synthetic heptapeptide 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.
Updated 2026-01-10. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
| Property | Value | Notes |
|---|---|---|
| 结构类别 | 线性合成七肽 | 无环化结构，不含二硫键 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | N 端为甲硫氨酸 |
| 分子量 | 约 814 Da | 游离碱形式的计算值 |
| 外观 | 白色至类白色粉末 | 具吸湿性 |
| 溶解性 | 易溶于水 | 亦可溶于甲醇等极性溶剂 |
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.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
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.
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.
The United States Army uses various personnel management systems to classify soldiers in different specialties which they receive specialized and formal training on once they have successfully completed Basic Combat Training (BCT). Enlisted soldiers are categorized by their assigned job called a Military Occupational Specialty (MOS). MOS are labeled with a short alphanumerical code called a military occupational core specialty code (MOSC), which consists of a two-digit number appended by a Latin letter. Related MOSs are grouped together by Career Management Fields (CMF). For example, an enlisted soldier with MOSC 11B works as an infantryman (his MOS), and is part of CMF 11 (the CMF for infantry). Commissioned officers are classified by their area of concentration, or AOC. Just like enlisted MOSCs, AOCs are two digits plus a letter. Related AOCs are grouped together by specific branch of the Army or by broader in scope functional areas (FA). Typically, an officer will start in an AOC of a specific branch and move up to an FA AOC. Warrant officers are classified by warrant officer military occupational specialty, or WOMOS. Codes consists of three digits plus a letter. Related WOMOS are grouped together by Army branch. The Army is currently restructuring its personnel management systems, as of 2019. Changes took place in 2004 and continued into 2013. Changes include deleting obsolete jobs, merging redundant jobs, and using common numbers for both enlisted CMFs and officer AOCs (e.g. "35" is military intelligence for both officers and enlisted).
Nu− + C−X → C−Nu + X− where X is some functional group and Nu is a nucleophile. The number of possible organic reactions is infinite. However, certain general patterns are observed that can be used to describe many common or useful reactions. Each reaction has a stepwise reaction mechanism that explains how it happens in sequence—although the detailed description of steps is not always clear from a list of reactants alone. The stepwise course of any given reaction mechanism can be represented using arrow pushing techniques in which curved arrows are used to track the movement of electrons as starting materials transition through intermediates to final products. The mechanism for certain organic reactions remain subjects of ongoing debate and have not been fully elucidated.
Complementary to the field of structural genomics, protein structure prediction develops efficient mathematical models of proteins to computationally predict the molecular formations in theory, instead of detecting structures with laboratory observation. The most successful type of structure prediction, known as homology modeling, relies on the existence of a "template" structure with sequence similarity to the protein being modeled; structural genomics' goal is to provide sufficient representation in solved structures to model most of those that remain. Although producing accurate models remains a challenge when only distantly related template structures are available, it has been suggested that sequence alignment is the bottleneck in this process, as quite accurate models can be produced if a "perfect" sequence alignment is known. Many structure prediction methods have served to inform the emerging field of protein engineering, in which novel protein folds have already been designed. Many proteins (in eukaryotes ~33%) contain large unstructured but biologically functional segments and can be classified as intrinsically disordered proteins. Predicting and analysing protein disorder is an important part of protein structure characterisation.
Sources: en.wikipedia.org
The death penalty response by Shanmugam during the BBC interview was well-received and supported by many members of the public on social media, who also voiced their support for capital punishment for drugs in Singapore. In light of the execution of Abdul Rahim Shapiee (and his accomplice), Pritam Singh, opposition leader of Parliament and chairman of Workers' Party, wrote to Singapore newspaper Today to express his support for the death penalty for drug crimes in Singapore and the execution of drug traffickers. Singh nonetheless argued that there should be changes made to rectify the shortcomings in determining the extent of one's cooperation with the authorities during investigations before sentencing, citing cases of traffickers receiving death sentences before courts decided they were couriers and could sentence them for life, as well as cases like Abdul Rahim's, who was sentenced to death despite being a courier and having provided substantive assistance. Singh also expressed concern about the need to curb the frequent abuse of court processes by drug traffickers and their lawyers. The Ministry of Home Affairs (MHA) revealed that from 2013 to early 2022, certificates of substantive assistance were issued to 82 out of 104 drug traffickers regardless of nationality, while there were 14 out of the remaining 22 sentenced to death and the other eight traffickers sentenced to life imprisonment due to mental illnesses.
