The short version of counterion fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-18 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.
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.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
| 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 |
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.
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.
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。
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.
== As a drug target == Aberrant activation of NF-κB is frequently observed in many cancers. Moreover, suppression of NF-κB limits the proliferation of cancer cells. In addition, NF-κB is a key player in the inflammatory response. Hence methods of inhibiting NF-κB signaling has potential therapeutic application in cancer and inflammatory diseases. Both the canonical and non-canonical NF-κB pathways require proteasomal degradation of regulatory pathway components for NF-κB signalling to occur. The proteosome inhibitor Bortezomib broadly blocks this activity and is approved for treatment of NF-κB driven Mantle Cell Lymphoma and Multiple Myeloma. The discovery that activation of NF-κB nuclear translocation can be separated from the elevation of oxidant stress gives a promising avenue of development for strategies targeting NF-κB inhibition. The drug denosumab acts to raise bone mineral density and reduce fracture rates in many patient sub-groups by inhibiting RANKL. RANKL acts through its receptor RANK, which in turn promotes NF-κB, RANKL normally works by enabling the differentiation of osteoclasts from monocytes. Disulfiram, olmesartan and dithiocarbamates can inhibit the NF-κB signaling cascade. Effort to develop direct NF-κB inhibitor has emerged with compounds such as (-)-DHMEQ, PBS-1086, IT-603 and IT-901. (-)-DHMEQ and PBS-1086 are irreversible binder to NF-κB while IT-603 and IT-901 are reversible binder. DHMEQ covalently binds to Cys 38 of p65. Anatabine's antiinflammatory effects are claimed to result from modulation of NF-κB activity.
The process of genetically engineering mammals is slow, tedious, and expensive. However, new technologies are making genetic modifications easier and more precise. The first transgenic mammals were produced by injecting viral DNA into embryos and then implanting the embryos in females. The embryo would develop and it would be hoped that some of the genetic material would be incorporated into the reproductive cells. Then researchers would have to wait until the animal reached breeding age and then offspring would be screened for the presence of the gene in every cell. The development of the CRISPR-Cas9 gene editing system as a cheap and fast way of directly modifying germ cells, effectively halving the amount of time needed to develop genetically modified mammals.
Production of biomass (viable cellular material) Production of extracellular metabolites (chemical compounds) Production of intracellular components (enzymes and other proteins) Transformation of substrate (in which the transformed substrate is itself the product) These types are not necessarily disjoined from each other, but provide a framework for understanding the differences in approach. The organisms used are typically microorganisms, particularly bacteria, algae, and fungi, such as yeasts and molds, but industrial fermentation may also involve cell cultures from plants and animals, such as CHO cells and insect cells. Special considerations are required for the specific organisms used in the fermentation, such as the dissolved oxygen level, nutrient levels, and temperature. The rate of fermentation depends on the concentration of microorganisms, cells, cellular components, and enzymes as well as temperature, pH and level of oxygen for aerobic fermentation. Product recovery frequently involves the concentration of the dilute solution.
=== Advanced treatment plant technology === For some emerging contaminants, several advanced technologies—sonolysis, photocatalysis, Fenton-based oxidation and ozonation—have treated pollutants in laboratory experiments. Another technology is "enhanced coagulation" in which the treatment entity would work to optimize filtration by removing precursors to contamination through treatment. In the case of THMs, this meant lowering the pH, increasing the feed rate of coagulants, and encouraging domestic systems to operate with activated carbon filters and apparatuses that can perform reverse osmosis. Although these methods are effective, they are costly, and there have been many instances of treatment plants being resistant to pay for the removal of pollution, especially if it wasn't created in the water treatment process as many EC's occur from runoff, past pollution sources, and personal care products. It is also difficult to incentivize states to have their own policies surrounding contamination because it can be burdensome for states to pay for screening and prevention processes. There is also an element of environmental injustice, in that lower income communities with less purchasing and political power cannot buy their own system for filtration and are regularly exposed to harmful compounds in drinking water and food. However, recent treads for light-based systems shows great potential for such applications. With the decrease in cost of UV-LED systems and growing prevalence of solar powered systems, it shows great potential to remove CEC while keeping costs low.
