The short version of synthetic heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-28. Anything still debated is marked as such rather than presented as settled.
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.
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.
| 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。
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
== In medicine == In medicine, immunophilins act as receptors for immunosuppressive drugs such as sirolimus (rapamycin), cyclosporin (such as CsA) and tacrolimus (FK506), which inhibit the prolyl isomerase activity of the immunophilins. The drug-immunophilin complexes (CsA-CyP and FK506-FKBP) bind to calcineurin, which inhibits the phosphatase activity of calcineurin and engenders the immunosuppressive effects. CsA and FK506 thus affect the calcium-dependent step of T cell response which prevents release of interleukin-2. Immunophilins also form protein complex with ryanodine and inositol triphosphate (IP3) which impacts the release of calcium. FK506 binds with high affinity to other smaller proteins, such as FKBP-12. FKBP-12 and cyclophilins both share common peptide-prolyl isomerase activity. While the majority of the Peptide bonds within proteins exist in trans (planar) conformation because of the partial double-bond nature of the peptide bond, a small fraction occurs in cis. Unlike regular peptide bonds, the X-Pro peptide bond does not adopt the intended trans conformation spontaneously, thus, cis-trans isomerization can be the rate-limiting (slowest) step in the process of protein folding. Immunophilins, with their prolyl isomerase activity, thus function as protein-folding chaperones.
Slavery, despite no longer being legally recognized anywhere in the world, is still prevalent in some form in all countries today, though some regions have more concentration of slaves: 60% in Asia and Pacific, 23% in Africa, 9% in Europe and Central Asia, 5% in the Americas, and 1% in Arab states. In 2019, approximately 40 million people, of whom 26% were children, were still enslaved throughout the world despite slavery being illegal. In the modern world, more than 50% of slaves provide forced labour, usually in the factories and sweatshops of the private sector of a country's economy. In industrialised countries, human trafficking is a modern variety of slavery; in non-industrialised countries, people in debt bondage are common, others include captive domestic servants, people in forced marriages, and child soldiers.
=== About Dyson === "Freeman Dyson's Brain", interview by Stewart Brand at Wired, 1998 2008 Video Interview with Freeman Dyson by Atomic Heritage Foundation, Voices of the Manhattan Project Roberts, Russ (7 March 2011). "Dyson on Heresy, Climate Change, and Science". EconTalk. Library of Economics and Liberty. "Freeman Dyson: 'I kept quiet for thirty years, maybe it's time to speak'". 52 Insights. 15 June 2018. Retrieved 25 November 2019. Remembering the Unstoppable Freeman Dyson Freeman Dyson at TED Freeman J. Dyson, a Biographical Memoir by Ann Finkbeiner and William H. Press.
Sources: en.wikipedia.org
One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights, and LED-based Christmas lights. Because of their long life, fast switching times, and visibility in broad daylight due to their high output and focus, LEDs have been used in automotive brake lights and turn signals. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, about 200 milliseconds faster than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED appear if the eyes quickly scan across the array. White LED headlamps are beginning to appear. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors. Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks and throwies. Artists have also used LEDs for LED art.
For services to Business and to the UK Film Industry. Catherine Anne Goodman, LVO. Artist and Educator. For services to Art. Professor Roger James Goodman. Nissan Professor of Modern Japanese Studies and Warden, St. Antony's College, University of Oxford. For services to Social Science. Gayle Jean Margaret Gorman. Lately HM Chief Inspector and Chief Executive, Education Scotland. For services to Education and Charity. Gerard Arthur Georges Grech. Founder, Tech Nation and Managing Director, Founders at the University of Cambridge. For services to the Technology Sector. The Reverend Nicholas Glyn Paul Gumbel. Lately Vicar, Holy Trinity Brompton, London. For services to the Church of England. Paul Harris. Deputy Chief Executive Officer and Operations Director, HM Courts and Tribunals Service. For Public and Voluntary Service. Martin James Hewitt, QPM. Lately Chair, National Police Chiefs Council. For services to Policing. Professor Peter Michael Hollingsworth. Director of Science and Deputy Keeper, Royal Botanic Garden, Edinburgh. For services to Botanical Science. Karl James Hoods. Chief Digital and Information Officer, Department for Science, Innovation and Technology and Department for Energy Security and Net Zero. For services to Technology and to Education. Professor Andrew Lee Hopkins, FRS, FMedSci, FRSE. Chief Executive Officer, Exscientia. For services to Science and to Innovation. Christian Edward Johnston Horner, OBE. Team Principal and Chief Executive Officer, Red Bull Racing. For services to Motor Sport. Pauline Jean Howie, OBE.
