This is a working overview of Oxidation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-06 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
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。
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Bruker develops and delivers a wide variety of professional and scientific analysis devices including mass spectrometers, single-Crystal and powder X-ray diffractometers, X-ray tomography devices, NMR spectroscopy devices, fluorescence microscopes, raman spectroscopes, atomic-force microscopes, and profilometers.
In addition to actions at receptors, Semax, as well as a related peptide drug, Selank, have been found to inhibit enzymes involved in the degradation of enkephalins and other endogenous regulatory peptides (IC50 = 10 μM), though the clinical significance of this property is uncertain. As a peptide, Semax has poor oral bioavailability and hence is administered parenterally as a nasal spray or subcutaneous injection.
==== Film and television ==== In season 7 episode 12 of the series House, M.D. is about a patient who has a temporary paralysis and creatine kinase. She has a "perfect memory" due to her hyperthymesia. It later concludes her hyperthymesia is the way her OCD presents and that taking SSRI to treat her OCD will dial down her hyperthymesia. In the 2014 film The Dark Place, the protagonist of the story, Keegan Dark, has hyperthymesia. Keegan uses it to solve the mystery at the heart of the story. His hyperthymesia memories are visually depicted in the movie as "screens" appearing to Keegan, often in an overwhelming and distressing manner. In season 2 episode 2 of the TV show The Blacklist a character involved in criminal banking enterprises identified herself as having hyperthymesia as a skillful trait to avoid leaving a paper trail for illegal activities. She provided the FBI agents in the episode with real examples by recitation of events of dates selected at random. Her skills seemed to be date oriented rather than triggered by "personal experience." Unforgettable (American TV series) The 2015 South Korean TV series Remember: War of the Son portrays a hyperthymestic lawyer who sought to prove the innocence of his father, who had been convicted and sentenced to death for the brutal rape-murder of a neighbour. The 2020 South Korean TV series Find Me in Your Memory portrays the love story between a hyperthymestic news anchorman and an actress with amnesia, connected by a past traumatic event.
1993/1579) Merchant Shipping (Prevention of Oil Pollution) (Amendment) Order 1993 (S.I. 1993/1580) Merchant Shipping (Prevention of Pollution by Garbage) (Amendment) Order 1993 (S.I. 1993/1581) International Carriage of Perishable Foodstuffs (Amendment) Regulations 1993 (S.I. 1993/1589) Swavesey Internal Drainage Board Award Drains Variation Order 1993 (S.I. 1993/1590) Wireless Telegraphy (Short Range Devices) (Exemption) Regulations 1993 (S.I. 1993/1591) Montrose Harbour Revision Order 1993 (S.I. 1993/1592) Local Government Superannuation (Scotland) Amendment Regulations 1993 (S.I. 1993/1593) Severn Bridge Regulations 1993 (S.I. 1993/1595)
== Sources == Benjamin, Denis R. (1995). Mushrooms: poisons and panaceas — a handbook for naturalists, mycologists and physicians. New York: WH Freeman and Company. ISBN 978-0-7167-2600-5. Jordan Peter; Wheeler Steven. (2001). The Ultimate Mushroom Book. London: Hermes House. ISBN 978-1-85967-092-7.
Sources: en.wikipedia.org
== Inhibitors == Proteinase K has two disulfide bonds, but it exhibits higher proteolytic activity in the presence of reducing agents (e.g. 5 mM DTT), suggesting that the presumed reduction of its own disulfide bonds does not lead to its irreversible inactivation. Proteinase K is inhibited by serine protease inhibitors such as phenylmethylsulfonyl fluoride (PMSF), diisopropylfluorophosphate (DFP), or 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF). Proteinase K activity is unaffected by the sulfhydryl modifying reagents: para-chloromercuribenzoic acid (PCMB), N-alpha-tosyl-L-lysyl-chloromethyl-ketone (TLCK), or N-alpha-Tosyl-l-phenylalanine Chloromethyl Ketone (TPCK), although presumably if these reagents were included alongside disulfide reducing reagents which exposed the typically-unavailable Proteinase K thiols, it may then become inhibited.
