The short version of heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Seven-residue peptide |
| Molecular mass | 813.9 Da | Monoisotopic value |
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Also soluble in saline and polar solvents |
| Storage (dry) | -20 °C or lower | Desiccated, protected from light |
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.
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.
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.
== Ecology == In nature, A. roeperi is found primarily on the walls of ambrosia beetle galleries within a wide variety of host trees, where it survives by degrading compounds within wood. Traditionally, although they facilitate beetle growth and reproduction in nutritionally poor xylem tissue, ambrosia fungi are considered to be ineffective agents of wood decomposition, producing enzymes primarily dedicated to degradation of xylan, glucomannan, and callose (common components of hemicellulose) rather than cellulose, mirroring similar analyses made for various saprotrophic fungi. However, no equivalent studies have been performed on A. roeperi specifically, and it is worth noting that the article often cited in support of this conclusion only examined the fungal galleries of one beetle (Xyleborinus saxenii) associated with a different symbiont, Raffaelea sulfurea. Interestingly, metabolomic studies incorporating A. roeperi indicate that when growing on wood, this fungus possesses a lipid profile more similar to non-mutualistic Ceratocystidaceae than to other ambrosia fungi, further supporting the idea that making sweeping conclusions about fungal lifestyles based on data from apparently similar convergent systems can be misleading, as well as reinforcing how much remains to be learned about this and other ambrosial species. There are various molecular indications that hint at other ways in which A. roeperi may interact with its woody hosts.
== Fibronectin genetic variation as a protective factor against Alzheimer's disease == A specific genetic variation in Fibronectin gene was shown to reduce the risk of developing Alzheimer's disease in a multicenter, multiethnic genetic epidemiology and functional genomics study. This effect is believed to be through enhancing the brain's ability to clear the toxic waste and protein accumulation through the blood–brain barrier. A follow-up mechanistic study showed that astrocyte-derived fibronectin accumulates at the gliovascular interface in the presence of the APOE ε4 allele, disrupting VEGFA/HB-EGF/IGF-1 growth factor signaling and causing blood–brain barrier leakage, thereby establishing fibronectin as a mediator of APOE4-driven vascular dysfunction in Alzheimer's disease.
=== Types of sutures === Serrate sutures – similar to a denticulate suture but the interlocking regions are serrated rather than square. Eg: Coronal suture, sagittal Sutures. Plane sutures – edges of the bones are flush with each other as in a normal butt joint. Eg: Internasal suture. Limbous sutures – edges are bevelled so the plane of the suture is sloping as in a mitre joint. Eg: Temporo-parietal suture. Schindylesis – formed by two bones fitting into each other similar to a bridle joint. Eg: Palatomaxillary suture. Denticulate sutures – the edges slot into each other as in a finger joint. Eg: Lambdoid suture.
Patients with heart disease, and patients who smoked cigarettes, were less likely to survive. Another trial, the Stem Cell Transplant vs. Cyclophosphamide (SCOT) trial, is ongoing. Asengeprast is an experimental systemic scleroderma drug candidate. It is a small molecule inhibitor of the G-protein coupled receptor GPR68 with antifibrotic activity.
Sources: en.wikipedia.org
Sitagliptin/simvastatin, sold under the brand name Juvisync, is a fixed-dose combination anti-diabetic medication used to treat type 2 diabetes and hypercholesterolemia. It contains sitagliptin and simvastatin. Sitagliptin is a dipeptidyl peptidase-4 inhibitor and simvastatin is an HMG-CoA reductase inhibitor. These two disorders commonly occur in people at the same time, and have been typically treated with administration of these medications separately. The combination was approved in 2011, and sold under the brand name Juvisync by Merck. Juvisync was later removed from the market in 2013, due to business reasons.
