Everything below concerns ACTH fragment. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
| Property | Value | Notes |
|---|---|---|
| Typical analytical method | Reversed-phase HPLC with UV detection | Separates target peptide from truncated and oxidised forms |
| Identity confirmation | LC-MS or ESI-MS | Compares observed and calculated molecular ion |
| Primary degradation route | Methionine oxidation | Forms the sulfoxide; monitored as an early-eluting peak |
| Short-term storage | 2 to 8 degrees Celsius | Applies to working vials and reconstituted portions |
| Common synonyms | ACTH(4–10) analogue, MEHFPGP | Descriptive names used in laboratory catalogues |
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。
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.
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.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
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。
Most teleost species are oviparous, having external fertilisation with both eggs and sperm being released into the water for fertilisation. Internal fertilisation occurs in 500 to 600 species of teleosts but is more typical for Chondrichthyes and many tetrapods. This involves the male inseminating the female with an intromittent organ. Fewer than one in a million of externally fertilised eggs survives to develop into a mature fish, but there is a much better chance of survival among the offspring of members of about a dozen families which are viviparous. In these, the eggs are fertilised internally and retained in the female during development. Some of these species, like the live-bearing aquarium fish in the family Poeciliidae, are ovoviviparous; each egg has a yolk sac which nourishes the developing embryo, and when this is exhausted, the egg hatches and the larva is expelled into the water column. Other species, like the splitfins in the family Goodeidae, are fully viviparous, with the developing embryo nurtured from the maternal blood supply via a placenta-like structure that develops in the uterus. Oophagy is practised by a few species, such as Nomorhamphus ebrardtii; the mother lays unfertilised eggs on which the developing larvae feed in the uterus, and intrauterine cannibalism has been reported in some halfbeaks. There are two major reproductive strategies of teleosts; semelparity and iteroparity. In the former, an individual breeds once after reaching maturity and then dies.
== Epidemiology == Certain populations are predisposed to develop ketoacidosis including people with diabetes, people with a history of prolonged and heavy alcohol use, pregnant women, breastfeeding women, children, and infants. People with diabetes that produce very little or no insulin are predisposed to develop ketoacidosis, especially during periods of illness or missed insulin doses. This includes people with type 1 diabetes or ketosis prone diabetes. Prolonged heavy alcohol use is a risk of ketoacidosis, especially in people with poor nutrition or a concurrent illness. Pregnant women have high levels of hormones including glucagon and human placental lactogen that increase circulating free fatty acids which increases ketone production. Lactating women also are predisposed to increased ketone production. These populations are at risk of developing ketoacidosis in the setting of metabolic stressors such as fasting, low-carbohydrate diets, or acute illness. Children and infants have lower glycogen stores and may develop high levels of glucagon and counter-regulatory hormones during acute illness, especially gastrointestinal illness. This allows children and infants to easily produce ketones and although rare, can progress to ketoacidosis in acute illness.
== Research == According to Kresge and colleagues Horecker "made seminal contributions to our understanding of the enzyme-catalyzed reactions in carbohydrate metabolism, especially those of the pentose phosphate pathway." He started his scientific career with a manometric study of succinate dehydrogenase. Later he worked with Arthur Kornberg on spectroscopic aspects of pyridine nucleotides, with whom he also studied glucose 6-phosphate dehydrogenase. However, he is best known for his work in elucidating the pentose phosphate pathway.
BMS-470539 is a small-molecule experimental drug which acts as a potent and highly selective full agonist of the MC1 receptor. It was discovered in 2003 as part of an effort to understand the role of the MC1 receptor in immunomodulation, and has since been used in scientific research to determine its role in inflammatory processes. The compound was designed with the intention of mimicking the central His-Phe-Arg-Trp pharmacophore of the melanocortins, and this proved to be successful based on its favorable pharmacodynamic profile.
Sources: en.wikipedia.org
== Background == The project was first unveiled in September 2025 and dedicated on 5 November 2025 during Trump's second term. In chronological order, every United States president is displayed via a black and white photograph in a gold frame, except for former president Joe Biden. In the place of Biden's portrait, Trump installed a photograph of an autopen, a device used to mechanically replicate a signature. In December 2025, the administration added permanent bronze plaques beneath each portrait, many of which were reportedly written or dictated by Trump himself. The descriptions on the plaques vary significantly based on Trump's personal and political assessment of his predecessors:
=== Sperm morphology === Regarding sperm morphology, the WHO criteria as described in 2021 state that a sample is normal (samples from men whose partners had a pregnancy in the last 12 months) if 4% (or 5th centile) or more of the observed sperm have normal morphology. If the sample has less than 4% of morphologically normal spermatozoa, it's classified as teratozoospermia. Normal sperm morphology is hard to classify because of lack of objectivity and variations in interpretation, for instance. In order to classify spermatozoa as normal or abnormal, the different parts should be considered. Sperm has a head, a midpiece and a tail. Firstly, the head should be oval-shaped, smooth and with a regular outline. What is more, the acrosomal region should comprise the 40–70% area of the head, be defined and not contain large vacuoles. The amount of vacuoles should not excess the 20% of the head's area. It should be 4–5 μm long and a width of 2.5–3.5 μm. Secondly, the midpiece and the neck should be regular, with a maximal width of 1 μm and a length of 7–8 μm. The axis of the midpiece should be aligned with the major axis of the head. Finally, the tail should be thinner than the midpiece and have a length of 45 μm approximately and a constant diameter along its length. It is important that it is not rolled up. Since abnormalities are frequently mixed, the teratozoospermia index (TZI) is really helpful. This index is the mean number of abnormalities per abnormal sperm. To calculate it, 200 spermatozoa are counted (this is a good number).
Pyrolysis has many applications in food preparation. Caramelization is the pyrolysis of sugars in food (often after the sugars have been produced by the breakdown of polysaccharides). The food goes brown and changes flavor. The distinctive flavors are used in many dishes; for instance, caramelized onion is used in French onion soup. The temperatures needed for caramelization lie above the boiling point of water. Frying oil can easily rise above the boiling point. Putting a lid on the frying pan keeps the water in, re-condensing some and keeping the temperature too cool to brown. Pyrolysis of food can also be undesirable, as in the charring of burnt food (at temperatures too low for the oxidative combustion of carbon to produce flames and burn the food to ash).
Sources: en.wikipedia.org
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.
Oxidation of the methionine residue to the sulfoxide is a frequently reported change, and it usually appears as an earlier-eluting peak in reversed-phase chromatography. Backbone hydrolysis products can also accumulate in aqueous solution.
Liquid chromatography coupled with mass spectrometry is the usual approach, because the observed molecular ion can be compared with a calculated mass of about 813.9 Da. Retention time alone does not establish identity.
It is a synthetic peptide of seven amino acids. Its backbone corresponds to a fragment of adrenocorticotropic hormone extended at the carboxyl end. The material is distributed as a lyophilized solid for laboratory use.