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Chemical Identity And Research Background — Evidence Review

By Editorial Desk · published 2026-06-08 · last reviewed 2026-07-06 · Guide

This is a working overview of ACTH 片段, written for readers who want more than a one-paragraph summary but less than a textbook.

This page was last updated on 2026-07-06 and is reviewed periodically as new material appears.

Chemical Identity and Research Background

Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.

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.

研发背景与监管地位

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。

Semax 是人工设计的七肽,序列为 Met-Glu-His-Phe-Pro-Gly-Pro,骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性,同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。

Semax at a glance

PropertyValueNotes
Molecular formulaC37H51N9O10SSeven-residue peptide
Molecular mass813.9 DaMonoisotopic value
AppearanceWhite to off-white powderLyophilized form
SolubilityFreely soluble in waterAlso soluble in saline and polar solvents
Storage (dry)-20 °C or lowerDesiccated, protected from light

Semax Background And Mechanism

Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.

The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.

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Semax Structure and Research Background

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.

Semax Origin and Molecular Structure

The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.

Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.

Semax Background and Molecular Structure

The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.

Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.

Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.

Further detail

In early March 1803, the Addington ministry received word that Cape Colony had been reoccupied by the British army, in accordance with the orders which had subsequently been countermanded. On 8 March they ordered military preparations to guard against possible French retaliation and justified them by claiming that it was only in response to French preparations and that they were conducting serious negotiations with France. In a few days, it was known that Cape Colony had been handed over in accordance with the counter-orders, but it was too late. Bonaparte berated the British ambassador Lord Whitworth in front of 200 spectators over the military preparations. The Addington ministry realised they would face an inquiry over their reasons for the military preparations, and during April unsuccessfully attempted to secure the support of William Pitt to shield them from damage. In the same month, the ministry issued an ultimatum to France, demanding a retention of Malta for at least ten years, the permanent acquisition of the island of Lampedusa from the Kingdom of Sicily, and the evacuation of Holland. They also offered to recognise French gains in Italy if they evacuated Switzerland and compensated the Kingdom of Sardinia for his territorial losses. France offered to place Malta in the hands of Russia to satisfy British concerns, pull out of Holland when Malta was evacuated, and form a convention to give satisfaction to Britain on other issues. The Addington ministry denied that Russia had made an offer, and Whitworth left Paris.

== History and folklore == Ciguatera was first described by the Scottish naturalist, William Anderson, when he was onboard the HMS Resolution in 1774. Researchers suggest that ciguatera outbreaks caused by warm climatic conditions in part propelled the migratory voyages of Polynesians between 1000 and 1400 CE.

The large, wrinkled colonies look like environmental contaminants, so are often discarded as being of no clinical significance. Colony morphology is very variable and a single strain may display multiple colony types, so inexperienced laboratory staff may mistakenly believe the growth is not pure. The organism grows more slowly than other bacteria that may be present in clinical specimens, and in specimens from nonsterile sites, is easily overgrown. Nonsterile specimens should, therefore, be cultured in selective media (e.g., Ashdown's or B. cepacia medium). For heavily contaminated samples, such as feces, a modified version of Ashdown's that includes norfloxacin, amoxicillin, and polymyxin B has been proposed. In blood culture, the BacT/ALERT MB system (normally used for culturing mycobacteria) by bioMérieux has been shown to have superior yields compared to conventional blood culture media. Even when the isolate is recognized to be significant, commonly used identification systems may misidentify the organism as Chromobacterium violaceum or other nonfermenting, Gram-negative bacilli such as Burkholderia cepacia or Pseudomonas aeruginosa. Again, because the disease is rarely seen in Western countries, identification of B. pseudomallei in cultures may not actually trigger alarms in physicians unfamiliar with the disease. Routine biochemical methods for identification of bacteria vary widely in their identification of this organism: the API 20NE system accurately identifies B.

