Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
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。
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.
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
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.
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.
This enhances their hearing, as sound waves make the bladder vibrate, and the bones transport the vibrations to the inner ear. They also have a chemical alarm system; when a fish is injured, the warning substance gets in the water, alarming nearby fish. The majority of teleost species belong to the clade Euteleostei, which consists of 17,419 species classified in 2,935 genera and 346 families. Shared traits of the euteleosts include similarities in the embryonic development of the bony or cartilaginous structures located between the head and dorsal fin (supraneural bones), an outgrowth on the stegural bone (a bone located near the neural arches of the tail), and caudal median cartilages located between hypurals of the caudal base. The majority of euteleosts are in the clade Neoteleostei. A derived trait of neoteleosts is a muscle that controls the pharyngeal jaws, giving them a role in grinding food. Within neoteleosts, members of the Acanthopterygii have a spiny dorsal fin which is in front of the soft-rayed dorsal fin. This fin helps provide thrust in locomotion and may also play a role in defense. Acanthomorphs have developed spiny ctenoid scales (as opposed to the cycloid scales of other groups), tooth-bearing premaxilla and greater adaptations to high speed swimming. The adipose fin, which is present in over 6,000 teleost species, is often thought to have evolved once in the lineage and to have been lost multiple times due to its limited function. A 2014 study challenges this idea and suggests that the adipose fin is an example of convergent evolution.
== Veterinary use == Apomorphine is used to inducing vomiting in dogs after ingestion of various toxins or foreign bodies. It can be given subcutaneously, intramuscularly, intravenously, or, when a tablet is crushed, in the conjunctiva of the eye. The oral route is ineffective, as apomorphine cannot cross the blood–brain barrier fast enough, and blood levels don't reach a high enough concentration to stimulate the chemoreceptor trigger zone. It can remove around 40–60% of the contents in the stomach. One of the reasons apomorphine is a preferred drug is its reversibility: in cases of prolonged vomiting, the apomorphine can be reversed with dopamine antagonists like the phenothiazines (for example, acepromazine). Giving apomorphine after giving acepromazine, however, will no longer stimulate vomiting, because apomorphine's target receptors are already occupied. Apomorphine does not work in cats, who have too few dopamine receptors.
=== Biochemical activities === p200 CUX1 is a very abundant protein that binds to DNA with extremely fast kinetics (rapid "on" and "off" rates). This is not consistent with a role as a classical transcription factor that binds stably to DNA and recruits a co-activator or a co-repressor, however, the p200 CUX1 protein may still be able to repress transcription by competition for binding site occupancy. Indeed, CUX1 was originally purified as the CCAAT-displacement protein (CDP). In addition to this potential role in transcriptional repression, recent studies revealed that p200 CUX1 functions as an auxiliary factor in base excision repair. In vitro, CUT domains of CUX1 stimulate the enzymatic activities of the 8-oxoguanine DNA glycosylase (OGG1) and the apurinic/apyrimidinic endonuclease 1 (APE1). In agreement with results from in vitro DNA repair assays, a p200 CUX1-GFP fusion protein is rapidly recruited to DNA damage generated by laser microirradiation, while CUX1 knockdown in human cells causes a delay in the repair of oxidative DNA damage and mono-alkylated bases in genomic DNA, and sensitizes cancer cells to treatments with H2O2, ionizing radiation and the mono-alkylating agent temozolomide. Conversely, p200 CUX1 overexpression increases the resistance of cancer cells to the same treatments.
coordination complex A chemical compound consisting of a central atom or ion, usually metallic and known as the coordination center, bonded to a surrounding array of other groups of atoms, e.g. molecules or ions, which are known as ligands or complexing agents. Many metal-containing compounds, especially those of the transition metals, are coordination complexes. See also complex.
