This is a working overview of heptapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-20. Anything still debated is marked as such rather than presented as settled.
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.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
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。
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.
Phosphomolybdic acid is used as a reagent for staining phenolics in thin layer chromatography. Polyphenols can be studied by spectroscopy, especially in the ultraviolet domain, by fractionation or paper chromatography. They can also be analysed by chemical characterisation. Instrumental chemistry analyses include separation by high performance liquid chromatography (HPLC), and especially by reversed-phase liquid chromatography (RPLC), can be coupled to mass spectrometry.
=== 30 April === Three people were killed in a Russian missile attack on Odesa. Russia subsequently claimed that it had struck the headquarters of the Ukrainian Operational Command South in the city. One person was killed in a Russian airstrike in Kharkiv. Russian-installed officials in southern Ukraine claimed that several Ukrainian missiles were shot down by air defenses over Crimea. The SBU arrested two people in Kyiv on suspicion of impersonating security officials on social media and establishing a bot farm as part of a Russian disinformation campaign. Germany announced a new military aid package for Ukraine, including a Skynex air defense system, missiles for the IRIS-T launchers, ammunition for Leopard 2 tanks, Gepard ammunition, 155 mm shells, small arms ammunition, grenade launchers, mine clearing equipment, bridge laying and first aid supplies. Latvia also pledged another military aid package that included anti-aircraft guns and tactical unmanned surveillance systems. Lithuania announced its support for repatriating Ukrainian military-aged men to be mobilised. Andriy Demchenko, head of the State Border Guard Service of Ukraine, said that 30 Ukrainians had died trying to leave the country since the invasion began.
== See also == Farkas, Etelka; Buglyó, Péter (2017). "Chapter 8. Lead(II) Complexes of Amino Acids, Peptides, and Other Related Ligands of Biological Interest". In Astrid, S.; Helmut, S.; Sigel, R. K. O. (eds.). Lead: Its Effects on Environment and Health. Metal Ions in Life Sciences. Vol. 17. de Gruyter. pp. 201–240. doi:10.1515/9783110434330-008. PMID 28731301. pp. 228–230 Dunaliella
Sources: en.wikipedia.org
In 2004, GSK agreed to settle charges of consumer fraud for $2.5 million. The legal discovery process also uncovered evidence of deliberate, systematic suppression of unfavorable Paxil research results. One of GSK's internal documents read, "It would be commercially unacceptable to include a statement that efficacy [in children] had not been demonstrated, as this would undermine the profile of paroxetine". In 2012, the United States Department of Justice fined GlaxoSmithKline $3 billion for withholding data, unlawfully promoting use in those under 18, and preparing an article that misleadingly reported the effects of paroxetine in adolescents with depression following its clinical trial study 329. In February 2016, the UK Competition and Markets Authority imposed record fines of £45 million on companies that were found to have infringed European Union and UK Competition law by entering into agreements to delay the market entry of generic versions of the drug in the UK. GlaxoSmithKline received the bulk of the fines, being fined £37,600,757. Other companies that produce generics were issued fines which collectively total £7,384,146. UK public health services are likely to claim damages for being overcharged in the period where the generic versions of the drug were illegally blocked from the market, as the generics are over 70% less expensive. GlaxoSmithKline may also face actions from other generic manufacturers who incurred losses as a result of the anticompetitive conduct.
Following the approval of eteplirsen, two other drugs of a similar kind, golodirsen and viltolarsen received provisional approval from the FDA for the treatment of people with a confirmed mutation of the dystrophin gene that is amenable to exon 53 skipping as well as casimersen for exon 45 skipping.
1 May – Brendan Walsh, 50, hurler (Killeagh, Imokilly, Cork senior team). 6 May Derek Keating, 67, politician, TD (2011–2016). Joe Young, 89, Gaelic footballer and hurler (St. Vincent's, Dublin junior team, Galway senior teams). 7 May Seán Keane, 76, fiddler. (The Chieftains). Patrick Joseph McGrath, 77, Roman Catholic prelate, Bishop of San Jose, California (1999–2019). 15 May – Marty Lynch, 59, Gaelic footballer (Newry Mitchels, Newry Bosco, Down senior team). Born in Northern Ireland. 19 May – Seán McCormack, 79, Gaelic footballer (Kilmainhamwood, Meath senior team). 27 May Hugh Callaghan, 93, a member of the Birmingham Six. Graham Knuttel, 69, painter and sculptor. 30 May – Michael Viney, 90, artist, author, journalist and broadcaster. 31 May – Peter Harbison, 84, archaeologist.
Sources: en.wikipedia.org
In 1957, the SAOCGA prohibited mixed-race competitions within its member bodies. In 1959, Dennis Brutus and others founded the South African Sports Association (SASA), which campaigned to allow non-white athletes to represent South Africa. The same year, IOC delegates questioned whether SAOCGA's operation violated the Olympic Charter's ban on discrimination. Reginald Honey, South Africa's IOC member, contended that nonwhite competitors had not been selected because none were of Olympic standard, and promised that any selected in future would be given passports. Brundage felt the discrimination rule only applied at the Olympics itself, not at domestic competition, and so South Africa was allowed to compete at the 1960 Olympics in Rome. The same year, it competed at the Winter Olympics for the first time. Its delegations were all white.
Escherichia coli: 0.12–128 μg/mL Klebsiella pneumoniae: 0.25–128 μg/mL Pseudomonas aeruginosa: ≤0.06–16 μg/mL For example, colistin in combination with other drugs is used to attack P. aeruginosa biofilm infection in lungs of patients with cystic fibrosis. Biofilms have a low-oxygen environment below the surface where bacteria are metabolically inactive, and colistin is highly effective in this environment. However, P. aeruginosa reside in the top layers of the biofilm, where they remain metabolically active. This is because surviving tolerant cells migrate to the top of the biofilm via pili and form new aggregates via quorum sensing.
Cathelicidins are mostly found in neutrophils, monocytes, mast cells, dendritic cells and macrophages after activation by bacteria, viruses, fungi, parasites or the hormone 1,25-D, which is the hormonally active form of vitamin D. They have been found in some other cells, including epithelial cells and human keratinocytes. Some viruses evolved immunomodulatory mechanisms to avoid cathelicidin exposure by downregulating the cellular vitamin D receptor.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Registered medical products are most often 0.1% nasal drops. Research suppliers ship lyophilized powder, usually in milligram quantities, which is dissolved before use. The active peptide is the same in both cases; presentation and excipients differ.