The Saviz served in this capacity until it was damaged in an Israeli limpet mine attack in April 2021, when it was replaced by the MV Behshad. The Behshad, like the Saviz, is based on a cargo ship. Meanwhile, in Yemen, the Houthis, presumably with the assistance of Iranian engineers, converted a number of 10-meter-long patrol craft donated by the UAE to the Yemeni Coast Guard in the early 2010s into WBIEDs (water born improvised explosive devices). In 2017, one of these was used to attack the Saudi frigate Al Madinah. In the years since, three more WBIED designs have been built: the Tawfan-1, Tawfan-2, and Tawfan-3. 15 different types of naval mines were also produced. These are being increasingly deployed in the Red Sea, but have yet to be successful against naval vessels. The delivery of 120 km-ranged Noor and 200 km-ranged Qader AShMs, 300 km-ranged Khalij Fars ASBMs, and Fajr-4CL and "Al-Bahr Al-Ahmar" anti-ship rockets by Iran, which were unveiled during a 2022 Houthi parade, was arguably the most significant escalation in support. They combine long range, low cost, and high mobility with various types of guidance to create a weapon well-suited to the Houthi Navy. Though the Houthis' ASBM arsenal has yet to be tested, the Houthi Navy has had notable success with AShMs. On 1 October 2016, it was able to hit the UAE Navy's HSV-2 Swift hybrid catamaran with a single C-801/C-802 AShM fired from a shore battery. Although the ship managed to stay afloat, the damage was so severe that it had to be decommissioned.
The trial, carried out between 1946 and 1947, aimed to test the efficacy of the chemical streptomycin for curing pulmonary tuberculosis. The trial was both double-blind and placebo-controlled. The methodology of clinical trials was further developed by Sir Austin Bradford Hill, who had been involved in the streptomycin trials. From the 1920s, Hill applied statistics to medicine, attending the lectures of renowned mathematician Karl Pearson, among others. He became famous for a landmark study carried out in collaboration with Richard Doll on the correlation between smoking and lung cancer. They carried out a case-control study in 1950, which compared lung cancer patients with matched control and also began a sustained long-term prospective study into the broader issue of smoking and health, which involved studying the smoking habits and health of more than 30,000 doctors over a period of several years. His certificate for election to the Royal Society called him "the leader in the development in medicine of the precise experimental methods now used nationally and internationally in the evaluation of new therapeutic and prophylactic agents". The ethics of selecting clinical trial subjects have been controversial for much of their modern history, especially in the United States. From the 1950s up until the early 1970s, the vast majority of pharmaceutical testing in America was performed on prison populations; only after widespread abuse during testing was reported at the Holmesburg Prison did research diminish in these areas.
By stabilizing the transition state: Creating an environment with a charge distribution complementary to that of the transition state to lower its energy By providing an alternative reaction pathway: Temporarily reacting with the substrate, forming a covalent intermediate to provide a lower energy transition state By destabilizing the substrate ground state: Distorting bound substrate(s) into their transition state form to reduce the energy required to reach the transition state By orienting the substrates into a productive arrangement to reduce the reaction entropy change (the contribution of this mechanism to catalysis is relatively small) Enzymes may use several of these mechanisms simultaneously. For example, proteases such as trypsin perform covalent catalysis using a catalytic triad, stabilize charge build-up on the transition states using an oxyanion hole, complete hydrolysis using an oriented water substrate.
