intranasal route raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-09-15. Anything still debated is marked as such rather than presented as settled.
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.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
| 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。
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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.
== Peptide-mRNA fusions == Puromycin is an analogue of the 3' end of a tyrosyl-tRNA with a part of its structure mimics a molecule of adenosine, and the other part mimics a molecule of tyrosine. Compared to the cleavable ester bond in a tyrosyl-tRNA, puromycin has a non-hydrolysable amide bond. As a result, puromycin interferes with translation, and causes premature release of translation products.
Major depressive disorder (MDD) Post-traumatic stress disorder (PTSD) Generalized anxiety disorder (GAD) Social anxiety disorder (SAD) Obsessive–compulsive disorder (OCD) Panic disorder Neuropathic pain Fibromyalgia Chronic musculoskeletal pain Neuropathic pain involves the descending noradrenergic pathways, which help regulate pain signals. By increasing norepinephrine in these pathways, SNRIs can help reduce pain transmission independently of its antidepressant effects.
To increase the potency they attached a phenolic group to the aromatic ring, N-methyl-trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine. That structure was used to design and develop other opioid receptors antagonists such as alvimopan. Alvimopan was approved later in 2008 for in-hospital use to increase the gastrointestinal function following a partial large or small bowel resection with primary anastomosis. Naloxegol was approved in September 2014 and naldemedine in March 2017, both for the treatment of OIC in adult patients with chronic cancer.
==== Increased antibiotic efficacy ==== Due to the presence of both ROS and excess heat, target cells are less able to resist each effect. Increased heat corresponds to heightened cell membrane permeability, allowing the generation of ROS within the target cell. This also removes/reduces the selectivity observed for PDT, as it is able to enter the cell unhindered.
== Mathematical models == Proprioceptors transfer the mechanical state of the body into patterns of neural activity. This transfer can be modeled mathematically, for example to better understand the internal workings of a proprioceptor or to provide more realistic feedback in neuromechanical simulations. Various proprioceptor models of complexity have been developed. They range from simple phenomenological models to complex structural models, in which the mathematical elements correspond to anatomical features of the proprioceptor. The focus has been on muscle spindles, but Golgi tendon organs and insects' hair plates have been modeled too.
Sources: en.wikipedia.org
== Clinical significance == Seminal plasma contains cadaverine. Elevated levels of cadaverine have been found in the urine of some patients with defects in lysine metabolism. The odor commonly associated with bacterial vaginosis has been linked to cadaverine and putrescine.
==== United Kingdom ==== In the UK, A.G. Barr (the Scottish company that makes IRN BRU) and Ben Shaw's (a Cott brand), manufacture their own brands of cream soda, which are both clear and vanilla-flavoured. Some supermarket chains sell Cream Soda under their respective own brands. Pepsi has also introduced a cream soda flavoured drink.
=== Hybridization === In northern Spain C. brunneus and C. jacobsi form a hybrid zone. It has been suggested that the two species diverged during Pleistocene ice age. Both have the same number of chromosomes (2n=17) with three pairs of long metacentric, four pairs of medium acrocentric, and one pair of short acrocentric chromosomes. Using in situ hybridization an extra rDNA sequence is consistently found on the X chromosome in C. brunneus that is absent in C. jacobsi. The additional rDNA is not expressed in either C. brunneus or the hybrids that possess the rDNA sequence. C. brunneus and C. jacobsi can also be differentiated based on song and by the difference in number of stridulatory pegs located on the hind femur. Using a mark and recapture procedure, the lifetime dispersal of C. brunneus and C. jacobsi were estimated to be similar to other grasshopper species that form hybrid zones. C. brunneus and C. jacobsi are dominant during different months. C. brunneus are dominant in August while C. jacobsi are dominant in June and July. Additionally C. brunneus are only found in valley habitats while C. jacobsi are found in both valley and mountain habitats This suggests both seasonal and temporal isolation between the two species. C. brunneus, C. jacobsi, and hybrid females all show a preference for male C. brunneus and C. jacobsi songs over hybrid male songs. Differences in song traits echeme, syllable, and phrase length have a small epistatic effect but cannot be fully explained by genetic factors.
Chymosin or rennin is a protease found in rennet. It is an aspartic endopeptidase belonging to MEROPS A1 family. It is produced by newborn ruminant animals in the lining of the abomasum to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. It is widely used in the production of cheese. Historically, chymosin was obtained by extracting it from the stomachs of slaughtered calves. Today, most commercial chymosin used in cheese production is produced recombinantly in Escherichia coli, Aspergillus niger var. awamori, and Kluyveromyces lactis.