In the US, newborn screening (NBS) is mandated in all states, though in some states parents may decline it for religious or philosophical reasons. Few parents opt for the program due to health concerns, and a lack of awareness of the ability to opt out. After the initial testing is complete, the residual dried blood spots (DBS) on newborn screening cards may be used for secondary purposes, including being shared with law enforcement and sold for research. The decreasing costs of whole genome sequencing have also raised concerns that blood spots may be sequenced in the future, limiting any de-identification procedures. While CLIA does specify minimum retention requirements, it does not specify a federal maximum retention period. Retention periods for NBS cards vary by state; for example, New Jersey stores them for 23 years, and Texas may keep them indefinitely. The absence of parental awareness and consent for these activities, and a lack of transparency and federal regulations, has led to significant public concern and apprehension.
C13H9−CH2−OC(O)NHR + (CH2)5NH → (CH2)5NH+2 + [C13H8−CH2−OC(O)NHR]− [C13H8−CH2−OC(O)NHR]− → C13H8=CH2 + −OC(O)NHR −OC(O)NHR + (CH2)5NH+2 → HOC(O)NHR + (CH2)5NH HOC(O)NHR → CO2 + RNH2 C13H8=CH2 + (CH2)5NH → C13H9−CH2N(CH2)5
Sources: en.wikipedia.org
== Chemistry == In the kidneys, the enzyme AGAT catalyzes the conversion of two amino acids—arginine and glycine—into guanidinoacetate (also called glycocyamine or GAA), which is then transported in the blood to the liver. A methyl group is added to GAA from the amino acid methionine by the enzyme GAMT, forming non-phosphorylated creatine. This is then released into the blood by the liver where it travels mainly to the muscle cells (95% of the body's creatine is in muscles), and to a lesser extent the brain, heart, and pancreas. Once inside the cells it is transformed into phosphocreatine by the enzyme complex creatine kinase. Phosphocreatine is able to donate its phosphate group to convert adenosine diphosphate (ADP) into adenosine triphosphate (ATP). This process is an important component of all vertebrates' bioenergetic systems. For instance, while the human body only produces 250 g of ATP daily, it recycles its entire body weight in ATP each day through creatine phosphate. Phosphocreatine can be broken down into creatinine, which is then excreted in the urine. A 70 kg man contains around 120 g of creatine, with 40% being the unphosphorylated form and 60% as creatine phosphate. Of that amount, 1–2% is broken down and excreted each day as creatinine. Phosphocreatine is used intravenously in hospitals in some parts of the world for cardiovascular problems under the name Neoton, and also used by some professional athletes, as it is not a controlled substance.
In 2015, Rachel reunites with Yoshi and they spend the night together catching up and later looking for his missing backpack. When asked about her falling out with Shira, Rachel, while looking a bit guilty, hastily says it was just teen stuff, but that Shira got mad for "no reason". She and Yoshi wind up ending their night in a make out session, which causes Yoshi to ejaculate and ruin his sperm sample for Kendra’s IVF treatment, and when Shira finds out Baby caused him to do so she becomes even more hurt and angry and cements her decision to use an anonymous donor. Danny Burstein as Uncle Barry, Naomi's boisterous, obnoxious uncle by marriage with her aunt Sylvia, the sister of Naomi's mother. Avia Fields as Walter and Benjamin Hooper-Schwooper, the hyperactive twin sons of Kendra and Shira, born in 2015 or 2016. Julie Klausner as Carol Schwartz, one of Naomi's older sisters. Zoe Lister-Jones as Susan Schwartz, one of Naomi's older sisters.
Greenland is an autonomous territory of the Kingdom of Denmark, and has been associated with the Scandinavian kingdoms of Denmark and Norway for more than a millennium, beginning in 986 AD when Norse settlers from what is now Norway and Iceland settled Greenland. The 13th century saw the arrival of the Inuit, the ancestors of today's majority population. After around 400 years, the Norse settlement in Greenland is believed to have died out in the late 15th century, but the legends of it persisted in Scandinavia. This prompted King Christian IV to send an expedition to Greenland in 1605 to locate the lost Eastern Norse Settlement and reassert sovereignty over Greenland. Norwegian priest Hans Egede reestablished a permanent Dano-Norwegian presence in 1721, founding the town of Godthaab (now Nuuk). Today's population is mainly Inuit, with a smaller Danish population, and many people are of mixed Inuit and Danish origin. Greenlanders often have close family, personal, and cultural ties to Denmark, with thousands living there. Greenland formally became part of the Kingdom of Norway in 1261, when the Norse inhabitants submitted to the King of Norway. Norway then entered a union with Denmark in 1380. Under the 1814 Treaty of Kiel, Greenland remained with the Danish Crown as part of the settlement with Sweden following the Napoleonic Wars. Denmark declared full sovereignty over all of Greenland, including the uninhabited parts, in 1921, in the aftermath of the Treaty of Versailles.
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.