Oxidation raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-07-28 and is reviewed periodically as new material appears.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
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。
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 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.
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.
Lasofoxifene, sold under the brand name Fablyn, is a nonsteroidal selective estrogen receptor modulator (SERM) which is marketed by Pfizer in Lithuania and Portugal for the prevention and treatment of osteoporosis and for the treatment of vaginal atrophy, and the result of an exclusive research collaboration with Ligand Pharmaceuticals (LGND). It also appears to have had a statistically significant effect of reducing breast cancer in women according to a study published in The Journal of the National Cancer Institute.
Cefiderocolα Ceftazidime/avibactam (ceftazidime + avibactam)α Ceftolozane/tazobactam (ceftolozane + tazobactam)α Colistinα Fosfomycinα Linezolidα Meropenem/vaborbactam (meropenem + vaborbactam)α Plazomicinα Polymyxin Bα
By starting from a weaker mobile phase and strengthening it during the runtime, gradient elution decreases the retention of the later-eluting components so that they elute faster, giving narrower (and taller) peaks for most components, while also allowing for the adequate separation of earlier-eluting components. This also improves the peak shape for tailed peaks, as the increasing concentration of the organic eluent pushes the tailing part of a peak forward. This also increases the peak height (the peak looks "sharper"), which is important in trace analysis. The gradient program may include sudden "step" increases in the percentage of the organic component, or different slopes at different times – all according to the desire for optimum separation in minimum time. In isocratic elution, the retention order does not change if the column dimensions (length and inner diameter) change – that is, the peaks elute in the same order. In gradient elution, however, the elution order may change as the dimensions or flow rate change. if they are no scaled down or up according to the change The driving force in reversed phase chromatography originates in the high order of the water structure. The role of the organic component of the mobile phase is to reduce this high order and thus reduce the retarding strength of the aqueous component.
=== Personal life === Flory was born in Sterling, Illinois, on June 19, 1910 to Ezra Flory and Martha Brumbaugh. His father worked as a clergyman-educator, and his mother was a school teacher. His ancestors were German Huguenots, who traced their roots back to Alsace. He first gained an interest in science from Carl W Holl, who was a chemistry professor at Manchester College. In 1936, he married Emily Catherine Tabor. They had three children together: Susan Springer, Melinda Groom and Paul John Flory, Jr. His first position was at DuPont with Wallace Carothers. He was posthumously inducted into the Alpha Chi Sigma Hall of Fame in 2002. Flory died on September 9, 1985, following a heart attack. His wife Emily died in 2006 aged 94.
Sources: en.wikipedia.org
Genetic engineering and cloning – Different monoclonal antibodies or antibody fragments are fused. Recombinant DNA technology is applied to generate one single, bispecific antibody. Preparation of expression system – An expression system is chosen and prepared for antibody expression. Frequently used expression systems for therapeutic bispecific antibodies are mammalian cells, such as CHO cells, as they are effective in performing complex post-translational modifications. Transfection and protein production – Either via stable or transient transfection, genetic information of the desired bispecific antibodies is inserted into the expression system, which consequently expresses the proteins accordingly. Protein purification – Steps to isolate and enrich bispecific antibodies are taken. This can include several purification processes, such as protein A affinity chromatography or peptide tagging. Antibody characterization – Characterization and quality control conclude the production process. Effector functions, stability and binding specificity are examined at this stage.
Lots of love from Teddy RyderTheodore Ryder became a librarian in Hartford, Connecticut and lived a life without significant diabetes-related complications. He remained on friendly terms with Banting through regular correspondence until his death in 1941. Banting visited Theodore Ryder twice in the years following his treatment. The letters from Ryder to Banting are part of his estate and have been reproduced several times in medical history treatises on the medical history of diabetes. The collection of letters from Banting to Ryder has been in the holdings of the Thomas Fisher Library at the University of Toronto since 1999. In one of these letters, Banting wrote in December 1938, among other things:I shall always follow your career with interest and you will forgive me if I add, a little pride, because I shall always remember the difficult times we had in the early days of insulin. The outstanding thing I remember was your strength and fortitude in observing your diet and the manly way in which you stood up to the punishment of hypodermic injections. I am sure that you will be a success in life if you maintain the same spirit in meeting the rebuffs of the world.Theodore Ryder rose to prominence in the 1980s, as from this point onwards the length of time that he had lived with his illness and his state of health made him an exception even among long-term survivors of diabetes. The American Diabetes Society sells a coloring book for preschool children called “Teddy Ryder Rides Again” that aims to provide them with basic knowledge about the disease and its treatment.