Raising Cane's Restaurants, LLC, doing business as Raising Cane's Chicken Fingers (commonly referred to as Raising Cane's or Cane's), is an American fast-food chain specializing in chicken fingers. As of 2025, Raising Cane's is ranked third in annual sales for quick-serve chicken chains, behind Chick-fil-A and Popeyes.
== Innovation == The Global Innovation Index 2024, by World Intellectual Property Organization: Thailand ranked 41 of 133 nations. The Global Innovation Index 2019 ranked Thailand 43 of 129 nations. Other ASEAN nations ranked were: Singapore, 8; Malaysia, 35; Vietnam, 42; Philippines, 54; Brunei, 71; Indonesia, 85; Cambodia, 98. The Bloomberg Innovation Index, 2018 ranked Thailand 45 of 50 nations (1=most innovative; 50=less innovative). Singapore was ranked 3 and Malaysia number 26. The Bloomberg Innovation Index, 2017 ranked Thailand 44 of 50 nations (1=most innovative; 50=less innovative), a rise from 47 in the 2016 ranking. Other ASEAN nations ranked were Singapore, 6 of 50 and Malaysia, 23 of 50. The Global Innovation Index 2015 ranked Thailand 55 of 141 (1=best; 141=worst) countries.
Heminasal and total nasal reconstruction The reconstruction rhinoplasty of an extensive heminasal defect or of a total nasal defect is an extension of the plastic surgical principles applied to resolving the loss of a regional aesthetic subunit. The skin layers are replaced with a paramedian forehead flap, but, if forehead skin is unavailable, the alternative corrections include the Washio retroauricular-temporal flap and the Tagliacozzi flap. The nasal skeleton is replaced with a rib-graft nasal dorsum and lateral nasal wall; septal cartilage grafts and conchal cartilage grafts are applied to correct defects of the nasal tip and of the alar lobules. The nasal lining of the distal two-thirds of the nose can be covered with anteriorly based septal mucosal flaps; however, if bilateral septal-flaps are used, the septal cartilage does become devascularized, possibly from iatrogenic septal perforation. Furthermore, if the nasal defect is beyond the wound-correction scope of a septal mucosal flap, the alternative techniques are either an inferiorly based pericranial-flap (harvested from the frontal bone) or a free flap of temporoparietal fascia (harvested from the head), either of which can be lined with free grafts of mucosa to achieve the nasal reconstruction.
== History == In the mid-twentieth century, mumps infections among children were not viewed as a serious public health issue, but adult men may develop debilitating testicular inflammation, which posed particular difficulty among close-quartered soldiers during wartime. As a result, during World War II (1939–1945), the United States government targeted mumps for scientific research. The first experimental mumps vaccine was licensed in 1948; developed from inactivated virus, it only had short-term effectiveness. Improved vaccines became commercially available in the 1960s. In 1963, Maurice Hilleman of Merck & Co. took samples of the mumps virus from his daughter, who had contracted the disease; she became the namesake for the resulting Jeryl Lynn strain. Building on then-recent advances that had led to vaccines for polio and measles, the mumps virus strains were developed in embryonic hens' eggs and chick embryo cell cultures. The resulting strains of virus were less well-suited for human cells, and are thus said to be attenuated. They are sometimes referred to as neuroattenuated in the sense that these strains are less virulent to human neurons than the wild strains. Hilleman's work led to the first effective mumps vaccine, called Mumpsvax. Licensed in 1967, its four-year development set a record for fastest development of a new vaccine, a record later surpassed by the COVID-19 vaccine, which was developed in less than a year.
