Everything below concerns methionine sulfoxide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-03-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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% or higher | By reversed-phase HPLC area |
| Identity method | Electrospray mass spectrometry | Confirms molecular mass |
| Purity method | Reversed-phase HPLC | Detection near 214 nm |
| Primary degradation | Methionine oxidation | Sulfoxide product, +16 Da |
| Solution storage | 2-8 °C, short term | Aliquot to avoid freeze-thaw |
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.
=== Arrival in Washington === Nixon had been elected in 1968 on the promise of achieving "peace with honor" and ending the Vietnam War. By promising to continue the peace talks which Johnson began in May 1968 in Paris, Nixon admitted that he had ruled out "a military victory" in Vietnam. Nixon wanted a diplomatic settlement similar to the armistice of Panmunjom that ended the Korean War and frequently stated in private he had no intention of being "the first president of the United States to lose a war". To force the North Vietnamese to sign an armistice, Nixon favored a two-pronged approach of the "madman theory" of seeking to act rashly to intimidate the North Vietnamese while at the same time trying using the strategy of "linkage" to improve relations with the Soviet Union and China in order to persuade both these nations to stop sending arms to North Vietnam. In office, Nixon implemented a policy of Vietnamization that aimed to gradually withdraw U.S. troops while expanding the combat role of the South Vietnamese Army so that it would be capable of independently defending its government against the National Front for the Liberation of South Vietnam, a Communist guerrilla organization, and the North Vietnamese army (Vietnam People's Army or PAVN). Kissinger was opposed to Vietnamization.
A denturist in the United States and Canada, clinical dental technologist in the United Kingdom and Ireland, dental prosthetist in Australia, or a clinical dental technician in New Zealand is a member of the oral health care team and role as primary oral health care provider who provides an oral health examination, planning treatment, takes impressions of the surrounding oral tissues, constructs and delivers removable oral prosthesis treatment (including dentures and partial dentures) directly to the patient.
=== Other methods === Of academic interest, palladium acetate, iodine, and oxygen can be used to couple cyclohexyl amine and cyclohexyl isocyanide. Yields of up to 67% have been achieved using this route:
T-tubules are microscopic tubes that run from the cell surface to deep within the cell. They are continuous with the cell membrane, are composed of the same phospholipid bilayer, and are open at the cell surface to the extracellular fluid that surrounds the cell. T-tubules in cardiac muscle are bigger and wider than those in skeletal muscle, but fewer in number. In the centre of the cell they join, running into and along the cell as a transverse-axial network. Inside the cell they lie close to the cell's internal calcium store, the sarcoplasmic reticulum. Here, a single tubule pairs with part of the sarcoplasmic reticulum, called a terminal cisterna, in a combination known as a diad. The functions of T-tubules include rapidly transmitting electrical impulses known as action potentials from the cell surface to the cell's core, and helping to regulate the concentration of calcium within the cell in a process known as excitation-contraction coupling. They are also involved in mechano-electric feedback, as evident from cell contraction induced T-tubular content exchange (advection-assisted diffusion), which was confirmed by confocal and 3D electron tomography observations.
Hydroxyzine, sold under the brand names Atarax (as hydrochloride) and Vistaril (as pamoate) among others, is an antihistamine medication. It is used in the treatment of itchiness, anxiety, insomnia, and nausea (including that due to motion sickness). It is used either by mouth or injection into a muscle. Hydroxyzine works by blocking the effects of histamine. It is a first-generation antihistamine in the piperazine family of chemicals. Common side effects include sleepiness, headache, and dry mouth. Serious side effects may include QT prolongation. It is unclear if use during pregnancy or breastfeeding is safe. It was first made by Union Chimique Belge in 1956 and was approved for sale by Pfizer in the United States later that year. In 2023, it was the 39th most commonly prescribed medication in the United States, with more than 15 million prescriptions.