Sources: en.wikipedia.org
== History == Protein C's anticoagulant role in the human body was first noted by Seegers et al. in 1960, who gave protein C its original name, autoprothrombin II-a. Protein C was first isolated by Johan Stenflo from bovine plasma in 1976, and Stenflo determined it to be a vitamin K-dependent protein. He named it protein C because it was the third protein ("peak C") that eluted from a DEAE-Sepharose ion-exchange chromotograph. Seegers was, at the time, searching for vitamin K-dependent coagulation factors undetected by clotting assays, which measure global clotting function. Soon after this, Seegers recognised Stenflo's discovery was identical with his own. Activated protein C was discovered later that year, and in 1977 it was first recognised that APC inactivates Factor Va. In 1980, Vehar and Davie discovered that APC also inactivates Factor VIIIa, and soon after, Protein S was recognised as a cofactor by Walker. In 1982, a family study by Griffin et al. first associated protein C deficiency with symptoms of venous thrombosis. Homozygous protein C deficiency and the consequent serious health effects were described in 1984 by several scientists. cDNA cloning of protein C was first performed in 1984 by Beckmann et al. which produced a map of the gene responsible for producing protein C in the liver. In 1987 a seminal experiment was performed (Taylor et al.) whereby it was demonstrated that activated protein C prevented coagulopathy and death in baboons infused with lethal concentrations of E. coli. In 1993, a heritable resistance to APC was detected by Dahlbäck et al.
== Treatment == There is no definitive treatment for hyperandrogenism as it varies with the underlying condition that causes it. As a hormonal symptom of PMOS, menopause, and other endocrine conditions, it is primarily treated as a symptom of these conditions. Drugs may be considered only in women who do not plan on becoming pregnant in the near future. Some effective drugs for facial hirsutism includes eflornithine, which may cause birth defects in pregnant women. Retinoids and antibiotics can be used for acne and minoxidil for alopecia. Systemically, it is treated with antiandrogens such as cyproterone acetate, flutamide and spironolactone to reduce androgenic signaling. For hyperandrogenism caused by late-onset congenital adrenal hyperplasia (LOCAH), treatment is primarily focused on providing the patient with glucocorticoids to combat the low cortisol production and the corresponding increase in androgens caused by the increase in size of the adrenal glands. Estrogen-based oral contraceptives are used to treat both LOCAH- and PMOS-associated hyperandrogenism. These hormonal treatments reduce the androgen excess and suppress adrenal androgen production, bringing about a significant decrease in hirsutism. Hyperandrogenism is often managed symptomatically. Hirsutism and acne both respond well to the hormonal treatments described above, with 60–100% of patients reporting an improvement in hirsutism. Androgenic alopecia however, does not show an improvement with hormonal treatments and requires other treatments, such as hair transplantation.
Under the weight of this offensive, Chinese forces drove MacArthur's forces out of North Korea and captured Seoul, but were subsequently pushed back south of Pyongyang north of the 38th Parallel. The war also catalyzed the rapid modernization of the People's Liberation Army Air Force (PLAAF). In 1962, the PLA Ground Force also fought India in the Sino-Indian War. In a series of border clashes in 1967 with Indian troops, the PLA suffered heavy numerical and tactical losses. Before the Cultural Revolution, military region commanders tended to remain in their posts for long periods. The longest-serving military region commanders were Xu Shiyou in the Nanjing Military Region (1954–74), Yang Dezhi in the Jinan Military Region (1958–74), Chen Xilian in the Shenyang Military Region (1959–73), and Han Xianchu in the Fuzhou Military Region (1960–74). In May 1965 during the Cultural Revolution, PLA abandoned the use of the military ranks that it had adopted in 1955. The Central Military Commission had deemed that ranks were an expression of bourgeois right and hierarchy which led to individualist attitudes, inequality, and a sense of disunity. This was reversed in September 1988. The establishment of a professional military force equipped with modern weapons and doctrine was the last of the Four Modernizations announced by Zhou Enlai and supported by Deng Xiaoping. In keeping with Deng's mandate to reform, the PLA has demobilized millions of men and women since 1978 and has introduced modern methods in such areas as recruitment and manpower, strategy, and education and training.
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.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.