The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-07-18 and is reviewed periodically as new material appears.
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.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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。
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。
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
Several methods have been used to determine the mechanisms of antimicrobial peptide activity. In particular, solid-state NMR studies have provided an atomic-level resolution explanation of membrane disruption by antimicrobial peptides. In more recent years, X-ray crystallography has been used to delineate in atomic detail how the family of plant defensins rupture membranes by identifying key phospholipids in the cell membranes of the pathogen. Human defensins have been thought to act through a similar mechanism, targeting cell membrane lipids as part of their function. In fact human beta-defensin 2 have now been shown to kill the pathogenic fungi Candida albicans through interactions with specific phospholipids. From the computational point of view, Molecular Dynamics simulations can provide detailed information about the structure and dynamics of the peptide-membrane interactions, including the orientation, conformation, and insertion of the peptide in the membrane, as well as specific peptide interactions with lipids, ions and solvent.
recreational drug supply in July 2020 by the Center for Forensic Science Research and Education (CFSRE) through its NPS Discovery program; however, earlier identifications by the Drug Enforcement Administration (DEA) may have come as early as late 2019. The rise of brorphine in the U.S. can be directly linked to the decline of isotonitazene due to scheduling by the DEA. Brorphine was first implicated in 20 deaths in the U.S., primarily in cases originating from Midwest states. Brorphine was commonly found with fentanyl and flualprazolam, a drug combination verified by drug product testing. Brorphine has also been identified in counterfeit opioid pills and tablets. Recently data from CFSRE and NMS Labs show that brorphine has been detected in more than 100 cases as of October 2020.
=== China === As of March 2025, the government is estimated to have 401 million barrels stored in above-ground facilities and 668 million barrels in above-ground commercial storage. By December 2025, United States Energy Information Administration estimated Chinese held around 1.4 billion barrels of crude oil in reserve from both government-held and state-owned national oil companies (NOC) inventories, which are both part of the strategic reserves. Outside of the official strategic reserves, Chinese corporate and commercial refineries also have several hundred million barrels of crude oil. China hiked prices serveal times during the war, but due to queue forming in the gas stations in multiple Chinese cities, the Chinese government reduced its planned fuel price hikes. China's large strategic reserve helped the country insulate itself significantly from the 2026 Iran war and ensuing global fuel crisis. By late June 2026, China's strategic petroleum reserve (SPR) remained nearly unchanged after the Iran war. To ensure domestic supplies without using strategic reserve, China halted its supplies of refined oil products to other countries. China is a major oil refiner and exporter of petroleum products. On 5 March, major Chinese refiners, including China Petroleum & Chemical (Sinopec) and Rongsheng Petrochemical Co Ltd, were ordered by the government to stop accepting new fuel export contracts. Jet fuel refuelling for international flights and supplies to Hong Kong and Macau are exempt from this guidance.
== Psychology and neuroscience == Cannabis use in pregnancy is not low risk. The tetrahydrocannabinol (THC) within cannabis crosses the placenta, directly exposing the developing fetus to this chemical. Cannabis use in pregnancy is linked to increased risk of preterm delivery and lower birth weight, along with a higher likelihood of infants needing placement in the neonatal intensive care unit. Additionally, infants exposed to cannabis in pregnancy may have increased rates of behavioral conditions such as hyperactivity and impulsivity, attention deficits, sleep disorders, emotional disturbances, and a higher chance of substance use. According to a 2015 study, 70% of pregnant American women that had used marijuana in the past year thought that consumption of cannabis once or twice per week carried low to no risk of general harm. True photographic memory (the ability to remember endless images, particularly pages or numbers, with such a high degree of precision that the image mimics a photo) has never been demonstrated to exist in any individual, although a small number of young children have eidetic memory, where they can recall an object with high precision for a few minutes after it is no longer present. Many people have claimed to have a photographic memory, but those people have been shown to have high precision memories as a result of mnemonic devices rather than a natural capacity for detailed memory encoding. There are rare cases of individuals with exceptional memory, but none of them have a memory that mimics that of a camera.
Sources: en.wikipedia.org
aurantium, whereas a close reading of the text of the paper itself reveals that the authors (although apparently uncertain about which synephrine regio-isomer had been found in the plant by earlier investigators) were aware that their analytical technique could not distinguish between m- and p-synephrine, and did not claim that m-synephrine was present. Thus the Abstract is at variance with the experimental findings given in the full text of the paper, but this error has propagated through subsequent publications. Even the name "p-synephrine" is not unambiguous, since it does not specify stereochemistry. The only completely unambiguous names for synephrine are: (R)-(−)-4-[1-hydroxy-2-(methylamino)ethyl]phenol (for the l-enantiomer); (S)-(+)-4-[1-hydroxy-2-(methylamino)ethyl]phenol (for the d-enantiomer); and (R,S)-4-[1-hydroxy-2-(methylamino)ethyl]phenol (for the racemate, or d,l-synephrine) (see Chemistry section).
Crick presented a type-written paper titled "On Degenerate Templates and the Adaptor Hypothesis: A Note for the RNA Tie Club" to the members of the club in January 1955, which "totally changed the way we thought about protein synthesis", as Watson recalled. The hypothesis states that the triplet code was not passed on to amino acids as Gamow thought, but carried by a different molecule, an adaptor, that interacts with amino acids. The adaptor was later identified as tRNA.
