If you have been reading about Certificate of analysis 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.
Updated 2025-12-31. Numbers and descriptions here follow the published literature rather than marketing material.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
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.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
== Biography == In 1993, he immigrated to Canada. Prior to the formation of DVS Sciences. Dr. Baranov, a senior scientist at MDS SCIEX, was a key member of the research team that developed and promoted the Dynamic Reaction Cell®, which remains today at the pinnacle of quadrupole ICP-MS technology. In 2005, together with Scott D. Tanner and Dmitry Bandura, he began independently developing an ICP-TOF-MS based cytometer and became a researcher at the University of Toronto in March 2005. After securing ample funding by 2010 from various sources, including National Institutes of Health, Ontario Institute for Cancer Research (OICR), the Ministry of Research and Innovation, Ontario Centres of Excellence, Health Technology Exchange, and Genome Canada via the Ontario Genomics Institute, and venture capital from 5 AM Ventures, Vladimir and the DVS Sciences team successfully commercialized their technology, leading to the acquisition of DVS Sciences by Fluidigm in 2014 Baranov was a principal scientist at DVS Sciences (and then Fluidigm) developing instrumental concepts and algorithmics that advance the CyTOF® line of products. He also and played a fundamental role in the development of the MaxPar line of metal-labeling reagents until his retirement in 2019.
=== India === In the 1990s, India stopped its research in cold fusion at the Bhabha Atomic Research Centre because of the lack of consensus among mainstream scientists and the US denunciation of the research. Yet, in 2008, the National Institute of Advanced Studies recommended that the Indian government revive this research. Projects were commenced at Chennai's Indian Institute of Technology, the Bhabha Atomic Research Centre and the Indira Gandhi Centre for Atomic Research. However, there is still skepticism among scientists and, for all practical purposes, research has stalled since the 1990s. A special section in the Indian multidisciplinary journal Current Science published 33 cold fusion papers in 2015 by major cold fusion researchers including several Indian researchers. A Hyderabad-based startup, Hylenr Technologies, showcased the amplification of electrical energy into significantly more heat energy using the a LENR system. The startup is being guided by a former DRDO scientist, Padma Shri awardee, Dr. Prahlada Ramarao.
In September 1936, Fry's released an aerated Crunchie bar made entirely of chocolate. They justified this move as not breaching the patent, saying it was not a block but a bar. As Aero sales began to dip, Rowntree's brought out variants, selling the first aerated chocolates with fruit and nut inclusions. After Fry's launched a second aerated chocolate in August 1937 called Ripple, Rowntree's had to decide whether they wanted to try to enforce their patent. By this time, Nestlé and Fry's had joined Cadbury in having expressed a willingness to challenge the patent in the courts despite it being officially approved by the patent office. On legal advice that there was a 50% likelihood of success in a court challenge, and the threat of court proceedings causing bad publicity, Rowntree's entered negotiations with other chocolate makers to discuss licensing aerated chocolate. Rival companies were dominant in the proceedings dialogues, and Rowntree's ultimately agreed to licence aerated chocolate from June 1938 under the conditions that chocolate makers pay a sum with the release of new aerated chocolate lines and a 0.5% royalty on sales. After this agreement was put in place, Cadbury only released aerated chocolate products in overseas dominions where Aero was not established. Nestlé-produced aerated chocolates included a chocolate called Bubblo, made in the UK for export to New Zealand under a New Zealand patent. Aerated chocolate was already being sold in some overseas markets, by 1936 for instance, Aero was being successfully exported to Australia.
The enzyme characterised from Azotobacter vinelandii hydrolyses the nucleotide, nicotinamide mononucleotide, to give nicotinate mononucleotide and ammonia. Manufacture of nicotinamide mononucleotide for use as a pharmaceutical drug has been studied and in this context its degradation by nicotinamide-nucleotide amidase is undesirable, so means to down-regulate the enzyme or remove its associated gene have been sought. This enzyme is a hydrolase, one acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is nicotinamide-D-ribonucleotide amidohydrolase. Other names in use include NMN deamidase, nicotinamide mononucleotide deamidase, and nicotinamide mononucleotide amidohydrolase.
transcript of unknown function (TUF) Any RNA transcript whose function is unclear. Such transcripts may include functional non-coding RNAs which have not yet been studied in detail as well as spurious transcripts without any definite function. The DNA sequences from which TUFs are transcribed are generally located in intergenic or intronic regions of the genome. See also junk RNA.
Sources: en.wikipedia.org
==== Electromechanical ==== Semiconducting carbon nanotubes have shown piezoresistive property when applying mechanical force. The structural deformation causes a change in the band gap which effects the conductance. This property has the potential to be used in strain sensors.
=== 18 July === In Crimea, the Russian-installed governor of Sevastopol claimed that a naval drone was intercepted while attempting to attack the city. SBU naval and aerial drones also attacked a Russian coast guard base on Lake Donuzlav during a Russian naval exercise, hitting the base headquarters, ammunition depot, a power substation and technical facilities. Ukraine claimed to have shot down a Russian drone over Kyiv with no casualties recorded. The Freedom of Russia Legion claimed to have launched an attack on the Bolshoye Savino airport in Perm hosting MiG-31 fighters. A video released showed two KAMAZ trucks burning, with the group claiming to have destroyed “several units of military equipment.” Ukrainian Prime Minister Denys Shmyhal announced the extension of a system to jam Russian TV and radio broadcasts into Donetsk, Mykolaiv, Kherson, and Zaporizhzhia Oblasts.
== Role in cell signaling == Protein quaternary structure also plays an important role in certain cell signaling pathways. The G protein-coupled receptor pathway involves a heterotrimeric protein known as a G protein. G proteins contain three distinct subunits known as the G-alpha, G-beta, and G-gamma subunits. When the G protein is activated, it binds to the G protein-coupled receptor protein and the cell signaling pathway is initiated. Another example is the receptor tyrosine kinase (RTK) pathway, which is initiated by the dimerization of two receptor tyrosine kinase monomers. When the dimer is formed, the two kinases can phosphorylate each other and initiate a cell signaling pathway.
=== Cost effectiveness === Cetacaine has been used in the medical and dental field for a long time now. Its main competitors have been benzocaine and other benzocaine-based drugs. The use of Cetacaine has allowed for faster in and out times for patients, cheaper costs, easier use for the doctors or dentists needing to apply an anesthetic and better patient compliance (less anxiety). Cetacaine compared to some of the leading competitors is considered by most a cheaper option. For the spray option the bottle containing 56g can dispense 100 doses and only cost the dentist $0.79 per dose. The liquid Cetacaine that comes in the 30 g bottle can dose 73 full mouths at a cost of about $0.75 per dose.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。