Gene expression genetically low (aceruloplasminemia) Copper levels are low in general Malnutrition/trace metal deficiency in the food source Zinc toxicity, due to induced copper deficiency Copper does not cross the intestinal barrier due to ATP7A deficiency (Menkes disease and Occipital horn syndrome) Delivery of copper into the lumen of the ER-Golgi network is absent in hepatocytes due to absent ATP7B (Wilson's disease)

Sources: en.wikipedia.org

Supporting material

Lysis: This step involves breaking open the cells to release the DNA. For example, in the case of bacterial cells, a solution of detergent and salt (such as SDS) can be used to disrupt the cell membrane and release the DNA. For plant and animal cells, mechanical or enzymatic methods are often used. Precipitation: Once the DNA is released, proteins and other contaminants must be removed. This is typically done by adding a precipitating agent, such as alcohol (such as ethanol or isopropanol), or a salt (such as ammonium acetate). The DNA will form a pellet at the bottom of the solution, while the contaminants will remain in the liquid. Purification: After the DNA is precipitated, it is usually further purified by using column-based methods. For example, silica-based spin columns can be used to bind the DNA, while contaminants are washed away. Alternatively, a centrifugation step can be used to purify the DNA by spinning it down to the bottom of a tube. Concentration: Finally, the amount of DNA present is usually increased by removing any remaining liquid. This is typically done by using a vacuum centrifugation or a lyophilization (freeze-drying) step. Some variations on these steps may be used depending on the specific DNA extraction protocol. Additionally, some kits are commercially available that include reagents and protocols specifically tailored to a specific type of sample.

=== Israel and Palestine === In August 2024, The Times of Israel reported that Pritzker previously served on the national board of the pro-Israel lobby group AIPAC. In March 2026, Pritzker clarified to The New York Times that while he had donated to AIPAC, he had not served on its board. In 2026, he was described as a "former supporter" of the group and his spokesperson said he had not donated to AIPAC in a decade and believed the group had "abandoned its bipartisan principles and become a pro-Trump organization". After the October 7 attacks on Israel in 2023, Pritzker issued a public condemnation of the attacks, saying that Illinois "unequivocally stands" with the Israeli people and that Hamas is a terrorist organization while acknowledging that "There are many peace-loving Palestinians" in Gaza. In February 2024, Pritzker criticized the Gaza ceasefire resolution passed by Chicago Mayor Brandon Johnson and rejected calls for an immediate permanent ceasefire in the Gaza war, arguing that a lasting ceasefire was not possible while Hamas retained the ability to attack Israel. In October 2024, he publicly supported a ceasefire, saying, "It's past time to honor the innocent Palestinian and Israeli lives lost by securing the release of the hostages and implementing a ceasefire" in a statement on social media. In June 2025, Pritzker said the question of whether what is happening in Gaza is a genocide was for others to determine in accordance with the term's definition.

The causes of common gynecomastia remain uncertain, but are thought to result from an imbalance between the actions of estrogen, which stimulates breast tissue growth, and androgens, which inhibit breast tissue growth. Breast prominence can result from enlargement of glandular breast tissue, chest adipose tissue (fat), and skin, and is typically a combination. As in females, estrogen stimulates the growth of breast tissue in males. In addition to directly stimulating breast tissue growth, estrogens indirectly decrease secretion of testosterone by suppressing luteinizing hormone secretion, resulting in decreased testicular secretion of testosterone.

Ejaculation is the ejection of semen from the penis. It is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis. Ejaculation usually happens as the result of sexual stimulation, but it can be due to prostatic disease in rare cases. Ejaculation may occur spontaneously during sleep (known as a nocturnal emission). Anejaculation is the condition of being unable to ejaculate. Sperm are produced in the testicles and stored in the attached epididymides. During ejaculation, sperm are propelled up the vasa deferentia, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vasa deferentia turn into the ejaculatory ducts, which join the urethra inside the prostate. The prostate, as well as the bulbourethral glands, add further secretions (including pre-ejaculate), and the semen is expelled through the penis. Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerves S2–4 via the pudendal nerve. A refractory period succeeds the ejaculation, and sexual stimulation precedes it. The ischiocavernosus muscle helps to stabilize the penis during erection by compressing the crus and slowing the return of blood through the veins. The bulbospongiosus muscle also contributes to erection along with the expulsion of urine and semen.

Hoyle said the early revelations were a "supreme discourtesy to the House". 30 October – October 2024 United Kingdom budget. 31 October – 2024 Conservative Party leadership election: Voting closes for the election of the Conservative Party's next leader.

