N-acetyl Semax is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-06-15. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
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.
| Property | Value | Notes |
|---|---|---|
| 外观 | 白色至类白色粉末 | 常见于冻干制剂 |
| 溶解度 | 易溶于水 | 在极性溶剂中一般也可溶 |
| 建议储存温度 | -20 °C | 冻干粉,避光密封 |
| 常见分析手段 | 反相高效液相色谱 | 常与质谱联用 |
| 主要降解路径 | 水解与氧化 | 溶液状态更显著 |
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。
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。
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
Gallocatechol or gallocatechin (GC) is a flavan-3-ol, a type of chemical compound including catechin, with the gallate residue being in an isomeric trans position. This compound possesses two epimers. The most common, (+)-gallocatechin (GC), is found notably in green tea. The other enantiomer is called (−)-gallocatechin or ent-gallocatechin. It was first isolated from green tea by Michiyo Tsujimura in 1934. Epigallocatechin is another type of catechin, with the gallate residue being in an isomeric cis position. It can be found in St John's wort.
== AFL career == Lovett-Murray was initially rookie listed by Collingwood, playing for the Williamstown Seagulls in the Victorian Football League. After switching to the Bendigo Bombers, he was rookie listed by Essendon in the 2003 Rookie Draft. Lovett-Murray was promoted to the senior list early in the 2004 season and played 20 games. He spent the 2005 season on the rookie list again, he was promoted again that season and stayed on the senior list since then. In 2006, Lovett-Murray copped a three-game suspension from the AFL Tribunal for intentionally striking Fremantle midfielder Matthew Carr in the Bombers' round fourteen loss to the Dockers at Subiaco Oval. This was one of many lowlights for the club, which finished 15th at the end of the season with just three wins and one draw from 22 matches played. Lovett-Murray, along with 33 other Essendon players, was found guilty of using a banned performance-enhancing substance, thymosin beta-4, as part of Essendon's sports supplements program during the 2012 season. He and his team-mates were initially found not guilty in March 2015 by the AFL Anti-Doping Tribunal, but a guilty verdict was returned in January 2016 after an appeal by the World Anti-Doping Agency. He was suspended for two years which, with backdating, ended in December 2016; as a result, he served approximately fifteen months of his suspension and missed the entire 2016 season, when he had intended to play and coach for Rumbalara Football Club.
Doses… were subcutaneously injected into young dogs and rabbit… with the following general results… great prostration, fear, and sleepiness speedily following the administration, the eyes being sensitive, and pupils constrict, considerable salivation being produced in dogs, and a slight tendency to vomiting in some cases, but no actual emesis. Respiration was at first quickened, but subsequently reduced, and the heart's action was diminished and rendered irregular. Marked want of coordinating power over the muscular movements, and loss of power in the pelvis and hind limbs, together with a diminution of temperature in the rectum of about 4°.
SIMS is a mass spectrometry method to measure small-scale elemental and isotopic variations of samples. Its ability to measure in spots with a narrow diameter (10–40 μm) makes it a useful tool to date small (<100 μm) mineral grains and individual domains within a single crystal. SIMS can achieve a precision of ~3%. Sensitive high-resolution ion microprobe (SHRIMP) is widely regarded as a powerful tool among SIMS. SIMS analyzes the mineral surface (a few μm) composition by sputtering the surface with a focused primary ion beam under vacuum. The secondary ions liberated from the mineral are accelerated, measured and analyzed in the mass spectrometer. Sample are analysed in rotation with a standard of known elemental or isotopic ratios in order to determine the ratios in the sample for dating.
Sources: en.wikipedia.org
In biochemistry, medicine, and related sciences, inositol generally refers to myo-inositol (formerly meso-inositol), the most important stereoisomer of the chemical compound cyclohexane-1,2,3,4,5,6-hexol. Its formula is C6H12O6; the molecule has a ring of six carbon atoms, each with a hydrogen atom and a hydroxy group (–OH). In myo-inositol, two of the hydroxyls, neither adjacent nor opposite, lie above the respective hydrogens relative to the mean plane of the ring. The compound is a carbohydrate, specifically a sugar alcohol with half the sweetness of the disaccharide sucrose (table sugar). It is one of the most ancient components of living beings with multiple functions in eukaryotes, including structural lipids and secondary messengers. A human kidney makes about two grams per day from glucose, but other tissues synthesize it too. The highest concentration is in the brain, where it plays an important role in making other neurotransmitters and some steroid hormones bind to their receptors. In other tissues, it mediates cell signal transduction in response to a variety of hormones, neurotransmitters, and growth factors and participates in osmoregulation. In most mammalian cells the concentrations of myo-inositol are 5 to 500 times greater inside cells than outside them. The other naturally occurring stereoisomers of cyclohexane-1,2,3,4,5,6-hexol are scyllo-, muco-, D-chiro-, L-chiro-, and neo-inositol, although they occur in minimal quantities compared to myo-inositol. The other possible isomers are allo-, epi-, and cis-inositol.
