reversed-phase HPLC is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2025-09-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | Analogue of the ACTH(4-10) fragment |
| Amino acid sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Single-letter form MEHFPGP |
| Molecular formula | C37H51N9O10S | Free peptide, nominal mass near 814 Da |
| First registration | 1994, Russia | Nasal formulation for neurological indications |
| Typical purity grade | 95% or higher by HPLC | Research material; higher grades used as reference standards |
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
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.
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.
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.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
The Gent hyperelastic material model is a phenomenological model of rubber elasticity that is based on the concept of limiting chain extensibility. In this model, the strain energy density function is designed such that it has a singularity when the first invariant of the left Cauchy-Green deformation tensor reaches a limiting value
from ectoderm (e.g., the epidermis); from endoderm (e.g., the lining of the gastrointestinal tract); from mesoderm (e.g., the inner linings of body cavities). However, pathologists do not consider endothelium and mesothelium (both derived from mesoderm) to be true epithelium. This is because such tissues present very different pathology. For that reason, pathologists label cancers in endothelium and mesothelium sarcomas, whereas true epithelial cancers are called carcinomas. Additionally, the filaments that support these mesoderm-derived tissues are very distinct. Outside of the field of pathology, it is generally accepted that the epithelium arises from all three germ layers.
==== Growth hormone receptor antagonists ==== The latest development in the medical treatment of acromegaly is the use of growth hormone receptor antagonists. The only available member of this family is pegvisomant (Somavert). By blocking the action of the endogenous growth hormone molecules, this compound is able to control the disease activity of acromegaly in virtually everyone with acromegaly. Pegvisomant has to be administered subcutaneously by daily injections. Combinations of long-acting somatostatin analogues and weekly injections of pegvisomant seem to be equally effective as daily injections of pegvisomant. Paltusotine (Palsonify) was approved for medical use in the United States in September 2025.
In the House of Lords, the Liberals had lost most of their members, who in the 1890s "became Conservative in all but name." The government could force the unwilling king to create new Liberal peers, and that threat did prove decisive in the battle for dominance of Commons over Lords in 1911.
=== Charges against UCC and UCIL employees === UCC chairman and CEO Warren Anderson was arrested and released on bail by the Madhya Pradesh Police in Bhopal on 7 December 1984. Anderson was taken to UCC's house after which he was released six hours later on $2,100 bail and flown out on a government plane. These actions were allegedly taken under the direction of then chief secretary of the state, who was possibly instructed from the chief minister's office, who himself flew out of Bhopal immediately. Later in 1987, the Indian government summoned Anderson, eight other executives and two company affiliates to appear in Indian court on homicide charges. In response, Union Carbide said the company is not under Indian jurisdiction. In May 1988, Indian businessman J. R. D. Tata wrote a confidential letter to the then Prime Minister, Rajiv Gandhi, conveying Henry Kissinger's concern about delay in reaching a settlement. At the time, Kissinger was an adviser to Union Carbide and other US corporations. Rajiv Gandhi indicated that he would consider Kissinger's advice. The opposition Bharatiya Janata Party alleged that Rajiv Gandhi protected Warren Anderson in a secret political deal with U.S. President Ronald Reagan, with Gandhi securing Reagan's pardon of Adil Shahryar in exchange. Dow was a named respondent in cases arising from Union Carbide's business in Bhopal.
Sources: en.wikipedia.org
==== Side reactions ==== When methionine is followed by serine or threonine, side reactions can occur that destroy the methionine without peptide bond cleavage. Normally, once the iminolactone is formed (refer to figure), water and acid can react with the imine to cleave the peptide bond, forming a homoserine lactone and new C-terminal peptide. However, if the adjacent amino acid to methionine has a hydroxyl or sulfhydryl group, this group can react with the imine to form a homoserine without peptide bond cleavage. These two cases are shown in the figure.
Both The Guardian newspaper (UK) and the American non-profit publication ICIJ received documents in July 2014 revealing the details of past and present offshore clients of wealth managers Kleinwort Benson, including the Nando's restaurant group. The Guardian published its belief that, through the use of businesses in Malta, Guernsey and the Netherlands, Enthoven legally reduces the group's UK corporation tax bill by "up to a third." According to the British newspaper, Enthoven's profits eventually accumulate in the Kleinwort Benson-managed "Taro III Trust" that is based in Jersey and contains at least £750 million. While no member of the Enthoven family agreed to speak with The Guardian, a company representative explained that UK tax laws are not applicable to Enthoven, as "he is not resident in the US or the UK." The spokesperson also stated that, in the UK, Nando's paid corporation tax of £12.6 million on a profit of £58.2 million for the year ending February 2013. In its 2023 tax strategy, the company states that "Nando's policy is to maintain its tax affairs responsibly and transparently. Nando's doesn’t enter into transactions simply to secure tax advantages."
