A practical reference on 反相色谱: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-25 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。
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.
| 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 |
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。
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.
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.
cell compartmentalization The subdivision of the interior of a cell into distinct, usually membrane-bound compartments, including the nucleus and organelles (endoplasmic reticulum, mitochondria, chloroplasts, intracellular vesicles, etc.), a defining feature of the Eukarya.
Amino acid-based formula is a type of infant milk formula made from individual amino acids. It is hypoallergenic and intended for infants suffering from severe allergy to milk and various gastrointestinal conditions, such as food protein-induced enterocolitis syndrome and malabsorption syndromes. It is sometimes referred to as elemental formula but this is considered a misleading name. Issues with the use of amino acid-based formula include its high cost and its unpalatable taste. Intake of amino-acid formula for healthy infants shows no advantage in growth.
Bryant Park contains a carousel called Le Carrousel Magique, located in the southern section of the park. The carousel was designed by Marvin Sylvor, created by the Fabricon Carousel Company, and installed in 2002. The company was selected after a carousel installation in Bryant Park was approved in 1997. The carousel has a diameter of 22 feet (6.7 m), weighs 12,000 pounds (5,400 kg), and contains 14 animal casts, of which 12 are capable of moving vertically. In keeping with the French theme of the park, it plays French music. It underwent a restoration in 2009. The carousel also has a ticket booth, measuring 7 feet (2.1 m) tall and 4 feet (1.2 m) wide, which was constructed in 1928 and was relocated from Paragon Park in Hull, Massachusetts.
=== Cor–Cz === Robert Corey (1897–1971). American protein chemist at Caltech, known for work with Linus Pauling on the α-helix and β-sheet. Member Natl. Acad. Sci. USA. Carl Ferdinand Cori (1896–1984). American biochemist at Washington University and Albert Einstein College of Medicine, who worked on glycogen. Nobel Prize in Physiology or Medicine (1947). Member Natl. Acad. Sci. USA. Gerty Cori (1896–1957). Czech-American biochemist at Washington University, known for glycogen research. Nobel Prize in Physiology or Medicine (1947). Athel Cornish-Bowden (b. 1943). British enzymologist at the CNRS, Marseille. He has contributed to the development of metabolic control analysis, and is the author of Fundamentals of Enzyme Kinetics. Suzanne Cory (b. 1942). Australian molecular biologist known fotr work on the genetics of the immune system, at the Walter and Eliza Hall Institute of Medical Research, Melbourne. Peter Coveney (b. 1958). British Computational molecular biology specialist at University College London, University of Amsterdam and Yale. Nicholas R. Cozzarelli (1938–2006). American biochemist at UC Berkeley, and former editor-in-chief of the Proceedings of the National Academy of Sciences. Member Natl. Acad. Sci. USA. Gerald Crabtree (b. 1946). American biochemist at Stanford, known for defining the Ca2+-calcineurin-NFAT signalling pathway, pioneering the development of synthetic ligands for regulation of biological processes. Robert K. Crane (1919–2010).
Sources: en.wikipedia.org
=== Diabetes === Januvia (sitagliptin) ($1.3 billion in 2024 revenues) is a dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes. In 2013, Januvia was the second largest selling diabetes drug worldwide. It has been popular due in part because unlike many other diabetes drugs, it causes little or no weight gain and is not associated with hypoglycemic episodes. There has been some concern that treatment with Januvia and other DPP-IV inhibitors may be associated with a modestly increased risk of pancreatitis. Janumet ($1.0 billion in 2024 revenues) is a single pill combination drug containing both Januvia and metformin.
coli bacteria stores proteins and pyrophosphates in its periplasmic membrane until either are needed within the cell. Recent advancement in phosphoproteomic identification has resulted in the discoveries of countless phosphorylation sites in proteins. This required an integrative medium for accessible data in which known phosphorylation sites of proteins are organized. A curated database of dbPAF was created, containing known phosphorylation sites in H. sapiens, M. musculus, R. norvegicus, D. melanogaster, C. elegans, S. pombe and S. cerevisiae. The database currently holds 294,370 non-redundant phosphorylation sites of 40,432 proteins. Other tools of phosphorylation prediction in proteins include NetPhos for eukaryotes, NetPhosBac for bacteria, and ViralPhos for viruses.
== Adenosine triphosphate == ATP is the only type of usable form of chemical energy for musculoskeletal activity. It is stored in most cells, particularly in muscle cells. Other forms of chemical energy, such as those available from oxygen and food, must be transformed into ATP before they can be utilized by the muscle cells.
Sources: en.wikipedia.org
== Description == Pileas: The cap is 15–55 mm (0.6–2.2 in) in diameter and conic to obtusely conic to convex. The cap margin is turned inwards when young, rarely becoming plane in age, often distinctly rippled, translucent-striate and bruising and aging greenish-bluish about the margin. It is dark olive brown to buff brown in color, occasionally steel blue; when dried it tends toward copper brown in the center. It is hygrophanous, fading to milk white, and viscid when moist from a gelatinous pellicle, usually separable. The flesh is thin and bruises blue easily. Gills: The gills are close with adnate to sinuate attachment and are grayish to cinnamon brown, with the edges remaining pallid. Spore Print: dark purplish brown Stipe: The stipe is 5–7 cm (2.0–2.8 in) long, 2–3 mm (0.1–0.1 in) thick, and equal to subequal. The color is pallid to brownish with white filaments, while often more yellowish towards the apex. Distinct rhizomorphs are found at the base. The stipe is brittle, stuffed with loose fibers, and the partial veil is evanescent and rapidly becomes indistinguishable. Taste: farinaceous Odor: farinaceous Stain: It stains blue easily where damaged.
=== New York === In January 2023, the New York City Bias Audit Law (Local Law 144) was enacted by the NYC Council in November 2021. Originally due to come into effect on 1 January 2023, the enforcement date for Local Law 144 has been pushed back due to the high volume of comments received during the public hearing on the Department of Consumer and Worker Protection's (DCWP) proposed rules to clarify the requirements of the legislation. It eventually became effective on July 5, 2023. From this date, the companies that are operating and hiring in New York City are prohibited from using automated tools to hire candidates or promote employees, unless the tools have been independently audited for bias. The Responsible AI Safety and Education Act (RAISE Act) is a New York State law that imposes transparency, safety, and reporting requirements on developers of large frontier artificial intelligence models. The law was signed by Governor Kathy Hochul on December 19, 2025. It is expected to take effect on January 1, 2027.
== Other activities == While in college, Conway was a member of the Ursinius Meistersingers vocal music group, and the performing arts honor society Pi Nu Epsilon. He became a volunteer for the American Red Cross Disaster Service in 1989, but quit in 1998 due to his perception of high-level corruption in the organization. He was an Emergency Management Coordinator while residing in Malvern, Pennsylvania. In March 1990, Conway became an experimental bone marrow donor for Mark Stevenson, a 4-year-old with Hunter syndrome. The operation was the first of its kind involving an unrelated donor, and was successful; Mark lived to 24. Conway became an active volunteer for the National Marrow Donor Program, claiming to have helped add over 500 entries to their donor registry. Since May 1996, Conway has participated in the MadSci Network, a free question-and-answer Ask-A-Scientist forum organized by the medical school of Washington University in St. Louis. While most active in the period 1997–2000, he remains a member as of 2009.
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。
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.