lyophilized powder 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 2025-09-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
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.
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.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
=== Detector === In GPC, the concentration by weight of polymer in the eluting solvent may be monitored continuously with a detector. There are many detector types available and they can be divided into two main categories. The first is concentration sensitive detectors which includes UV-VIS absorption, differential refractometer (DRI) or refractive index (RI) detectors, infrared (IR) absorption and density detectors. The second category is molecular weight sensitive detectors, which include low angle light scattering detectors (LALLS) and multi angle light scattering (MALS). The resulting chromatogram is therefore a weight distribution of the polymer as a function of retention volume. The most sensitive detector is the differential UV photometer and the most common detector is the differential refractometer (DRI). When characterizing copolymer, it is necessary to have two detectors in series. For accurate determinations of copolymer composition at least two of those detectors should be concentration detectors. The determination of most copolymer compositions is done using UV and RI detectors, although other combinations can be used.
=== Excipients === Excipients are materials inert to the drug, which are added into dosage forms to improve the overall quality of the dosage form. Some examples include antioxidants, sweetening agents, stabilizers, dispersing agents, penetration enhancers, buffers and preservatives. Penetration enhancers are excipients that can increase skin permeability. Many classes of excipients can be used as penetration enhancers, such as glycerin, sulfoxides and related analogues, pyrrolidines, fatty acid and ethanol, surfactants etc. Buffers can be added to control the pH of aqueous or hydroalcoholic based gels. Examples of buffers include phosphate and citrate.
The cytoskeleton acts to organize and maintain the cell's shape; anchors organelles in place; helps during endocytosis, and in the uptake of external materials by a cell. The cytoskeleton is composed of microtubules, intermediate filaments and microfilaments. There are a great number of proteins associated with them, each controlling a cell's structure by directing, bundling, and aligning filaments. The outermost part of the cytoskeleton is the cell cortex, or actin cortex, a thin layer of cross-linked actomyosins. Its thickness varies with cell type and physiology. It directs the transport through the ER and the Golgi apparatus. The cytoskeleton in the animal cell also plays a part in cytokinesis, in the formation of the spindle apparatus during cell division, the separation of daughter cells.
The Mizar-class stores ships were six United Fruit passenger and refrigerated cargo liners built in 1931–1933 that the United States Maritime Commission requisitioned in 1941–1942. They were USS Antigua, USS Ariel, USS Merak, USS Mizar, USS Talamanca and USS Tarazed. Antigua, although requisitioned, was never commissioned into the Navy. United States Maritime Commission Type R ship were Reefer ships. In April 1943, the Navy also requisitioned SS Ulua from the United Fruit Co. After US navy officers boarded the ship and took possession as it approached the Golden Gate Bridge, the ship became the USS Octans. It was the last of the UFC 'reefer' ships to be taken over. Other reefers converted for US Navy use were the Danish ships USS Pontiac, USS Roamer and USS Uranus. In addition, the US Maritime Commission ordered 41 new refrigerated ships for the Navy. Because of the difficulty of building refrigerated ships only two were delivered in 1944. 26 were delivered in 1945 and the remainder in 1946–1948.
Sources: en.wikipedia.org
Insulin on board: This calculation is based on the size of a bolus, the time elapsed since the completion of the bolus, and a programmable metabolic rate. The pump software will estimate the insulin remaining in the bloodstream and relay it to the user. This supports the process of performing a new bolus before the effects of the last bolus are complete and, thereby, helps prevent the user from overcompensating for high blood sugar with unnecessary correction boluses. Bolus calculators: Pump software helps by calculating the dose for the next insulin bolus. The user enters the grams of carbohydrates to be consumed, and the bolus "wizard" calculates the units of insulin needed. It adjusts for the most recent blood glucose level and the insulin on board, and then suggests the best insulin dose to the user to approve and deliver. Custom alarms: The pump can monitor for activities during specific times of day and alarm the user if an expected activity did not occur. Examples include a missed meal bolus, a missed blood glucose test, a new blood glucose test 15 minutes after a low blood glucose test, etc. The alarms are customized for each user. Touch bolus: For persons with visual impairments, this button on the pump can be used to bolus for insulin without using the display. This works with a system of beeps or vibrations to confirm the bolus parameters to the pump user. This feature is described as 'touch', 'audio', or 'easy' bolus depending on brand. The feature was first introduced in the mid- to late 1990s.
Lefse (Norwegian pronunciation: [ˈlɛ́fsə̌], cognate to loaf), dialectally also lefsa (among others), is a traditional soft Norwegian flatbread, also found regionally in Sweden (Swedish: läfsa, löfsa). It is made with riced potatoes, can include all purpose (wheat) flour, and includes butter, and milk, cream, or lard. It is cooked on a large, flat griddle. Special tools are used to prepare lefse, including a potato ricer, long wooden turning sticks and special rolling pins with deep grooves.
1962 Waksman Merck postdoc fellowship, USA. 1967 Humboldt assistant professorship stipend at the Max-Planck Institute, Munich, Germany. 1970 visiting professorship at the Weizmann Institute of Science, Rehovot, Israel. 1973 guest professorship in Dallas, Texas, USA. 1978 guest professorship (Japan Society for the Promotion of Science) in Japan. 1982–1986 Full Professor (Ordinarius) in biotechnology at The Federal Institute of technology, ETH Zurich, Switzerland. 1993 honorary visiting professorship in biochemistry at the University of Bath, UK. 1995 honorary visiting professorship in biochemistry at the Université Catholique de Louvain, Louvain-la-Neuve, Belgium. During these stays he collaborated with Nobel Prize winners Lynen, Waksman as well as with Professors Estabrook and Srere, Katchalski-Katzir and Wilchek, Fukui, Chibata, Suzuki, Rees and Creighton respectively.
In the widely used Couinaud system, the functional lobes are further divided into a total of eight subsegments based on a transverse plane through the bifurcation of the main portal vein. The caudate lobe is a separate structure that receives blood flow from both the right- and left-sided vascular branches. The Couinaud classification divides the liver into eight functionally independent liver segments. Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment are branches of the portal vein, hepatic artery, and bile duct. In the periphery of each segment is vascular outflow through the hepatic veins. The classification system uses the vascular supply in the liver to separate the functional units (numbered I to VIII) with unit 1, the caudate lobe, receiving its supply from both the right and the left branches of the portal vein. It contains one or more hepatic veins which drain directly into the inferior vena cava. The remainder of the units (II to VIII) are numbered in a clockwise fashion:
oxoacid Also oxyacid or oxacid. 1. Any acid having oxygen in the acidic group. 2. Any compound which contains oxygen, at least one other element, and at least one hydrogen atom bound to oxygen, and which produces a conjugate base by the loss of positively charged hydrogen protons.
Sources: en.wikipedia.org
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.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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。