=== EC 1.14.20 With 2-oxoglutarate as one donor, and the other dehydrogenated === EC 1.14.20.1: deacetoxycephalosporin-C synthase EC 1.14.20.2: Now EC 1.14.11.59, 2,4-dihydroxy-1,4-benzoxazin-3-one-glucoside dioxygenase EC 1.14.20.3: (5R)-carbapenem-3-carboxylate synthase EC 1.14.20.4: anthocyanidin synthase EC 1.14.20.5: flavone synthase I EC 1.14.20.6: flavonol synthase EC 1.14.20.7: 2-oxoglutarate/L-arginine monooxygenase/decarboxylase (succinate-forming) EC 1.14.20.8: (–)-deoxypodophyllotoxin synthase EC 1.14.20.9: L-tyrosine isonitrile desaturase EC 1.14.20.10: L-tyrosine isonitrile desaturase/decarboxylase EC 1.14.20.11: 3-[(Z)-2-isocyanoethenyl]-1H-indole synthase EC 1.14.20.12: 3-[(E)-2-isocyanoethenyl]-1H-indole synthase EC 1.14.20.13: 6β-hydroxyhyoscyamine epoxidase EC 1.14.20.14: hapalindole-type alkaloid chlorinase EC 1.14.20.15: L-threonyl-[L-threonyl-carrier protein] 4-chlorinase
Many street-level harm-reduction strategies have succeeded in reducing HIV transmission in people who inject substances and sex-workers. HIV education, HIV testing, condom use, and safer-sex negotiation greatly decreases the risk of acquiring and transmitting HIV.
MSPs vote 68–55 in favour of the 2024 Scottish budget, which includes a council tax freeze and 45% and 48% income tax rates for higher earners. Fergus Ewing loses his appeal against a week-long suspension from the SNP group at Holyrood in September 2023 after he criticised the party leadership. MPs vote to suspend Scott Benton from Parliament for 35 days, triggering a recall petition. 28 February – The UK government announces a £31m financial package to improve MPs security. Pro-Palestinian groups say they will continue to march after Home Secretary James Cleverly questioned whether holding regular marches "adds value" to calls for a ceasefire in Gaza during an interview with The Times. The High Court in Belfast rules that conditional immunity from prosecutions for Troubles-era crimes, contained in the Northern Ireland Troubles (Legacy and Reconciliation) Act 2023, is in breach of the European Convention on Human Rights. Addressing a meeting of police leaders, Sunak warns of a "growing consensus that mob rule is replacing democratic rule" and says that "a pattern of increasingly violent and intimidatory [sic] behaviour" cannot be allowed to stop elected representatives doing their job. 29 February – 2024 Rochdale by-election: In an unusually chaotic by-election, George Galloway wins for the Workers Party of Britain, marking his return to parliament. Independent candidate David Tully comes second, with the Conservative candidate Paul Ellison coming third. Both the Labour and Green Party candidates were disowned by their respective parties.
