to the University of Oxford. Samantha Brown, an MSc student at the University of Oxford, worked on the project as part of her dissertation research, screening more than 2000 bone fragments. Using Zooarchaeology by Mass Spectrometry (ZooMS) and working with the laboratory of Michael Buckley at the University of Manchester, they were able to compare the collagen protein fingerprints derived from the Denisova Cave bones to animals and humans of known origin, and they discovered that one of these bones (DC1227) belonged to an archaic human.
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.
Reversed-phase HPLC gives the main purity figure, most often with UV detection near 214 nanometres. Mass spectrometry then confirms the molecular mass. Together the two methods distinguish a correct sequence from a closely related impurity.