counterion comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
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.
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.
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.
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。
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
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。
=== Reduced food waste === Worldwide, one third of the total food produced for consumption, around 1.6 billion tons per year, goes to waste. Food waste happens during processing, distribution and consumption. 3D food printing is a very promising way of reducing food waste during the phase of consumption, by utilizing food products like meat off-cuts, distorted fruits and vegetables, sea food by-products and perishables. These products can be processed in a suitable form for printing. Upprinting Food, a Dutch startup, has been blending and combining different ingredients from food waste to create purees which are then used as materials for 3D printing. Chefs are also creating different dishes from leftover food using 3D food printers.
== Tissues distribution == Studies have reported that humans express FFAR3 in their: (a) enteroendocrine L cells and K cells of the intestines; (b) endothelium of blood vessels in the frontal cortex of the brain, pancreatic β-cells, and adipose. i.e., fat, tissue (but not in mouse adipose tissue); (c) the vascular endothelium of the myometrium, the epithelium of the amnion, chorion and placenta, and certain immune cells in these tissues of pregnant women; (d) the hippocampus of the brain; (e) sympathetic ganglia, i.e., autonomic ganglia of the sympathetic nervous system; (f) certain types of immune cells, i.e., blood monocytes (but not mouse monocytes), basophils, dendritic cells derived from human monocytes isolated from whole blood, and the tissues containing these blood cells, i.e., the bone marrow, spleen, lymph nodes, and thymus; and (g) alveolar macrophages, and macrophages in various other tissues; and (h) certain immortalised cell lines, i.e., MCF-7 breast cancer, HCT116 colorectal cancer, HEK293 embryonic kidney, U937 leukemic promonocyte, THP-1 leukemic monocyte, EoL-1 leukemic eosinophil, Jurcat leukemic T lymphocyte, MOLT-4 T lymphoblast leukemic, and HL60 acute myeloid leukemia cells (but only when the HL60 cells are pre-treated with phorbol 12-myristate 13-acetate to promote their cellular differentiation). As noted, the expression of FFAR3 in the cells and tissues of animals are not always the same as those in humans.
=== Regulation of algicidal activity === To perform algicidal processes, bacteria require mechanisms to detect and regulate their responses. Some common bacterial mechanisms associated with algicidal activities include chemotaxis, attachment and biofilm formation, and quorum sensing.
Sources: en.wikipedia.org
== Pharmacokinetics == The metabolism of topically applied nitrofurazone is thought to be by 5-nitro reduction and cleavage of the -CH=N- linkage to generate a reactive species which can covalently bond to cellular macromolecules, none of the end products are thought to be antimicrobial.
== Success of insulin == MacLeod was overseeing the work of Frederick Banting and Charles Best in their search for a treatment for diabetes which they had begun in May 1921. In December, when Banting and Best were having difficulties in refining the pancreatic extract, MacLeod freed Collip from his other research to enable him to join the research team. Collip's task was to prepare insulin in a more pure, usable form than Banting and Best had been able to achieve to date. In January 1922, after 14-year-old Leonard Thompson suffered a severe allergic reaction to an injection of insulin, Collip achieved the goal of preparing a pancreatic extract pure enough for Thompson to recover and to use in clinical trials. Despite Collip's breakthrough, Banting was furious as he saw that "Collip's discoveries were not a cause for celebration but a new threat". At some point between January 17 and 24, Collip and Banting reportedly had a physical altercation in the labs, supposedly when "Collip visited Banting and Best in their lab and told them that he wasn’t going to share the latest extract formulation (which may or may not have had Macleod's blessing) and that he was contemplating leaving the research team and patenting the process on his own". A colleague later lampooned this incident with a "cartoon showing Banting sitting on Collip and titled 'The Discovery of Insulin.'" Nonetheless, successful trials were soon completed and the future of insulin was assured.
== Works cited == "The Best of 2004; The 14th Annual Computer Games Awards". Computer Games Magazine. No. 172. Fort Lauderdale, Florida: theGlobe.com. March 2005. pp. 48–56. "2004 Games of the Year". Computer Gaming World. No. 249. Cambridge, Massachusetts: Ziff Davis. March 2005. pp. 56–67. Retrieved November 3, 2020. Osborn, Chuck (2003). "Cover Story: Bloodlines - The Half Life 2 Engine Gets Dead Sexy". PC Gamer US. Vol. 10, no. 114. United States: Ace St. Germain. pp. 46–54. ISSN 1080-4471. Osborn, Chuck (2005). "Reviews - Vampire: The Masquerade - Bloodlines". PC Gamer US. Vol. 12, no. 132. United States: Ace St. Germain. pp. 92–94. ISSN 1080-4471.
=== Economics === In 2008, it generated the tenth-highest amount of money for a medication in the U.S. in 2008, with sales exceeding $2.4 billion. To 2020, no study has examined the socioeconomic effects of utilization of pioglitazone.
Sources: en.wikipedia.org
=== Separation techniques and electrophoresis === Proteomics, the study of the proteome, has largely been practiced through the separation of proteins by two dimensional gel electrophoresis. In the first dimension, the proteins are separated by isoelectric focusing, which resolves proteins on the basis of charge. In the second dimension, proteins are separated by molecular weight using SDS-PAGE. The gel is stained with Coomassie brilliant blue or silver to visualize the proteins. Spots on the gel are proteins that have migrated to specific locations.
Mammals are a clade, and therefore the cladists are happy to acknowledge the traditional taxon Mammalia; and birds, too, are a clade, universally ascribed to the formal taxon Aves. Mammalia and Aves are, in fact, subclades within the grand clade of the Amniota. But the traditional class Reptilia is not a clade. It is just a section of the clade Amniota: The section that is left after the Mammalia and Aves have been hived off. It cannot be defined by synapomorphies, as is the proper way. Instead, it is defined by a combination of the features it has and the features it lacks: reptiles are the amniotes that lack fur or feathers. At best, the cladists suggest, we could say that the traditional Reptilia are 'non-avian, non-mammalian amniotes'. Despite the early proposals for replacing the paraphyletic Reptilia with a monophyletic Sauropsida, which includes birds, that term was never adopted widely or, when it was, was not applied consistently.
== Tribute == Since 1941, the American Diabetes Association confers Banting Medals for those with long-term contribution to diabetes research and treatment. In 1991, International Diabetes Federation and World Health Organization (WHO) made his birthday the World Diabetes Day. On November 14, 2016, Google celebrated his 125th birthday with a Google Doodle. 2021 marks the centenary of Dr. Banting's co-discovery of insulin at the University of Toronto. Canada Post issued a commemorative stamp.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.