lyophilized powder comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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.
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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.
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.
=== Inorganic hydroponic solutions === The formulation of hydroponic solutions is an application of plant nutrition, with nutrient deficiency symptoms mirroring those found in traditional soil based agriculture. However, the underlying chemistry of hydroponic solutions can differ from soil chemistry in many significant ways. Important differences include:
Lore [pronounced "Lo'-re," rhymes with "story"] Rogers was born in the town of Patten, Maine. His father, Col. Luther B. Rogers, was a veteran of the Civil War, and became a partner in a prominent lumbering operation called Ayer and Rogers. Lore's mother, Mary Elizabeth Barker Rogers, bore seven children, and it is said she might have become a "remarkable journalist" had she been given the chance. In an unpublished autobiography, she described the children
Chemical fixatives are used to preserve and maintain the structure of tissues and cells; fixation also hardens tissues which aids in cutting the thin sections of tissue needed for observation under the microscope. Fixatives generally preserve tissues (and cells) by irreversibly cross-linking proteins. The most widely used fixative for light microscopy is 10% neutral buffered formalin, or NBF (4% formaldehyde in phosphate buffered saline). For electron microscopy, the most commonly used fixative is glutaraldehyde, usually as a 2.5% solution in phosphate buffered saline. Other fixatives used for electron microscopy are osmium tetroxide or uranyl acetate. The main action of these aldehyde fixatives is to cross-link amino groups in proteins through the formation of methylene bridges (−CH2−), in the case of formaldehyde, or by C5H10 cross-links in the case of glutaraldehyde. This process, while preserving the structural integrity of the cells and tissue can damage the biological functionality of proteins, particularly enzymes. Formalin fixation leads to degradation of mRNA, miRNA, and DNA as well as denaturation and modification of proteins in tissues. However, extraction and analysis of nucleic acids and proteins from formalin-fixed, paraffin-embedded tissues is possible using appropriate protocols.
== Safety == Most of the available einsteinium toxicity data is from research on animals. Upon ingestion by rats, only ~0.01% of it ends in the bloodstream. From there, about 65% goes to the bones, where it would remain for ~50 years if not for its radioactive decay, not to speak of the three-year maximum lifespan of rats, 25% to the lungs (biological half-life ~20 years, though this is again rendered irrelevant by the short half-life of einsteinium), 0.035% to the testicles or 0.01% to the ovaries—where einsteinium stays indefinitely. About 10% of the ingested amount is excreted. The distribution of einsteinium over bone surfaces is uniform and is similar to that of plutonium.
Sources: en.wikipedia.org
=== Gavi Foundation === On March 24, 2025, the Department of Government Efficiency (DOGE) announced the termination of a $2.63 billion grant from USAID to the Gavi Foundation because the Gavi Foundation "prioritizes 'zero-dose' children who have not received a single vaccine shot as well as missed communities. The zero-dose agenda is also a key priority for the global community’s immunization agenda 2030, which was endorsed by the World Health Assembly in May 2020." DOGE stated the United States federal government saved $1.75 billion by cancelling the grant, which was 6.575% of the total USAID budget.
The active site is located in a long cleft running parallel with the 3 strand across the lower part of the transpeptidase domain. When carbenicillin binds to penicillin binding protein 3, it forms an acyl-enzyme complex which means the β-lactam is chemically attached to PBP3. The β-lactams are covalently bound to S294 which inactivates the enzyme. Also, the N-terminal end of PBP3 is more flexible, however, the C-terminal part, which contains the enzyme’s active site, is very stable and does not change much. The binding of carbenicillin to the active site increases the enzyme's thermostability with conformational changes. The first carboxylate group in carbenicillin forms hydrogen bonding interactions with S485, T487, and N351. These hydrogen bonding interactions help stabilize the binding between carbenicillin and PBP 3.
