ACTH fragment raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-03-19. Anything still debated is marked as such rather than presented as settled.
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 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.
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。
| 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 |
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.
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.
This result shattered the Centre Party's hopes of being indispensable for obtaining a majority in parliament. The party was now faced with two alternatives – either to persist in protesting and risk reprisals like Communists and Social Democrats, or to declare their loyal cooperation, in order to protect their members. As shown by subsequent events, though deeply uncomfortable with the new government, the party opted for the latter alternative.
Noncatalytic functions that FAD can play in flavoproteins include as structural roles, or involved in blue-sensitive light photoreceptors that regulate biological clocks and development, generation of light in bioluminescent bacteria.
=== Toxicity === In rodents and primates, sufficiently high doses of amphetamine cause dopaminergic neurotoxicity, or damage to dopamine neurons, which is characterized by dopamine terminal degeneration and reduced transporter and receptor function. There is no evidence that amphetamine is directly neurotoxic in humans. However, large doses of amphetamine may indirectly cause dopaminergic neurotoxicity as a result of hyperpyrexia, the excessive formation of reactive oxygen species, and increased autoxidation of dopamine. Animal models of neurotoxicity from high-dose amphetamine exposure indicate that the occurrence of hyperpyrexia (i.e., core body temperature ≥ 40 °C) is necessary for the development of amphetamine-induced neurotoxicity. Prolonged elevations of brain temperature above 40 °C likely promote the development of amphetamine-induced neurotoxicity in laboratory animals by facilitating the production of reactive oxygen species, disrupting cellular protein function, and transiently increasing blood–brain barrier permeability.
== Structure == There is little information related to the p3 peptides composition and structure, and moreover most of it has to do with characteristics that concern to its role in Alzheimer's disease. p3 can be found as a 24 or 26 residues peptide, depending on which is gamma secretase's cleavage. The peptide which has 26 residues, presents the following sequence:
Sources: en.wikipedia.org
=== Allegations of illegal marketing === In 2004, separate civil suits alleging illegal marketing of citalopram and escitalopram for use by children and teenagers by Forest were initiated by two whistleblowers: a physician named Joseph Piacentile and a Forest salesman named Christopher Gobble. In February 2009, the suits were joined. Eleven states and the District of Columbia filed notices of intent to intervene as plaintiffs in the action. The suits alleged that Forest illegally engaged in off-label promotion of Lexapro for use in children; hid the results of a study showing lack of effectiveness in children; paid kickbacks to physicians to induce them to prescribe Lexapro to children; and conducted so-called "seeding studies" that were, in reality, marketing efforts to promote the drug's use by doctors. Forest denied the allegations but ultimately agreed to settle with the plaintiffs for over $313 million.
==== Pregnancy ==== It has not been shown to cause birth defects in animal studies when given intravenously. There are no controlled studies to show if pentamidine can harm the fetus in pregnant women. It is only recommended if the drug of choice trimethoprim-sulfamethoxazole is contraindicated.
Au-catalyzed Cys alkylation Cysteine-containing peptides have been shown to undergo 1,2-addition to allenes in the presence of gold(I) and/or silver(I) salts, producing hydroxyl substituted vinyl thioethers. The reaction with peptides proceeds with high yields and is selective for cysteines over other nucleophilic residues. However, the reactivity towards proteins is much decreased, potentially due to the coordination of gold to the protein backbone.
Kimon Georgiev Stoyanov (Bulgarian: Кимон Георгиев Стоянов; August 11, 1882 – September 28, 1969) was a Bulgarian general who was the Prime Minister of the Kingdom of Bulgaria from 1934 to 1935 and again from 1944 to 1946. He was considered a "master in the art of coup d'états".
=== 1960s === 1960: Rosalyn Yalow received the Nobel Prize in Physiology or Medicine "for the development of radioimmunoassays of peptide hormones" along with Roger Guillemin and Andrew V. Schally who received it "for their discoveries concerning the peptide hormone production of the brain". 1962: Katherine Johnson performed the calculations for the NASA orbital mission, launching John Glenn as the first person into orbit and returning them safely. 1963: Maria Goeppert Mayer became the first American woman to receive a Nobel Prize in Physics; she shared the prize with J. Hans D. Jensen "for their discoveries concerning nuclear shell structure” and Eugene Paul Wigner "for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles". She was born in Poland, but became a U.S. citizen in 1933. 1965: Sister Mary Kenneth Keller became the first American woman to earn a Ph.D. in Computer Science. Her thesis was titled "Inductive Inference on Computer Generated Patterns."
