neurotrophic signaling raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-05. 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.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
| 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 |
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
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。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Buttenwieser (1958), educator, Democratic Party fundraiser, member of the Lehman family Allen Rosenshine (1959), founder of the Omnicom Group, chairman and CEO of BBDO Doug Morris (1960), CEO of Sony Music Entertainment and former CEO of Universal Music Group Bernard Selz (1960), fund manager, philanthropist and anti-vaccination supporter Frank Lorenzo (1961), former chairman of Eastern Airlines, Texas Air Corporation and Texas International Airlines Douglas H. McCorkindale (1961), former chairman and CEO of Gannett William Campbell (1962), chairman of the board of Intuit, former board director of Apple Inc.; founder of Claris Sanford Greenberg (1962), investor, author and philanthropist Kenneth Lipper (1962), financier and deputy mayor of New York City; Academy Award-winning producer of The Holocaust documentary The Last Days Jerry Speyer (1962), billionaire, founding partner, chairman and CEO of Tishman Speyer and chairman of the Museum of Modern Art Robert Kraft (1963), chairman and CEO of The Kraft Group; owner of the New England Patriots Mark H.
== Procedure == To prepare cytocentrifuge smears, a funnel assembly is attached to the front of a microscope slide. The surface of the funnel assembly that is in contact with the slide is lined with filter paper to absorb excess fluid. A few drops of fluid are placed in the funnel. The assembly is placed in the cytocentrifuge, which operates at a low force (600–800 x g) to preserve cellular structure. Centrifugal force pushes the fluid through the funnel's opening and concentrates the cells in a small area of the slide. The centrifugation process concentrates cells by about twenty-fold and creates a one-cell-thick monolayer, allowing for assessment of cellular morphology. The slide can then be fixed and stained.
The dehydrogenation of 17α-hydroxyprogesterone acetate [302-23-8] (1) with chloranil (tetrachloro-p-benzoquinone) gives a compound that has been called melengestrol acetate [425-51-4] (2). Dehydrogenation with selenium dioxide gives 17-acetoxy-1,4,6-pregnatriene-3,20-dione [2668-75-9] (3). Reacting this with diazomethane results in a 1,3-dipolar addition reaction at C1–C2 of the double bond of the steroid system, which forms a derivative of dihydropyrazole, CID:134990386 (4). This compound cleaves when reacted with perchloric acid, releasing nitrogen molecules and forming a cyclopropane derivative, 6-deschloro cyproterone acetate [2701-50-0] (5). Selective oxidation of the C6=C7 olefin with benzoyl peroxide gives the epoxide, i.e. 6-deschloro-6,7-epoxy cyproterone [15423-97-9] (6). The penultimate step involves a reaction with hydrochloric acid in acetic acid, resulting in the formation of chlorine and its subsequent dehydration, and a simultaneous opening of the cyclopropane ring giving 1α-(chloromethyl) chlormadinone acetate [17183-98-1] (7). The heating of this in collidine reforms the cyclopropane ring, completing the synthesis of CPA (8).
== Metabolism == The enzyme taxifolin 8-monooxygenase uses taxifolin, NADH, NADPH, H+, and O2 to produce 2,3-dihydrogossypetin, NAD+, NADP+, and H2O. The enzyme leucocyanidin oxygenase uses leucocyanidin, alpha-ketoglutarate, and O2 to produce cis-dihydroquercetin, taxifolin, succinate, CO2, and H2O.
Sources: en.wikipedia.org
Thus, the ability of low doses of trazodone to improve sleep in depressed patients may be an important mechanism whereby trazodone can augment the efficacy of other antidepressants. Trazodone's potent α1-adrenergic blockade may cause some side effects like orthostatic hypotension and sedation. Conversely, along with 5-HT2A and H1 receptor antagonism, it may contribute to its efficacy as a hypnotic. Trazodone lacks any affinity for the muscarinic acetylcholine receptors, so does not produce anticholinergic side effects. mCPP, a non-selective serotonin receptor modulator and serotonin releasing agent, is an active metabolite of trazodone and has been suggested to possibly play a role in its therapeutic benefits. However, research has not supported this hypothesis and mCPP might actually antagonize the efficacy of trazodone as well as produce additional side effects.
US forces reported killing approximately 144 individuals identified as narco-terrorists in airstrikes on suspected trafficking vessels during the Venezuelan authorities and human rights organizations disputed the US characterization, alleging many victims were civilians or fishermen. Casualties among Venezuelan military personnel and allies from related ground operations are covered in 2026 United States intervention in Venezuela.
== Education == Cooks received Bachelor of Science and Master of Science degrees from the University of Natal in South Africa in 1961 and 1963, respectively. He received a Ph.D. from the University of Natal in 1965 and a second Ph.D. from Cambridge University in 1967, where he worked with Peter Sykes. He then did post-doctoral work at Cambridge with Dudley Williams.
===== Phase I ===== Phenyl-hydroxy bromazolam, 4-hydroxy bromazolam, α-hydroxy bromazolam, and α-4-dihydroxy bromazolam. The formation of phenyl-hydroxy bromazolam was catalysed by CYP2B6, CYP2C19, and CYP3A4. 4-hydroxy bromazolam, as well as α-hydroxy bromazolam, were formed by CYP2B6, CYP2C19, CYP3A4, and CYP3A5. Additionally, CYP2C9 was found to catalyse the formation of α-hydroxy bromazolam as well. α-4-dihydroxy bromazolam was only found in incubations with CYP3A4.
=== Geroprotective activity === Didymin is the principal flavonoid constituent of Monarda didyma L. (scarlet beebalm) extract, occurring at concentrations approximately 80-fold higher than the only other detectable flavonoid, isosakuranetin. In a randomized clinical trial, supplementation with 100 mg/day of Monarda didyma L. extract over 12 weeks was associated with reduced telomere attrition and improvements in markers of biological aging and quality of life, with the effects attributed primarily to didymin.
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.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.