ACTH analog 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 2025-08-13. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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 |
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.
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.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
2.A: Porters (uniporters, symporters, antiporters), SLCs. Excitatory amino acid transporters (EAATs) EAAT1 EAAT2 EAAT3 EAAT4 EAAT5 Glucose transporter Monoamine transporters, including: Dopamine transporter (DAT) Norepinephrine transporter (NET) Serotonin transporter (SERT) Vesicular monoamine transporters (VMAT) Adenine nucleotide translocator (ANT) 2.B: Nonribosomally synthesized porters, such as: The Nigericin family The Ionomycin family 2.C: Ion-gradient-driven energizers
Arabinogalactan-proteins (AGPs) are highly glycosylated proteins (glycoproteins) found in the cell walls of plants. Each one consists of a protein with sugar molecules attached (which can account for more than 90% of the total mass). They are members of the wider class of hydroxyproline (Hyp)-rich cell wall glycoproteins, a large and diverse group of glycosylated wall proteins. AGPs have been reported in a wide range of higher plants in seeds, roots, stems, leaves and inflorescences. AGPs account for only a small portion of the cell wall, usually no more than 1% of dry mass of the primary wall. They have also been reported in secretions of cell culture medium of root, leaf, endosperm and embryo tissues, and some exudate producing cell types such as stylar canal cells are capable of producing lavish amounts of AGPs. They are implicated in various aspects of plant growth and development, including root elongation, somatic embryogenesis, hormone responses, xylem differentiation, pollen tube growth and guidance, programmed cell death, cell expansion, salt tolerance, host-pathogen interactions, and cellular signaling. AGPs have attracted considerable attention due to their highly complex structures and potential roles in signalling. In addition, they have industrial and health applications due to their chemical/physical properties (water-holding, adhesion and emulsification).
==== Europe ==== In May 1963, Scheer and Maier-Borst were the first to introduce the use of 99mTc for medical applications. In 1968, Philips-Duphar (later Mallinckrodt, today Covidien) marketed the first technetium-99m generator produced in Europe and distributed from Petten, the Netherlands.
== History == In June 2000, the European Commission formally approved the launching of Lantus by Sanofi-Aventis Germany in the European Union. The admission was prolonged on 9 June 2005. A three-fold more concentrated formulation, brand name Toujeo, was introduced after FDA approval in 2015.
Sources: en.wikipedia.org
EBAC is the estimated blood alcohol concentration (in g/L) A is the mass of alcohol consumed (g). T is the amount of time during that alcohol was present in the blood (usually time since consumption began), in hours. β is the rate at which alcohol is eliminated, averaging around 0.15 g/L/hr. Vd is the volume of distribution (L); typically body weight (kg) multiplied by 0.71 L/kg for men and 0.58 L/kg for women although estimation using TBW is more accurate. A standard drink, defined by the WHO as 10 grams of pure alcohol, is the most frequently used measure in many countries. Examples:
According to Dikotter et al., the prohibition targeted madak smoking not as such, but as a dangerous form of unacceptable social life feared by the Forbidden City (and thus was akin to A Counterblaste to Tobacco written a century earlier by James I of England). Madak had a "very narrow consumer base" confined to Fujian, Guangdong and Taiwan. Peak consumption, according to Dutch records, was under 12 tonnes of opium per annum. The British East India Company (EIC) complied with the ban until 1780; Portuguese merchant ships continued small-scale deliveries of "medicinal" opium. In 1780 the East India Company faced a dire financial crisis and resorted to opium smuggling . Their opium did not sell at all: only 15% of the English shipment found customers within China. However, in the next two decades consumption of opium rapidly grew. The Chinese replaced madak with raw opium; madak remained in limited use by the Malay people. In 1793 the EIC assumed a monopoly on now profitable opium trade into China. The Chinese government banned opium in 1796, temporarily driving the market underground. Historian Xiao Yishan reasoned that the surge in opium consumption was directly influenced by the 1729 prohibition. According to Dikotter et al., exact causes of the change remain unknown.
