Everything below concerns heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-24. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C37H51N9O10S | 游离碱形式 |
| 等电点 | 约 6.5 | 估算值，随缓冲体系变化 |
| 主要降解途径 | 水解与氧化 | 侧链氧化最为常见 |
| 溶液储存 | 2 至 8 摄氏度避光 | 避免反复冻融 |
| 常规分析手段 | 反相色谱与质谱联用 | 氨基酸分析辅助核对 |
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.
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.
=== Other uses === Possible applications that are currently investigated include the binding and inactivation of cholera toxin and the cross linkage of surface proteins of various viruses (HIV, Ebola virus). Further the group of Christian Schafmeister developed molecular hinges, which can be used for the construction of molecular machines, such as nano-valves or data storage systems.
=== Creationism === Crick was a firm critic of young Earth creationism. In the 1987 United States Supreme Court case Edwards v. Aguillard, Crick joined a group of other Nobel laureates who advised, "'Creation-science' simply has no place in the public-school science classroom." Crick was also an advocate for the establishment of Darwin Day as a British national holiday.
April 27, 1999, A small fan site known as contaminated.net is relaunched as "Planet Half-Life", covering Half-Life and editing resources. November 16, 1999, Major changes to layout and color scheme, plus new sections covering Half-Life: Opposing Force and the announcement of Half-Life 2. December 3, 2000, New sections covering Counter-Strike and Team Fortress Classic. June 19, 2001, New section covering Half-Life: Blue Shift. September 14, 2002, New section covering Day of Defeat. May 24, 2003, Half-Life 2 section re-opens amid rumors of a September 2003 launch and early media releases. July 17, 2003, Major changes to color scheme and graphics in anticipation of Half-Life 2 launch. June 11, 2006, PHLWiki is launched, with bulk of content made up by staff writers prior to public unveiling. September 13, 2006, Complete site format change to accommodate new PNAP article submission system, as well as new color scheme and graphics that were used until the absence of site updating. September 13, 2007, PHL Steam Community officially announced to the public. August 13, 2012, Last entry posted.
The gastroesophageal junction between the esophagus and the stomach is controlled by the lower esophageal sphincter, which remains constricted at all times other than during swallowing and vomiting to prevent the contents of the stomach from entering the esophagus. As the esophagus does not have the same protection from acid as the stomach, any failure of this sphincter can lead to heartburn.
Sources: en.wikipedia.org
The immune system is thought to play an important role in autism. Children with autism have been found by researchers to have inflammation of both the peripheral and central immune systems as indicated by increased levels of pro-inflammatory cytokines and significant activation of microglia. Biomarkers of abnormal immune function have also been associated with increased impairments in behaviors that are characteristic of the core features of autism such as, deficits in social interactions and communication. Interactions between the immune system and the nervous system begin early during the embryonic stage of life, and successful neurodevelopment depends on a balanced immune response. It is thought that activation of a pregnant mother's immune system such as from environmental toxicants or infection can contribute to causing autism through causing a disruption of brain development. This is supported by recent studies that have found that infection during pregnancy is associated with an increased risk of autism. Some evidence suggests that gut–brain axis abnormalities may be involved by means of impaired serotonin signaling and inflammation. A 2015 review proposed that immune dysregulation, gastrointestinal inflammation, autonomic nervous system malfunction, gut microbiota alterations, and food metabolites may cause brain neuroinflammation and dysfunction. A 2016 review concluded that enteric nervous system abnormalities might play a role in neurological disorders such as autism.
== Safety risk == HCPs in biopharmaceutical products pose a potential safety risk to humans by introducing foreign proteins and biomolecules to the human immune system. Since common host cells used to produce biopharmaceutical drugs are E. coli, yeast, mouse myeloma cell line (NS0) and Chinese hamster ovary (CHO), the resultant HCPs are genetically different to what the human body recognizes. As a consequence of this, the presence of HCPs in humans can activate an immune response, which can lead to possibly severe health concerns. There is a correlation between the amount of foreign antigens (HPCs) in our body and the level of immune response our body produces. The more HCPs present in a drug, the higher the immune response that will be activated. Several studies have linked a reduction in HCPs to a decline in specific inflammatory cytokines. Other HCPs may be very similar to a human protein and may induce an immune response with cross reactivity against the human protein or the drug substance protein. The exact consequences of HCPs for an individual patient is uncertain and difficult to determine with the current analytical methods used in biopharmaceutical production and analysis.