Sources: en.wikipedia.org
== January 9, 1982 (Saturday) == A frigid blast of Arctic air began in the U.S. Midwest and South, setting records for cold in numerous cities, including a record low in Chicago of 26° below zero F (-32 °C) on the morning of January 10 and a wind chill factor of -100 °F (-73 °C). By January 17, there were 261 deaths attributed to hypothermia form the cold weather. The first World Cup series of cross-country skiing was started by the International Ski Federation, beginning with a meet in West Germany at Reit im Winkl for men and Klingenthal for women. Born: Catherine, Princess of Wales, wife since 2011 of William, Prince of Wales, heir apparent to the British throne; as Catherine Middleton in Reading, Berkshire Anusha Dandekar, Sudanese-born and Australian-raised Indian supermodel, veejay on MTV India, as well as a film actress, known for Juna Furniture (2024) and Baap Manus (2022); in Khartoum
National Food and Nutrition Policy Brazilian Dietary Guidelines (Guia Alimentar para a População Brasileira) National School Feeding Program Physical activity promotion campaigns Food labelling regulations The Brazilian Dietary Guidelines, first published in 2014, received international recognition for emphasising minimally processed foods and warning against excessive consumption of ultra-processed foods. Public health experts continue to debate additional interventions, including taxation of sugar-sweetened beverages, restrictions on food marketing directed at children, and expanded access to obesity treatment services.
== Neem patent == In 1995, the European Patent Office (EPO) granted a patent on an anti-fungal product derived from the neem tree to the United States Department of Agriculture and W. R. Grace. The Indian government challenged the patent when it was granted, claiming that the process for which the patent had been granted had been in use in India for more than 2,000 years. In 2000, the EPO ruled in India's favour, but W. R. Grace appealed, claiming that prior art about the product had never been published in a scientific journal. On March 8, 2005, that appeal was lost and the EPO revoked the Neem patent.
Robin Harper, a former leader of the Scottish Greens, joins Scottish Labour, citing his former party's failure on the environment for his decision. 12 June – MSPs vote for the early release of 500 prisoners in order to ease overcrowding in the Scottish Prison Service. Edinburgh City Council approves plans by AEG to build an 8,500 capacity stadium at Edinburgh Park. 13 June – Stagecoach Group announces plaans to cut services in north Scotland as it launches a review of its operations. 14 June – Five Scotland fans are taken to hospital after their hire car crashed as they left an airport in Germany driving on the wrong side of the road. The Independent Parliamentary Standards Authority clears Douglas Ross of misusing his travel expenses following an investigation. The 2024 Birthday Honours are published. Among Scots to be recognised are former Prime Minister Gordon Brown, who becomes a Companion of Honour, and footballers Graeme Souness (CBE) and Ally McCoist (MBE). 16 June – Aberdeen City Council cancels the 2024 Highland Games shortly before it is due to commence following "heavier than forecast" rain. 17 June – NHS Dumfries and Galloway warns residents living in the area to assume some of their data has been published online after its database was hacked. 18 June – Scottish Labour launches its general election manifesto. 19 June – The Scottish National Party launches its election manifesto, with plans to "end Westminster cuts" and increase investment in the NHS.
Until recently, brown adipose tissue in humans was thought to be primarily limited to infants, but new evidence has overturned that belief. Metabolically active tissue with temperature responses similar to brown adipose was first reported in the neck and trunk of some human adults in 2007, and the presence of brown adipose in human adults was later verified histologically in the same anatomical regions.
