If you have been reading about 肽纯度 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-27. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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。
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.
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.
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。
Myomesin plays an important role in the structure of sarcomeres. They are found in the M-band region of the sarcomere, between the thick filaments (myosin). Its main purpose in this setting is to provide structural integrity by linking the antiparallel myosin fibers and titin filaments which are connected to the Z-discs. These myosin filaments form a hexagonal lattice with titin and myomesin. This shape allows the M-band to withstand large conformational changes during muscle contraction and return to their original shape upon relaxation. Since the Z-disc region of the sarcomere is very stiff and unable to bend for contraction, the elastic activity of myomesin in the M-band is what makes muscle contraction possible as it acts as a molecular spring.
== Treatment == Symptomatic treatment usually involves analgesics for both cranial and spinal CSF leaks. Initial measures can include rest, caffeine intake (via coffee or intravenous infusion), and hydration. Corticosteroids may provide transient relief for some patients. An abdominal binder, which increases intracranial pressure by compressing the abdomen, can temporarily relieve symptoms for some people. Sometimes a CSF leak will heal on its own. Otherwise, symptoms may last months or even years.
Arginine:glycine amidinotransferase deficiency or AGAT deficiency is an autosomal recessive cerebral creatine deficiency caused by a deficiency of the enzyme arginine:glycine amidinotransferase. This enzyme deficiency results in decreased creatine synthesis, and is caused by biallelic pathogenic variants in GATM. Individuals with AGAT deficiency are intellectually disabled and have muscle weakness. The symptoms of AGAT deficiency are caused by the lack of creatine in specific tissues, most notably muscle and brain. Oral creatine supplementation can be used to treat AGAT deficiency, with early intervention providing the best results. All creatine deficiencies are rare, and there have been fewer than 20 individuals reported in medical literature with AGAT deficiency. This disorder was first described in 2000.
=== Adrenomedullin receptor === CALCRL binds Ramp2 to form the adrenomedullin receptor 1 (AM1), while it binds Ramp3 to form adrenomedullin receptor 2 (AM2). Adrenomedullin is a multifunctional 52 amino acid peptide widely expressed throughout the body. Its most prominent functions include regulation of blood pressure, endothelial barrier development and stability, and inflammation. Administration of adrenomedullin causes vasodilation and decreased blood pressure via binding to its receptors.
Sources: en.wikipedia.org
Myocardial infarction (MI) refers to tissue death (infarction) of a part of the heart muscle (myocardium), caused by ischemia, the lack of oxygen delivery to myocardial tissue. It is a type of acute coronary syndrome, which describes a sudden or short-term change in symptoms related to blood flow to the heart. Unlike the other type of acute coronary syndrome, unstable angina, a myocardial infarction occurs when there is cell death, which can be estimated by a blood test that measures biomarkers (the cardiac protein troponin). When there is evidence of an MI, it may be classified as an ST elevation myocardial infarction (STEMI) or non-ST elevation myocardial infarction (NSTEMI) based on the results of an ECG. Another approach suggests categorizing MI as either occlusion myocardial infarction (OMI) or non-occlusion myocardial infarction (NOMI), depending on evidence of coronary occlusion on ECG. Preliminary research suggests that using OMI/NOMI above STEMI/NSTEMI leads to improved clinical outcomes, as such terminology does not limit the diagnosis of acute coronary occlusion to current STEMI criteria, which alone have poor sensitivity for MI. The phrase "heart attack" is often used non-specifically to refer to myocardial infarction. An MI is different from—but can cause—cardiac arrest, where the heart is not contracting at all or so poorly that all vital organs cease to function, thus leading to death. It is also distinct from heart failure, in which the pumping action of the heart is impaired. However, an MI may lead to heart failure.
Adatlap a Magyar Tudományos Akadémia honlapján részletes publikációs listával Szakmai életrajz a drugdesign.hu-n Szakmai életrajz a vichem.hu-n Gábor Dénes-díjasok Klubjának honlapja Semmelweis Hírek: Dr. Kéri György akadémiai kutatócsoportja Novofer Alapítvány: Dr. Kéri György Magyar Tudomány, 2004/1 70. o.
== Description == Mikania micrantha has ribbed stems that grow up to 6 metres (20 ft) in length with 4–13-centimetre (1.6–5.1 in) long leaves that have a heart-shaped base and a pointed apex. 4.5–6.0-millimetre (0.18–0.24 in) white flowers grow in clusters.
24 November – Colin Renfrew, Baron Renfrew of Kaimsthorn, 87, British archaeologist, academic and peer, member of the House of Lords (1991–2021). 1 December – Sir Richard Carew Pole, 13th Baronet, 85, British aristocrat. 2 December – Rosalie Wilkins, Baroness Wilkins, 78, British politician, member of the House of Lords (1999–2015). (death announced on this date) 8 December – Tony Lloyd, Baron Lloyd of Berwick, 95, British jurist, lord of appeal in ordinary (1993–1998), member of the House of Lords (1993–2015). 15 December – Andrew Bennett, 85, British politician, MP (1974–2005). 18 December – Patrick Conolly-Carew, 7th Baron Carew, 86, Irish equestrian and aristocrat, Member of the House of Lords as a hereditary peer (1994–1999).
== Track listing == "Strange Meridian" (Russ Gershon) – 8:28 "Premonitions" (Curtis Hasselbring) – 5:29 "The Half-Life of Desire" (Gershon) – 5:30 "He Who Hesitates" (Hasselbring) – 7:54 "Temptation" (Nacio Herb Brown, Arthur Freed) – 5:17 "Circle in the Round/I Got It Bad" (Miles Davis/Duke Ellington) – 11:18 "Red" (Robert Fripp) – 11:21
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.