A practical reference on 合成七肽: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-27 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。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
| 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 |
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.
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.
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.
In early May 1990, one of the two A&M researchers, Kevin Wolf, acknowledged the possibility of spiking, but said that the most likely explanation was tritium contamination in the palladium electrodes or simply contamination due to sloppy work. In June 1990 an article in Science by science writer Gary Taubes destroyed the public credibility of the A&M tritium results when it accused its group leader John Bockris and one of his graduate students of spiking the cells with tritium. In October 1990 Wolf finally said that the results were explained by tritium contamination in the rods. An A&M cold fusion review panel found that the tritium evidence was not convincing and that, while they couldn't rule out spiking, contamination and measurements problems were more likely explanations, and Bockris never got support from his faculty to resume his research. On 30 June 1991, the National Cold Fusion Institute closed after it ran out of funds; it found no excess heat, and its reports of tritium production were met with indifference. On 1 January 1991, Pons left the University of Utah and went to Europe. In 1992, Pons and Fleischmann resumed research with Toyota's IMRA lab in France. Fleischmann left for England in 1995, and the contract with Pons was not renewed in 1998 after spending $40 million with no tangible results. The IMRA laboratory stopped cold fusion research in 1998 after spending £12 million. Pons has made no public declarations since, and only Fleischmann continued giving talks and publishing papers.
Following his death, Logan appears posthumously in two recordings - the first for the assisted living community Living+ and the second an archival recording of a dinner party with his employees and Connor, of which his children Kendall, Roman, and Shiv become emotional upon viewing.
=== Neurological === Although the dermatological changes are the most obvious symptoms of Urbach–Wiethe disease, many patients also have neurological symptoms. About 50–75% of the diagnosed cases of Urbach–Wiethe disease also show bilateral symmetrical calcifications on the medial temporal lobes. These calcifications often affect the amygdala and the periamygdaloid gyri. The amygdala is thought to be involved in processing biologically relevant stimuli and in emotional long-term memory, particularly those associated with fear, and both PET and MRI scans have shown a correlation between amygdala activation and episodic memory for strongly emotional stimuli. Therefore, Urbach–Wiethe disease patients with calcifications and lesions in these regions may suffer impairments in these systems. These calcifications are the result of a buildup of calcium deposits in the blood vessels within this brain region. Over time, these vessels harden and the tissue they are a part of dies, causing lesions. The amount of calcification is often related to disease duration. The true prevalence of these calcifications is difficult to accurately state as not all patients undergo brain imaging. Some patients also exhibit epilepsy and neuropsychiatric abnormalities. Epilepsy symptoms could begin with light anxiety attacks and can be controlled with anti-epileptic medications. Other patients present with symptoms similar to schizophrenia while some suffer from mood, anxiety, and psychotic disorders.
== Function == Adenine is one of the two purine nucleobases (the other being guanine) used in forming nucleotides of the nucleic acids. In DNA, adenine binds to thymine via two hydrogen bonds to assist in stabilizing the nucleic acid structures. In RNA, which is used for protein synthesis, adenine binds to uracil.
Sources: en.wikipedia.org
1925: British-American astronomer and astrophysicist Cecilia Payne-Gaposchkin established that hydrogen is the most common element in stars, and thus the most abundant element in the universe. 1926: American scientist Katharine Burr Blodgett became the first woman to earn a PhD in physics at the University of Cambridge, under the supervision of Sir Ernest Rutherford. 1927: Japanese biologist and cytologist Kono Yasui became the first Japanese woman to earn a doctorate in science, studying at the Tokyo Imperial University and completing her thesis on "Studies on the structure of lignite, brown coal, and bituminous coal in Japan". 1927: Bohumila Bednářová, the first Czech woman to become professionally involved in astronomy, co-founds the Prague Observatory. 1928: American microbiologist Alice Evans became the first woman elected president of the Society of American Bacteriologists. 1928: Helen Battle became the first woman to earn a PhD in marine biology in Canada. 1928: British biologist Kathleen Carpenter published the first English-language textbook devoted to freshwater ecology: Life in Inland Waters. 1929: American botanist Margaret Clay Ferguson became the first female president of the Botanical Society of America. 1929: Scottish-Nigerian physician Agnes Yewande Savage became the first West African woman to graduate from medical school, obtaining her degree at the University of Edinburgh Medical School.
In Chinese, the most commonly used names are fěnsī (Chinese: 粉絲; lit. 'noodle thread') and fěntiáo or hóngshǔfěn (Chinese: 粉條 or Chinese: 紅薯粉; lit. 'noodle strip' or 'sweet potato noodles'). They are also marketed under the name saifun, the Cantonese pronunciation of the Mandarin xìfěn (Chinese: 細粉; lit. 'slender noodle', though the name fánsī (粉絲) is the term most often used in Cantonese. In China, glass noodles are a popular ingredient used in stir-fries, soups, and particularly hot pots. They can also be used as an ingredient in fillings for a variety of Chinese jiaozi (dumplings) and bing (flatbreads), especially in vegetarian versions of these dishes. Thicker glass noodles are also commonly used to imitate the appearance and texture of shark's fin in vegetarian soups. Thicker varieties, most popular in China's northeast, are used in stir-fries as well as cold salad-like dishes. A popular Shanghai cuisine using the ingredient is fried tofu with thin noodles (Chinese: 油豆腐線粉湯; pinyin: yóu dòu fu-xiàn fěn tāng). A popular Sichuan dish called "ants climbing a tree" consists of stewed glass noodles with a spicy ground pork meat sauce. In Tibetan cuisine, glass noodles are called phing or fing and are used in soup, in pork curry, or with mushrooms.
Glutathione peroxidase 3 (GPx-3), also known as plasma glutathione peroxidase (GPx-P) or extracellular glutathione peroxidase is an enzyme that in humans is encoded by the GPX3 gene. GPx-3 belongs to the glutathione peroxidase family, which functions in the detoxification of hydrogen peroxide. It contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon, which normally signals translation termination. The 3' UTR of Sec-containing genes have a common stem-loop structure, the sec insertion sequence (SECIS), which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal.
Sources: en.wikipedia.org
In the 2021–22 season Freiburg reached the final of the DFB-Pokal for the first time. In the league Freiburg finished sixth to qualify to the next season's Europa League, where they reached the round of 16. In the following season, they finished fifth in the league to achieve another direct qualification to the Europa League group stage, despite being in the Champions League spots most of the season; however, two consecutive losses against rivals RB Leipzig and Union Berlin had them drop down in the league table with two games remaining. In the DFB-Pokal of the same season, defeated Bayern Munich 2–1 in the quarter-finals, in an away match for the first time in their history, before losing in the semi-finals at home 1–5 to RB Leipzig.
=== Beyond Meat === In July 2018, A&W locations began serving Beyond Meat's vegan Beyond Burger. The chain had a shortage of the Beyond Burger in August 2018, but announced that all locations would receive stock by October 2018. In 2019 A&W expanded its Beyond Meat offerings with the release of the Beyond Meat Sausage N' Egger.
=== Neurotoxicity === Dextromethorphan was once thought to cause Olney's lesions when administered intravenously; however, this was later proven inconclusive, due to lack of research on humans. Tests were performed on rats, giving them 50 mg or more every day for as long as a month. Neurotoxic changes, including vacuolation, have been observed in posterior cingulate and retrosplenial cortices of rats administered other NMDA receptor antagonists such as PCP, but not with dextromethorphan.
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。
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。