ACTH fragment 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.
Last reviewed on 2026-01-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
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.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
In the diet, β-glucans are a source of soluble, fermentable fiber – also called prebiotic fiber – which provides a substrate for microbiota within the large intestine, increasing fecal bulk and producing short-chain fatty acids as byproducts with wide-ranging physiological activities. This fermentation impacts the expression of many genes within the large intestine, which further affects digestive function and cholesterol and glucose metabolism, as well as the immune system and other systemic functions.
== History == Balmer Lawrie was founded as a partnership firm on 1 February 1867 in Calcutta, British India, by two Scotsmen: George Stephen Balmer and Alexander Lawrie. It became a private limited company in 1924 with a paid-up share capital of ₹40 lakhs, a public limited company in 1936 and then a Government of India Enterprise in 1972. BL is classified as a category-I Miniratna company.
GSH + R• → RH + GS• → 1/2 GSSG Thiyl radicals (such as glutathionyl radicals) are themselves oxidizing species in biology, with a single-electron reduction potential sufficient for oxidation of nucleic acids, proteins and polyunsaturated lipids. Therefore, GSH itself may not be effective at direct reduction of reactive oxygen species under physiological conditions. Under oxidizing conditions, hydrogen sulfide may react with glutathione (or other electrophilic oxidized forms of glutathione) to form glutathione hydropersulfide (GS–SH), which is a superior radical-trapping antioxidant and reductant. GSH is a highly important indirect antioxidant by acting as a coenzyme for various enzymes that couple GSH-to-GSSG oxidation to the reduction of harmful oxidizing species. Such enzymes include the glutathione peroxidase family, the glutaredoxin family, the peroxiredoxin family, and others.
Sources: en.wikipedia.org
=== Late === There is also a later form of hemorrhagic smallpox (referred to late hemorrhagic smallpox, or variolosa pustula hemorrhagica). The prodrome is severe and similar to that observed in early hemorrhagic smallpox, and the fever persists throughout the course of the disease. Bleeding appears in the early eruptive period (but later than that seen in purpura variolosa), and the rash is often flat and does not progress beyond the vesicular stage. Hemorrhages in the mucous membranes appear to occur less often than in the early hemorrhagic form. Sometimes the rash forms pustules which bleed at the base and then undergo the same process as in ordinary smallpox. This form of the disease is characterized by a decrease in all of the elements of the coagulation cascade and an increase in circulating antithrombin. This form of smallpox occurs anywhere from 3% to 25% of fatal cases, depending on the virulence of the smallpox strain. Most people with the late-stage form die within eight to 10 days of illness. Among the few who recover, the hemorrhagic lesions gradually disappear after a long period of convalescence. The case fatality rate for late hemorrhagic smallpox is around 90–95%. Pregnant women are slightly more likely to experience this form of the disease, though not as much as early hemorrhagic smallpox.
== In culture == The jalapeño is a Mexican chili but was designated by the Texas Legislature as the official "State Pepper of Texas" in 1995. In Mexico, jalapeños are used in many forms such as in salsa, pico de gallo, or grilled jalapeños. Jalapeños were included as food on the Space Shuttle as early as 1982. Guinness World Records recognizes Alfredo Hernandes for the most jalapeños eaten in a minute: 16, on 17 September 2006 at the La Costeña Feel the Heat Challenge in Chicago, Illinois. Patrick Bertoletti holds the Major League Eating jalapeño records at 275 pickled jalapeños in 8 minutes on 1 May 2011, and 191 pickled jalapeños in 6.5 minutes on 16 September 2007 in the 'Short-Form'. Joaquín Guzmán, also known as "El Chapo", the leader of the Sinaloa Cartel, operated a cannery in Guadalajara producing "Comadre Jalapeños" in order to ship cocaine to the US. The official mascot of the 1986 FIFA World Cup was Pique, a jalapeño pepper, characteristic of Mexican cuisine, with a moustache, a Colimote sombrero, and Mexican football team colors. Its name comes from picante, a Spanish word meaning "spicy", and was also a pun on the "PK" abbreviation of the football term penalty kick. Pique is also a common Spanish name. September 5th is recognized as National Jalapeno Day.
With intramuscular injection, a dose of 25 mg results in normal luteal phase serum levels of progesterone within 8 hours, and a 100 mg dose produces mid-pregnancy levels of 40 to 80 ng/mL at peak. At these doses, levels of progesterone remain elevated above baseline for at least 48 hours (6 ng/mL at this point for 100 mg), with an elimination half-life of about 22 hours. Due to the high concentrations achieved, progesterone by intramuscular injection at the usual clinical dose range is able to suppress gonadotropin secretion from the pituitary gland, demonstrating antigonadotropic efficacy (and therefore suppression of gonadal sex steroid production). Intramuscular progesterone often causes pain when injected. It irritates tissues and is associated with injection site reactions such as changes in skin color, pain, redness, transient indurations (due to inflammation), ecchymosis (bruising/discoloration), and others. Rarely, sterile abscesses can occur. Large doses of progesterone by intramuscular injection, for instance 100 mg, are associated with moderate-to-severe injection site reactions.
Sources: en.wikipedia.org
== Plasticity == Cell plasticity is the idea that cells can switch phenotypes in response to environmental cues. In the context of regeneration, this environmental cue is damage or injury to a limb. Cell plasticity is closely related to dedifferentiation, implying that a cell with ‘plasticity’ can dedifferentiate to change phenotypes. Cell plasticity suggests that cells can change phenotypes slightly; not fully de-differentiating, to serve a better function. A strong example of this is lens regeneration in the newt.
Eliminates competition between male and female Osedax as resources are limited, Sessile lifestyle: attach to and rely on females for food, Decreases difficulty in finding a mate. Interestingly, Osedax priapus lack the frequently observed male dwarfism. Males live freely and compete for space and food with females. Being larger, they produce and carry more sperm. However, sexual size dimorphism is still observed in O. priapus: most males are one-third the volume of females. Annelid sex is typically determined by genetic factors, however models of environmental sex determination have been proposed for Osedax, in which larvae that settle on bones mature into females, while larvae that settle on female Osedax do not fully develop and mature into males. Osedax japonicus in particular has showcased an environmental form of sex determination.
The end of the Cold War and the emergence of the "unipolar moment" have generated considerable debate about how to explain the absence of a great-power balancing coalition against the United States… That the United States, which is generally regarded as the "greatest superpower ever", has not provoked such a balancing coalition is widely regarded as a puzzle for the balance of power theory.
Sources: en.wikipedia.org
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。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.