== Disease relevance == MMP-3 has been implicated in exacerbating the effects of traumatic brain injury (TBI) through its disruption of the blood-brain barrier (BBB). Different studies have shown that after the brain undergoes trauma and inflammation has begun, MMP production in the brain is increased. In a study conducted using MMP-3 wild type (WT) and knockout (KO) mice, MMP-3 was shown to increase BBB permeability after traumatic injury. The WT mice were shown to have lower claudin-5 and occludin levels than the KO mice after TBI. Claudin and occludin are proteins that are essential for the formation of the tight junctions between the cells of the blood-brain barrier. Tissue from uninjured WT and KO mice brains was also treated with active MMP-3. Both the WT and KO tissues showed a drop in claudin-5, occludin, and laminin-α1 (a basal lamina protein), suggesting that MMP-3 directly destroys tight junction and basal lamina proteins. MMP-3 also does damage to the blood-spinal cord barrier (BSCB), the functional equivalent of the blood-brain barrier, after spinal cord injury (SCI). In a similar study conducted using MMP-3 WT and KO mice, MMP-3 was shown to increase BSCB permeability, with the WT mice showing greater BSCB permeability than the KO mice after spinal cord injury. The same study also found decreased BSCB permeability when spinal cord tissues were treated with a MMP-3 inhibitor. These results suggest that the presence of MMP-3 serves to increase BSCB permeability after SCI.
Sources: en.wikipedia.org
The snails within this family are sophisticated predatory animals. They hunt and immobilize prey using a modified radular tooth along with a venom gland containing neurotoxins; the tooth is launched out of the snail's mouth in a harpoon-like action. Cone snails are carnivorous. Their prey consists of marine worms, small fish, molluscs, and other cone snails. Cone snails are slow-moving, and use their venomous harpoon to disable faster-moving prey. The osphradium in cone snails is more specialized than in other groups of gastropods. It is through this sensory modality that cone snails are able to sense their prey. The cone snails immobilize their prey using a modified, dartlike, barbed radular tooth, made of chitin, along with a venom gland containing neurotoxins. Molecular phylogeny research has shown that preying on fish has evolved at least twice independently in cone snails. Some species appear to have also evolved prey mimicry, where they release chemicals that resemble the sex pheromones certain ragworms release during their short breeding season. The researchers hypothesize that these chemicals cause the prey to be more easily harpooned, but are still uncertain as to exactly how this occurs in the wild.
In August 2020, British and American officials stated that the Gam-COVID-Vac vaccine would likely be rejected due to concerns that the normally rigorous process of vaccine clinical testing was not followed. As of December 2020, Belarus and Argentina granted emergency use authorization for the vector-based vaccine. On 21 January 2021, Hungary became the first European Union country to register the shot for emergency use, as well as the United Arab Emirates in the Persian Gulf region. On 19 January 2021, the Russian authorities applied for the registration of Sputnik V in the European Union, according to the RDIF. On 10 February, the European Medicines Agency (EMA) said that they had "not received an application for a rolling review or a marketing authorisation for the vaccine". The developers have only expressed their interest that the vaccine be considered for a rolling review, but EMA's Human Medicines Committee (CHMP) and the COVID-19 EMA pandemic Task Force (COVID-ETF) need to give their agreement first before developers can submit their application for initiation of the rolling review process. On 4 March 2021, the Committee for Medicinal Products for Human Use (CHMP) of the EMA started a rolling review of Sputnik V. The EU applicant is R-Pharm Germany GmbH, a subsidiary of the Russian R-Pharm. On 16 June, Reuters reported that approval of Sputnik V will be delayed at least until September because not all the necessary clinical data has been submitted by the deadline.
Jaerae-hansik-ganjang (재래한식간장, "traditional Korean-style soy sauce") – made with traditional style meju and brine. Gaeryang-hansik-ganjang (개량한식간장, "modernized Korean-style soy sauce") – made with nontraditional meju (which can be made of regular soybean, rice, barley, wheat, or soybean meal, and ripened using traditional method or Aspergillus) and brine.
=== Phytochemicals === At least twenty-seven phytochemicals have been detected in G. globosa including six phenolic acid derivatives and fifteen specific flavonoids. The most abundant phenolic compounds present are flavonoids. A major phenol was found to be kaempferol 3-O-rutinoside based on chromatographic and mass spectrometry techniques. Gomphrenol derivatives also contribute to phenolic content. Other flavanols include quercetin, kaempferol, and isorhamnetin derivatives.
Sources: en.wikipedia.org
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.
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.
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.
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。