== Life == Archerd was always interested in medicine but had neither the discipline nor the money to pursue his interest. In 1940 and 1941, he worked as an assistant at the Camarillo State Mental Hospital in wards where patients were treated with insulin shock therapies. In 1950, he was sentenced to five years of probation for possession of morphine in San Francisco. After another conviction, this parole was revoked. After escaping from a minimum-security prison in Chino, he was rearrested, put in San Quentin Prison, and released again in 1953 on probation. His home was in the Alhambra region of the San Gabriel Valley in Los Angeles County, California.
The two substrates of this enzyme are D-mannitol and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are D-mannose, reduced NADH and a proton. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is mannitol:NAD+ 1-oxidoreductase. Other names in common use include MTD, and NAD+-dependent mannitol dehydrogenase.
== Treatment == Conservative treatment of craniocervical instability includes physical therapy and the use of a cervical collar to keep the neck stable. Cervical spinal fusion is performed on patients with more severe symptoms.
Sources: en.wikipedia.org
Some synapses dispense with the "middleman" of the neurotransmitter, and connect the presynaptic and postsynaptic cells together. When an action potential reaches such a synapse, the ionic currents flowing into the presynaptic cell can cross the barrier of the two cell membranes and enter the postsynaptic cell through pores known as connexons. Thus, the ionic currents of the presynaptic action potential can directly stimulate the postsynaptic cell. Electrical synapses allow for faster transmission because they do not require the slow diffusion of neurotransmitters across the synaptic cleft. Hence, electrical synapses are used whenever fast response and coordination of timing are crucial, as in escape reflexes, the retina of vertebrates, and the heart.
Djalikatou Diallo- former vice-president Guinean Football Federation, former vice-president Nation Assembly, former Minister of National unity and Citizenship. Diaka Sidibé- former Minister of Higher Education, Scientific Research and Innovation, former Minister of Trade, Industry and Small and Medium-sized Enterprises. Kadiatou Émilie Diaby - former Minister of Public Works. Ibrahima Abé Sylla - Minister of Energy, Hydropower and Hydrocarbons, Guinea. Aïssatou Bobo Baldé - former vice president National Assembly. Barry Diawadou – Civil clerk and politician, former member of the French National Assembly and former Minister of Education. Guinea Mamoudou Nagnalen Barry - former minister of Agriculture. Sidibé Fatoumata Kaba (diplomat) - former minister of foreign affairs, former permanent Representative to the African union And The United Nations, former ambassador to Nigeria, Ethiopia. Ambassador to the united states, Guinea. Mama Kanny Diallo - Economist, former Minister of Planning and Economic Development, Guinea. Saifoulaye Diallo –Politician and lawmaker, former member of the French National Assembly, former president of the Territorial Assembly and President of the National Assembly; former Minister of State (foreign affairs, finance, social services). Elhadj Gando Barry - former Minister of Infrastructure and Public Works, CEO Électricité de Guinée. Ibrahima Barry (popularly known as Barry III) – Lawyer and politician, former Minister from Guinea Oumar Diouhé Bah - Minister of Health and public hygiene, Guinea.
NeoGenomics Laboratories, Inc., also known as NeoGenomics or Neo, is an American CLIA-certified clinical laboratory, pharma services and information services company that specializes in cancer genetics diagnostic testing. The company's testing services include cytogenetics, fluorescence in situ hybridization (FISH), flow cytometry, immunohistochemistry, anatomic pathology, and molecular genetics. Headquartered in Fort Myers, FL, NeoGenomics maintains a network of testing facilities across the US, with laboratories in Florida, California, Tennessee, and Texas.
== Interactions == Inhibitors and inducers of the cytochrome P450 enzyme CYP3A4 may interact with CPA. Examples of strong CYP3A4 inhibitors include ketoconazole, itraconazole, clotrimazole, and ritonavir, while examples of strong CYP3A4 inducers include rifampicin, rifampin, phenytoin, carbamazepine, phenobarbital, and St. John's wort. Certain anticonvulsant medications can substantially reduce levels of CPA, by as much as 8-fold.
Sources: en.wikipedia.org
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。