This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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。
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。
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
| 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 |
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
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.
=== Biochemistry === Several studies have suggested that vanillin can affect the performance of antibiotics in laboratory conditions. Vanillin–HCl staining can be used to visualize the localisation of tannins in cells.
=== Neurotransmitters === T3 may increase serotonin in the brain, in particular in the cerebral cortex, and down-regulate 5HT-2 receptors, based on studies in which T3 reversed learned helplessness in rats and physiological studies of the rat brain.
In Australia, diamorphine is listed as a schedule 9 prohibited substance under the Poisons Standard (October 2015). The state of Western Australia, in its Poisons Act 1964 (Reprint 6: amendments as at 10 September 2004), described a schedule 9 drug as: "Poisons that are drugs of abuse, the manufacture, possession, sale or use of which should be prohibited by law except for amounts which may be necessary for educational, experimental or research purposes conducted with the approval of the Governor."
For the above reasons, the demand for in-situ analysis is increasing. In-situ means analyzing monazite grains in their original host rocks without separation (refer to in situ) such that the texture and zonation pattern are kept intact in order to reveal a more comprehensive geological history of the host rock. Direct sampling techniques, high spatial resolution and precision are required for in-situ analysis. With technological advancement, more and more measurement tools such as laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and laser microprobe mass spectrometer (LMMS) are capable of such analysis.
Sources: en.wikipedia.org
=== Approval of discoveries === In December 2015, the conclusions of a new JWP report were published by IUPAC in a press release, in which element 113 was awarded to Riken; elements 115, 117, and 118 were awarded to the collaborations involving the JINR. A joint 2016 announcement by IUPAC and IUPAP had been scheduled to coincide with the publication of the JWP reports, but IUPAC alone decided on an early release because the news of Riken being awarded credit for element 113 had been leaked to Japanese newspapers. For the first time in history, a team of Asian physicists would name a new element. The JINR considered the awarding of element 113 to Riken unexpected, citing their own 2003 production of elements 115 and 113, and pointing to the precedents of elements 103, 104, and 105 where IUPAC had awarded joint credit to the JINR and LBNL. They stated that they respected IUPAC's decision, but reserved determination of their position for the official publication of the JWP reports. The full JWP reports were published on 21 January 2016. The JWP recognised the discovery of element 113, assigning priority to Riken. They noted that while the individual decay energies of each nuclide in the decay chain of 278113 were inconsistent, their sum was now confirmed to be consistent, strongly suggesting that the initial and final states in 278113 and its daughter 262Db were the same for all three events. The decay of 262Db to 258Lr and 254Md was previously known, firmly anchoring the decay chain of 278113 to known regions of the chart of nuclides.
== Preparation == The dessert is commonly made by taking a scoop of ice cream frozen well below the temperature at which ice cream is generally kept, possibly coating it in raw egg, rolling it in cornflakes or cookie crumbs, and briefly deep frying it. The extremely low temperature of the ice cream prevents it from melting while being fried. It may be sprinkled with cinnamon and sugar and a touch of peppermint; whipped cream or honey may be used, as well.
The Wagler's pit viper is sexually dimorphic: the females grow to approximately 1 m (39+1⁄4 in) in total length (including tail), their bodies being black with yellow stripes. Males, on the other hand, typically do not exceed 75 cm (29+1⁄2 in). Males have large triangular-shaped heads, with relatively thin green bodies. They are almost entirely arboreal, and their tails are prehensile to aid in climbing. They are found in a wide variety of colors and patterns, often referred to as "phases". In the past, some researchers classified the different phases as subspecies. The phases vary greatly from having a black or brown coloration as a base, with orange and yellow banding, to others having a light green as the base color, with yellow or orange banding, and many variations therein.
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。
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.