A practical reference on intranasal route: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-06. Anything still debated is marked as such rather than presented as settled.
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
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.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
I hated authority like hell." From 1964 to 1965, Biko studied at St. Francis College, a Catholic boarding school in Mariannhill, Natal. The college had a liberal political culture, and Biko developed his political consciousness there. He became particularly interested in the replacement of South Africa's white minority government with an administration that represented the country's black majority. Among the anti-colonialist leaders who became Biko's heroes at this time were Algeria's Ahmed Ben Bella and Kenya's Jaramogi Oginga Odinga. He later said that most of the "politicos" in his family were sympathetic to the PAC, which had anti-communist and African racialist ideas. Biko admired what he described as the PAC's "terribly good organisation" and the courage of many of its members, but he remained unconvinced by its racially exclusionary approach, believing that members of all racial groups should unite against the government. In December 1964, he travelled to Zwelitsha for the ulwaluko circumcision ceremony, symbolically marking his transition from boyhood to manhood.
=== Intrinsically disordered proteins === Using a method for the rapid and multiplexed gene synthesis of repetitive polypeptides, Chilkoti created new variants of ELPs that show phase separation. He then built upon these findings to identify new sequence heuristics that enable the de novo design of repetitive polypeptides that show LCST and UCST phase behavior. He postulated that the low sequence complexity, structural disorder, and phase separation behavior of these repetitive polypeptides make them an interesting class of minimal synthetic intrinsically disordered proteins IDPs (synIDPs), and suggested that these SynIDPs can provide insights into the behavior of other more complex, native IDPs. His group has started to exploit the phase transition behavior of two classes of SynIDPs—ELPs that exhibit LCST phase behavior and resilin-like polypeptides (RLPs) that exhibit UCST phase behavior—to create artificial condensates within cells whose material properties and function can be precisely programmed at the sequence level of the SynIDP to reprogram cellular function by spatio-temporally controlling the flow genetic information and biochemical signals within the cell. His later work on functional artificial condensates of SynIDPs in cells includes sequestration of mRNA in a condensate regulate protein translation, sequestration of an enzyme in an artificial condensate to amplify its activity, sequestration of a plasmid to control gene flow in bacteria and recruitment of the transcriptional machinery to amplify gene expression.
The New York Times described Harris's economic policy as embracing "the idea that the federal government must act aggressively to foster competition and correct distortions in private markets". Harris proposed raising taxes on corporations and high-earners to fund services for the lower and middle classes and reduce the deficit. Harris stated she supported increasing the top tier capital gains tax rate to 28%, up from 20% and lower than Biden's proposed 39.6%. Harris stated her support for a Billionaire Minimum Income Tax, increasing the tax on stock buybacks to 4%, and a ten-fold tax reduction for small business ranging from $5,000 to $50,000 in relief. Harris also supported efforts to create a tax on unrealized gains for those with more than a $100 million in net worth if they do not pay a minimum 25% tax rate on their income inclusive of unrealized gains so long as 80% of said wealth is in tradeable assets. The plan would impact a small percentage of the wealthy in the United States, and Axios reported most tech founders and investors would be spared. Harris also announced support for restoring the corporate tax rate to 28% among several other tax proposals to raise taxes and close loopholes for corporations and the wealthy that would bring in $5 trillion in additional revenue over 10 years. Harris proposed tax breaks to companies delivering economic benefit, such as manufacturing technologies that mitigate climate change and building affordable housing, and proposed a ban on corporate price gouging to "help the food industry become more competitive".
Sources: en.wikipedia.org
== Structural properties == Traditionally, PPII has been considered to be relatively rigid and used as a "molecular ruler" in structural biology, e.g., to calibrate FRET efficiency measurements. However, subsequent experimental and theoretical studies have called into question this picture of a polyproline peptide as a "rigid rod". Further studies using terahertz spectroscopy and density functional theory calculations highlighted that polyproline is in fact much less rigid than originally thought. Interconversions between the PPII and PPI helix forms of poly-proline are slow, due to the high activation energy of X-Pro cis-trans isomerization (Ea ≈ 20 kcal/mol); however, this interconversion may be catalyzed by specific isomerases known as prolyl isomerases or PPIases. The interconversion between the PPII and PPI helices involve the cis-trans peptide bond isomerization along the whole peptide chain. Studies based on ion-mobility spectrometry revealed existence of a defined set of intermediates along this process.
A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle cramp which is accompanied by a sudden burst of pain. A muscle cramp is usually harmless and ceases after a few minutes. It is typically caused by ion imbalance or muscle fatigue. There are other causes of involuntary muscle contractions, and some of these may cause a health problem.
The first writer to advocate a lectin-free diet was Peter J. D'Adamo, a naturopath best known for promoting the blood type diet. He argued that lectins may damage a person's blood type by interfering with digestion, food metabolism, hormones, insulin production—and so should be avoided. D'Adamo provided no scientific evidence nor published data for his claims, and his diet has been criticized for making inaccurate statements about biochemistry. Steven Gundry proposed a lectin-free diet in his book The Plant Paradox (2017). It excludes a large range of commonplace foods including whole grains, legumes, and most fruit, as well as the nightshade vegetables: tomatoes, potatoes, eggplant, bell peppers, and chili peppers. Gundry's claims about lectins are considered pseudoscience. His book cites studies that have nothing to do with lectins, and some that show—contrary to his own recommendations—that avoiding the whole grains wheat, barley, and rye will allow increase of harmful bacteria while diminishing helpful bacteria.
Sources: en.wikipedia.org
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。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.