Sources: en.wikipedia.org
== History == 麹 (Chinese: qū, Japanese: kōji), which means mold used in fermented foods, was first mentioned in the Zhouli (Rites of the Zhou dynasty) in China in 300 BCE. Its development is a milestone in Chinese food technology, for it provides the conceptual framework for three major fermented soy foods: soy sauce, jiang/miso, and douchi, not to mention grain-based wines (including Japanese sake and Chinese huangjiu) and li (the Chinese forerunner of Japanese amazake). The process of making rice wine and fermented bean paste using molds was first documented in the 4th century B.C. In 725 AD the Japanese book Harima no Kuni Fudoki (Geography and Culture of the Harima Province) first mentioned kōji outside of China and described that the Japanese produced kōji with fungal spores from the air. Around the 10th century, the kōji production method underwent a change and moved from the natural sowing system in rice to the so-called tomodane. This involved cultivating kōji until spores were released and using the spores to start a new batch of production. In the Meiji era, the integration of new microbiological techniques made it possible to isolate and propagate kōji in pure cultures for the first time. These advances facilitated the improvement of fungal culture quality and the selection of desirable characteristics. It later became known that Kōji comprises different species of Aspergillus. Aspergillus oryzae was first described in 1878 as Eurotium oryzae Ahlb. and in 1883 as Aspergillus oryzae (Ahlb.) Cohn.
== Treatment in the future == N-terminal acetylation plays a larger role overall in cell homeostasis and changing one of the NATs has a large impact, mostly due to the vast number of substrates that are subjected to N-terminal acetylation. The mechanism and impact on the proteome level are much needed to be studied, to understand the molecular mechanisms underlying the phenotypes of the affected individuals. There could be many proteins involved in such mechanisms, and this needs to be studied to reveal new angles for improved treatment.
By the mid-2000s, Liebling had nearly disappeared from public life. He spent his days isolated in his parents' basement, trapped in a relentless cycle of addiction and self-destructive behavior. The toll of decades of substance abuse was evident in his skeletal frame, which was covered in sores and barely functioning, leading many to believe he was beyond redemption. This chapter of his life, which took an unexpected turn, became the subject of the documentary Last Days Here (2011), directed by Don Argott and Demian Fenton. Filmed over four years, the documentary follows Liebling, who is in his 50s and living in the basement of his parents' house in Alexandria, Virginia, as he battles severe drug addiction. His friend, manager, and longtime Pentagram fan Sean "Pellet" Pelletier took it upon himself to pull Liebling out of the abyss and get him back to music and a healthier life. Alongside Pelletier, the film features interviews with former Pentagram members, friends, Liebling's parents, and his then-girlfriend, Hallie. The documentary ends on a hopeful note; by 2010, Pentagram had returned to the stage, and Liebling was sober, married to Hallie, and expecting their first child. When Argott and Fenton first met Liebling, they had little hope that his story would lead anywhere. "Bobby was in such bad shape when Pellet introduced us to him that we didn't think his story would go anywhere. It really seemed like he was going to smoke himself to death in his parents' basement, something we weren't interested in documenting," Fenton recalled.
Polycarbonates contain Bisphenol A. Since 2008, at least 40 countries have banned the use of plastics containing Bisphenol A in baby bottles due to safety concerns (see Regulation). Bottles made of polycarbonate may be marked as "#7 PC". Bisphenol S (BPS) and Bisphenol F (BPF) have been used as substitutes for BPA. They are structurally similar. Comparisons of BPA, BPS and BPF have found that these chemicals have similar potency and action to BPA and may pose similar dangers in terms of endocrine-disrupting effects. This has led to criticisms of the chemical industry and for calls to deal with bisphenols in groups, not individually. In 2021, the Canadian government agencies Environment and Climate Change Canada (ECCC) and Health Canada (HC) held consultations with the goal of grouping 343 known BPA analogs and functional alternatives. Polyethersulfone plastic (PES) does not contain BPA but does include Bisphenol S (BPS). An assessment of a variety of different baby bottles in use in 2016, reported 4 bottles to be of "high concern", 14 bottles to be of "concern"; and only 6 bottles to be of "no concern" These of "no concern" included two polyamide (PA) and two polyethersulfone (PES) bottles, a stainless steel bottle, and one of the 17 polypropylene (PP) bottles tested. Phthalates, found in polyvinyl chloride (PVC), are another area of concern. Referred to as "everywhere chemicals" because they are so common, phthalates make plastic more flexible, and have been used in pacifiers and nipples or teats for bottles.
Sources: en.wikipedia.org
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.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.