Heptapeptide comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-01-11. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
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.
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.
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.
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.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
effector Also modifier and modulator. Any small molecule or ligand which by interacting with a particular enzyme changes its catalytic activity but is not itself changed. A positive effector enhances the enzyme's activity while a negative effector reduces it.
Caution is advised for the use of morphine during pregnancy or breastfeeding, as it may affect the health of the baby. Morphine was first isolated in 1804 by German pharmacist Friedrich Sertürner. This is believed to be the first isolation of a medicinal alkaloid from a plant. Merck began marketing it commercially in 1827. Morphine was more widely used after the invention of the hypodermic syringe in 1853–1855. Sertürner originally named the substance morphium, after the Greek god of dreams, Morpheus, as it has a tendency to cause sleep. The primary source of morphine is isolation from poppy straw of the opium poppy. In 2013, approximately 523 tons of morphine were produced. Approximately 45 tons were used directly for pain, an increase of 400% over the last twenty years. Most use for this purpose was in the developed world. About 70% of morphine is used to make other opioids such as hydromorphone, oxymorphone, and heroin. It is a Schedule II drug in the United States, Class A in the United Kingdom, and Schedule I in Canada. It is on the World Health Organization's List of Essential Medicines. In 2023, it was the 156th most commonly prescribed medication in the United States, with more than 3 million prescriptions. It is available as a generic medication.
Medical genetics is concerned with the diagnosis and management of hereditary disorders. Neurology is concerned with diseases of the nervous system. In the UK, neurology is a subspecialty of general medicine. Obstetrics and gynecology (often abbreviated as OB/GYN (American English) or Obs & Gynae (British English)) are concerned respectively with childbirth and the female reproductive and associated organs. Reproductive medicine and fertility medicine are generally practiced by gynecological specialists. Pediatrics (AE) or paediatrics (BE) is devoted to the care of infants, children, and adolescents. Like internal medicine, there are many pediatric subspecialties for specific age ranges, organ systems, disease classes, and sites of care delivery. Pharmaceutical medicine is the medical scientific discipline concerned with the discovery, development, evaluation, registration, monitoring and medical aspects of marketing of medicines for the benefit of patients and public health. Physical medicine and rehabilitation (or physiatry) is concerned with functional improvement after injury, illness, or congenital disorders. Podiatric medicine is the study of, diagnosis, and medical and surgical treatment of disorders of the foot, ankle, lower limb, hip and lower back. Preventive medicine is the branch of medicine concerned with preventing disease. Community health or public health is an aspect of health services concerned with threats to the overall health of a community based on population health analysis.
Sources: en.wikipedia.org
== History == In 1976, two cats were described with diabetes mellitus and acidophilic pituitary adenomas. Whilst growth hormone levels were not measured it was proposed that growth hormone excess from the tumours was the cause of the diabetes. In the following three decades further cases would only be written about infrequently and feline hypersomatotropism was considered a rare disease. This was challenged in 2007 after a study looking at the IGF-1 levels in cats with diabetes found a marked increase in 32% of cats. Growth hormone excess induced by progestogens in dogs was first described in the 1970s and 1980s. In 1980 a crossbred Belgian Shepherd bitch with acromegaly that had been administered excessive amounts of medroxyprogesterone acetate (MPA); following cessation of MPA administration symptoms improved and hormone levels returned to normal. In 1981 it was reported that fifteen bitches receiving MPA injections to prevent oestrus. All fifteen showed signs of acromegaly and thirteen showed hyperglycaemia. Clinical signs were improved after cessation of MPA. Later studies would confirm an association between progestogen administration and acromegaly, glucose intolerance, and diabetes mellitus.
After Mister Donut was acquired by Dunkin' Donuts in 1990, most stores either closed or became Dunkin' Donuts. There were nine outlets in the Pennsylvania and Ohio region that remained Mister Donut, mostly due to being close to existing Dunkin' Donuts stores. Their owners formed a cooperative to continue receiving bulk pricing on materials. As of May 2006, these stores rebranded as Donut Connection, serving the same items as Mister Donut. Some locations of the Donut Connection partnership have retained the original fixtures of the original Mister Donut location, such as the outlet in Shakopee, Minnesota, which still has the orange motif and original Mister Donut price board. Most of the stores, while located in areas where Dunkin' remains prominent, also compete with Starbucks and (largely through grocer distribution) Krispy Kreme alongside mom-and-pop shops, but largely do not overlap with Tim Hortons. Only one store located in 2720 Grovelin Street, Godfrey, Illinois, continues to operate as Mister Donut.
== Publications == J. Kopeček, J. Yang, "Polymer Nanomedicines". Advanced Drug Delivery Reviews 156, 40–66 (2020) L. Li, Y. Li, C.-H. Yang, D.C. Radford, J. Wang, M. Janát-Amsbury, J. Kopeček, J. Yang, "Inhibition of Immunosuppresive Tumors by Polymer-Assisted Inductions of Immunogenic Cell Death and Multivalent PD-L1 Crosslinking". Advanced Functional Materials 30:1908961 (2020) L. Li, J. Wang, Y. Li, D.C. Radford, J. Yang, J. Kopeček, "Broadening and Enhancing Functions of Antibodies by Self-Assembling Multimerization at Cell Surface". ACS Nano 13, 11422–11432 (2019) J. Yang, L. Li, J. Kopeček, "Biorecognition: A Key to Drug-free Macromolecular Therapeutics". Biomaterials 190–191, 11–23 (2019) J. Wang, L. Li, J. Yang, P.M. Clair, M. Glenn, D.M. Stephens, D.C. Radford, K.M. Kosak, M.W. Deininger, P.J. Shami, J. Kopeček, "Drug-free Macromolecular Therapeutics Induce Apoptosis in Cells Isolated from Patients with B Cell Malignancies with Enhanced Apoptosis Induction by Pretreatment with Gemcitabine". Nanomedicine: Nanotechnology, Biology and Medicine 16, 217–225 (2019). J. Yang, R. Zhang, H. Pan, Y. Li, Y. Fang, L. Zhang, J. Kopeček, "Backbone Degradable HPMA Copolymer Conjugates with Gemcitabine and Paclitaxel: Impact of Molecular Weight on Activity toward Human Ovarian Carcinoma Xenografts". Molecular Pharmaceutics 14, 1384–1394 (2017) J.M. Hartley, T.-W. Chu, E.M. Peterson, R. Zhang, J. Yang, J. Harris, J.
Sources: en.wikipedia.org
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。