=== British Empire Medal (BEM) === Alwyn Enoe. For services to Entrepreneurships. The Reverend Dave King, Presiding Bishop, River Sallee Pentecostal Church/Temple of Deliverance, Grenada District. For services to Religious Affairs and Social Work
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=== Laboratory Analysers === Automated analysers, by the association of robotics and spectrophotometry, have allowed these last decades better reproducibility of the results, in particular in medical biochemistry and hematology. Efficiency and productivity can be enhanced by automating the pre-analytical processing, including barcode reading, sorting, centrifuging, and aliquoting specimens. The analysers must undergo daily controls prior to performing patient testing. Analysers must also undergo daily, weekly and monthly maintenance. Quality management involves reviewing quality control trends to detect emerging problems in instrument calibration, correlating results between instruments that perform similar testing, and running standardized samples to prove linearity and precision. Some laboratory processes involve automated analysis combined with manual review by technologists. For example, when hematology analysers flag samples as abnormal, automated white blood cell differential counts may be superseded by manual differential counts using stained slides read at the microscope or scanned by digital imaging software. Laboratory technologists may flag abnormal samples for pathologist review. The pathologist may recommend additional testing, such as flow cytometry to identify lymphoma or leukemia cells, or cytology to characterize solid tumor cells.
C13H9−CH2−OC(O)NHR + (CH2)5NH → (CH2)5NH+2 + [C13H8−CH2−OC(O)NHR]− [C13H8−CH2−OC(O)NHR]− → C13H8=CH2 + −OC(O)NHR −OC(O)NHR + (CH2)5NH+2 → HOC(O)NHR + (CH2)5NH HOC(O)NHR → CO2 + RNH2 C13H8=CH2 + (CH2)5NH → C13H9−CH2N(CH2)5
The petition seeks to have the risk of serious sexual side effects persisting after discontinuation mentioned in the product labels of SSRIs and SNRIs. The lawsuit was dismissed by the United States District Court for the District of Columbia on March 25, 2025, due to the plaintiff lacking legal standing, as the court found no specific informational or physical injury. The FDA has not mandated comprehensive PSSD warnings across all SSRI and SNRI labels, though fluoxetine (Prozac) has included a warning about persistent sexual side effects since 2011. Most other SSRI and SNRI labels address sexual dysfunction during use but not explicitly after discontinuation.
== Side effects == The US prescribing information for datopotamab deruxtecan includes warnings and precautions for interstitial lung disease/pneumonitis, ocular adverse reactions, stomatitis/oral mucositis, and embryo-fetal toxicity. Datopotamab deruxtecan is associated with a range of adverse events. The most common side effects are stomatitis, nausea, fatigue, alopecia (hair loss), constipation, vomiting, dry eye, keratitis, anemia, decreased appetite, increased aspartate transferase (AST), rash, diarrhea, neutropenia, and increased alanine aminotransferase (ALT).
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Since 2015, the city of Le Havre is divided over six Cantons, some of which also cover neighbouring communes. For the parliamentary elections, Le Havre spans two constituencies: the seventh (former cantons I, V, VI, and VII) and the eighth (former cantons II, III, IV, VIII, IX).
Xenopus egg extract is a lysate that is prepared by crushing the eggs of the African clawed frog Xenopus laevis. It offers a powerful cell-free (or in vitro) system for studying various cell biological processes, including cell cycle progression, nuclear transport, DNA replication and chromosome segregation. It is also called Xenopus egg cell-free system or Xenopus egg cell-free extract.
Supercritical water oxidation Photodegradation Sonochemical oxidation Electrochemical oxidation Plasma treatment Hydrothermal alkaline treatment Incineration Private and public sector applications of one or more of these methodologies above are being applied to remediation sites throughout the United States and other international locations. The U.S.-based Interstate Technology and Regulatory Council (ITRC) has undertaken an extensive evaluation of ex-situ and in-situ treatment technologies for PFAS-impacted liquid matrices. These technologies are divided into field-implemented technologies, limited application technologies, and developing technologies and typically fit into one of three technology types, namely separation, concentration, and destruction.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。