A practical reference on Semax: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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。
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
| 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 |
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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.
Only 231Pa and 234Pa have been found in nature. All the isotopes have short lifetimes, except for protactinium-231 (half-life 32,760 years). The most important isotopes are 231Pa and 233Pa, which is an intermediate product in obtaining uranium-233 and is the most affordable among artificial isotopes of protactinium. 233Pa has convenient half-life and energy of γ-radiation, and thus was used in most studies of protactinium chemistry. Protactinium-233 is a β-emitter with a half-life of 26.97 days. There are 27 known isotopes of uranium, having mass numbers 215–242 (except 220). Three of them, 234U, 235U and 238U, are present in appreciable quantities in nature. Among others, the most important is 233U, which is a final product of transformation of 232Th irradiated by slow neutrons. 233U has a much higher fission efficiency by low-energy (thermal) neutrons, compared e.g. with 235U. Most uranium chemistry studies were carried out on uranium-238 owing to its long half-life of 4.4×109 years. There are 25 isotopes of neptunium with mass numbers 219–244 (except 221); they are all highly radioactive. The most popular among scientists are long-lived 237Np (t1/2 = 2.20×106 years) and short-lived 239Np, 238Np (t1/2 ~ 2 days). There are 21 known isotopes of plutonium, having mass numbers 227–247. The most stable isotope of plutonium is 244Pu with half-life of 8.13×107 years. Eighteen isotopes of americium are known with mass numbers from 229 to 247 (with the exception of 231).
1996: Insulin lispro, which was originally manufactured by Eli Lilly and Company, is granted approval. 2000: Insulin aspart, which was created by Novo Nordisk, is approved. 2000: Insulin glargine, which was developed by Sanofi-Aventis, is approved. 2004: Insulin glulisine, also developed by Sanofi-Aventis, is approved. 2005: Insulin detemir, which was formulated by Novo Nordisk, gets approval. 2015: Insulin degludec, created by Novo Nordisk, is approved. 2020: Insulin lispro-aabc, a faster insulin lispro formulation created by Eli Lilly and Company, is approved. 2021: Insulin glargine-yfgn, the first approved insulin biosimilar, which is produced by Viatris, is approved. 2021: Insulin glargine-aglr, a biosimilar produced by Eli Lilly and Company, is granted approval. 2024: Insulin icodec, the newest commercially available analogue by Novo Nordisk, gets approval. 2025: Insulin aspart-szjj, the first short-acting biosimilar, created by Viatris, is approved.
The cable sent from NATO headquarters on 11 August 2008 said that "A number of Allies - especially Germany - are parroting Russian points on Georgian culpability for the crisis" and "intelligence releasable to NATO Allies on this point might be a useful tool" to counter these allegations. One cable reported on 14 August: "Merabishvili told us that the escalation of the conflict occurred after the villages of Nuli and Avnevi were destroyed. Since OSCE observers were hunkered down in Tskhinvali, they could not hear the bombing in Avnevi". The cable reported on 15 August that Ainārs Šlesers, Latvian minister of transport, who suggested that Saakashvili was guilty for the war, made money on deals involving Russia. Russian ambassador to Latvia appealed to business interests of Latvian politicians to prevent sanctioning of Russia.
In 2015 fire and heat resulted in 67 million injuries. This resulted in about 2.9 million hospitalizations and 238,000 dying. This is down from 300,000 deaths in 1990. This makes it the fourth leading cause of injuries after motor vehicle collisions, falls, and violence. About 90% of burns occur in the developing world. This has been attributed partly to overcrowding and an unsafe cooking situation. Overall, nearly 60% of fatal burns occur in Southeast Asia with a rate of 11.6 per 100,000. The number of fatal burns has decreased from 280,000 in 1990 to 176,000 in 2015. In the developed world, adult males have twice the mortality as females from burns. This is most probably due to their higher risk occupations and greater risk-taking activities. In many countries in the developing world, however, females have twice the risk of males. This is often related to accidents in the kitchen or domestic violence. In children, deaths from burns occur at more than ten times the rate in the developing than the developed world. Overall, in children it is one of the top fifteen leading causes of death. From the 1980s to 2004, many countries have seen both a decrease in the rates of fatal burns and in burns generally.
