methionine sulfoxide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-10-02. Numbers and descriptions here follow the published literature rather than marketing material.
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.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
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.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
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。
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.
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.
Rutherford was the first to realize that all such elements decay in accordance with the same mathematical exponential formula. Rutherford and his student Frederick Soddy were the first to realize that many decay processes resulted in the transmutation of one element to another. Subsequently, the radioactive displacement law of Fajans and Soddy was formulated to describe the products of alpha and beta decay. The early researchers also discovered that many other chemical elements, besides uranium, have radioactive isotopes. A systematic search for the total radioactivity in uranium ores also guided Pierre and Marie Curie to isolate two new elements: polonium and radium. Except for the radioactivity of radium, the chemical similarity of radium to barium made these two elements difficult to distinguish. Marie and Pierre Curie also coined the term "radioactivity" to define the emission of ionizing radiation by some heavy elements. (Later the term was generalized to all elements.) Their research on the penetrating rays in uranium and the discovery of radium launched an era of using radium for the treatment of cancer. Their exploration of radium could be seen as the first peaceful use of nuclear energy and the start of modern nuclear medicine.
Lambda ( ; uppercase Λ, lowercase λ; Greek: λάμ(β)δα, lám(b)da; Ancient Greek: λά(μ)βδα, lá(m)bda), sometimes rendered lamda, labda or lamma, is the eleventh letter of the Greek alphabet, representing the voiced alveolar lateral approximant IPA: [l]; it derives from the Phoenician letter Lamed, and gave rise to Latin L and Cyrillic El (Л). In the system of Greek numerals, lambda has a value of 30. The ancient grammarians typically called it λάβδα (lắbdă, [lábda]) in Classical Greek times, whereas in Modern Greek it is λάμδα (lámda, [ˈlamða]), while the spelling λάμβδα (lámbda) was used (to varying degrees) throughout the lengthy transition between the two. In early Greek alphabets, the shape and orientation of lambda varied. Most variants consisted of two straight strokes, one longer than the other, connected at their ends. The angle might be in the upper-left, lower-left ("Western" alphabets) or top ("Eastern" alphabets). Other variants had a vertical line with a horizontal or sloped stroke running to the right. With the general adoption of the Ionic alphabet, Greek settled on an angle at the top; the Romans put the angle at the lower-left.
Heinz Kähler: Die Augustusstatue von Primaporta. Köln 1959. Erika Simon: Der Augustus von Prima Porta. Bremen, Dorn 1959. (Opus nobile 13) Hans Jucker: Dokumentationen zur Augustusstatue von Primaporta, in: Hefte des Archäologischen Seminars Bern 3 (1977) S. 16–37. Paul Zanker: Augustus und die Macht der Bilder. München, C. H. Beck 1987, ISBN 3-406-32067-8 Kaiser Augustus und die verlorene Republik, Ausstellung Berlin 1988. Mainz, Zabern 1988. S. 386 f. Nr. 215. Erika Simon: Altes und Neues zur Statue des Augustus von Primaporta, in: G. Binder (Hrsg.), Saeculum Augustum, Bd. 3, Darmstadt, WBG 1991, S. 204–233. Dietrich Boschung: Die Bildnisse des Augustus, Gebr. Mann Verlag, Berlin 1993 (Das römische Herrscherbild, Abt. 1, Bd. 2) ISBN 3-7861-1695-4 Thomas Schäfer: Der Augustus von Primaporta im Wechsel der Medien, in: H. J. Wendel u.a. (Hrsg.), Wechsel des Mediums. Zur Interdependenz von Form und Inhalt, Rostock 2001, S. 37–58. Vinzenz Brinkmann und Raimund Wünsche (eds.): Bunte Götter. Die Farbigkeit antiker Skulptur. Eine Ausstellung der Staatlichen Antikensammlungen und Glyptothek München in Zusammenarbeit mit der Ny Carlsberg Glyptotek Kopenhagen und den Vatikanischen Museen, Rom, Staatliche Antikensammlungen und Glyptothek, München 2004 ISBN 3-933200-08-3. In Italian
Some of the functions of tears include lubricating the eyes (basal tears), removing irritants (reflex tears), and also aiding the immune system. Tears also occur as a part of the body's natural pain response. Emotional secretion of tears may serve a biological function by excreting stress-inducing hormones built up through times of emotional distress. Tears have symbolic significance among humans.
Sources: en.wikipedia.org
== Early life and education == Rudolf Schoenheimer was born in Berlin, Germany on 10 May 1898. He was the son of Gertrude Edel and Hugo Schoenheimer, who was a physician. He was Jewish, however his family converted to Christianity. He attended local schools in Berlin before graduating from the Dorotheen-Stadtische Gymnasium in 1916. Following his graduation Schoenheimer was drafted into the German army. He served in the artillery on the western front for two years during world war 1. Following his service in the war, he began his study of medicine at the University of Berlin. In 1922 he received his M.D. His M.D dissertation was titled "Über die experimentelle Cholesterinkrankheit der Kaninchen" ("About the experimental cholesterol disease of rabbits"). He then spent a year working at the Moabit Hospital in Berlin as a pathologist. He continued his scientific research during this time and studied the production of atherosclerosis in animals through administering cholesterol. In 1924, Schoenheimer began his 3-year study at the University of Leipzig, in a program aimed at advancing his knowledge in chemistry. The program was aided by the Rockefeller Foundation and taught by Karl Thomas, professor of physiological chemistry at the University of Leipzig. During his time at Leipzig, Schoenheimer was able to develop a method of synthesising peptides.
== External links == Die Geschichte des Wirkstoffs Cyproteronazetat: Von der "Pille für den Mann" zum "Hautpflegemittel mit Empfängnisschutz" [The History of Cyproterone Acetate: From the "Pill for Men" to the "Skin Care Product and Contraceptive"] - Arznei-Telegramm (in German) [Google Translate]
=== Tuberous sclerosis complex === Sirolimus also shows promise in treating tuberous sclerosis complex (TSC), a congenital disorder that predisposes those afflicted to benign tumor growth in the brain, heart, kidneys, skin, and other organs. After several studies conclusively linked mTOR inhibitors to remission in TSC tumors, specifically subependymal giant-cell astrocytomas in children and angiomyolipomas in adults, many US doctors began prescribing sirolimus (Wyeth's Rapamune) and everolimus (Novartis's RAD001) to TSC patients off-label. Numerous clinical trials using both rapamycin analogs, involving both children and adults with TSC, are underway in the United States.
Sources: en.wikipedia.org
It is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.