== Signs and symptoms == The hallmark of polymyositis is weakness and/or loss of muscle mass in the proximal musculature, as well as flexion of the neck and torso. These symptoms can be associated with marked pain in these areas as well. The hip extensors are often severely affected, leading to particular difficulty in climbing stairs and rising from a seated position. The skin involvement of dermatomyositis is absent in polymyositis. Dysphagia (difficulty swallowing) or other problems with esophageal motility occur in as many as 1/3 of patients. Low grade fever and enlarged lymph nodes may be present. Foot drop in one or both feet can be a symptom of advanced polymyositis and inclusion body myositis. The systemic involvement of polymyositis includes interstitial lung disease (ILD) and heart disease, such as heart failure and conduction abnormalities. Polymyositis tends to become evident in adulthood, presenting with bilateral proximal muscle weakness often noted in the upper legs due to early fatigue while walking. Sometimes the weakness presents itself as an inability to rise from a seated position without help or an inability to raise one's arms above one's head. The weakness is generally progressive, accompanied by lymphocytic inflammation (mainly cytotoxic T cells).
Glycogen phosphorylase is activated by phosphorylation, whereas glycogen synthase is inhibited. Glycogen phosphorylase is converted from its less active "b" form to an active "a" form by the enzyme phosphorylase kinase. This latter enzyme is itself activated by protein kinase A and deactivated by phosphoprotein phosphatase-1. Protein kinase A itself is activated by the hormone adrenaline. Epinephrine binds to a receptor protein that activates adenylate cyclase. The latter enzyme causes the formation of cyclic AMP from ATP; two molecules of cyclic AMP bind to the regulatory subunit of protein kinase A, which activates it allowing the catalytic subunit of protein kinase A to dissociate from the assembly and to phosphorylate other proteins. Returning to glycogen phosphorylase, the less active "b" form can itself be activated without the conformational change. 5'AMP acts as an allosteric activator, whereas ATP is an inhibitor, as already seen with phosphofructokinase control, helping to change the rate of flux in response to energy demand. Epinephrine not only activates glycogen phosphorylase but also inhibits glycogen synthase. This amplifies the effect of activating glycogen phosphorylase. This inhibition is achieved by a similar mechanism, as protein kinase A acts to phosphorylate the enzyme, which lowers activity. This is known as co-ordinate reciprocal control. Refer to glycolysis for further information of the regulation of glycogenesis.
Sources: en.wikipedia.org
In matrix-assisted laser desorption ionization (MALDI), a fragmented peptide sample is loaded onto a matrix and ionized through the use of a high energy laser. The fragmented ions are then separated by mass-to-charge ratio based on the time of flight (TOF) through the spectrometer. They can then be further fragmented and re-analyzed in tandem mass spectrometry, often with a quadrupole ion trap, but also possible with tandem time of flight. The output received from a mass spectrometer comes in the form of a peak list. This spectrum shows the masses and relative abundances of the peptide fragments present in the sample. In reading a spectrum like the one shown, all possible major fragmentations of a protein would need to be considered. Then the masses of those fragments would correlate to the numbers in the peaks of the spectrum. While it can be analyzed to some degree on its own, in forming a peptide-mass fingerprint, the peak list is run through a database search to find homologous peptide sequences.
Adult T-cell leukemia/lymphoma Angiocentric lymphoma (extranodal natural killer cell lymphoma, nasal-type NK lymphoma, NK/T-cell lymphoma, polymorphic/malignant midline reticulosis) Angioimmunoblastic T-cell lymphoma (angioimmunoblastic lymphadenopathy with dysproteinemia) Blastic NK-cell lymphoma CD30+ cutaneous T-cell lymphoma (primary cutaneous anaplastic large cell lymphoma) Cutaneous lymphoid hyperplasia (borrelial lymphocytoma, lymphadenosis benigna cutis, lymphocytoma cutis, pseudolymphoma, pseudolymphoma of Spiegler and Fendt, sarcoidosis of Spiegler and Fendt, Spiegler–Fendt lymphoid hyperplasia, Spiegler–Fendt sarcoid) Cutaneous lymphoid hyperplasia with bandlike and perivascular patterns Cutaneous lymphoid hyperplasia with nodular pattern (nodular pattern of cutaneous lymphoid hyperplasia) Diffuse large B-cell lymphoma (primary cutaneous large B-cell lymphoma) Granulocytic sarcoma (chloroma, myeloid sarcoma) Granulomatous slack skin Hairy-cell leukemia Hodgkin's disease Ichthyosis acquisita (acquired ichthyosis) IgG4-related skin disease Intravascular large B-cell lymphoma (angiotropic large cell lymphoma, intralymphatic lymphomatosis, intravascular lymphomatosis, malignant angioendotheliomatosis) Jessner lymphocytic infiltrate of the skin (benign lymphocytic infiltration of the skin, Jessner lymphocytic