=== Natural populations of Drosophila === In the 1930s, Dobzhansky and his coworkers collected Drosophila pseudoobscura and D. persimilis from wild populations in California and neighboring states. Using Painter's technique they studied the polytene chromosomes and discovered that the wild populations were polymorphic for chromosomal inversions. All the flies look alike whatever inversions they carry: this is an example of a cryptic polymorphism. Evidence rapidly accumulated to show that natural selection was responsible. Using a method invented by L'Héritier and Teissier, Dobzhansky bred populations in population cages, which enabled feeding, breeding and sampling whilst preventing escape. This had the benefit of eliminating migration as a possible explanation of the results. Stocks containing inversions at a known initial frequency can be maintained in controlled conditions. It was found that the various chromosome types do not fluctuate at random, as they would if selectively neutral, but adjust to certain frequencies at which they become stabilised. By the time Dobzhansky published the third edition of his book in 1951 he was persuaded that the chromosome morphs were being maintained in the population by the selective advantage of the heterozygotes, as with most polymorphisms.
== Side effects == Adverse effects by incidence: Note: Serious (that is, those that can either result in permanent injury or are irreversible or are potentially life-threatening) are written in bold text. Very common (>10% incidence) adverse effects include:
Sources: en.wikipedia.org
The first organ ever induced and made in the lab was the bladder, which was created in 1999. By 2014, there had been various tissues regenerated by the 3D printer and these tissues included: muscle, vagina, penis and the thymus. In 2014, a conceptual human lung was first bioengineered in the lab. In 2015, the lab robustly tested its technique and regenerated a pig lung. The pig lung was then successfully transplanted into a pig without the use of immunosuppressive drugs. In 2015, researchers developed a proof of principle biolimb inside a laboratory; they also estimated that it would be at least a decade for any testing of limbs in humans. The limb demonstrated fully functioning skin, muscles, blood vessels and bones. In April 2019, researchers 3D printed a human heart. The prototype heart was made by human stem cells but only to the size of a rabbit's heart. In 2019, the researchers hoped to one day place a scaled up version of the heart inside humans.
=== 2010s onwards === The closure of the Delta hub resulted in several changes at the Memphis airport. Passenger traffic declined from eleven million in 2007 to four million in 2017. The terminal, with its three concourses and unoccupied gates, was too large. In 2014, the Memphis–Shelby County Airport Authority announced a renovation of the airport that would involve modernizing Concourse B and mothballing the other two concourses. On the other hand, airfares dropped and new low-cost airlines entered the market, such as Southwest Airlines. The airport continued to see a high level of cargo activity due to the FedEx hub. As of 2018, Memphis was the second-busiest cargo airport in the world. The refurbishment of Concourse B was completed in February 2022. The building features wider hallways and higher ceilings. The southwest wing of the concourse was not renovated because of cost and a lack of need for the additional gates. Work commenced on an expansion of the landside portion of the terminal in 2024. The program includes tearing down Concourse A to make room for an administrative and baggage-inspection building. Following the death of Frederick W. Smith, founder of FedEx, in June 2025, the airport authority decided to rename the facility in his honor due to his contributions to the city of Memphis and the airport in particular. The Federal Aviation Administration was working on implementing the change as of December 2025. On August 11, 2026, the airport was officially renamed to Frederick W. Smith International Airport.
== Literature == Kitagaki H (2021). "Medical Application of Substances Derived from Non-Pathogenic Fungi and -Containing". Journal of Fungi. 7 (4): 4. doi:10.3390/jof7040243. PMC 8063943. PMID 33804991. J. E. Smith (6 December 2012). Aspergillus. Springer US. pp. 46ff. ISBN 978-1-4615-2411-3.
Sources: en.wikipedia.org
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。
Semax 对应 ACTH 第 4 至第 10 位的片段，并在两端做了替换与延长，使其不再具备促肾上腺皮质激素的典型内分泌活性。这一改动同时改变了它在体内的稳定性与分布特征。
俄罗斯将其列为处方药物，需要医生开具处方。多数其他国家把它当作研究化合物，不能作为药品销售或宣称疗效。具体合法性取决于当地法规。
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.