A practical reference on ACTH fragment: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-03-07. Anything still debated is marked as such rather than presented as settled.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
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.
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.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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.
| Property | Value | Notes |
|---|---|---|
| Typical analytical method | Reversed-phase HPLC with UV detection | Separates target peptide from truncated and oxidised forms |
| Identity confirmation | LC-MS or ESI-MS | Compares observed and calculated molecular ion |
| Primary degradation route | Methionine oxidation | Forms the sulfoxide; monitored as an early-eluting peak |
| Short-term storage | 2 to 8 degrees Celsius | Applies to working vials and reconstituted portions |
| Common synonyms | ACTH(4–10) analogue, MEHFPGP | Descriptive names used in laboratory catalogues |
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.
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.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
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。
== History == Lixisenatide is a GLP-1 receptor agonist that was created by Zealand Pharma A/S of Denmark; in 2003 Zealand licensed it to Sanofi which developed the drug. Lixisenatide was approved by the European Commission on 1 February 2013. Sanofi submitted an NDA in the US, which was accepted for review by the US FDA in February 2013 but after discussions with the FDA about the cardiovascular safety data included in the package (starting in 2008, the FDA had required stronger CV safety data for new anti-diabetes drugs, following the controversy around the risks of Avandia) Sanofi decided to withdraw the NDA and wait for the results of a Phase III study that was scheduled to be completed in 2015. Sanofi resubmitted the application which the FDA accepted in September 2015, by which time Sanofi had lost the lead in the field of anti-diabetic drugs to Novo Nordisk. Lixisenatide received FDA approval on 28 July 2016. In 2010, Sanofi extended a license agreement it had with Zealand for lixisenatide to allow Sanofi to combine it with insulin glargine, which was Sanofi's best selling drug at the time, with sales of around €3 billion in 2009. Sanofi planned to start the Phase III trial that year. Sanofi submitted the new drug application in December 2015 for the combination and spent a US$245M priority voucher to gain a faster review, to try to outrace Novo Nordisk’s Xultophy, a similar combination drug of Novo's insulin Tresiba and Novo's GLP-1 agonist Victoza.
=== From vitamers === Animals are auxotroph for this enzyme co-factor and require it or an intermediate to be supplemented, hence its classification as a vitamin, unlike MoCo or CoQ10 for example. PLP is synthesized from pyridoxal by the enzyme pyridoxal kinase (gene PDXK), requiring one ATP molecule. PDXK can also produce 5'-phosphates of the other vitamers (pyridoxine and pyridoxamine), with pyridoxine 5′-phosphate oxidase converting these alternative 5'-phosphates into PLP. PLP is made and metabolized in the liver. PLP and other vitamin B6 phosphates can be broken down by pyridoxal phosphatase, which removes the phosphate group.
The International Ink Library and its Digital Ink Library are an FBI forensic database of inks. It is used to identify writing instruments, makes, models, ink types, and document authenticity. It contains over 15,000 samples of pen, marker, and printer inks dating from the 1920s. As part of the FBI Questioned Documents Branch, it is used to investigate criminal and terrorist cases, fraudulent documents, forgeries, checks, money orders, and threats to persons. It uses high-performance thin-layer chromatography, electrophoresis, ultraviolet spectra, electrospray ionization and mass spectrometry. It also analyzes chemical date tags expressly inserted by ink manufacturers. The database originated in the 1960s from the collection of Antonio Cantu, former Chief Forensic Chemist at the Secret Service, which dedicated the lab in his honor. There is no cost to access, but is limited to U.S. Secret Service directorates, students through coordinated research initiatives, and law enforcement entities. It handles over 500 cases per year. It has been used in such cases as the Jasper Johns forged documents, the Martha Stewart conviction, as well as the 9/11 attacks.
The sites are separate to prevent radioactive contamination after therapy. The patient receives therapy by automated syringe, infusion pump, or gravity using long/short needles, tubing, and sodium chloride solution. Antiemetic (anti-nausea) medications or short/long acting octreotide (cancer growth control) can be used post-therapy for symptom management. The most common side effects include decreased blood cell counts, increased liver enzymes, vomiting, nausea, increased blood glucose, and decreased blood potassium levels. Lutathera is not given to pregnant or breastfeeding individuals. The therapy shrinks tumors by an average of 30%, reduces disease progression by 72%, and delays the growth of tumors.
