Semax is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-10-27. Numbers and descriptions here follow the published literature rather than marketing material.
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。
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。
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.
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.
| 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。
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
NADPH deficiency can cause a dysfunction in glutathione peroxidase which is an enzyme that converts hydrogen peroxide (a reactive oxygen species) into water. G6PD (glucose-6-phosphate dehydrogenase) deficiency exacerbated by administration of oxidant drugs (e.g., primaquine, dapsone, quinidine) can also result in Heinz bodies. G6PD deficient red cells in combination with high levels of oxidants causes a cross-linking of sulfhydryl groups on globin chains which causes a denaturing and formation of Heinz body precipitates. Heinz bodies can also be found in chronic liver disease. Alpha-thalassemia. Normal adult hemoglobin is composed of two alpha and two beta chains. Alpha thalassemia patients have partial or complete defects in alpha globin production, leading to a relative abundance of beta globin chains in the cell. These excess beta globin chains aggregate to form HbH, which has decreased solubility and precipitates in the red blood cell cytoplasm. This is not direct damage to hemoglobin per se, but rather a perturbation in the quaternary structure of hemoglobin. The presence of Heinz bodies may also be a feature of hyposplenism or asplenia, when a damaged or absent spleen cannot remove these damaged cells from circulation.
5-Hydroxyeicosanoid dehydrogenase (5-HEDH) or more formally, nicotinamide adenine dinucleotide phosphate (NADP+)-dependent dehydrogenase, is an enzyme that metabolizes between two eicosanoid metabolites of arachidonate 5-lipoxygenase (5-LOX): 5-hydroxyeicosatetraenoic acid (5-(S)-HETE), and its 5-keto analog 5-oxo-eicosatetraenoic acid (5-oxo-ETE). It also acts in the reverse direction, metabolizing 5-oxo-ETE to 5(S)-HETE. Since 5-oxo-ETE is 30–100-fold more potent than 5(S)-HETE in stimulating various cell types, 5-HEDH is regarded as a regulator and promoter of the influence that 5-LOX and its metabolites have on cell function. Although 5-HEDH has been evaluated in a wide range of intact cells and in crude microsome preparations, it has not yet been evaluated for its structure or gene, and most studies on it have been limited to human tissues.
=== Physical === Lawrencium is the last actinide. Authors considering the subject generally consider it a group 3 element, along with scandium, yttrium, and lutetium, as its filled f-shell is expected to make it resemble the other 7th-period transition metals. In the periodic table, it is to the right of the actinide nobelium, to the left of the 6d transition metal rutherfordium, and under the lanthanide lutetium with which it shares many physical and chemical properties. Lawrencium is expected to be a solid under normal conditions and have a hexagonal close-packed crystal structure (c/a = 1.58), similar to its lighter congener lutetium, though this is not yet known experimentally. The enthalpy of sublimation of lawrencium is estimated at 352 kJ/mol, close to the value of lutetium and strongly suggesting that metallic lawrencium is trivalent with three electrons delocalized, a prediction also supported by a systematic extrapolation of the values of heat of vaporization, bulk modulus, and atomic volume of neighboring elements to lawrencium. This makes it unlike the immediately preceding late actinides which are either known to be (fermium and mendelevium) or expected to be (nobelium) divalent. The estimated enthalpies of vaporization show that lawrencium deviates from the trend of the late actinides and instead matches the trend of the succeeding 6d elements rutherfordium and dubnium, consistent with lawrencium's interpretation as a group 3 element.
. You can make sense of this by considering the ideal gas law p = ρRT (which is valid if the Reynolds number is large enough that viscous friction becomes unimportant). Then, even for an adiabatic, chemically-homogenous fluid, the density can vary when the pressure changes, e.g. with Bernoulli. For inviscid fluids, the viscosity tensor τ is zero. Thus for an inviscid, barotropic fluid with conservative body forces, the vorticity equation simplifies to
Sources: en.wikipedia.org
First, the species is compatible with the main wine yeast Saccharomyces cerevisiae, though in cases where both MLF and alcoholic fermentation are started together, the yeast most often outcompetes the bacterium for nutritional resources which may cause a delay in the onset of malolactic fermentation. Second, most strains of O. oeni are tolerant to the low pH levels of wine and can usually deal with the standard alcohol levels that most wines reach by the end of fermentation. Additionally, while sulfur dioxide levels above 0.8 molecular SO2 (pH dependent but roughly 35-50 ppm) will inhibit the bacteria, O. oeni is relatively resistant compared to other LAB. Finally, O. oeni tends to produce the least amount of biogenic amines (and most lactic acid) among the lactic acid bacteria encountered in winemaking.