Sources: en.wikipedia.org
Guzmán G. (1983). The genus Psilocybe: A Systematic Revision of the Known Species Including the History, Distribution and Chemistry of the Hallucinogenic Species. Nova Hedwigia Beihefte. Vol. 74. Berlin: J. Cramer. ISBN 978-3-7682-5474-8. Bresinsky A, Besl H (1989). A Colour Atlas of Poisonous Fungi: a Handbook for Pharmacists, Doctors, and Biologists. London, UK: Manson Publishing Ltd. ISBN 978-0-7234-1576-3. Stamets P. (1996). Psilocybin Mushrooms of the World: An Identification Guide. Berkeley, California: Ten Speed Press. ISBN 978-0-89815-839-7. Gartz J. (1997). Magic Mushrooms Around the World. Los Angeles, California: LIS Publications. ISBN 978-0-9653399-0-2.
== Structure == The gene encoding LepA is known to be the first cistron as part of a bicistron operon. LepA is a polypeptide of 599 amino acids with a molecular weight of 67 kDa. The amino acid sequence of LepA indicates that it is a G protein, which consists of five known domains. The first four domains are strongly related to domains I, II, III, and V of primary elongation factor EF-G. However, the last domain of LepA is unique. This specific domain resides on the C-terminal end of the protein structure. This arrangement of LepA has been observed in the mitochondria of yeast cells to human cells.
The ion source is the part of the mass spectrometer that transforms the sample from the sample inlet into a stream of ions. There are many techniques with various dimensions for tradeoffs between different choices of ion sources, in terms of monetary cost, accuracy, precision, compatibility with other stages of spectroscopy, ease of use, etc. For example, electron ionization (EI) gives a high degree of fragmentation, yielding highly detailed mass spectra which when skilfully analysed can provide important information for structural elucidation/characterisation and facilitate identification of unknown compounds by comparison to mass spectral libraries obtained under identical operating conditions. However, EI is not suitable for coupling to HPLC, i.e. LC-MS, since at atmospheric pressure, the filaments used to generate electrons burn out rapidly. Thus EI is coupled predominantly with GC, i.e. GC-MS, where the entire system is under high vacuum. Two techniques often used with liquid and solid biological samples include electrospray ionization (invented by John Fenn) and matrix-assisted laser desorption/ionization (MALDI, initially developed as a similar technique Soft Laser Desorption) by K. Tanaka for which a Nobel Prize was awarded and as MALDI by M. Karas and F. Hillenkamp).
This is a list of published International Organization for Standardization (ISO) standards and other deliverables. For a complete and up-to-date list of all the ISO standards, see the ISO catalogue. The standards are protected by copyright and most of them must be purchased. However, about 300 of the standards produced by ISO and IEC's Joint Technical Committee 1 (JTC 1) have been made freely and publicly available.
The major source of nickel exposure is oral consumption, as nickel is essential to plants. Typical background concentrations of nickel do not exceed 20 ng/m3 in air, 100 mg/kg in soil, 10 mg/kg in vegetation, 10 μg/L in freshwater and 1 μg/L in seawater. Environmental concentrations may be increased by human pollution. For example, nickel-plated faucets may contaminate water and soil; mining and smelting may dump nickel into wastewater; nickel–steel alloy cookware and nickel-pigmented dishes may release nickel into food. Air may be polluted by nickel ore refining and fossil fuel combustion. Humans may absorb nickel directly from tobacco smoke and skin contact with jewelry, shampoos, detergents, and coins. A less common form of chronic exposure is through hemodialysis as traces of nickel ions may be absorbed into the plasma from the chelating action of albumin. The average daily exposure is not a threat to human health. Most nickel absorbed by humans is removed by the kidneys and passed out of the body through urine or is eliminated through the gastrointestinal tract without being absorbed. Nickel is not a cumulative poison, but larger doses or chronic inhalation exposure may be toxic, even carcinogenic, and constitute an occupational hazard. Nickel compounds are classified as human carcinogens based on increased respiratory cancer risks observed in epidemiological studies of sulfidic ore refinery workers. This is supported by the positive results of the NTP bioassays with Ni sub-sulfide and Ni oxide in rats and mice.
