The short version of peptide degradation fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-04 and is reviewed periodically as new material appears.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
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。
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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.
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.
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.
=== Before the search === The earliest mention of some matter with the properties of deuterium was a passing mention in Ernest Rutherford's 1919 Bakerian lecture. In this theory, the deuterium nucleus with mass two and charge one would contain two protons and one nuclear electron. Also in 1919, Otto Stern and Max Volmer reported on diffusion experiments with water which they claimed disproved the existence of isotopes of hydrogen; their conclusions were assumed to be correct throughout the 1920s.
Most drugs were discovered by empirical means, including observation, accident, and trial and error. One famous example is the discovery of penicillin, the first antibiotic in the world. The substance was discovered by Alexander Fleming in 1928 after a combination of unanticipated events occurred in his laboratory during his summer vacation. The Penicillium mold on the petri dish was believed to secrete a substance (later named "penicillin") that inhibited bacterial growth. Large pharmaceutical companies then started to establish their microbiological departments and search for new antibiotics. The screening program for antimicrobial compounds also led to the discovery of drugs with other pharmacological properties, such as immunosuppressants like Cyclosporin A.The discovery of penicillin was a serendipitous (i.e. chance) discovery. Another, more advanced approach to drug discovery is rational drug design. The method is underpinned by an understanding of the biological targets of the drugs, including enzymes, receptors, and other proteins. In the late 19th century, Paul Ehrlich observed the selective affinity of dyes for different tissues and proposed the existence of chemoreceptors in our bodies. Receptors were believed to be the specific binding sites for drugs. The drug-receptor recognition was described as a key-and-lock interplay by Emil Fischer in the early 1890s. It was later found that the receptors can either be stimulated or inhibited by chemotherapeutic agents to attain the desired physiological response.
=== Effector === The arcuate nucleus of the hypothalamus, a part of the brain, is the main regulatory organ for the human appetite. Many brain neurotransmitters affect appetite, especially dopamine and serotonin. Dopamine acts primarily through the reward centers of the brain, whereas serotonin primarily acts through effects on neuropeptide Y (NPY)/agouti-related peptide (AgRP) [stimulate appetite] and proopiomelanocortin (POMC) [induce satiety] neurons located in the arcuate nucleus. Similarly, the hormones leptin and insulin suppress appetite through effects on AgRP and POMC neurons. Hypothalamocortical and hypothalamolimbic projections contribute to the awareness of hunger, and the somatic processes controlled by the hypothalamus include vagal tone (the activity of the parasympathetic autonomic nervous system), stimulation of the thyroid (thyroxine regulates the metabolic rate), the hypothalamic-pituitary-adrenal axis and a large number of other mechanisms. Opioid receptor-related processes in the nucleus accumbens and ventral pallidum affect the palatability of foods. The nucleus accumbens (NAc) is the area of the brain that coordinates neurotransmitter, opioid and endocannabinoid signals to control feeding behaviour. The few important signalling molecules inside the NAc shell modulate the motivation to eat and the affective reactions for food. These molecules include the dopamine (DA), acetylcholine (Ach), opioids and cannabinoids and their action receptors inside the brain, DA, muscarinic and μ-opioid receptor (MOR) and CB1 receptors respectively.
Sources: en.wikipedia.org
Acetylcysteine or N-acetylcysteine (NAC) is a mucolytic that is used to treat paracetamol (acetaminophen) overdose and to loosen thick mucus in individuals with chronic bronchopulmonary disorders, such as pneumonia and bronchitis. It has been used to treat lactobezoar in infants. It can be taken intravenously, orally (swallowed by mouth), or by inhalation by use of a nebulizer. It is also sometimes used as a dietary supplement. Common side effects include nausea and vomiting when taken orally. The skin may occasionally become red and itchy with any route of administration. A non-immune type of anaphylaxis may also occur. It appears to be safe in pregnancy. For paracetamol overdose, it works by increasing the level of glutathione, an antioxidant that can neutralize the toxic breakdown products of paracetamol. When inhaled, it acts as a mucolytic by decreasing the thickness of mucus. Acetylcysteine was initially patented in 1960 and came into medical use in 1968. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication.
== Terrorist and other designations == Three days after Hegseth unveiled Operation Southern Spear, Marco Rubio, the US Secretary of State, announced the US would designate Cartel of the Suns—which the US alleges is headed by Venezuelan president Nicolás Maduro—as a Foreign Terrorist Organization. Rubio stated that cartels are "responsible for terrorist violence throughout our hemisphere as well as for trafficking drugs into the United States and Europe"; Maduro denies the US allegation that he is "complicit with armed criminal gangs that smuggle drugs" to the US. The Miami Herald wrote: "The designation would effectively label Maduro and senior officials, including Interior Minister Diosdado Cabello and Defense Minister Vladimir Padrino López, as terrorists." The US listed the Gulf Clan (Clan del Golfo), described by The Guardian as "Colombia's largest and most powerful illegal armed criminal group" as a Foreign Terrorist Organization on 16 December 2025. On 15 December 2025, Trump signed an executive order designating fentanyl as a weapon of mass destruction. Two days later, Trump stated he would designate the "Maduro regime" a Foreign Terrorist Organization.