Sources: en.wikipedia.org
In 1997, Freeman narrated the Academy Award-winning documentary The Long Way Home, about Jewish refugees' liberation after World War II and the establishment of Israel. He also appeared in Steven Spielberg's historical epic Amistad alongside Djimon Hounsou, Anthony Hopkins, and Matthew McConaughey. Based on the events in 1839 aboard the slave ship La Amistad, the film was mostly well-received and earned four nominations at the Academy Awards. The critic from Salon magazine, however, thought the film lacked inspiration and Freeman's role was "utterly cryptic". In that same year, he was cast as psychologist Alex Cross in Kiss the Girls, a thriller based on James Patterson's 1995 novel of the same name. In a mixed review, Peter Stack of San Francisco Chronicle thought Freeman and co-star Ashley Judd gave strong performances despite the lengthy plot. Freeman went on to star in Deep Impact (1998), a science-fiction disaster film in which he played President Tim Beck. The story depicts humanity's attempt to destroy a 7-mile (11 km) wide comet set to collide with Earth and cause a mass extinction. The film was a box-office hit, despite competition from Armageddon, another summer blockbuster of the year. Continuing with the disaster genre, he then starred opposite Christian Slater in 1998's Hard Rain, centering on a heist and man-made treachery amidst a natural disaster in a small Indiana town. The film was unpopular with critics; Lawrence Van Gelder of The New York Times called the characters "one-dimensional" and the film "routine".
Birch wood is fine-grained and pale in colour, often with an attractive satin-like sheen. Ripple figuring may occur, increasing the value of the timber for veneer and furniture-making. The highly decorative Masur (or Karelian) birch, from Betula verrucosa var. carelica, has ripple textures combined with attractive dark streaks and lines. Birch plywood is made from laminations of birch veneer. It is light but strong, and has many other good properties. It is among the strongest and dimensionally most stable plywoods, although it is unsuitable for exterior use. Birch plywood is used to make longboards (skateboard), giving it a strong yet flexible ride. It is also used (often in very thin grades with many laminations) for making model aircraft. Birch wood is often used in the manufacture of popsicle sticks due to its durability, smoothness and neutral flavour. Extracts of birch are used for flavoring and leather oil, and in cosmetics such as soap and shampoo. In the past, commercial oil of wintergreen (methyl salicylate) was made from the sweet birch (Betula lenta). Birch-tar or Russian oil extracted from birch bark is thermoplastic and waterproof; it was used as a glue on, for example, arrows, and also for medicinal purposes. Fragrant twigs of wintergreen group birches are used in saunas. Birch is also associated with the feast of Pentecost in Central and Eastern Europe and Siberia, where its branches are used as decoration for churches and homes on this day.
=== Ca2+ storage === An indirect means of inhibiting NAADP action is to deplete its target Ca2+ stores. As noted above, this usually entails collapsing the H+ gradient with either V-ATPase inhibitors (e.g. Bafilomycin A1) or protonophores (e.g. nigericin or monensin). In platelets it has been suggested that SERCA3 inhibition with tBHQ can also abrogate NAADP-dependent signals.
Sources: en.wikipedia.org
== Biography == Frederick Sachs was born on January 8, 1941. He grew up on a farm in Hudson Valley, where he learned how to milk cows, raise chickens, and pigs. He completed his Bachelor of Arts degree in physics from the University of Rochester in 1962 and his PhD in physiology at the State University of New York Upstate Medical University in 1971. Sachs died in Buffalo, New York, on December 27, 2023, at the age of 82.
Research on the viability of this new technique, as well as many others, as a means of monitoring the levels of rBST in dairy cattle continues to be an issue of practicality, profitability, and humaneness towards livestock in the dairy industry.
The enlisted corps ranks were: private, noncommissioned officers, and officers. The private classes were: jōtō-hei or upper soldier, ittō-sotsu or first-class soldier, and nitō-sotsu or second-class soldier. The noncommissioned officer class ranks were: gochō or corporal, gunsō or sergeant, sōchō or sergeant major, and tokumu-sōchō or special sergeant major.
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。
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.