Charitable activities include aid for the Bohemian Home for the Aged; school for retarded children, Chicago Lung Association, American Red Cross, Heart Research Foundation, Cancer Research Foundation, Muscular Dystrophy Association, firemen's and police benevolent associations, and other humanitarian projects. Czech Catholic Union - Founded in 1879 as the Czech Roman Catholic Central Union of Women by the merger of two altar and rosary societies at the St. Wenceslaus Church in Cleveland - St. Ann Society #1, founded in 1867 and St. Ludnila Society #2 founded in 1871. The union was arranged by Rev. Anthony Hynek and Emil Prucha. Adopted current name in 1938. Headquartered in Cleveland. 6,600 members in 1967. 9,800 in 1979, 10,000 in the mid 1980s and 5,000 in 1995. Sponsors seminary scholarship for St. Procopius Abbey, supports Czech Benedictines, youth programs, etc. Bought a bomber during WWII and the Cleveland local a Red Cross ambulance. Slavonic Benevolent Order of the State of Texas - Founded December 28, 1896, in La Grange, Texas. Headquarters in Temple, Texas. Local groups called lodges, of which there were 130 in the late 1970s. There are currently "almost 100 lodges". These are divided into 7 districts covering Texas. The "Supreme Lodge" meets quadrennially. Membership open to both sexes if of good health and US citizens. Had 35,000 in 1969, 54,000 in 1979, and 60,000 in 1995. Initiation is done once each year, every lodge choosing its date, five votes necessary to reject a candidate for initiation.
== Current practice == The clinical setting in which patients are evaluated determines the scope of practice, diagnostic, and therapeutic interventions. For the purposes of general discussion, the typical encounters between patients and genetic practitioners may involve:
Sources: en.wikipedia.org
=== Pharmacodynamics === Isoergine shows affinity for serotonin receptors labeled with serotonin or LSD in rat brain membranes. It has about 10- to 25-fold lower affinity for these receptors than serotonin or LSD and has the same affinity as ergine and iso-LSD (IC50Tooltip half-maximal inhibitory concentration = 100–200 nM for isoergine, 200 nM for ergine and iso-LSD, and 8–10 nM for LSD). No other receptor interaction data are available for isoergine as of 2020. However, computer-predicted receptor affinities are available for ergine/isoergine (stereochemistry not taken into account). The drug is said to have about 4.3% of LSD's antiserotonergic potency in vitro. It is 5- to 33-fold less potent than LSD in producing behavioral changes in the conditioned avoidance test in rodents.
Local chemical messengers, not generally considered part of the endocrine system, include autocrines, which act on the cells that secrete them, and paracrines, which act on a different cell type nearby. The ability of a target cell to respond to a hormone depends on the presence of receptors, within the cell or on its plasma membrane, to which the hormone can bind. Hormone receptors are dynamic structures. Changes in the number and sensitivity of hormone receptors may occur in response to high or low levels of stimulating hormones. Blood levels of hormones reflect a balance between secretion and degradation/excretion. The liver and kidneys are the major organs that degrade hormones; breakdown products are excreted in urine and faeces. Hormone half-life and duration of activity are limited and vary from hormone to hormone. Interaction of hormones at target cells Permissiveness is the situation in which a hormone cannot exert its full effects without the presence of another hormone. Synergism occurs when two or more hormones produce the same effects in a target cell and their results are amplified. Antagonism occurs when a hormone opposes or reverses the effect of another hormone.
== History of electric slow cookers == Slow cookers achieved popularity in the United States during the 1940s, when many women began to work outside the home. They could start dinner cooking in the morning before going to work and finish preparing the meal in the evening when they came home. The Naxon Utilities Corporation of Chicago, under the leadership of electrical engineer Irving Naxon (born Irving Nachumsohn), developed the Naxon Beanery All-Purpose Cooker for the purposes of cooking a bean meal. Naxon was inspired by a story related by his mother, how in her native Lithuanian town his grandmother made a traditional Jewish stew called cholent, which took several hours to cook in an oven. A 1950 advertisement shows a slow cooker called the "Simmer Crock" made by the Industrial Radiant Heat Corporation of Gladstone, New Jersey. The Rival Company of Kansas City, Missouri, bought Naxon in 1970, acquiring Naxon's 1940 patent for the bean simmer cooker. Rival asked inventor Alex MacMaster, from Boonville, Missouri, to develop Naxon's bean cooker into a large scale production model that could cook an entire family meal, going further than just cooking a bean meal. Alex also designed and produced the mass-production machines for Rival's manufacturing line of the Crock-Pot. The cooker was then reintroduced under the trademark "Crock-Pot" in 1971. In 1974, Rival introduced removable stoneware inserts, making the appliance easier to clean. As of 2016, the Crock-Pot brand belongs to Newell Brands.
Sources: en.wikipedia.org
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.
No. The peptide is synthetic, although it is modelled on a fragment of a naturally occurring hormone. ACTH(4-10) is generated when ACTH is cleaved, but the Pro-Gly-Pro extension is not a known endogenous sequence. It is therefore a designed analogue rather than a natural metabolite.
The label reflects reported effects on attention, memory and recovery after neurological injury in regional clinical reports. Those reports are mostly small and have not been widely replicated outside the region. The classification is descriptive and does not imply a single defined mechanism.
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.