=== Marching band === The University of Arizona marching band, named The Pride of Arizona, played at the halftime of the first Super Bowl. Most recently, the Pride's 2014 Daft Punk show was chosen by the CBDNA (College Band Directors National Association) as one of ten in the nation to be presented at their National Conference in March 2015. In 2024, the Pride of Arizona became the 34th recipient of the Sudler Trophy.
Sources: en.wikipedia.org
==== Closed-loop recycling ==== There are several other harmful environmental impact from synthetic textile production, including large amount of greenhouse gas emissions, high energy consumption and landfill waste. A typical textile mill consumes approximately 1.6 million liters of water to produce 8,000 kilograms of fabric. This is a worldwide problem since the textile industry contributes to about 10 percent of global greenhouse gas emissions. During 2016 alone, only 1 percent of the 180,000 tons of textile waste produced was recycled into new clothes. The remaining old textile fibers ended up in a landfill as waste. One solution that is currently being implemented within the textile industry to combat these issues is a closed loop recycling system. In the context of the textile industry, closed loop recycling involves collecting used textiles, processing them through various mechanical, chemical or biological recycling methods to turn used, worn down textiles into new textiles. Within a closed loop recycling system, textiles can either be recycled into a similar product, upcycled into a new, higher quality product, or downcycled into a new, lower quality product. This approach reduces waste, conserves resources, and minimizes the environmental impact of textile production by promoting a circular economy where materials are recycled and reused in a continuous, closed loop.
Historical novels like Ryōtarō Shiba's Tobu ga Gotoku mention characters like Saigō Takamori enjoying TKG (though likely fictionalized). An essay by Shōtarō Ikenami describes the Forty-seven Rōnin eating a version with duck and negi (historical accuracy uncertain). The book 365 Nichi Tamago Kake Gohan no Hon (2007) introduced 365 variations and popularized the abbreviation "TKG" for creative tamago kake gohan recipes. The idol group Nama Ham to Yaki Udon has a song titled "Tamago Kake Gohan" (2015).
Hemp juice is a beverage derived from industrial hemp, made from the result of pressing the Cannabis sativa plant. The juice is obtained through a large-scale industrial cold-pressing procedure using the upper parts of the hemp plant as well as the leaves. This procedure distinguishes hemp juice from other hemp products such as hemp oil, hemp sprouts or hemp milk, which are obtained through the seeds of the hemp plant. Proponents of hemp juice claim it as a base for a variety of drug-free products in the areas of nutrition, medicine, cosmetics, and beverages. Hemp juice has also been used as a flavor enhancer due to its umami flavor. Hemp juice has also appeared as a health food product due to the high amounts of proteins it contains. Studies point out the medical potential of the cannabinoid CBD, which is found in industrial hemp and hemp juice. Drug-free industrial hemp and the hemp juice produced from it offer the advantages of legal cultivation and utilization in many countries, as opposed to the Cannabis Indica and Sativa plants, which have higher tetrahydrocannabinol (THC) content and are not legal in many countries. People have found alternative uses for hemp juice. Hemp juice and its pressed remnants have been used to substitute some portion of flour in bread. It has also been used as a food supplement in the form of freeze-dried hemp juice powder for nutritional reasons, mostly thanks to the high percentage of protein hemp juice possesses.
The Wallerian degeneration pathway has been further illuminated by the discovery that sterile alpha and TIR motif containing 1 (SARM1) protein plays a central role in the Wallerian degeneration pathway. The gene was first identified in a Drosophila melanogaster mutagenesis screen, and subsequently knockouts of its homologue in mice showed robust protection of transected axons comparable to that of WldS. SARM1 catalyzes the synthesis and hydrolysis of cyclic ADP-ribose (cADPR) from NAD+ to ADP-ribose. SARM1 activation locally triggers a rapid collapse of NAD+ levels in the distal section of the injured axon, which then undergoes degeneration. This collapse in NAD+ levels was later shown to be due to SARM1's TIR domain having intrinsic NAD+ cleavage activity. The SARM1 protein has four domains, a mitochondrial localization signal, an auto-inhibitory N-terminus region consisting of armadillo/HEAT motifs, two sterile alpha motifs responsible for multimerization, and a C-terminus Toll/Interleukin-1 receptor that possesses enzymatic activity. Activation of SARM1 is sufficient to collapse NAD+ levels and initiate the Wallerian degeneration pathway. The activity of SARM1 helps to explain the protective nature of the survival factor NMNAT2, as NMNAT enzymes have been shown to prevent SARM1-mediated depletion of NAD+. This relationship is further supported by the fact that mice lacking NMNAT2, which are normally not viable, are completely rescued by SARM1 deletion, placing NMNAT2 activity upstream of SARM1.
Sources: en.wikipedia.org
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
一般不建议常温长期保存。多数说明指向 -20 °C 冷冻避光。常温运输通常被视为短期可接受，但会加快降解风险。