Sources: en.wikipedia.org
== Further reading == Hill, A. V.; Long, C. N. H.; Lupton, H. (1924). "Muscular Exercise, Lactic Acid, and the Supply and Utilisation of Oxygen". Proceedings of the Royal Society B: Biological Sciences. 96 (679): 438–75. doi:10.1098/rspb.1924.0037. JSTOR 81203. Laforgia, J.; Withers, R. T.; Gore, C. J. (2006). "Effects of exercise intensity and duration on the excess post-exercise oxygen consumption". Journal of Sports Sciences. 24 (12): 1247–64. doi:10.1080/02640410600552064. PMID 17101527. S2CID 25579756. Lee, C. G. (2003). "Excess post-exercise oxygen consumption in adult sockeye (Oncorhynchus nerka) and coho (O. Kisutch) salmon following critical speed swimming". Journal of Experimental Biology. 206 (18): 3253–60. doi:10.1242/jeb.00548. PMID 12909706. Thornton, M. K.; Potteiger, J. A. (2002). "Effects of resistance exercise bouts of different intensities but equal work on EPOC". Medicine & Science in Sports & Exercise. 34 (4): 715–22. doi:10.1249/00005768-200204000-00024. PMID 11932584. Gore, C. J.; Withers, R. T. (1990). "The effect of exercise intensity and duration on the oxygen deficit and excess post-exercise oxygen consumption". European Journal of Applied Physiology and Occupational Physiology. 60 (3): 169–74. doi:10.1007/BF00839153. PMID 2347316. S2CID 11724610. Lee, C. G.; Devlin, R. H.; Farrell, A. P. (2003). "Swimming performance, oxygen consumption and excess post-exercise oxygen consumption in adult transgenic and ocean-ranched coho salmon". Journal of Fish Biology. 62 (4): 753–66. doi:10.1046/j.1095-8649.2003.00057.x.
=== 2021 poisoning at Darmstadt Technical University === In August 2021, several people fell severely ill after consuming drinks at building L2.01 at the Lichtwiese Campus of Darmstadt Technical University, Germany. Seven showed severe symptoms, two were transported to a hospital in Frankfurt am Main, and a 30-year-old person was, for a time, in a critical state. Butane-1,4-diol had been detected in milk packages, as well as in water filters. At the location, detectives also found bromophenols and dicyclohexylamine.
The regeneration fibers must cross the injury site and regeneration through the proximal or retrograde area of degeneration may require several weeks. Then the neuritis tip progresses down the distal site, such as the wrist or hand. Proximal lesion may grow distally as fast as 2 to 3 mm per day and distal lesion as slowly as 1.5 mm per day. Regeneration occurs over weeks to years.
== Cancer immunotherapy == In the cancer disease state, the interaction of PD-L1 on the tumor cells with PD-1 on a T-cell reduces T-cell function signals to prevent the immune system from attacking the tumor cells. Use of an inhibitor that blocks the interaction of PD-L1 with the PD-1 receptor can prevent the cancer from evading the immune system in this way. Several PD-1 and PD-L1 inhibitors are being trialled within the clinic for use in advanced melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancer and Hodgkin lymphoma, amongst other cancer types. Immunotherapy with these immune checkpoint inhibitors appears to shrink tumours in a higher number of patients across a wider range of tumour types and is associated with lower toxicity levels than other immunotherapies, with durable responses. However, de-novo and acquired resistance is still seen in a large proportion of patients. Hence PD-L1 inhibitors are considered to be the most promising drug category for many different cancers. Not all patients respond to PD-1/PD-L1 inhibitors. The FDA has approved several assays to measure the level of PD-L1 expressed by tumor cells, in order to predict the likelihood of response to an inhibitor. PD-L1 levels have been found to be highly predictive of response. Higher tumor mutational burden is also predictive of response to anti-PD-1/PD-L1 agents. However, these markers are far from perfect, and there is a clinical interest in the search for new biomarkers predictive of the benefit of these therapies beyond PD-L1 and TMB levels.
Sources: en.wikipedia.org
Dry powder is normally held at -20 °C or lower, away from light and moisture. Sealed vials can also be kept at 2-8 °C for shorter intervals. Warming to room temperature before opening prevents condensation.
In solution, hydrolysis of peptide bonds and oxidation of the methionine residue are the principal concerns. Oxidation converts methionine to its sulfoxide form, shifting the mass by sixteen daltons. Both processes are slowed by cold storage and by avoiding alkaline conditions.
A certificate documents what the supplier measured on a specific lot, not how a laboratory will use the material. Independent verification of identity and purity is common practice. Acceptance criteria should be defined before a batch is ordered.
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.