鼻内给药 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 2025-11-11. Numbers and descriptions here follow the published literature rather than marketing material.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
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。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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。
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。
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。
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
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.
=== R139w === One further single nucleotide polymorphism, found homozygous in 0% to 5% of different ethnic population, is leading to an amino acid exchange on position 139 from arginine to tryptophane. Furthermore, an alternative RNA splicing site is created leading to a loss of the quinone binding site. The variant protein of NQO1*3 has similar stability as its wild-type counterpart. The variation between the two is substrate specific and it has reduced activity for some substrates. It has been recently shown that the NQO1*3 polymorphism may also lead to reduced NQO1 protein expression.
Combination of small size, ease of engineering, high affinity and specificity makes Affibody molecules suitable alternative as monoclonal antibodies for both molecular imaging and therapeutical applications, especially for the receptor-overexpressing tumors. These proteins are characterized by a high rate of extravasation and rapid clearance of non-bound tracer from the circulation, as well as other nonspecific compartments, when compared to antibodies and their fragments
Zverev is a baseline counterpuncher who relies on his massive serve and powerful backhand. He is able to hit strong groundstrokes to open the court, and finish points effectively at the net. Although his height slows him down on the court, it also adds to his reach and gives him the ability to get more balls back in play. Novak Djokovic has commented, "He moves well for his height." His backhand, in particular, is regarded as his strength and one of the best in the game. He can generate a lot of power off it with high accuracy, and his ability to absorb pace makes it one of the best shots in the modern game for both attack and defense. He often uses a semi-open stance and employs a western grip on his forehand. He has a continental-eastern grip on his backhand. Zverev can also slice his backhands that require a low centre of gravity, despite his height. He is often criticized for being too passive in the big moments. With Zverev's height of 1.98 metres (6 ft 6 in), he can generate big serves at 220 kilometres per hour (140 mph) or faster at sharper angles than shorter players. The year Zverev first broke into the top 20, he was still not one of the better servers on tour, ranking just 38th in serve rating. This was well behind him ranking 18th in return rating, showing that his return game was much stronger than his serving. By 2018, he had improved in both categories, ranking 19th in serve rating and 8th in return rating. Zverev excels in particular at hitting a high percentage of first serves in, landing 64.2% in 2018.
Sources: en.wikipedia.org
(in French) Stéphane Sawas, «Entre amnésie collective et mémoire retrouvée: La guerre civile grecque au cinéma,» [Between Collective Amnesia and Rediscovered Memory: The Greek Civil War in Cinema] dans Carola Hähnel-Mesnard, Marie Liénard-Yeterian, et Cristina Marinas, directeurs de publication, Culture et mémoire: Représentations contemporaines de la mémoire dans les espaces mémoriels, les arts du visuel, la littérature et le théâtre [Culture and Memory: Contemporary Representations of Memory in Memorial Spaces, Visual Arts, Literature and Theater], Paris, Éditions de l'École Polytechnique et Éditions Ellipses, 2008, 534 pages, ISBN 978-2-7302-1492-6. (in French) Γιάννης Σολδάτος [Yannis Soldatos], Ιστορία του ελληνικού κινηματογράφου [History of Greek Cinema, tr. Istoría tou ellinikoú kinimatográfou], Β' Τόμος: 1967–1990, Αθήνα, Αιγόκερως, 2002, 383 σελίδες, ISBN 960-322-124-4. (in Greek)
On the other hand, hybrids of tomato and diploid potato can be created in the lab by somatic fusion, and are partially fertile, providing evidence of the close relationship between these species. Newer genomic studies have found that the tomato and the potato are very close relatives, forming a tight clade within Solanum. A 2025 study suggests that the potato lineage may have been created by hybridization of a plant from the tomato lineage (not necessarily the modern tomato species) with a plant from the S. etuberosum lineage.
It will however, place its current focus on following the sale, to operate its other retail businesses in Singapore, primarily focusing on 7-Eleven (convenience stores) and Guardian (health and beauty stores).
=== Biological characteristics === Its rapid growth and its ability to reproduce from buried rhizomes and tubers facilitates the Jerusalem artichoke's uncontrolled spread. The vegetative propagules can be transported via rivers and water streams and begin a new population on riverbanks. Dispersal by animal is also possible, as animals feed on tubers and rhizomes and excrete the propagules in new areas. With humans' cultivation, there is also a risk of the plant's unintended escape into the wild. It can also be propagated by seed. Its relatively long flower period enables the Jerusalem artichoke to increase its reproductive potential.
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.