Sources: en.wikipedia.org
== Nonrennet coagulation == Many soft cheeses are produced without use of rennet, by coagulating milk with acid, such as citric acid or vinegar, or the lactic acid produced by soured milk. Cream cheese, paneer, rubing, and other acid-set cheeses are traditionally made this way. The acidification can also come from bacterial fermentation such as in cultured milk. Vegan alternatives to cheese are manufactured without using animal milk but instead use soy, wheat, rice or cashew. These can be coagulated with acid using sources such as vinegar or lemon juice.
Several forms of genital piercings can be made in the vulva, and include the Christina, Princess Albertina, Isabella, Nefertiti, fourchette, and labia piercings. Piercings are usually performed for aesthetic purposes, but some forms like the clitoral hood piercing (or rarely glans piercing) might also enhance pleasure during sex. Though they are common in traditional cultures, intimate piercings are a fairly recent trend in Western society. Other forms of permanent modifications of the vulva for cultural, decorative or aesthetic reasons are genital tattoos or scarification (so-called "Hanabira"). Female genital surgery includes laser resurfacing of the labia to remove wrinkles, labiaplasty (reducing the size of the labia) and vaginoplasty. In September 2007, the American College of Obstetricians and Gynecologists (ACOG) issued a committee opinion on these and other female genital surgeries, including "vaginal rejuvenation", "designer vaginoplasty", "revirgination", and "G-spot amplification". This opinion states that the safety of these procedures has not been documented. The ACOG and the ISSVD recommend that women seeking these surgeries need to be informed about the lack of data supporting these procedures and the potential associated risks such as infection, altered sensation, dyspareunia, adhesions, and scarring. With the growing popularity of female cosmetic genital surgeries, the practice increasingly draws criticism from an opposition movement of cyberfeminist activist groups and platforms, called the labia pride movement.
It is commonly suggested by scholars that the EPRDF's decision to establish a federal administrative structure along ethnic lines was a move towards reinforcing its political dominance. By dividing the country and facilitating the creation of accompanying ethnically-based parties under the government's control, the TPLF (which represented less than 10% of the country's population) could intensify its hold on power. Dissatisfied opposition parties argued that this form of federalization was not appropriate for the country. For instance, the All Amhara People's Organisation (AAPO) and the Ethiopian Democratic Union Party expressed in 2000 that they preferred a strong unitary state with representation of the country's nationalities at the core. Other groups, such as the Oromo National Congress (ONC) and the Ethiopia Democratic Party (EDP), were not opposed to the idea of establishing a federal system, arguing that it set the foundation for regional autonomy, but believed that it was a mistake for it to conducted along ethnic lines.
=== Environmental rehabilitation === When the factory was closed in 1986, pipes, drums and tanks were sold. The MIC and the Sevin plants are still there, as are storages of different residues. Isolation material is falling down and spreading. The area around the plant was used as a dumping area for hazardous chemicals. In 1982, tube wells in the vicinity of the UCIL factory had to be abandoned and tests in 1989 performed by UCC's laboratory revealed that soil and water samples collected near the factory and inside the plant were toxic to fish. Several other studies had also shown polluted soil and groundwater in the area. Reported polluting compounds include 1-naphthol, naphthalene, Sevin, tarry residue, toxic organochlorines, volatile organochlorine compounds, mercury, chromium, copper, nickel, lead, hexachloroethane, hexachlorobutadiene, and the pesticide HCH (Hexachlorocyclohexane). In order to provide safe drinking water to the population around the UCIL factory, the government of Madhya Pradesh proposed a water-supply improvement scheme. In December 2008, the Madhya Pradesh High Court decided that the toxic waste should be incinerated at Ankleshwar in Gujarat, which was met by protests from activists all over India. On 8 June 2012, the centre for incineration of toxic Bhopal waste agreed to pay ₹250 million (US$2.6 million) to dispose of UCIL chemical plants' waste in Germany. On 9 August 2012, Supreme court directed the Union and Madhya Pradesh Governments to take immediate steps for disposal of toxic waste lying around and inside the factory within six months.
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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.