This is a working overview of Electrospray ionization, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity specification | ≥ 95 % of peak area by HPLC | Some suppliers quote 98 % or higher |
| Identity confirmation | Mass spectrometry (electrospray or MALDI) | Observed mass is compared with the calculated mass |
| Common analytical method | Reversed-phase HPLC on a C18 column | Acetonitrile and water gradients with trifluoroacetic acid |
| Primary degradation route | Oxidation of the methionine residue | Yields a sulfoxide that separates cleanly on chromatography |
| Storage of dissolved material | Aliquoted and frozen at −20 °C or below | Single-use aliquots avoid repeated temperature cycling |
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.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
In mid-2001, a report by the American Civil Liberties Union (ACLU), "The Drug War is the New Jim Crow", tied the vastly disproportionate rate of African American incarceration to the range of rights lost once convicted. It stated that, while "whites and blacks use drugs at almost exactly the same rates ... African-Americans are admitted to state prisons at a rate that is 13.4 times greater than whites, a disparity driven largely by the grossly racial targeting of drug laws." Between federal and state laws, those convicted of even simple possession could lose the right to vote, eligibility for educational assistance including loans and work-study programs, custody of their children, and personal property including homes. The report concluded that the cumulative effect of the war on drugs amounted to "the US apartheid, the new Jim Crow". This view was further developed by lawyer and civil rights advocate Michelle Alexander in her 2010 book, The New Jim Crow: Mass Incarceration in the Age of Colorblindness. In the year 2000, the US drug-control budget reached $18.4 billion, nearly half of which was spent financing law enforcement while only one-sixth was spent on treatment. In the year 2003, 53% of the requested drug control budget was for enforcement, 29% for treatment, and 18% for prevention. During his presidency, Barack Obama (2009–2017) implemented his "tough but smart" approach to the war on drugs. While he claimed that his method differed from those of previous presidents, in reality, his practices were similar.
The likelihood of ionization is a function of the filament temperature, the work function of the filament substrate and the ionization energy of the element. This is summarised in the Saha–Langmuir equation:
This was from the notion that depression was primarily due to norepinephrine deficits, partly based on the fact that drugs that relieve depression increase brain norepinephrine levels. To date, a great number of potent and selective and mixed norepinephrine reuptake inhibitors (NRIs) have been marketed as antidepressants. The first commercially available selective norepinephrine reuptake inhibitor (sNRI) was reboxetine (Edronax) and was developed as a first-line therapy for major depressive disorder. The selectivity of reboxetine for the norepinephrine transporter (NET) results in benign side effect profile because the drug is well tolerated. In the laboratories of Chemistry of Farmitalia Carlo Erba (Milan, Italy), reboxetine was synthesized according to the general method described by Melloni et al. In 1993 Kabi Pharmacia, Swedish based pharmaceutical giant, bought Farmitalian and in 2003 Pfizer bought Pharmacia. Atomoxetine (Strattera) is another potent and selective NRI which is also effective and well tolerated treatment for adults with ADHD. This drug was the first ADHD treatment to be specially approved for adult use. Studies showed that atomoxetine is a nonstimulant and carries negligible risk of abuse. This discovery was groundbreaking as a beneficial new treatment option for adults with ADHD, specially those patients at risk of substance abuse.
Sources: en.wikipedia.org
== People == C. Rajagopalachari, Indian politician Christina Ricci, American actress Chris Rock, American comedian and actor Cristiano Ronaldo, Portuguese footballer Christopher Reeve, American actor A Royal cypher representing a monarch Charles Rex (CR / CIIIR), the royal cypher of King Charles III
=== Haber's ammonia (1913) === The development of the Haber process from 1908 to 1912, made it possible to synthesize ammonia (a major industrial chemical as the primary source of nitrogen), and, after acquiring exclusive rights to the process, in 1913, BASF started a new production plant in Oppau, adding fertilizers to its product range. BASF also acquired and began mining anhydrite for gypsum at the Kohnstein in 1917.
== Sources == Vitamin K1 is primarily from plants, especially leafy green vegetables. Small amounts are provided by animal-sourced foods. Vitamin K2 is primarily from animal-sourced foods, with poultry and eggs much better sources than beef, pork or fish. One exception to the latter is nattō, which is made from bacteria-fermented soybeans. It is a rich food source of vitamin K2 variant MK-7, made by the bacteria.
