neurotrophic signaling 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 2026-01-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
| 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 |
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。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
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。
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
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.
== History == Dimethocaine was originally synthesized by the Hoffmann-La Roche company in 1930. It was sold under the market name larocaine. During the 1930s dimethocaine gained popularity in the US as a local anesthetic. Just like cocaine and procaine, it was used during surgery, primarily in dentistry, ophthalmology and otolaryngology. However, in the 1940s, it was removed from the market because of its psychoactive effects and risk of addiction. Nowadays dimethocaine is abused for these psychoactive effects. It is sold as a cocaine surrogate to circumvent legislation issues.
== Career == Thomsen worked as a pharmacologist at Leo Pharma from 1989 to 1991 and was thereafter employed by Novo Nordisk in as head of Growth Hormone Research. He became senior vice president for diabetes R&D in 1994 and was appointed senior vice president of Health Care Discovery in 1995. In November 2000, he was appointed executive vice president of Global R&D and chief scientific officer (CSO). As chief scientific officer, he was responsible for the research and development of 20 medicine products within diabetes, obesity and biopharmaceuticals. He led the development of GLP-1 therapies that today are among the leading treatments within type 2 diabetes and obesity. He left the position as executive vice president of R&D on February 28, 2021, and took the role as CEO of the Novo Nordisk Foundation on March 1, 2021. He has been the president of the Danish Academy of Technical Sciences and has been on the board of directors at the Technical University of Denmark (DTU) and University of Copenhagen. From 2017 to 2020, Thomsen was the chairman of the board of directors at University of Copenhagen. Mads Krogsgaard Thomsen received the royal decoration of Knight of the Order of the Dannebrog by the Danish Royal House on 12 December 2022. In 2024, Thomsen received the Golden Plate Award of the American Academy of Achievement, presented by Awards Council member Robert S. Langer.
== J == Jacksonian seizure A type of focal seizure that begins in one area of the body (typically a finger or toe) and "marches" to adjacent areas, reflecting orderly spread of abnormal activity in the motor cortex. James–Lange theory A historical theory of emotion proposing that emotions result from physiological responses to stimuli (e.g., "We are afraid because we tremble"). While outdated, it laid groundwork for modern affective neuroscience. Jaw jerk reflex A stretch reflex elicited by tapping the chin, which causes the jaw to jerk upward. Used clinically to assess integrity of the trigeminal nerve and brainstem reflex circuits. Jitter The variability in timing of neural spike trains or signal transmission, especially in motor units or brain-computer interface systems. High jitter can affect signal fidelity. JNK pathway (c-Jun N-terminal kinase pathway) A signaling cascade involved in stress responses, apoptosis, and neurodegeneration. Dysregulation of the JNK pathway is linked to Alzheimer’s disease and neuronal injury. Joubert syndrome A rare genetic disorder characterized by abnormal development of the cerebellar vermis and brainstem, leading to hypotonia, ataxia, abnormal breathing, and developmental delay. Juxtacrine signaling A form of cell-to-cell communication where signaling molecules are transmitted directly through contact, rather than being secreted. Important in neural development and synaptogenesis.
The former provinces of Farther Pomerania, East Prussia, Silesia and Posen-West Prussia fell under Polish administration with the Soviet Union taking the area around Königsberg (now Kaliningrad), pending a final peace conference with Germany which eventually never took place. More than 8 million Germans had been expelled from these territories that had formed part of the German-speaking lands for centuries and which mostly did not have sizable Polish minorities before 1945. However, no attempts were made to establish new states in these territories, as they lay outside the jurisdiction of West Germany at that time. In 1948, the military governors of the three Western Allies handed over the so-called Frankfurt Documents to the minister-presidents in the Western occupation zones. Among other things, they recommended revising the boundaries of the West German states in a way that none of them should be too large or too small in comparison with the others. As the premiers did not come to an agreement on this question, the Parliamentary Council was supposed to address this issue. Its provisions are reflected in Article 29 of the Basic Law. There was a binding provision for a new delimitation of the federal territory: the Federal Territory must be revised (paragraph 1). Moreover, in territories or parts of territories whose affiliation with a Land had changed after 8 May 1945 without a referendum, people were allowed to petition for a revision of the current status within a year after the promulgation of the Basic Law (paragraph 2).
Sources: en.wikipedia.org
== Cancer research == Since the inception of phosphoproteomics, cancer research has focused on changes to the phosphoproteome during tumor development. Phosphoproteins could be cancer markers useful to cancer diagnostics and therapeutics. In fact, research has shown that there are distinct phosphotyrosine proteomes of breast and liver tumors. There is also evidence of hyperphosphorylation at tyrosine residues in breast tumors but not in normal tissues. Findings like these suggest that it is possible to mine the tumor phosphoproteome for potential biomarkers. Increasing amounts of data are available suggesting that distinctive phosphoproteins exist in various tumors and that phosphorylation profiling could be used to fingerprint cancers from different origins. In addition, systematic cataloguing of tumor-specific phosphoproteins in individual patients could reveal multiple causative players during cancer formation. By correlating this experimental data to clinical data such as drug response and disease outcome, potential cancer markers could be identified for diagnosis, prognosis, prediction of drug response, and potential drug targets.
Neurotoxins, which primarily affect the nervous systems of animals, such as ion channel toxins. These are found in many venomous taxa, including mambas, black widow spiders, scorpions, box jellyfish, cone snails, centipedes and blue-ringed octopuses. Myotoxins, which damage muscles by binding to a receptor. These small, basic peptides are found in snake (such as rattlesnake) and lizard venoms. Cytotoxins, which kill individual cells and are found in the apitoxin of honey bees and the venom of black widow spiders. A subclass of cytotoxins is the necrotoxins, which cause necrosis (i.e., death) in the cells and tissues they encounter. The complex venoms of vipers and bees contain phospholipases; viper venoms often also contain trypsin-like serine proteases.
=== Tiegs Museum === The University of Melbourne's zoological museum, established in 1887, is now named The Tiegs Museum after Oscar Tiegs. Oscar Tiegs was responsible for substantially improving the museum's collection, which was housed in its own room in the old Zoology Building. The room was called "The Tiegs Museum" and this title was now officially adopted, and followed the museum to its new location in the Zoology Department's new premises in 1988.
=== Particular studies === In a Bulgarian study, after five years, 34% had developed into a defined connective tissue disease (with the highest probability of development being within the first two years after onset of symptoms), 54% continued undifferentiated, and 12% were in remission. In a US study, after 10 years, 37% had developed into a defined connective tissue disease, 43% continued undifferentiated, and 20% were in remission. In a Spanish study, after a mean follow-up of 11±3 years, 14% had developed a definite CTD, 62% continued undifferentiated, and 24% were in remission. In an Italian study (in which 58% had ANA abnormalities), after five years, 6% had developed a defined autoimmune disease. The remaining 94% saw clinical and serological features little changed in the period and quite stable. 11% of these were and remained asymptomatic.
This activity might explain why kratom can be dangerous when used in combination with other sedatives. Kratom also contains rhynchophylline, a non-competitive NMDA receptor antagonist. Mitragynine is metabolized in humans via phase I and phase II mechanisms with the resulting metabolites excreted in urine. In in vitro experiments, kratom extracts inhibited CYP3A4, CYP2D6, and CYP1A2 enzymes, which results in significant potential for drug interactions.
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.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.