Sources: en.wikipedia.org

Notes from published material

=== Air === U.S. Government air transport regulations permit the transport of plutonium by air, subject to restrictions on other dangerous materials carried on the same flight, packaging requirements, and stowage in the rearmost part of the aircraft. In 2012, media revealed that plutonium has been flown out of Norway on commercial passenger airlines—around every other year—including one time in 2011. Regulations permit a plane to transport 15 grams of fissionable material. Such plutonium transportation is without problems, according to a senior advisor (seniorrådgiver) at Statens strålevern.

== Medical uses == Phenelzine is primarily used in the treatment of major depressive disorder, including treatment-resistant depression. Modern guidance on classic MAOIs recommends considering phenelzine, tranylcypromine, or isocarboxazid after insufficient response to other antidepressant treatments and before electroconvulsive therapy when a rapid treatment response is not required. Patients with atypical depression may respond particularly well to phenelzine, but evidence also supports the use of classic MAOIs in melancholic depression. Phenelzine may be especially useful when depression is accompanied by premorbid anxiety, comorbid panic disorder, or other treatment-resistant anxiety symptoms, reflecting its additional effects on GABA metabolism. Phenelzine has also been studied or used in anxiety-related and other psychiatric conditions including panic disorder, social anxiety disorder, post-traumatic stress disorder (PTSD), obsessive–compulsive disorder (OCD), dysthymia, bipolar depression, and bulimia nervosa.

JTT (1992). Published in the same year as BLOSOM, it also performs clustering and uses an implicit model. This may help reduce the systematic error from maximum parismony (MP), but also wastes sequence information. VTML (2001), a PAM-like matrix based on the alignments in the SYSTERS database, iteratively improved using a maximum likelihood estimator starting from the 1970s Dayhoff PAM model. WAG (Wheelan And Goldman, 2001) uses a maximum likelihood estimating procedure instead of any form of MP over a "BRKALN" dataset. The substitution scores are calculated based on the likelihood of a change considering multiple tree topologies derived using neighbor-joining. The scores correspond to a substitution model which includes also amino-acid stationary frequencies and a scaling factor in the similarity scoring. There are two versions of the matrix: WAG matrix based on the assumption of the same amino-acid stationary frequencies across all the compared protein and WAG* matrix with different frequencies for each of included protein families. PMB (Probability Matrix from Blocks, 2003), a set of "true" substitution frequencies estimated from the observed frequencies of BLOSUM, taking into account the possibility of a later substitution masking a previous one. It thus creates a evolutionary model where the distances have theoretical meaning (BLOSUM does not have this feature, unlike PAM, WAG, and most other later matrices, and hence is not recommended for phylogeny by IQ-TREE). LG (2008), which uses a larger dataset (Pfam-based) than WAG.

USAAF Lt Col. James H. Howard of the 356th Fighter Squadron, 354th Fighter Group was awarded the Medal of Honor for his action during a bomber escort mission near Oschersleben, Germany on 11 January 1944, flying P-51B, serial number 43-6315 nicknamed "Ding Hao". Despite being outnumbered, Howard shot down three German planes and continued to defend the bombers even when his guns went out of action and fuel supply became dangerously low. USAAF Maj. William A. Shomo of the 82nd Reconnaissance Squadron, 71st Reconnaissance Group was awarded the Medal of Honor for his action during a mission over Luzon, Philippines on 11 January 1945, flying an F-6D, the armed photo reconnaissance variant of the P-51, serial number 44-14841 nicknamed "Snooks the 5th". On that mission, Shomo shot down seven Japanese planes and became an "ace in a day".

Sources: en.wikipedia.org

Frequently asked questions

What is Semax chemically?

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.

Why was the Pro-Gly-Pro tail added?

The extension was introduced to slow enzymatic breakdown of the peptide in biological systems. Natural ACTH fragments are degraded rapidly by peptidases. Adding the tripeptide was intended to extend the window during which the molecule remains intact.

How strong is the clinical evidence?

Most published work consists of animal experiments conducted in a small number of laboratories. Human data are limited in number and size. Whether the observed effects translate into reliable clinical benefit is still unresolved.

Semax 在自然界中存在吗?

不存在。它是依据 ACTH 的一段序列人工设计的分子,天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号,而非天然物质名。

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