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 2026-06-03 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。
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.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
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.
| 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 |
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
Systematizing, naming and classifying dominated natural history throughout much of the 17th and 18th centuries. Carl Linnaeus published a basic taxonomy for the natural world in 1735 (variations of which have been in use ever since), and in the 1750s introduced scientific names for all his species. While Linnaeus conceived of species as unchanging parts of a designed hierarchy, the other great naturalist of the 18th century, Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Though he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought; his work would influence the evolutionary theories of both Lamarck and Darwin. The discovery and description of new species and the collection of specimens became a passion for researchers and explorers, in addition to becoming a lucrative business for entrepreneurs. Many naturalists travelled the globe in search of scientific knowledge and adventure.
=== Androgen signaling === The androgen response mechanism involves androgens binding to androgen receptors in the cytoplasm, which then move into the nucleus and control gene transcription by interacting with specific DNA regions called androgen response elements. This response mechanism is involved in male sexual differentiation and puberty, as well as other tissue types and processes, such as the prostate gland (regulate secretory functions), hair follicles (androgens influence hair growth patterns), skin (androgens regulate sebum production and the thickening and maturation of the skin), and muscle (contribute to the development and maintenance of muscle mass and strength). Such tissues, where androgens exert their effects, are called 'androgen target tissues'. Different androgens have different effects on androgen receptors because they have different degrees of binding and activating the receptors. Physiologically significant androgens are those androgens that have a strong influence on the development and functioning of male sexual characteristics, unlike physiologically insignificant androgens, which have low biological activity or are quickly metabolized into other steroids. Physiologically insignificant androgens do not have a notable influence on the development and functioning of male or female sexual characteristics, they can be products of the metabolism of more active androgens, such as testosterone (T), or their precursors.
=== Coat length === Medical students in their first year of residency traditionally wear a shorter coat that reaches only to the hips. This is done so that medical staff can identify first-year residents at a glance, as they may need additional help from senior staff. Residents in their second year and up wear a traditional knee-length coat.
Nicomorphine (Vilan, Subellan, Gevilan, MorZet) is the 3,6-dinicotinate ester of morphine. It is a strong opioid agonist analgesic two to three times as potent as morphine with a side effect profile similar to that of dihydromorphine, morphine, and diamorphine. Nicomorphine was first synthesized in 1904 and was patented as Vilan by Lannacher Heilmittel G.m.b.H. of Austria in 1957.
Sources: en.wikipedia.org
=== Freeze drying === In planning for the long-duration Apollo missions, NASA conducted extensive research into space food. One of the techniques developed in 1938 by Nestlé was freeze drying. The foods are cooked, quickly frozen, and then slowly heated in a vacuum chamber to remove the ice crystals formed by the freezing process. The final product retains 98% of its nutrition and weighs much less than before drying. The ratio of weight before and after drying depends strongly on the particular food item but a typical freeze-dried weight is 20% of the original weight. In the United States, Action Products later commercialized this technique for other foods, concentrating on snack food resulting in products like Space ice cream. Today, one of the benefits of this advancement in food preservation includes simple, nutritious meals available to disabled and otherwise homebound senior adults unable to take advantage of existing meal programs.
The British Lions were regular visitors to South Africa until the 1980s, and the less formally segregated colony long before that. They would alternate these tours with tours to Australia and/or New Zealand. In the years 1948–1980, the Lions made five tours to South Africa, more or less one for every decade, and half of their total ten tours in this period. Their first tour in the apartheid period was in 1955, seven years after the formal inauguration of apartheid. They made further tours in 1962, 1968, 1974 and one final one in 1980. The controversy caused by this matter meant that the Lions did not go back there until their 1997 tour when the South Africa team was ostensibly mixed. The Lions would have toured South Africa in 1986 if the regular schedule had been kept to, but in December 1985 the South African Rugby Board announced they would not be inviting the Lions to tour the following year. Political objections to South Africa's apartheid policies including a potential boycott of the 1986 Commonwealth Games and state of emergency in South Africa at the time lay behind this decision. The squad selected for an International Rugby Board centenary match was the closest thing to an official 1986 British Lions side. It was managed by Clive Rowlands and coached by Mick Doyle. The 21 players selected were issued with Lions' blazers and ties and considered to be official British Lions.
His Russian handlers intercept him after tracing his burner phone and force him to proceed with the takeover attempt. As investigations mount, Whitney contacts Henry and urges him to flee with him to Lithuania, revealing the Russians' involvement in Tender; Henry refuses and leaves him. Some time later, news reports state that Interpol is still looking for Whitney. A single frame of Whitney flashes onscreen right before the end credits of the series 4 finale; series creators Mickey Down and Konrad Kay revealed in an interview that the shot was from a deleted scene of Whitney at a club in Lithuania, looking through a glory hole, in a scene similar to his night out with Henry.
Sources: en.wikipedia.org
=== Awards and honours === As of 2015, Sanger is one of the only two people to have been awarded the Nobel Prize in Chemistry twice (the other being Karl Barry Sharpless in 2001 and 2022), and one of only five two-time Nobel laureates: The other four were Marie Curie (Physics, 1903 and Chemistry, 1911), Linus Pauling (Chemistry, 1954 and Peace, 1962), John Bardeen (twice Physics, 1956 and 1972), and Karl Barry Sharpless (twice Chemistry, 2001 and 2022).
=== Military legacy === The war was the harbinger of a new type of combat: guerrilla warfare. The counterinsurgency techniques and lessons learned (restriction of movement, containment of space, targeting of anything that could give sustenance to guerrillas, harassment through sweeper groups coupled with rapid reaction forces, sourcing and co-ordination of intelligence, and nurturing of native allies) were used by the British, and other forces, in future guerrilla campaigns including to counter Malayan communist rebels during the Malayan Emergency. In World War II the British adopted concepts of raiding from the Boer commandos when they set up special raiding forces, and in acknowledgement chose the name British Commandos.
Hydrophobins have been found to be structurally and functionally similar to cerato-platanins, another group of small cysteine-rich proteins, which also contain a high percentage of hydrophobic amino acids, and are also associated with hyphal growth. This family of proteins includes the rodlet proteins of Neurospora crassa (gene eas) and Emericella nidulans (gene rodA), these proteins are the main component of the hydrophobic sheath covering the surface of many fungal spores. Genomic sequencing of two fungi from dry or salty environments (Wallemia sebi and W. ichthyophaga) revealed that these species contain predicted hydrophobins with unusually high proportion of acidic amino acids and therefore with potentially novel characteristics. High proportion of acidic amino acids is thought to be an adaptation of proteins to high concentrations of salt.
If an adsorbate molecule enters the precursor state at a location that is remote from any other previously adsorbed adsorbate molecules, the sticking probability is reflected by the size of the SD constant. These factors were included as part of a single constant termed a "sticking coefficient", kE, described below:
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。
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.