infiltration of the skin, Jessner–Kanof lymphocytic infiltration of the skin, lymphocytic infiltrate of Jessner) Kikuchi's disease (histiocytic necrotizing lymphadenitis) Large plaque parapsoriasis (parapsoriasis en plaques) Lennert lymphoma (lymphoepitheliod lymphoma) Leukemia cutis Lymphoma cutis Lymphomatoid granulomatosis Lymphomatoid papulosis Malignant histiocytosis (histiocytic medullary reticulosis) Marginal zone B-cell lymphoma Mucosa-associated lymphoid tissue lymphoma Mycosis fungoides Non-mycosis fungoides CD30− cutaneous large T-cell lymphoma Nonspecific cutaneous conditions associated with leukemia (leukemid) Pagetoid reticulosis (acral mycoses fungoides, localized epidermotropic reticulosis, mycosis fungoides palmaris et plantaris, unilesional mycosis fungoides, Woringer–Kolopp disease) Pityriasis lichenoides chronica (chronic guttate parapsoriasis, chronic pityriasis lichenoides, dermatitis psoriasiformis nodularis, parapsoriasis chronica, parapsoriasis lichenoides chronica) Pityriasis lichenoides et varioliformis acuta (acute guttate parapsoriasis, acute parapsoriasis, acute pityriasis lichenoides, Mucha–Habermann disease, parapsoriasis acuta, parapsoriasis lichenoides et varioliformis acuta, parapsoriasis varioliformis) Plasmacytoma Plasmacytosis Pleomorphic T-cell lymphoma (non-mycosis fungoides CD30− pleomorphic small/medium-sized cutaneous T-cell lymphoma) Polycythemia vera (erythremia) Primary cutaneous follicular lymphoma (follicular center cell lymphoma, follicular center lymphoma) Primary cutaneous immunocytoma Primary cutaneous marginal zone lymphoma Retiform parapsoriasis Secondary cutaneous CD30+ large cell lymphoma Sézary syndrome Sinus histiocytosis with massive lymphadenopathy (Rosai–Dorfman disease) Subcutaneous T-cell lymphoma (panniculitis-like T-cell lymphoma) Vesiculopustular eruption and leukemoid reaction in Down syndrome
MDMA is an entactogen or empathogen, as well as a stimulant, euphoriant, and weak psychedelic. It is a substrate of the monoamine transporters (MATs) and acts as a monoamine releasing agent (MRA). The drug is specifically a well-balanced serotonin–norepinephrine–dopamine releasing agent (SNDRA). To a lesser extent, MDMA also acts as a serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI). MDMA enters monoaminergic neurons via the MATs and then, via poorly understood mechanisms, reverses the direction of these transporters to produce efflux of the monoamine neurotransmitters rather than the usual reuptake. Induction of monoamine efflux by amphetamines in general may involve intracellular Na+ and Ca2+ elevation and PKC and CaMKIIα activation. MDMA also acts on the vesicular monoamine transporter 2 (VMAT2) on synaptic vesicles to increase the cytosolic concentrations of the monoamine neurotransmitters available for efflux. By inducing release and reuptake inhibition of serotonin, norepinephrine, and dopamine, MDMA increases levels of these neurotransmitters in the brain and periphery and thereby indirectly activates the receptors of these neurotransmitters. There are species differences in the balance of MAT activities of MDMA, with it showing greater influence on serotonin in rodents than in humans. In addition to its actions as an SNDRA, MDMA directly interacts with a number of monoamine and other receptors.
=== Post-production === The filmmakers experimented with the visuals of Mega-City One, including the design and positioning of the city's tower blocks, to create the impression that the city had risen out of the remains of another. They found that replicating the comic visuals of blocks close together made the blocks appear small. Instead, they allowed more space between the buildings to emphasise the larger buildings and allow for the presence of roads and cars to allow for extrapolation outside of the picture. Outcrops and appendages were added to break up the buildings' straight lines. On 7 October 2011, the Los Angeles Times reported that Travis was prohibited from participating in the editing process following creative disagreements between producers and executives. Garland took over the editing process; his contribution was considered significant enough for him to seek a co-director credit—a situation considered unusual as Garland had never directed a film before and had not been in charge of any filming. The disagreement concerned a disapproval over the footage that Travis was providing. Although Travis was removed from the editing process, he was monitoring the progress of the film. On 10 October, Travis and Garland released a joint statement saying that they had agreed on an "unorthodox collaboration" before production began, that Travis was still involved in the film and that Garland was not seeking a co-director credit. In March 2018, Urban said that he believed Dredd should be considered Garland's directorial debut.
Sources: en.wikipedia.org
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。
公开资料对此没有统一答案。普遍建议现配现用,或冷藏并在数日内用完。含甲硫氨酸的序列更易氧化,放置时间越长风险越高。
反相高效液相色谱是最常用的手段,配合质谱确认分子量。氨基酸组成分析和肽图分析可补充序列层面的验证。
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.