Sources: en.wikipedia.org
In Situ and Ex Situ NMR Techniques NMR technology can be divided into two main experimental approaches in battery research: In Situ NMR and Ex Situ NMR. Each offers unique advantages depending on the research goals.
However, in chemical nomenclature, the prefix "oxy" is associated with ether functional groups, i.e., a compound with an oxygen atom connected to two alkyl or aryl groups (R-O-R), therefore, using "oxy" within the name of a steroid class may be misleading. One can find clear examples of "oxygenated" to refer to a broad class of organic molecules containing a variety of oxygen containing functional groups in other domains of organic chemistry, and it is appropriate to use this convention. Even though "keto" is a standard prefix in organic chemistry, the 1989 recommendations of the Joint Commission on Biochemical Nomenclature discourage the application of the prefix "keto" for steroid names, and favor the prefix "oxo" (e.g., 11-oxo steroids rather than 11-keto steroids), because "keto" includes the carbon that is part of the steroid nucleus and the same carbon atom should not be specified twice.
It reaches from here all the way back to where it came from." Apparently because of his status as The One, he has a direct connection to the Source in the real world, and can therefore affect everything connected to it, including Sentinels, although the first use of this ability overwhelms him and he falls into a coma as his mind somehow plugs into the Matrix without a physical connection. Neo also begins to perceive everything connected to the Source, including the Machine City itself, as silhouettes of golden light. This ability becomes beneficial after he is blinded in the fight against Smith/Bane, thus he is able to see Smith/Bane and kill him. In The Matrix Resurrections, the resurrected Neo at first doesn't have access to his powers, although he slowly regains them over time, particularly during his fight with Smith. Neo is now able to create powerful telekinetic shockwaves, particularly when touching Trinity, and while he can still stop bullets, it appears to take him more effort. At one point, he telekinetically deflects a missile into a helicopter and shields himself from Smith smashing a porcelain sink down on his head. However, he is unable to fly while trying to escape from the Analyst's forces after reuniting with Trinity or after jumping off of a roof. Instead, Trinity develops the ability to fly and takes them both to safety. Neo appears to have regained his full powers by the end of the movie as he and Trinity fly off together after confronting the Analyst.
C.D. Cone studied the role of resting potential in regulating cell differentiation and proliferation. Subsequent work has identified specific regions of the resting potential spectrum that correspond to distinct cell states such as quiescent, stem, cancer, and terminally differentiated. Although this body of work generated a significant amount of high-quality physiological data, this large-scale biophysics approach has historically come second to the study of biochemical gradients and genetic networks in biology education, funding, and overall popularity among biologists. A key factor that contributed to this field lagging behind molecular genetics and biochemistry is that bioelectricity is inherently a living phenomenon – it cannot be studied in fixed specimens. Working with bioelectricity is more complex than traditional approaches to developmental biology, both methodologically and conceptually, as it typically requires a highly interdisciplinary approach.
In 2022 global production of sugar beets was 260 million tonnes, led by Russia with 18.8% of the world total (table). Sugar beet became a major source of sugar in the 19th century when methods for extracting the sugar became available. It is a biennial plant, a cultivated variety of Beta vulgaris in the family Amaranthaceae, the tuberous root of which contains a high proportion of sucrose. It is cultivated as a root crop in temperate regions with adequate rainfall and requires a fertile soil. The crop is harvested mechanically in the autumn and the crown of leaves and excess soil removed. The roots do not deteriorate rapidly and may be left in the field for some weeks before being transported to the processing plant where the crop is washed and sliced, and the sugar extracted by diffusion. Milk of lime is added to the raw juice with calcium carbonate. After water is evaporated by boiling the syrup under a vacuum, the syrup is cooled and seeded with sugar crystals. The white sugar that crystallises can be separated in a centrifuge and dried, requiring no further refining.
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.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。