After the invasion, the Iraqi military looted over $1 billion in banknotes from Kuwait's Central Bank. At the same time, Saddam Hussein made the Kuwaiti dinar equal to the Iraqi dinar, thereby lowering the Kuwaiti currency to one-twelfth of its original value. In response, Sheikh Jaber al-Ahmad al-Sabah ruled the banknotes as invalid and refused to reimburse stolen notes, which became worthless because of a UN embargo. After the conflict ended, many of the stolen banknotes made their way back into circulation. The stolen banknotes are a collectible for numismatists.
Biphalin is a dimeric enkephalin endogenous peptide (Tyr-D-Ala-Gly-Phe-NH)2 composed of two tetrapeptides derived from enkephalins, connected 'tail-to-tail' by a hydrazide bridge. The presence of two distinct pharmacophores confers on biphalin a high affinity for both μ and δ opioid receptors (with an EC50 of about 1–5 nM for both μ and δ receptors), therefore it has analgesic activity. Biphalin presents a considerable antinociceptive profile. In fact, when administered intracerebroventricularly in mice, biphalin displays a potency almost 7-fold greater than that of the ultra-potent alkaloid agonist, etorphine and 7000-fold greater than morphine; biphalin and morphine were found to be equipotent after intraperitoneal administration. The extraordinary in vivo potency shown by this compound is coupled with low side-effects, in particular, to produce no dependency in chronic use. For these reasons, several efforts have been carried out in order to obtain more information about structure-activity relationship (SAR). Results clearly indicate that, at least for μ receptor binding, the presence of two pharmacophores is not necessary; Tyr1 is indispensable for analgesic activity, while replacing Phe at the position 4 and 4' with non-aromatic, but lipophilic amino acids does not greatly change the binding properties and in general 4,4' positions are found to be important to design biphalin analogues with increased potency and modified μ/δ selectivity.
=== Health === In 2001, Kardashian suffered a traumatic brain injury in a car accident. She went through the windshield and suffered a severe concussion, causing long-term memory loss. In October 2022, Kardashian revealed she had had a "rare" tumor removed from her face, having initially assumed it to be a zit. She had previously had an operation to remove melanoma when she was 19 years old.
Sources: en.wikipedia.org
To overcome this effect, a new index was created, named the Equatorial Southern Oscillation Index (EQSOI). To generate this index, two new regions, centered on the Equator, were defined. The western region is located over Indonesia and the eastern one over the equatorial Pacific, close to the South American coast. However, data on EQSOI goes back only to 1949. Sea surface height (SSH) changes up or down by several centimeters in Pacific equatorial region with the ENSO: El Niño causes a positive SSH anomaly (raised sea level) because of thermal expansion while La Niña causes a negative SSH anomaly (lowered sea level) via contraction.
Ancestim is a recombinant methionyl human stem cell factor, branded by Amgen as StemGen. It was developed by Amgen and sold to Biovitrium, now Swedish Orphan Biovitrum, in December, 2008. It is a 166 amino acid protein produced by E. coli bacteria into which a gene has been inserted for soluble human stem cell factor. It has a monomeric molecular weight of approximately 18,500 daltons and normally exists as a noncovalently associated dimer. The protein has an amino acid sequence that is identical to the natural sequence predicted from human DNA sequence analysis, except for the addition of an N-terminal methionine retained after expression in E. coli. Because Ancestim is produced in E. coli, it is nonglycosylated. Ancestim is supplied as a sterile, white, preservative-free, lyophilised powder for reconstitution and administration as a subcutaneous (SC) injection and is indicated for use in combination with filgrastim for mobilizing peripheral hematopoietic stem cells for later transplantation in certain cancer patients.
In 1947, scrolls were discovered in caves near the Dead Sea that proved to contain writing in Hebrew and Aramaic, most of which are thought to have been produced by the Essenes, a small Jewish sect. These scrolls are of great significance in the study of Biblical texts because many of them contain the earliest known version of books of the Hebrew bible. A sample of the linen wrapping from one of these scrolls, the Great Isaiah Scroll, was included in a 1955 analysis by Libby, with an estimated age of 1,917 ± 200 years. Based on an analysis of the writing style, palaeographic estimates were made of the age of 21 of the scrolls, and samples from most of these, along with other scrolls which had not been palaeographically dated, were tested by two AMS laboratories in the 1990s. The results ranged in age from the early 4th century BC to the mid 4th century AD. In all but two cases the scrolls were determined to be within 100 years of the palaeographically determined age. The Isaiah scroll was included in the testing and was found to have two possible date ranges at a 2σ confidence level, because of the shape of the calibration curve at that point: there is a 15% chance that it dates from 355 to 295 BC, and an 84% chance that it dates from 210 to 45 BC. Subsequently, these dates were criticized on the grounds that before the scrolls were tested, they had been treated with modern castor oil in order to make the writing easier to read; it was argued that failure to remove the castor oil sufficiently would have caused the dates to be too young.
A 2023 study also found evidence that Neanderthal single nucleotide polymorphisms (SNPs) likely play a "significant role" in autism susceptibility and heritability in autism populations across the United States. According to the study, "Although most studies on autism genomics focus on the deleterious nature of variants, there is the possibility some of these autism-associated Neanderthal SNPs have been under weak positive selection. In support, recent studies have identified genetic variants implicated in both autism and high intelligence. Meanwhile, autistic people often perform better on tests of fluid intelligence than neurotypicals." Another 2017 study that analyzed 68 genes associated with neurodevelopmental disorders, including autism, found that these disorders were also affected by natural selection and interbreeding between Homo sapiens and other archaic human species. The study also recommended further research into the link between Neanderthal single nucleotide polymorphisms (SNPs) and neurodevelopmental disorders, including autism, in modern-day humans.
Sources: en.wikipedia.org
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.
The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.
Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.