This is a working overview of Heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-04-17 and is reviewed periodically as new material appears.
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.
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White lyophilized powder | Typical for synthetic peptides |
| Solubility | Freely soluble in water | Also soluble in saline |
| Storage temperature | -20 C or below | Protect from repeated freeze-thaw |
| Analytical method | Reverse-phase HPLC | Confirms purity and identity |
| Common synonym | ACTH(4-10) analog | Reflects structural origin |
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
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。
Sulfonamides Sulfonamide compound 5 (Table 1) was identified through high-throughput screening studies as a potential allosteric selective inhibitor, binding at the interface between domain II and IV of ERAP1. It activates small peptide hydrolysis but effectively inhibits processing of long peptides with 8−13 residues (IC50 = 5.3 μM) and displays selectivity over ERAP2 and IRAP.
Thomson further explained that ions are atoms that have a surplus or shortage of electrons. Thomson's model is popularly known as the plum pudding model, based on the idea that the electrons are distributed throughout the sphere of positive charge with the same density as raisins in a plum pudding. Neither Thomson nor his colleagues ever used this analogy. It seems to have been a conceit of popular science writers. The analogy suggests that the positive sphere is like a solid, but Thomson likened it to a jelly, as he proposed that the electrons moved around in it in patterns governed by the electrostatic forces. The positive electrification in Thomson's model was a temporary concept, which he hoped would ultimately be explained by some phenomena of the electrons. Like all atomic models of that time, Thomson's model was incomplete, it could not predict any of the known properties of the atom such as emission spectra. In 1910, Robert A. Millikan and Harvey Fletcher reported the results of their oil drop experiment in which they isolated and measured the charge of an electron. Careful measurements over several years gave the charge -4.774 × 10−10esu.
=== The American Revolution === After his disenchantment with socialism, Hitchens increasingly emphasized the centrality of the American Revolution and the U.S. Constitution to his political philosophy. As early as 2002, Hitchens wrote, "as the third millennium gets under way, and as the Russian and Chinese and Cuban revolutions drop below the horizon, it is possible to argue that the American revolution, with its promise of cosmopolitan democracy, is the only 'model' revolution that humanity has left to it". His enthusiasm for the U.S. Bill of Rights contrasts with a dim opinion of constitutional politics on the other side of the Atlantic. Hitchens notes, "the utter failure [of the EU] to compose a viable constitution" and the "brevity of the British constitution, perhaps because the motherland of the English-speaking peoples has absent-mindedly failed to evolve one in written form".
=== MAGNET designation === In 2008, Southern Ohio Medical Center became the first hospital in the tri-state region (Ohio, Kentucky, West Virginia) to earn Magnet Recognition from the American Nurses Credentialing Center. The Magnet Recognition Program recognizes healthcare organizations for quality patient care, nursing excellence and innovations in professional nursing practice. In 2011, less than 7% of hospitals in the United States were able to achieve Magnet Recognition. SOMC earned Magnet re-designation in 2013.
Sources: en.wikipedia.org
Serous acinar cells are roughly pyramid shape, with the apex of the pyramid pointing towards to the center of the (roughly spherical) acinus. Inside of the cell on the side with the apex, there are specialize saliva-material containing structures called secretory granules. Compared to mucous acinar cells, their nuclei is more round, and centrally located.
== Timeline and list of outbreaks == 1960: Outbreak of Turkey 'X' disease in England, and aflatoxin discovery. 1961: Identified Aspergillus flavus associated with toxicity of groundnuts. 1962: Aflatoxin B and G identified in TLC analysis. Isolation and synthesis of aflatoxins. 1963: Aflatoxin B2, G1, and G2 were identified and chemically characterized as difurocoumarin derivatives. 1965: FDA approved the first regulation on aflatoxins 30 μg/kg. 1966: Milk toxins were designated as AFM1 and AFM2, and AFM1 was detected in milk, urine, kidney, and liver. 1973 Poland: 10 died following the opening of the tomb of Casimir IV Jagiellon, which contained aflatoxin-producing molds. 2004 Kenya: acute outbreak of aflatoxicosis resulting from ingestion of contaminated maize, 125 confirmed deaths. 2005 US: Diamond Pet Foods recalled aflatoxin-contaminated pet food manufactured from corn at their facility in Gaston, South Carolina. 2009–2011 International: Commercial peanut butter, cooking oils (e.g. olive, peanut and sesame oil), and cosmetics were identified as contaminated with aflatoxin. In some instances, liquid chromatography–tandem mass spectrometry (LC–MS/MS), and other analytical methods, revealed that 48–80% of selected product samples contained detectable quantities of aflatoxin. In many of these contaminated food products, the aflatoxin exceeded the safe limits of the U.S. Food and Drug Administration (FDA) or other regulatory agencies. February–March 2013: Romania, Serbia, Croatia imported into western Europe – 2013 aflatoxin contamination. February 2013: Iowa contamination.
Troponin C binds to calcium ions (Ca2+) to produce a conformational change in TnI Troponin T binds to tropomyosin, interlocking them to form a troponin-tropomyosin complex with thin filaments Troponin I binds to actin in thin myofilaments to hold the actin-tropomyosin complex in place. It inhibits the ATPase activise of actomyosin. Inside the cardiac troponin complex, the strongest interaction between molecules is the cTnI–TnC binary complex, especially in the presence of Ca2+ (KA = 1.5 × 10−8 M−1). TnC, forming a complex with cTnI, changes the conformation of cTnI molecule and shields part of its surface. According to the latest data cTnI is released in the blood stream of the patient in the form of binary complex with TnC or ternary complex with cTnT and TnC. cTnI-TnC complex formation plays an important positive role in improving the stability of cTnI molecule. cTnI, which is extremely unstable in its free form, demonstrates significantly better stability in complex with TnC or in ternary cTnI-cTnT-TnC complex. It has been demonstrated that stability of cTnI in native complex is significantly better than stability of the purified form of the protein or the stability of cTnI in artificial troponin complexes combined from purified proteins.
Sources: en.wikipedia.org
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.
Peptidases degrade the compound within minutes in circulation. This short half-life is one reason nasal delivery is used, placing the substance close to the olfactory and trigeminal pathways.
No large multicenter trials have been published in English-language journals. The existing human evidence consists mainly of smaller studies conducted in Russia, which limits generalization.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.