heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-06-29. Anything still debated is marked as such rather than presented as settled.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
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.
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.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
The main etiologic factor of ACC is unknown, although families with Li–Fraumeni syndrome, caused by an inherited inactivation mutation in TP53, have increased risk. Several genes have been shown to be recurrently mutated, including TP53, CTNNB1, MEN1, PRKAR1A, RPL22, and DAXX. The telomerase gene TERT is often amplified while ZNRF3 and CDKN2A are often homozygously deleted. The genes h19, insulin-like growth factor II (IGF-II), and p57kip2 are important for fetal growth and development. They are located on chromosome 11p. Expression of the h19 gene is markedly reduced in both nonfunctioning and functioning adrenal cortical carcinomas, especially in tumors producing cortisol and aldosterone. Also, a loss occurs of activity of the p57kip2 gene product in virilizing adenomas and adrenal cortical carcinomas. In contrast, IGF-II gene expression has been shown to be high in adrenal cortical carcinomas. Finally, c-myc gene expression is relatively high in neoplasms, and it is often linked to poor prognosis. Bilateral adrenocortical tumors are less common than unilateral. The majority of bilateral tumours can be distinguished according to size and aspect of the nodules: primary pigmented nodular adrenocortical disease, which can be sporadic or part of Carney complex, and primary bilateral macro nodular adrenal hyperplasia.Metastasis is most commonly to the liver and lung.
An ion-exchange membrane is a semi-permeable membrane that transports certain dissolved ions, while blocking other ions or neutral molecules. Ion-exchange membranes are therefore electrically conductive. They are often used in desalination and chemical recovery applications, moving ions from one solution to another with little passage of water. Important examples of ion-exchange membranes include the proton-exchange membranes, that transport H+ cations, and the anion exchange membranes used in certain alkaline fuel cells to transport OH− anions.
12(S)-HETE and 12(S)-HpETE stimulate the dilation of rat mesenteric arteries; 12(S)-HETE stimulates the dilation of coronary microvessels in pigs and the mesenteric arteries of mice, one or more of these three metabolites are implicated in the vasodilation of rat basilar artery, 12(R)-HETE and to a slightly lesser extent 12(S)-HETE constrict the renal artery of dogs and 12-HETE (stereoisomer undetermined) is implicated in the angiotensin II-induced arterial hypertension response of human placenta. The vasodilating effect on mouse mesenteric arteries appears due to 12S-HETE's ability to act as a thromboxane receptor antagonist and thereby block the vasoconstricting actions of thromboxane A2. These results indicate that the cited metabolites have dilating or constricting effects that depend on the arterial vascular site and or species of animal examined; their role in human blood pressure regulation is unclear. Excessive 12-HETE production is implicated in psoriasis. 5-Hydroxyeicosatetraenoic acid 15-Hydroxyeicosatetraenoic acid
Sources: en.wikipedia.org
=== Nuclear weapons === When gram quantities of plutonium were first produced in the Manhattan Project, it was discovered that a minor isotope (240Pu) underwent significant spontaneous fission, which brought into question the viability of a plutonium-fuelled gun-type nuclear weapon. While the Los Alamos team began work on the implosion-type weapon to circumvent this issue, the Chicago team discussed reactor design solutions. Eugene Wigner proposed to use the 240Pu-contaminated plutonium to drive the conversion of thorium into 233U in a special converter reactor. It was hypothesized that the 233U would then be usable in a gun-type weapon, though concerns about contamination from 232U were voiced. Progress on the implosion weapon was sufficient, and this converter was not developed further, but the design had enormous influence on the development of nuclear energy. It was the first detailed description of a highly enriched water-cooled, water-moderated reactor similar to future naval and commercial power reactors. In 1943 the Manhattan Project contracted two private companies, Union Carbide and Chevron, to quietly compile a survey of uranium and thorium deposits around the world. The primary focus was uranium but early in the process thorium was also included. Deposits of monazite sands where identified in Brazil, Netherlands East Indies, and Travancore in India but none of these were pursued by the project. During the Cold War the United States explored the possibility of using 232Th as a source of 233U to be used in a nuclear bomb and it fired a test bomb in 1955.
== Mechanism of action == Through recombinant DNA technology, the final lysine and proline residues on the C-terminal end of the B-chain are reversed. This modification does not alter receptor binding, but blocks the formation of insulin dimers and hexamers. This allows larger amounts of active monomeric insulin to be immediately available for postprandial injections.
According to Ahmed Addaghashi, a professor at Sanaa University, the Houthis began as a moderate theological movement that preached tolerance and held a broad-minded view of all the Yemeni peoples. Their first organization, "the Believing Youth" (BY), was founded in 1992 in Saada Governorate by either Mohammed al-Houthi, or his brother Hussein al-Houthi. The Believing Youth established school clubs and summer camps in order to "promote a Zaydi revival" in Saada. By 1994–95, between 15,000 and 20,000 students had attended BY summer camps. The religious material included lectures by Mohammed Hussein Fadhlallah (a Lebanese Shia scholar) and Hassan Nasrallah (Secretary General of Hezbollah). The formation of the Houthi organisations has been described by Adam Baron of the European Council on Foreign Relations as a reaction to foreign intervention. Their views include shoring up Zaydi support against the perceived threat of Saudi-influenced ideologies in Yemen and a general condemnation of the former Yemeni government's alliance with the United States, which, along with complaints regarding the government's corruption and the marginalisation of much of the Houthis' home areas in Saada, constituted the group's key grievances. Although Hussein al-Houthi, who was killed in 2004, had no official relation with Believing Youth (BY), according to Zaid, he contributed to the radicalisation of some Zaydis after the 2003 invasion of Iraq. BY-affiliated youth adopted anti-American and anti-Israel slogans, which they chanted in the Al Saleh Mosque in Sanaa after Friday prayers.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
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.