A practical reference on Certificate of analysis: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-19 and is reviewed periodically as new material appears.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide (ACTH fragment analog) | Not a steroid; does not belong to the melanocortin agonist drugs by marketing category |
| Molecular formula | C37H51N9O10S (commonly cited) | Reported values vary slightly with salt and counter-ion content |
| Appearance | White to off-white lyophilized powder | A single batch may appear as a loose cake or fluffy solid |
| Solubility | Freely soluble in water and aqueous buffer | Stock solutions are usually prepared in sterile water or saline |
| Typical storage | −20 °C or below, desiccated and protected from light | Seal opened vials promptly to limit moisture uptake |
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。
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
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.
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.
It is characterized by mild summers with only 1 to 3 months above 10 °C or 50 °F and cold, snowy, extremely windy winters below −3 °C or 26.6 °F, although usually above −10 °C or 14 °F. The chain ranges from temperate to sub-Arctic climate types, and the vegetative cover consequently ranges from tundra in the north to dense spruce and larch forests on the larger southern islands. The highest elevations on the islands are Alaid Volcano (highest point: 2,339 m or 7,674 ft) on Atlasov Island at the northern end of the chain and Tyatya volcano (1,819 m or 5,968 ft) on Kunashir Island at the southern end. Landscape types and habitats on the islands include many kinds of beach and rocky shores, cliffs, wide rivers and fast gravelly streams, forests, grasslands, alpine tundra, crater lakes and peat bogs. The soils are generally productive, owing to the periodic influxes of volcanic ash and, in certain places, owing to significant enrichment by seabird guano. However, many of the steep, unconsolidated slopes are susceptible to landslides and newer volcanic activity can entirely denude a landscape. Only the southernmost island has large areas covered by trees, while more northerly islands have no trees, or spotty tree cover.
Overall, automated synthesis has improved the efficiency for the parallel synthesis and combinatorial methods of polymers. These techniques aim to design new materials, in addition to studying the relationships of their structure and properties. However, while screening for polymers enables this investigation, it becomes increasingly demanding for researchers to create the libraries for these synthetic compositions. In addition, preparation requires a large number of repetitive reactions to be completed, leading to an immense burden of planning and labor. Using automated synthesis, this process can be refined, increasing the efficiency of the reaction and removing the impact of human error.
Anthony Tiran Todd (December 4, 1954 – November 6, 2024) was an American actor. Known for his distinctly deep and gravelly voice, he amassed numerous credits on screen and in video games since the 1980s, including the title character in the Candyman film series (1992–2021) and William Bludworth in the Final Destination franchise (2000–2025). For the former, he was nominated at the Critics' Choice and Fangoria Chainsaw Awards. Todd's films include Platoon (1986), Night of the Living Dead (1990), The Crow (1994), The Rock (1996), Wishmaster (1997), Hatchet, Minotaur (both 2006), The Man from Earth (2007), Frankenstein (2015), Death House (2017), and Hell Fest (2018). On television, he played Kurn in Star Trek: The Next Generation (1990–1991) and Star Trek: Deep Space Nine (1996), Lord Haikon on Stargate SG-1 (2005–2006), and appeared in the MTV series Scream (2019) and Devil May Cry (2025). Todd was a prolific voice actor, notably voicing the Vortigaunts in the Half-Life series of games, the Fallen in Michael Bay's Transformers: Revenge of the Fallen (2009), Zoom in The Flash (2014–2023), Darkseid in the DC Animated Movie Universe (2015–2020), Venom in the video game Marvel's Spider-Man 2 (2023), and Locus in the video game Indiana Jones and the Great Circle (2024). For Spider-Man 2, he received a British Academy Games Award nomination.
== History == Insulin was first used as a medication in Canada by Charles Best and Frederick Banting in 1922. This is a chronology of key milestones in the history of the medical use of insulin. For more details on the discovery, extraction, purification, clinical use, and synthesis of insulin, see Insulin
=== Prototrophy === Two natural pathways for PLP are currently known: one requires deoxyxylulose 5-phosphate (DXP), while the other does not, hence they are known as DXP-dependent and DXP-independent. These pathways have been studied extensively in Escherichia coli and Bacillus subtilis, respectively. Despite the disparity in the starting compounds and the different number of steps required, the two pathways possess many commonalities.
Sources: en.wikipedia.org
== Applications == Linear elasticity is used widely in the design and analysis of structures such as beams, plates and shells, and sandwich composites. This theory is also the basis of much of fracture mechanics. Hyperelasticity is primarily used to determine the response of elastomer-based objects such as gaskets and of biological materials such as soft tissues and cell membranes.
Embalming chemicals are a variety of preservatives, sanitizers, disinfectant agents, and additives used in modern embalming to temporarily delay decomposition and restore a natural appearance for viewing a body after death. A mixture of these chemicals is known as embalming solution, and is used to preserve deceased individuals, sometimes only until the funeral, other times indefinitely. Typical embalming solution contains a mixture of formaldehyde, glutaraldehyde, methanol, humectants and wetting agents, and other solvents that can be used. The formaldehyde content generally ranges from 5–35%, and the methanol content may range from 9–56%. Environmentalists sometimes have concerns about embalming because of the harmful chemicals involved and their potential interactions with the environment. Recently, more eco-friendly embalming methods have become available, including formaldehyde-free mixtures of chemicals.
== Use in meat production == In 2026, China refused a shipment of Argentinian beef that tested positive for chloramphenicol and banned any future shipments from that major refrigerator. The antibiotic is banned in meat production in both China and Argentina.
Thousands of suspicious transactions have been detected in French overseas territories. Free trade zones such as Aruba, meanwhile, remain the preferred areas for money laundering. The offshore banking centers, the secret bank accounts and the tourist complexes are the channels through which the launderers whiten the proceeds of the illicit money. Casinos continue to attract organizations that deal with money laundering. Aruba and the Netherlands Antilles, the Cayman Islands, Colombia, Mexico, Panama and Venezuela are considered high priority countries in the region, due to the strategies used by the washers.
Sources: en.wikipedia.org
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.
It was developed in the Soviet Union during the early 1980s by groups at the Institute of Molecular Genetics in Moscow. Russian approval for intranasal use followed, and it has been marketed there since. Western laboratories encountered it mainly through translated literature and, later, through online research-chemical trade.
It holds a Russian registration as a prescription nasal product but has no approval from the European Medicines Agency or the United States Food and Drug Administration. Buyers outside Russia usually receive material sold strictly for laboratory research. That distinction matters because research-grade and pharmaceutical-grade products carry different documentation and testing expectations.
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。