A practical reference on lyophilized powder: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-01-04 and is reviewed periodically as new material appears.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
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.
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.
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.
=== National Insurance Company Limited === National Insurance Company Limited (NICL) was established in 1976 to provide insurance cover to the Government/Semi Government organizations. National Insurance Company Limited is 100% owned by Government of Pakistan and working under the administrative control of federal ministry of commerce.
=== Solubility in a strong or weak acid solution === Solutions of strong (HCl), moderately strong (sulfamic) or weak (acetic, citric, sorbic, lactic, phosphoric) acids are commercially available. They are commonly used as descaling agents to remove limescale deposits. The maximum amount of CaCO3 that can be "dissolved" by one liter of an acid solution can be calculated using the above equilibrium equations.
=== Imaging === Right upper quadrant abdominal ultrasound is most commonly used to diagnose cholecystitis. Ultrasound findings suggestive of acute cholecystitis include gallstones, pericholecystic fluid (fluid surrounding the gallbladder), gallbladder wall thickening (wall thickness over 3 mm), dilation of the bile duct, and sonographic Murphy's sign. Given its higher sensitivity, hepatic iminodiacetic acid (HIDA) scan can be used if ultrasound is not diagnostic. CT scan may also be used if complications such as perforation or gangrene are suspected.
Ulrich Hersel; Claudia Dahmen; Horst Kessler (2003). "RGD modified polymers: biomaterials for stimulated cell adhesion and beyond". Biomaterials. 24 (24): 4385–4415. doi:10.1016/s0142-9612(03)00343-0. PMID 12922151. Wikidata Q34223126. Marco Arnold; Elisabetta A Cavalcanti-Adam; Roman Glass; Jacques Blümmel; Wolfgang Eck; Martin Kantlehner; Horst Kessler; Joachim P Spatz (2004). "Activation of integrin function by nanopatterned adhesive interfaces". ChemPhysChem. 5 (3): 383–388. doi:10.1002/cphc.200301014. PMID 15067875. Wikidata Q44832858. Kessler, Horst (July 1982). "Conformation and Biological Activity of Cyclic Peptides". Angewandte Chemie International Edition in English. 21 (7): 512–523. doi:10.1002/anie.198205121. ISSN 0570-0833. Dechantsreiter MA; Planker E; Mathä B; Lohof E; Hölzemann G; Jonczyk A; Goodman SL; Kessler H (1999). "N-Methylated cyclic RGD peptides as highly active and selective alpha(V)beta(3) integrin antagonists". Journal of Medicinal Chemistry. 42 (16): 3033–3040. doi:10.1021/jm970832g. PMID 10447947. Wikidata Q30580638. Elisabetta A Cavalcanti-Adam; Tova Volberg; Alexandre Micoulet; Horst Kessler; Benjamin Geiger; Joachim Pius Spatz (2007). "Cell spreading and focal adhesion dynamics are regulated by spacing of integrin ligands". Biophysical Journal. 92 (8): 2964–2974. doi:10.1529/biophysj.106.089730. PMC 1831685. PMID 17277192. Wikidata Q30479140. Kessler, Horst (2023). NMR: Mein Kompass in der Organischen und Medizinischen Chemie [NMR: my compass in organic and medicinal chemistry]. Berlin: GNT Publishing GmbH. ISBN 978-3-86225-132-2.
Sources: en.wikipedia.org
Amphotericin B is an antifungal medication used for serious fungal infections and leishmaniasis. The fungal infections it is used to treat include mucormycosis, aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, and cryptococcosis. It is sometimes used as a drug of last resort for primary amoebic meningoencephalitis. For certain infections it is given with flucytosine. It is typically given intravenously. Common side effects include a reaction with fever, chills, and headaches soon after the medication is given, as well as kidney problems. Allergic symptoms including anaphylaxis may occur. Other serious side effects include low blood potassium and myocarditis (inflammation of the heart). It appears to be relatively safe in pregnancy. There is a lipid formulation that has a lower risk of side effects. It is in the polyene class of medications and works in part by interfering with the cell membrane of the fungus. Amphotericin B was isolated from Streptomyces nodosus in 1955 at the Squibb Institute for Medical Research from cultures isolated from the streptomycete obtained from the river bed of Orinoco in that region of Venezuela and came into medical use in 1958. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication.
an α-amino acid + an alcohol This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name is α-amino-acid-ester aminoacylhydrolase. This enzyme is also called α-amino acid ester hydrolase.
Kimon Georgiev became prime minister on 19 May 1934, after the coup d'état. He served as Minister of Foreign Affairs and Religious Affairs (19-23 May 1934) and Minister of Justice (23 May 1934 – 22 January 1935) and temporarily served as Minister of War on 19 May 1934. Kimon Georgiev led the new Cabinet, which was primarily made up of Zveno and Military League representatives. Although they denounced the coup, the other bourgeois parties and the non-fascist bourgeois parties accepted it. The BCP called it a fascist coup, but they were unable to put up a united front to fight it due to mistakes in secretarian doctrine. The coup's perpetrators said in their manifesto that a "national supra-party power" would be established. They abolished the Parliament, dissolved the IMRO, and restructured the governmental apparatus on a fascist basis.
Sulfite reductase (NADPH) (EC 1.8.1.2, sulfite (reduced nicotinamide adenine dinucleotide phosphate) reductase, NADPH-sulfite reductase, NADPH-dependent sulfite reductase, H2S-NADP oxidoreductase, sulfite reductase (NADPH2)) is an enzyme with systematic name hydrogen-sulfide:NADP+ oxidoreductase. This enzyme catalises the following chemical reaction:
At low enough temperatures, a distinction can be made between the axial and equatorial hydrogens in cyclohexane. An example of nuclear magnetic resonance being used in the determination of a structure is that of buckminsterfullerene (often called "buckyballs", composition C60). This now famous form of carbon has 60 carbon atoms forming a sphere. The carbon atoms are all in identical environments and so should see the same internal H field. Unfortunately, buckminsterfullerene contains no hydrogen and so 13C nuclear magnetic resonance has to be used. 13C spectra require longer acquisition times since carbon-13 is not the common isotope of carbon (unlike hydrogen, where 1H is the common isotope). However, in 1990 the spectrum was obtained by R. Taylor and co-workers at the University of Sussex and was found to contain a single peak, confirming the unusual structure of buckminsterfullerene.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
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.