Midtown Raleigh is a relatively new term used to describe the residential and commercial area lying on the northside of the I-440 Beltline and is part of North Raleigh. It is roughly framed by Glenwood/Six Forks Road to the West, Wake Forest Road to the East, and Millbrook Road to the North. It includes shopping centers such as North Hills and Crabtree Valley Mall. It also includes North Hills Park and part of the Raleigh Greenway System. The term was coined by the Greater Raleigh Chamber of Commerce, developer John Kane and planning director Mitchell Silver. The News & Observer newspaper started using the term for marketing purposes only. The Midtown Raleigh Alliance was founded on July 25, 2011, as a way for community leaders to promote the area. The center of the area, especially around the North Hills development at the junction of Six Forks Road and the Beltline, is experiencing rapid urbanization as several high-rise buildings have been built since 2010.
Sources: en.wikipedia.org
Coeliac disease (Commonwealth English) or celiac disease (American English) is a chronic autoimmune disease, mainly affecting the small intestine. It is caused by an abnormal immune system response to gluten, a protein found in wheat and other grains such as barley and rye. Coeliac disease causes a wide range of symptoms and complications that can affect multiple organs outside the gastrointestinal tract. The classic form of the disease can affect any age group, but is usually diagnosed in early childhood and causes symptoms of malabsorption such as weight loss, diarrhoea, and stunted growth. Non-classic coeliac disease is more commonly seen in adults, characterised by vague abdominal symptoms and complications in organs outside the gastrointestinal tract, such as bone disease, anaemia, and other consequences of nutritional deficiencies. In people with a genetic predisposition to the condition, eating gluten causes inflammation in the small intestine, damaging its lining and leading to malabsorption. The development of coeliac disease is believed to be influenced by other environmental factors, such as infections. Diagnosis is based on symptoms, blood tests, and biopsies of the small intestine. For people who have already cut gluten from their diet, gluten may need to be reintroduced before testing to ensure an accurate diagnosis. A lack of awareness and the diverse symptoms, which overlap with other disorders, often complicate the diagnosis by leading to a delay in diagnosis.
Portugal has contributed to the popularity and globalisation of sport through internationally recognised athletes such as Cristiano Ronaldo, Ricardinho, Naide Gomes, and Carlos Lopes, as well as through the popularity of its three largest football clubs. Football is the most popular sport in Portugal. The Portugal men's national football team won the UEFA European Championship in 2016 and the UEFA Nations League in 2019 and 2025. Portugal is among the world's leading futsal countries, with its men's national team having won the FIFA Futsal World Cup in 2021, the UEFA Futsal Championship in 2018 and 2022, and the Futsal Finalissima in 2022. In athletics, the country has set several records and has earned more medals in this sport than in any other at both the Olympic and Paralympic Games. In traditional sport, Portugal is noted for its classical dressage as well as native sports such as jogo do pau and jogo da malha. Portugal has several established sporting centres across the country, including the Algarve and Lisbon, which are international golf destinations and have hosted motorsport events such as Formula One and Grand Prix motorcycle racing, as well as Nazaré and Peniche, which are known for surfing and annually host the TUDOR Nazaré Big Wave Challenge and the MEO Rip Curl Pro Portugal, respectively.
=== Subdivisions === One recent classification recognised 297 species of clematis. Consequently, taxonomists and gardeners subdivide the genus. Several classification systems exist. Magnus Johnson divided Clematis into 19 sections, several with subsections. Christopher Grey-Wilson divided the genus into 9 subgenera (Clematis, Cheiropsis, Flammula, Archiclematis, Campanella, Atragene, Tubulosae, Pseudanemone, Viorna), several with sections and subsections within them. Several of the subdivisions are fairly consistent between these two systems; for example, all of Grey-Wilson's subgenera are used as sections by Johnson. Alternatively, John Howell defined twelve groups: the Evergreen, Alpina, Macropetala, Montana, Rockery, Early Large-Flowered, Late Large-Flowered, Herbaceous, Viticella, Texensis, Orientalis, and Late Mixed groups. Many of the most popular garden forms are cultivars belonging to the Viticella section of the subgenus Flammula as defined by Grey-Wilson. These larger-flowered cultivars are often used within garden designs to climb archways, pergolas, or wall-mounted trellises, or to grow through companion plants. These forms normally have large 12–15 cm diameter upward-facing flowers and are believed to involve crosses of C. patens, C. lanuginosa, and C. viticella. Early-season, large-flowering forms such as 'Nelly Moser' tend towards the natural flowering habit of C. patens or C. lanuginosa while later-flowering forms such as ×jackmanii are nearer in habit to C. viticella.
Sources: en.wikipedia.org
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.
The methionine residue at the start of the chain is vulnerable to oxidation, producing a sulfoxide variant. Amide bonds can also hydrolyze, though more slowly under neutral conditions. Cold storage, oxygen exclusion and minimization of freeze-thaw cycles slow both processes but do not stop them.
A purity number on a certificate does not establish that a powder is the same product as a registered nasal medicine. Counter-ion content, residual solvents and peptide-related impurities may differ between the two. Independent verification is the only way to narrow that gap.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.