Further development of IWP derivatives resulted in improved IWP-based ATP-competitive inhibitors of CK1δ. In summary, it can be concluded that the cellular effects mediated by IWPs are not only due to the inhibition of Porcn, but also to inhibition of CK1δ dependent signaling pathways. These data clearly show a high potential of CK1δ specific inhibitors for personalized therapy concepts for the treatment of various tumor entities (e.g. breast cancer, colorectal cancer, and glioblastoma), leukemia, neurodegenerative disease like AD, PD, and ALs, and sleeping disorders. Furthermore, CK1δ specific inhibitors seem to exhibit high relevance for prognostic applications. In this context [11C] labeled highly potent difluoro-dioxolo-benzoimidazol-benzamides can be used as PET radiotracers and for imaging of AD. Since small molecule inhibitors often have various disadvantages, including low bioavailability, off-target effects as well as severe side effects, the interest in the development and validation of new biological tools like identification of biological active peptides either able to inhibit CK1δ activity or the interaction of CK1δ with cellular proteins is more and more growing. The use of peptide libraries resulted in the identification of peptides able to specifically block the interaction of CK1δ with tubulin, the RNA helicase DDX3X and Axin. Binding of peptide δ-361 to α-tubulin not only lead to blocking of the interaction of CK1δ with α-tubulin, it also selectively inhibited phosphorylation of GST-α-tubulin by CK1δ.
== Regulation around the world == On 6 July 2012, the international reference standard Codex Alimentarius Commission narrowly approved the adoption of a maximum residue limit (MRL) of 10 parts per billion (ppb) for muscle cuts of beef and pork. Setting any limit was a controversial move. Countries with major meat export markets had been lobbying for the establishment of such a standard for several years to use it as leverage to erode individual national-level bans in World Trade Organization disputes. Consumers International, a world federation of consumer groups that represents 220 consumer organizations in 115 countries, strongly opposed the move. A 2020 petition to the Food and Drug Administration to reconsider the approval of ractopamine stated that 168 other nations had banned or restricted its use. In 2025 and in response to an unreasonable delay lawsuit, the FDA responded acknowledging the number had increased from 160 in 2012, and questioned the relevance of the figure.
Sources: en.wikipedia.org
== Farmed insects not used for protein == Many vegans avoid honey and silk because these require insect farming, even though the insects are not eaten. Silk production involves boiling silk worms alive in their cocoons. The red pigment carmine is produced from powdered bodies of scale insects, so some vegans avoid it. Shellac is produced from a resin secreted by the lac bug on specific trees in Asia. In addition to its use in industry, shellac is incorporated into some fruits, coffee beans, and candies as confectioner's glaze. Some vegans avoid confectioner's glaze because lac bugs may be killed during shellac production. Lac used to produce red dye may be even more injurious to lac bugs because while shellac comes from lac-bug secretions, lac dye's color comes from the insect bodies themselves. Insects are also farmed in large numbers for biological control, where large numbers of parasitic or predatory insects might be reared and then released into the wild to control a pest species. Alternately, in the sterile insect technique, large numbers of sterile male insects may be reared and released in order to reduce wild populations of pest insects or prevent their range expansion, such as with the screwworm. Finally, insects may play an unusual role in specific protein production: fruit flies can be used to generate recombinant proteins which can be used for the production of cell-cultured meat or across many other industries.
== Recalls and safety corrections == In 2014, Tandem recalled selected lots of t:slim cartridges because leaks could cause too much or too little insulin to be delivered. In 2024, the FDA classified a correction of version 2.7 of the iOS t:connect app as a Class I recall. Repeated app crashes and automatic relaunches could increase Bluetooth communication, drain a connected t:slim X2 battery and interrupt insulin delivery. The action covered 85,863 distributed app installations; the FDA reported 224 injuries and no deaths as of April 15, 2024. Tandem released updated app versions and advised users to monitor pump batteries. In April 2025, the FDA classified a correction of Control-IQ+ software version 7.9 as a Class I recall. A defect affecting 85 pumps could incorrectly interpolate glucose values after gaps in CGM data and cause too much or too little insulin to be delivered. Tandem instructed affected users to turn off Control-IQ+ until the software was corrected. Later in 2025, Tandem issued two further corrections that the FDA classified as Class I recalls. One covered 171,750 t:slim X2 pumps whose speakers could fail and stop insulin delivery; the company reported 59 injuries and no deaths. The other covered 17,745 Mobi pumps that could falsely detect vibration-motor failure and enter a non-operational state, stopping insulin delivery and CGM sessions. Tandem directed users to install corrected pump software.
The sulfur dioxide is used for the production of sulfuric acid, which is necessary for the leaching process. If deposits of zinc carbonate, zinc silicate, or zinc-spinel (like the Skorpion Deposit in Namibia) are used for zinc production, the roasting can be omitted. For further processing two basic methods are used: pyrometallurgy or electrowinning. Pyrometallurgy reduces zinc oxide with carbon or carbon monoxide at 950 °C (1,740 °F) into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser. The equations below describe this process:
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 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.