Sources: en.wikipedia.org
== Substrates == The substrate specificity of 5-HEDH has been evaluated in a variety of intact cells and in crude microsome preparations isolated from cultured human blood monocytes differentiated into macrophages. These studies indicate that the enzyme efficiently oxidizes long chain unsaturated fatty acids possessing a hydroxy residue at carbon 5 and a trans double bond at carbon 6 to their corresponding 5-oxo products. It is therefore most efficient in metabolizing 5(S)-HETE to 5-oxo-ETE and, with somewhat lesser efficiency, in metabolizing other 5(S)-hydroxyl-6-trans unsaturated fatty acids such as 5(S)-hydroxy-eicosapentaenoic acid, 5(S)-hydroxy-eicosatrienoic acid, 5(S)-hydroxy-eicosadeinoic acid, 5(S)-hydroxy-eicosamonoenoic acid, 5(S)-hydroxy-octadecadienoic acid, 5(S),15(S)-dihydroxyeicosatetraenoic acid, and the 6-trans isomer of leukotriene B4 (which is a 5(S),12(S)-dihydroxyeicosatetraeonic acid) to their corresponding oxo analogs. 5-HEDH has relatively little ability to oxidize 5(S)-hydroxyl-tetradecadienoic acid, the R stereoisomer of 5(S)-HETE (5(R)-HETE), or a racemic mixture of 8-HETE, and does not oxidize 12(S)-HETE, 15(S)-HETE, leukotriene B4, a racemate mixture of 9-HETE, a racemate mixture of 11-HETE, or a 5(S)-hydroxy-6-trans 12 carbon dienoic fatty acid. 5-HEDH is therefore hydroxy dehydrogenase that acts in a stereospecific manner to oxidize 5(S)-hydoxy residues in 6-trans unsaturated intermediate but not short-chain fatty acids.
Depleted uranium (DU), also referred to in the past as Q-metal, depletalloy, or D-38, is uranium with a lower content of the fissile isotope 235U than natural uranium. The less radioactive and non-fissile 238U is the main component of depleted uranium. It is antonymous to "enriched uranium". Uranium is notable for the extremely high density of its metallic form: at 19.1 grams per cubic centimetre (0.69 lb/cu in), uranium is 68.4% more dense than lead. Because depleted uranium has nearly the same density as natural uranium but far less radioactivity, it is desirable for applications that demand high mass without added radiation hazards. Civilian uses include counterweights in aircraft, radiation shielding in medical radiation therapy, research and industrial radiography equipment, and containers for transporting radioactive materials. Military uses include armor plating and armor-piercing projectiles. The use of DU in ammunitions is controversial because of concerns about potential long-term health effects. Normal functioning of the kidney, brain, liver, heart, and numerous other systems can be affected by exposure to uranium, a toxic metal. It is only weakly radioactive because of the long radioactive half-life of 238U (4.468 billion years) and the low amounts of 234U (half-life about 246,000 years) and 235U (half-life 700 million years). The biological half-life (the average time it takes for the human body to eliminate half the amount in the body) for uranium is about 15 days.
Tin-121m (121mSn) is a nuclear isomer of tin with a half-life of 43.9 years, making it technically a medium-lived fission product. In a normal thermal reactor, it has a very low fission product yield; thus, this isotope is not a significant contributor to nuclear waste. Fast fission or fission of some heavier actinides will produce it at higher yields. For example, its yield from uranium-235 is 0.0007% per thermal fission and 0.002% per fast fission.
In 2003, Burger King hired the Miami-based advertising agency Crispin Porter + Bogusky (CP+B), which completely reorganized its advertising with a series of new campaigns. CP+B was known for having a hip, subversive tack when creating campaigns for its clients, exactly what BK was looking for. Their strategy centered on a redesigned Burger King character used during the 1970s/1980s Burger King Kingdom children's advertising campaign as a caricatured variation, now simply called "the King". While highly successful, some of CP+B's commercials were derided for perceived sexism or cultural insensitivity. Burger King's new owner, 3G Capital, later terminated the relationship with CP+B in 2011 and moved its advertising to McGarryBowen to begin a new product-oriented campaign with expanded demographic targeting. Additionally, CP+B created a series of new characters like the Subservient Chicken and the faux nu-metal band Coq Roq, featured in a series of viral web-based advertisements on sites such as MySpace and various Burger King corporate pages, to complement various television and print promotional campaigns. One of the more successful promotions that CP+B devised was the creation of a series of three advergames for the Xbox 360. Created by UK-based Blitz Games and featuring company celebrity spokesman Brooke Burke, the games sold more than 3.2 million copies, placing them as one of the top selling games along with another Xbox 360 hit, Gears of War.
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.