If you have been reading about heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-16. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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。
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
=== Open === The high cost of sterilizing the fermentor between batches can be avoided using various open fermentation approaches that are able to resist contamination. One is to use a naturally evolved mixed culture. This is particularly favored in wastewater treatment, since mixed populations can adapt to a wide variety of wastes. Thermophilic bacteria can produce lactic acid at temperatures of around 50 °Celsius, sufficient to discourage microbial contamination; and ethanol has been produced at a temperature of 70 °C. This is just below its boiling point (78 °C), making it easy to extract. Halophilic bacteria can produce bioplastics in hypersaline conditions. Solid-state fermentation adds a small amount of water to a solid substrate; it is widely used in the food industry to produce flavors, enzymes and organic acids.
5p partial monosomy syndrome Bloom syndrome Branchiootorenal syndrome 1 Cardiofaciocutaneous syndrome 4 Christianson syndrome Congenital disorder of glycosylation, type IIw Congenital myasthenic syndrome 2A Congenital myopathy 4A, autosomal dominant Congenital myopathy 4B, autosomal recessive Creatine transporter deficiency Cutis laxa, X-linked Ehlers-Danlos syndrome, Beasley-Cohen type Granulocytopenia with immunoglobulin abnormality Hereditary spastic paraplegia 23 and 51 Intellectual disability, autosomal recessive 5 Intellectual disability, X-linked 107, 58, and 61 Knobloch syndrome Marfan syndrome Mitochondrial DNA depletion syndrome 13 Nance-Horan syndrome Oculofaciocardiodental syndrome Otofaciocervical syndrome 1 Proximal myopathy with extrapyramidal signs Radioulnar synostosis-developmental delay-hypotonia syndrome Renpenning syndrome Seckel syndrome 9 Severe X-linked myotubular myopathy SIN3A-related intellectual disability syndrome due to a point mutation Symphalangism-brachydactyly syndrome Syndromic X-linked intellectual disability 14 Torsion dystonia 4 X-linked intellectual disability with marfanoid habitus XFE progeroid syndrome
=== Side effects === Side effects after intravenous TRH administration are minimal. Nausea, flushing, urinary urgency, and mild rise in blood pressure have been reported. After intrathecal administration, shaking, sweating, shivering, restlessness, and mild rise in blood pressure were observed.
==== Cannabis effectively outlawed, prescription drugs ==== With the passage of the Marihuana Tax Act of 1937, federal law reflected state law – by 1936, the non-medical use of cannabis had been banned in every state. That year, the first two arrests for tax non-payment under the act, for possession of a quarter-ounce (7g), and trafficking of four pounds (1.8 kg), resulted in sentences of nearly 18 months and four years respectively. The American Medical Association (AMA) had opposed the tax act on grounds that it unduly affected the medical use of cannabis. The AMA's legislative counsel, a physician, testified that the claims about cannabis addiction, violence and overdoses were not supported by evidence. Scholars have posited that the act was orchestrated by powerful business interests – Andrew Mellon, Randolph Hearst, and the Du Pont family – to head off cheap competition to pulp and timber and plastics from the hemp industry. After the act, cannabis research and medical testing became rare. In 1939, New York City Mayor Fiorello LaGuardia, an opponent of the Marihuana Tax Act, formed the LaGuardia Committee to conduct the first US in-depth study of cannabis use. The report, produced by the New York Academy of Medicine and released in 1944, systematically contradicted government claims, finding that cannabis is not physically addictive, and its use does not lead to using other drugs or to crime. The FBN's Anslinger branded the study "unscientific", denounced all involved, and disrupted other cannabis studies at the time.
Sources: en.wikipedia.org
=== MDP-apatite or dentin interactions === The adhesive interaction of MDP with synthetic hydroxyapatite was observed using x-ray photoelectron spectroscopy and atomic absorption spectrophotometry. MDP readily adhered to hydroxyapatite and this bond appeared very stable, as confirmed by the low dissolution rate of its calcium salt in water. MDP, which effectively interacts chemically with hydroxyapatite and the calcium salt of which is hardly soluble, showed no signs of degradation in bond strength. Micro-tensile bond strength (μTBS) to dentin of a self-etch adhesive that contains MDP were measured up to 100,000 thermocycles. The μTBS of the MDP-based adhesive to dentin after 100,000 thermocycles was not significantly different from that of the control. Experimental primers, which were prepared by three different purity grade MDP monomers, were tested. Impurities and the presence of MDP dimer affected not only hybridization, but also reduced the formation of MDP_Ca salts and nano-layering. MDP in a high purity grade is essential to achieve durable bonding.
After the corporate acquisition of the original patent holder, the pharmaceutical company Pfizer admitted that there had been violations of FDA guidelines regarding the promotion of unproven off-label uses for gabapentin in the Franklin v. Parke-Davis case. While off-label prescriptions are common for many drugs, marketing of off-label uses of a drug is not. In 2004, Warner-Lambert (which subsequently was acquired by Pfizer) agreed to plead guilty for activities of its Parke-Davis subsidiary, and to pay $430 million in fines to settle civil and criminal charges regarding the marketing of Neurontin for off-label purposes. The 2004 settlement was one of the largest in US history up to that point, and the first off-label promotion case brought successfully under the False Claims Act. Kaiser Foundation Hospitals and Kaiser Foundation Health Plan sued Pfizer Inc., alleging that the pharmaceutical company had misled Kaiser by recommending Neurontin as an off-label treatment for certain conditions (including bipolar disorder, migraines, and neuropathic pain). In 2010, a federal jury in Massachusetts ruled in Kaiser's favor, finding that Pfizer violated the federal Racketeer Influenced and Corrupt Organizations (RICO) Act and was liable for US$47.36 million in damages, which was automatically trebled to just under $142.1 million. Aetna, Inc. and a group of employer health plans prevailed in their similar Neurontin-related claims against Pfizer.
