ACTH analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-02-03. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
| 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 |
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
==== Base-specific cleavage/MALDI-TOF ==== A recently described method by Ehrich et al. further takes advantage of bisulfite-conversions by adding a base-specific cleavage step to enhance the information gained from the nucleotide changes. By first using in vitro transcription of the region of interest into RNA (by adding an RNA polymerase promoter site to the PCR primer in the initial amplification), RNase A can be used to cleave the RNA transcript at base-specific sites. As RNase A cleaves RNA specifically at cytosine and uracil ribonucleotides, base-specificity is achieved by adding incorporating cleavage-resistant dTTP when cytosine-specific (C-specific) cleavage is desired, and incorporating dCTP when uracil-specific (U-specific) cleavage is desired. The cleaved fragments can then be analyzed by MALDI-TOF. Bisulfite treatment results in either introduction/removal of cleavage sites by C-to-U conversions or shift in fragment mass by G-to-A conversions in the amplified reverse strand. C-specific cleavage will cut specifically at all methylated CpG sites. By analyzing the sizes of the resulting fragments, it is possible to determine the specific pattern of DNA methylation of CpG sites within the region, rather than determining the extent of methylation of the region as a whole. This method demonstrated efficacy for high-throughput screening, allowing for interrogation of numerous CpG sites in multiple tissues in a cost-efficient manner.
The best-known practitioner in this genre was the English taxidermist Walter Potter, whose most famous work was The Death and Burial of Cock Robin. Among his other scenes were "a rat's den being raided by the local police rats ... [a] village school ... featuring 48 little rabbits busy writing on tiny slates, while the Kittens' Tea Party displayed feline etiquette and a game of croquet." Apart from the simulations of human situations, he had also added examples of bizarrely deformed animals such as two-headed lambs and four-legged chickens. Potter's museum was so popular that an extension was built to the platform at Bramber railway station. Other Victorian taxidermists known for their iconic anthropomorphic taxidermy work are William Hart and his son Edward Hart. They gained recognition with their famous series of dioramas featuring boxing squirrels. Both William and Edward created multiple sets of these dioramas. One 4-piece set of boxing squirrel dioramas (circa 1850) sold at auction in 2013 for record prices. The four dioramas were created as a set (with each diorama portraying the squirrels at a different stage during their boxing match); however, the set was broken up and each was sold separately at the same auction. The set was one of a number they created over the years featuring boxing squirrels.
== Controversies == Following a shortage that led a court to delay an execution in California, a company spokesman for Hospira, the sole American manufacturer of the drug, objected to the use of thiopental in lethal injection. "Hospira manufactures this product because it improves or saves lives, and the company markets it solely for use as indicated on the product labeling. The drug is not indicated for capital punishment and Hospira does not support its use in this procedure." On January 21, 2011, the company announced that it would stop production of sodium thiopental from its plant in Italy, because it could not provide Italian authorities with guarantees that exported doses would not be used in executions. According to a company spokesperson, Italy was the only viable place where it could produce the drug, leaving the US without a supplier. In October 2015 the US Food and Drug Administration (FDA) confiscated an overseas shipment of thiopental destined for the states of Arizona and Texas. The FDA said in a statement, "Courts have concluded that sodium thiopental for the injection in humans is an unapproved drug and may not be imported into the country".
Afamelanotide (brand name Scenesse) has been approved for the treatment of erythropoietic protoporphyria in Europe and is also being investigated as a method of photoprotection in the treatment of polymorphous light eruption, actinic keratosis and squamous cell carcinoma (a form of skin cancer). An additional analogue called melanotan II causes enhanced libido and erections in most male test subjects and arousal with corresponding genital involvement in most female test subjects. Bremelanotide (formerly PT-141) which stemmed from melanotan II research is currently under development for its aphrodisiac effects. These effects are mediated by actions in the hypothalamus on neurons that express MC3 and MC4 receptors.
Sources: en.wikipedia.org
==== P-51 introduction ==== The P-51 Mustang was a solution to the need for an effective bomber escort. It used a common, reliable engine and had internal space for a larger-than-average fuel load. With external fuel tanks, it could accompany the bombers from England to Germany and back. By the time the Pointblank offensive resumed in early 1944, matters had changed. Bomber escort defenses were initially layered, using the shorter-range P-38s and P-47s to escort the bombers during the initial stages of the raid before handing over to the P-51s when they were forced to turn for home. This provided continuous coverage during the raid. The Mustang was so clearly superior to earlier US designs that the 8th Air Force began to steadily switch its fighter groups to the Mustang, first swapping arriving P-47 groups to the 9th Air Force in exchange for those that were using P-51s, then gradually converting its Thunderbolt and Lightning groups. By the end of 1944, 14 of its 15 groups flew Mustangs.
=== Mechanical lysis === Mechanical lysis involves the use of physical force, such as grinding or sonication, to break down bacterial cells and release the plasmid DNA. There are several different mechanical lysis methods that can be used, including French press, bead-beating, and ultrasonication.
== Treatment == There is no cure for McLeod syndrome; the treatment is supportive depending on symptoms. Medication may assist with management of epilepsy, and cardiac and psychiatric features, although patients may respond poorly to treatment for chorea.
Sources: en.wikipedia.org
=== Wound healing === Research on novel drug formulations for the delivery of doxycycline in wound treatment is expanding, focusing on overcoming stability limitations for long-term storage and developing consumer-friendly, parenteral antibiotic delivery systems. The most common and practical form of doxycycline delivery is through wound dressings, which have evolved from mono- to three-layered systems to maximize healing effectiveness. Research directions on the use of doxycycline in wound healing include the continuous stabilization of doxycycline, scaling up technology and industrial production, and exploring non-contact wound treatment methods like sprays and aerosols for use in emergencies and when medical care is not readily accessible.
While tyrosine phosphorylation is found in relatively low abundance, it is well studied due to the ease of purification of phosphotyrosine using antibodies. Receptor tyrosine kinases are an important family of cell surface receptors involved in the transduction of extracellular signals such as hormones, growth factors, and cytokines. Binding of a ligand to a monomeric receptor tyrosine kinase stabilizes interactions between two monomers to form a dimer, after which the two bound receptors phosphorylate tyrosine residues in trans. Phosphorylation and activation of the receptor activates a signaling pathway through enzymatic activity and interactions with adaptor proteins. Signaling through the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, is critical for the development of multiple organ systems including the skin, lung, heart, and brain. Excessive signaling through the EGFR pathway is found in many human cancers.
=== Stockfish === Stockfish is unsalted fish, especially cod, dried by cold air and wind on wooden racks on the foreshore. The drying racks are known as fish flakes. Cod is the most common fish used in stockfish production, though other whitefish, such as pollock, haddock, ling and cusk, are also used.
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 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.