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 2026-06-10 and is reviewed periodically as new material appears.
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.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
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.
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.
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
== Early years and education == Hans Charles Freeman was the first and only son of Karl and Lotte Freeman and was born in Breslau in Germany in 1929 (now Wrocław, Poland). In 1938, following a tip-off from a Nazi party member, Karl decided to relocate his Jewish family to Australia. Karl brought his knowledge of detergents (a novelty in Australia at the time) to his new homeland, applying it to the problem of cleaning blood-stained blankets that would otherwise be wasted. After the war, he founded K. H. Freeman Pty Ltd, a detergent and soap manufacturing company; Hans spent many weekends working in the factory, gaining a practical insight into chemistry. Hans adapted well to his new environment, quickly mastering his new language and demonstrating his outstanding scholastic ability. He was dux of his primary school, dux of Sydney Boys High in 1945, and took his bachelor's degree with the university medal in chemistry in 1949. He was one of the ten chemistry students in his class at Sydney Boys High to go on to become Professors of Chemistry. After receiving his MSc in 1952 under the supervision of Raymond Le Fèvre FRS, Freeman attended Caltech on a Rotary Foundation Fellowship where, at the urging of Linus Pauling, he learned the fundamentals of crystallography. He received a PhD in 1957 for his work on the structure of biuret hydrate, where he completed most of the calculations for the crystal structure by hand.
Colombia nonetheless entered the qualifying tournament for the finals they had abandoned, finishing third in a group won by Argentina and reaching the CONMEBOL play-offs. A 3–0 defeat in Asunción on 27 October 1985, Ramón Hicks, Romerito and Roberto Cabañas scoring, left the tie beyond recovery; goals from Sergio Angulo and Ortiz gave Colombia a 2–1 win in Cali a week later before a crowd of only 6,000, and Paraguay progressed 4–2 on aggregate.
=== Coolant additive === Graphene's high thermal conductivity suggests that it could be used as an additive in coolants. Preliminary research work showed that 5% graphene by volume can enhance the thermal conductivity of a base fluid by 86%. Another application due to graphene's enhanced thermal conductivity was found in PCR.
He forgets that one of the most cunning and interesting aspects of consumer music, the mass media, and indeed of capitalism itself, is their fluidity, their unending capacity for adaptation and assimilation." On the other hand, the scholar Slavoj Žižek has written a foreword to Adorno's In Search of Wagner, in which Žižek attributes an "emancipatory impulse" to the same book—although Žižek also suggests that fidelity to this impulse demands "a betrayal of the explicit theses of Adorno's Wagner study" In a 2014 New Yorker article, music critic Alex Ross discussed the continued relevance of Theodor Adorno's work in the digital age, stating, "The pop hegemony is all but complete, its superstars dominating the media and wielding the economic might of tycoons ... Culture appears more monolithic than ever, with a few gigantic corporations—Google, Apple, Facebook, Amazon—presiding over unprecedented monopolies." Adorno's critique of commercial media capitalism has continued to influence academic discussions. Scholars often reference his work to explore how Western entertainment industries may contribute to the reinforcement of global capitalism and Western cultural dominance. This perspective is reflected in studies that examine the role of transnational media corporations in shaping cultural production. For example, in The US Empire's Culture Industry, Tanner Mirrlees explores how Western commercial entertainment is often maintained by large transnational media corporations, rather than emerging organically from local cultural traditions.
Sources: en.wikipedia.org
A psychedelic substance is a psychoactive drug whose primary action is to alter cognition and perception. Psychedelics tend to affect and explore the mind in ways that result in the experience being qualitatively different from those of ordinary consciousness. The psychedelic experience is often compared to non-ordinary forms of consciousness such as trance, meditation, yoga, religious ecstasy, dreaming and even near-death experiences.
=== Disadvantages === While molecular farming is one application of genetic engineering, there are concerns that are unique to it. In the case of genetically modified (GM) foods, concerns focus on the safety of the food for human consumption. In response, it has been argued that the genes that enhance a crop in some way, such as drought resistance or pesticide resistance, are not believed to affect the food itself. Other GM foods in development, such as fruits designed to ripen faster or grow larger, are believed not to affect humans any differently from non-GM varieties. In contrast, molecular farming is not intended for crops destined for the food chain. It produces plants that contain physiologically active compounds that accumulate in the plant's tissues. Considerable attention is focused, therefore, on the restraint and caution necessary to protect both consumer health and environmental biodiversity. The fact that the plants are used to produce drugs alarms activists. They worry that once production begins, the altered plants might find their way into the food supply or cross-pollinate with conventional, non-GM crops. These concerns have historical validation from the ProdiGene incident, and from the StarLink incident, in which GMO corn accidentally ended up in commercial food products. Activists also are concerned about the power of business. According to the Canadian Food Inspection Agency, in a recent report, says that U.S. demand alone for biotech pharmaceuticals is expanding at 13 percent annually and to reach a market value of $28.6 billion in 2004.
Charlemagne founded the Carolingian Empire in 800; it was divided in 843. The eastern successor kingdom of East Francia stretched from the Rhine in the west to the Elbe river in the east and from the North Sea to the Alps. Subsequently, the Kingdom of Germany and the Holy Roman Empire emerged from it. The Ottonian rulers (919–1024) consolidated several major duchies. In 996, Gregory V became the first German Pope, appointed by his cousin Otto III, whom he shortly after crowned Holy Roman Emperor. The Holy Roman Empire absorbed northern Italy and Burgundy under the Salian emperors (1024–1125), although the emperors lost power through the Investiture Controversy. Under the Hohenstaufen emperors (1138–1254), German princes encouraged German settlement to the south and east (Ostsiedlung). Members of the Hanseatic League, mostly north German towns, prospered in the expansion of trade. The population declined starting with the Great Famine in 1315, followed by the Black Death of 1348–1350. The Golden Bull issued in 1356 provided the constitutional structure of the Empire and codified the election of the emperor by seven prince-electors. Johannes Gutenberg introduced moveable-type printing to Europe, laying the basis for the democratisation of knowledge. Following Martin Luther's 1517 Protestant Reformation, bolstered by his standardised Bible translation, led to the 1555 Peace of Augsburg, which recognised Lutheranism under the principle of cuius regio, eius religio (ruler's faith dictates subjects' faith).
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As a result, engineered variants of the enzyme have been developed with improved substrate tolerance and higher incorporation efficiency, enhancing their suitability for controlled enzymatic oligonucleotide synthesis.
Sources: en.wikipedia.org
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.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.