Sources: en.wikipedia.org
=== Bibliography === Amis, Martin (2000). Experience. Vintage. ISBN 978-0-099-28582-3. Blundell, Nigel (1996). Encyclopaedia of Serial Killers. Promotional Reprint Company Ltd. ISBN 978-1-856-48328-5. Burn, Gordon (1998). Happy Like Murderers. Faber and Faber (London). ISBN 978-0-571-19546-6. Carter Woodrow, Jane (2011). Rose West: The Making of a Monster. Hodder & Stoughton. ISBN 9781848946866. Cawthorne, Nigel (2007). Serial Killers and Mass Murderers: Profiles of the World's Most Barbaric Criminals. Ulysses Press. ISBN 978-1-569-75578-5. Cresswell, Kim (2016). Garden of Bones - The Story of Fred and Rosemary West. KC Publishing. ISBN 9780995057807. Roberts, Caroline (2005). The Lost Girl: How I Triumphed Over Life at the Mercy of Fred and Rose West. Metro Books (London). ISBN 978-1-84358-088-1. Sounes, Howard (1995). Fred and Rose: The Full Story of Fred and Rose West and the Gloucester House of Horrors. Warner Books (London). ISBN 978-0-7515-1322-6. Wansell, Geoffrey (1996). An Evil Love: The Life of Frederick West. Hodder Headline (London). ISBN 978-0-7472-1760-2. West, Anne Marie (1995). Out of the Shadows: Fred West's Daughter Tells Her Harrowing Story of Survival. Simon & Schuster. ISBN 978-0-671-71968-5. Wilson, Colin (1998). The Corpse Garden. True Crime Library (London). ISBN 978-1-874358-24-4. "Fred & Rosemary West". Murder in Mind. No. 1. 1996. ISSN 1364-5803.
== Organisational structure == The NNPC's business operations are managed through Strategic Business and Corporate Services Units (SBUs/CSUs) in diverse locations across Nigeria. The NNPC Group comprises the NNPC Board, the group managing director's office, Five directorates as listed below. Each of the directorate is headed by an executive vice president (EVP). Its divisions are headed by chiefs, while its subsidiary companies are headed by managing directors. NNPC has several subsidiaries, two partly owned subsidiaries and 16 associated companies. Directorates:
Israeli defense minister Yoav Gallant met with mayors and local council heads in Nahariya, northern Israel to discuss the threat of Hezbollah to northern residents. Gallant said that if diplomacy fails, Israel will use its military to force Hezbollah north of the Litani River. On 11 December, the mayor of the southern Lebanese village of Taybeh was killed in an Israeli airstrike. Two other Hezbollah fighters were killed by Israeli airstrikes and artillery shelling in Aitaroun, and three civilians were injured. Other airstrikes were carried out by the IAF, destroying five houses and damaging 17 others. Four batches of missiles fired from Lebanon towards northern Israel were intercepted by the Iron Dome defense system, while the Islamic Resistance claimed it attacked several Israeli sites. According to Israeli media, three soldiers were injured. Hezbollah and other militias attacked nine Israeli towns and military positions. Israeli war cabinet minister and former defense minister Benny Gantz discussed security in northern Israel in a phone call with US secretary of state Antony Blinken. Gantz said he conveyed that Hezbollah's heightened aggression and attacks mean that Israel must "remove" the threat from northern Israel. Gantz's statement singled out the Lebanese state, not just Hezbollah, and called for international pressure on Lebanon to stop attacks on its southern border. The Syrian Social Nationalist Party in Lebanon announced the death of one member of their military wing, the Eagles of the Whirlwind, on 15 December.
Sources: en.wikipedia.org
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.
Oxidation of the methionine residue to the sulfoxide is a frequently reported change, and it usually appears as an earlier-eluting peak in reversed-phase chromatography. Backbone hydrolysis products can also accumulate in aqueous solution.
Liquid chromatography coupled with mass spectrometry is the usual approach, because the observed molecular ion can be compared with a calculated mass of about 813.9 Da. Retention time alone does not establish identity.
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.