== N == N-formylmethionine - N-formylmethionine leucyl-phenylalanine - N-methyl-D-aspartate receptor - N-methylaspartate - N-terminus - NADH - NADPH - NaKATPase - native state - nef gene product - neoplasm protein - Nernst equation - nerve - nerve growth factor - nerve growth factor receptor - nerve tissue protein - nerve tissue protein S 100 - nervous system - neurobiology - neurofilament protein - neurokinin A - neurokinin K - neurokinin-1 receptor - neurokinin-2 receptor - neuron - neuronal cell adhesion molecule - neuropeptide - neuropeptide receptor - neuropeptide Y - neuropeptide Y receptor - neuroscience - neurotensin - neurotensin receptor - neurotransmitter - neurotransmitter receptor - neutral theory of molecular evolution - neutron - neutron activation analysis - NF-kappa B - nicotinic receptor - nitrogen - nitroglycerine - Nobel Prize in Chemistry - non-competitive inhibition - nuclear lamina - nuclear localization signal - nuclear magnetic resonance - NMR - nuclear protein - nucleic acid - nucleic acid regulatory sequence - nucleic acid repetitive sequence - nucleic acid sequence homology - nucleon - nucleophile - nucleoside - nucleosome - nucleotide - nutrition
Sources: en.wikipedia.org
== Adverse effects == The most common adverse effects found in the clinical trials were nausea, headache, diarrhea, vomiting, and dizziness. Tedizolid has also been found to have hematologic (blood) effects, as shown in Phase-I studies in which subjects exposed to doses longer than 6 days showed a possible dose and duration effect on hematologic parameters. Its safety in patients with decreased levels of white blood cells has not been established. Patients on tedizolid are also at low risk of peripheral and optic neuropathy, similar to other members of the oxazolidinone class.
Sometimes I do not understand them their Inca language, I don't know if they are calm or not!""We no longer have to count on the Chileans and Argentines, and these Peruvians are the most miserable men for war. Of course, we must resolve to sustain this fight alone." Hiram Paulding, a US sailor who visited him in his camp in Huaraz, recounts that Bolívar told him that the Peruvians "were cowards and that, as a people, they did not have a single manly virtue. In short, his insults were harsh and unreserved... Then they told me that he always used to speak like that about Peruvians." According to Jorge Basadre, Bolívar's anti-Peruvian feelings would explain his triumphalist proclamations with Colombia, where he declared, after the Battle of Ayacucho, that "The loyalty, perseverance and courage of the Colombian army has done everything". Given this, it has been denounced that Bolívar had a very unpleasant treatment with the Peruvian troops under his command, an example is in a case that occurred with Ramon Castilla, who for trying to prevent a Peruvian cavalry corps from being arbitrarily added to a Gran Colombian unit during the Junín campaign, the young Peruvian soldier would suffer a humiliating insult: the Venezuelans (under the command of Bolívar) would have him put in stocks, and even wanted to shoot him, despite being part of the same side and in combat against the royalists. In the process a duel took place between the Cuiraceros of Peru and the Hussars of Colombia that took place on December 26, 1823.
== Research use == Since C. hemisphaerica passes through planula, polyp, and medusa stages during its life cycle, it is regarded as a good model for studying how one genome can produce variable phenotypes. This is especially useful when considering that two of the more common Cnidarian model organisms, Hydra and Nematostella, do not have the same "complete' life-cycle that alternates between a vegetative polyp and sexually reproducing, free-swimming medusa form. Clytia has characteristics that make it favorable for laboratory culture and experimental manipulation. All stages of Clytia's life cycle can be reproduced under laboratory conditions; polyp colonies, due to their essentially immortal nature, are easily maintained, and adult medusa can be fed with Artemia larvae. Adult male and female medusa spawn daily, and can be entrained with controlled light conditions to spawn at specific times. The oocytes, eggs, embryos, and planulae of Clytia are easily visualized under a microscope and, much like those of popular model organisms like sea urchins, the zygotes of C. hemisphaerica are relatively large (around 200 um in diameter) and can be microinjected to form transgenic planulae, polyp colonies, and medusa. Clytia is also unique in that its gonads can function autonomously; a gonad separated from an adult medusa will undergo oocyte development and ovulation under the same entrained light cues as would a gonad still attached to a medusa.
Sources: en.wikipedia.org
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。
甲硫氨酸侧链含硫醚，在氧气、光照或金属离子存在时容易被氧化。氧化产物极性略增，常在色谱图上表现为主峰之前的肩峰或前伸峰。
通常建议冷藏避光，并在较短时间内使用。不存在适用于所有配方的统一期限，具体取决于浓度、缓冲体系与容器材质。
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.