Present in most species pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase (also called α-ketoglutarate dehydrogenase) branched-chain α-keto acid dehydrogenase 2-hydroxyphytanoyl-CoA lyase transketolase Present in some species: pyruvate decarboxylase (in yeast) several additional bacterial enzymes The enzymes transketolase, pyruvate dehydrogenase (PDH), and 2-oxoglutarate dehydrogenase (OGDH) are important in carbohydrate metabolism. PDH links glycolysis to the citric acid cycle. OGDH catalyzes the overall conversion of 2-oxoglutarate (alpha-ketoglutarate) to succinyl-CoA and CO2 during the citric acid cycle. The reaction catalyzed by OGDH is a rate-limiting step in the citric acid cycle. The cytosolic enzyme transketolase is central to the pentose phosphate pathway, a major route for the biosynthesis of the pentose sugars deoxyribose and ribose. The mitochondrial PDH and OGDH are part of biochemical pathways that result in the generation of adenosine triphosphate (ATP), which is the main energy transfer molecule for the cell. In the nervous system, PDH is also involved in the synthesis of myelin and the neurotransmitter acetylcholine.
If early organisms had been driven by the same environmental conditions to evolve similar biochemistry convergently, they might independently have acquired similar genetic sequences. Theobald's "formal test" was accordingly criticised by Takahiro Yonezawa and colleagues for not including consideration of convergence. They argued that Theobald's test was insufficient to distinguish between the competing hypotheses. Theobald has defended his method against this claim, arguing that his tests distinguish between phylogenetic structure and mere sequence similarity. Therefore, Theobald argued, his results show that "real universally conserved proteins are homologous."
As part of supply provisions within the Comecon, Lot was allocated four Il-86s as barter for component manufacture; the airline deferred deliveries which were cancelled by 1987. In 1988 the East German airline Interflug is said to have prepared to take delivery of two Il-86s and to have allocated them the registrations DDR-AAA and DDR-AAB. Instead, that same year the airline took delivery of two Airbus A310s. The sole export order for the Il-86 − and the sole commercial transactions involving factory-built rather than secondhand examples − was by China Xinjiang Airlines which received three aircraft in 1990. The first Il-86 to be built was displayed at the Paris Salon International de l'Aéronautique in 1977. It was noted that its interior used patented fire-resistant materials and hydraulics employed a fire-resistant fluid. At that time a version without the "luggage at hand" system was offered, seating 375 or alternatively weighing 3,000 kg (6,600 lb) less and having longer range. This version offered 7% lower seat-mile operational costs. The type was again displayed at Paris in 1979, 1981, 1983 and 1985, the Farnborough Air Show in 1984 and other world air events. Setting records was a traditional Soviet way of promoting aviation products. On Tuesday September 22, 1981, an Il-86 flown by Commander G Volokhov and Second Pilot A Tyuryumin set Fédération Aéronautique Internationale records for flying payloads of 35, 40, 45, 50, 55, 60 and 65 tonnes over a 2,000 km closed circuit at an average of 975.3 km per hour.
Sources: en.wikipedia.org
In cell biology, cell fractionation is the process used to separate cellular components while preserving individual functions of each component. This is a method that was originally used to demonstrate the cellular location of various biochemical processes. Other uses of subcellular fractionation is to provide an enriched source of a protein for further purification, and facilitate the diagnosis of various disease states.
Antineoplastic agents – Substances that inhibit or prevent the proliferation of neoplasms. Antisickling agents – Agents used to prevent or reverse the pathological events leading to sickling of erythrocytes in sickle cell conditions. Nucleic acid synthesis inhibitors – Compounds that inhibit cell production of DNA or RNA. Enzyme inhibitors – Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction. Cytochrome P-450 CYP2D6 inhibitors – Agents that inhibit one of the most important enzymes involved in the metabolism of xenobiotics in the body, CYP2D6, a member of the cytochrome P450 mixed oxidase system.
One person was killed in a Russian attack in Chasiv Yar. A Russian Black Sea Fleet tug boat of the Project 498 "Saturn"/"Proteus" class was sunk by HUR drones on Lake Panske, northwestern Crimea. In Russia, several explosions and a fire occurred at the Novoshakhtinsk oil refinery, which the governor of Rostov Oblast claimed was caused by a drone attack. A Ukrainian Su-25 belonging to the 299th Tactical Aviation Brigade was heavily damaged by a Russian Lancet drone at Krivoi Rog Air Base in Kryvyi Rih. No casualties were reported. President Macron announced that France would send Ukraine an unspecified number of Mirage 2000-5 jet fighters and train Ukrainian pilots to fly them. Japan donated 101 military vehicles to Ukraine, including PC-065B tracked engineering vehicles, Mitsubishi Type 73 Kogata off-road vehicles and Toyota HMVs.
diagnosis, prevention, or treatment of disease or impairment health assessments An objective of the CLIA is to ensure the accuracy, reliability, and timeliness of test results regardless of where the test was performed. Most laboratory-developed tests have been regulated under this program. In 2014, the FDA started a public discussion about regulating some LDTs.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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。