=== Pharmacodynamics === Ripasudil's mechanism of action affects intraocular pressure, or IOP, "by directly acting on the trabecular meshwork, thereby increasing conventional outflow through the Schlemm’s canal." More simply, it is an "out-flow" drug that reduces IOP by stimulating the movement of aqueous humour from the ciliary body away from the eye. It is a selective rho-associated coiled-coil-containing protein kinase 1 (ROCK1) inhibitor, where ROCK1 is "an important downstream effector of Rho guanosine trisphosphates (GTP)," proteins that are significant in the contractile control of smooth muscle tissue. The S configuration at the 2-position on the 1,4-diazepane ring of Ripasudil is what gives the drug its characteristic effect. Ripasudil was originally developed from fasudil, as both compounds share the same core structure of 5-(1,4-diazepan-1-ylsulfonyl)isoquinoline. Fasudil was already recognized as a potent Rho-kinase inhibitor, but after exploring the chemical derivatives of fasudil, developers observed that the incorporation of a fluorine atom at the C4 position of isoquinoline moiety and the chiral attachment of a methyl group to the C2’ position of 1,4-diazepane moiety dramatically improved the pharmacological action. In short, "ripasudil showed much more potent and selective Rho-kinase inhibitory activity than fasudil".
At least 130 million adults have received the first dose, while 84 million adults have also received the second dose. April 20 Trial of Derek Chauvin: Derek Chauvin is found guilty on all counts in the murder of George Floyd. Killing of Ma'Khia Bryant: A 16 year old in Columbus, Ohio is shot and killed by police officer, Nicholas Reardon. April 21 COVID-19 pandemic Michigan surpasses 800,000 confirmed cases and 17,000 confirmed deaths. South Dakota confirms their first case of the Lineage P.1 variant in Pennington County. April 22 – President Biden pledges to cut greenhouse gas emissions in half by 2030 compared to 2005 levels. April 24 A runoff election is held in Louisiana's 2nd congressional district vacant since Representative Cedric Richmond resigned to become the Director of the Office of Public Liaison and an advisor to President Biden. Troy Carter wins with 48,511 of the 87,806 votes cast (55.25%). A viral Internet meme encourages users named Josh Swain to compete at an event in Lincoln, Nebraska and battle for the right to use the name Josh Swain. The event draws a crowd of several hundred people, and raises over $8,000 in charity. April 25 – The 93rd Academy Awards, the third in a row with no official host, are held at both Union Station and Dolby Theatre in Los Angeles. Due to the ceremony's delay from February 28 due to the impact of the COVID-19 pandemic on cinema, films from two calendar years were eligible at the same point, with the cut-off date being the intended original Awards date.
=== Detectors === HPLC detectors fall into two main categories: universal or selective. Universal detectors typically measure a bulk property (e.g., refractive index) by measuring a difference of a physical property between the mobile phase and mobile phase with solute while selective detectors measure a solute property (e.g., UV-Vis absorbance) by simply responding to the physical or chemical property of the solute. HPLC most commonly uses a UV-Vis absorbance detector; however, a wide range of other chromatography detectors can be used. A universal detector that complements UV-Vis absorbance detection is the charged aerosol detector (CAD). A kind of commonly utilized detector includes refractive index detectors, which provide readings by measuring the changes in the refractive index of the eluant as it moves through the flow cell. In certain cases, it is possible to use multiple detectors, for example LCMS normally combines UV-Vis with a mass spectrometer. When used with an electrochemical detector (ECD) the HPLC-ECD selectively detects neurotransmitters such as: norepinephrine, dopamine, serotonin, glutamate, GABA, acetylcholine and others in neurochemical analysis research applications. The HPLC-ECD detects neurotransmitters to the femtomolar range. Other methods to detect neurotransmitters include liquid chromatography-mass spectrometry, ELISA, or radioimmunoassays.
Sources: en.wikipedia.org
==== Oral activity and hepatotoxicity ==== Non-17α-alkylated testosterone derivatives such as testosterone itself, DHT, and nandrolone all have poor oral bioavailability due to extensive first-pass hepatic metabolism and hence are not orally active. A notable exception to this are AAS that are androgen precursors or prohormones, including dehydroepiandrosterone (DHEA), androstenediol, androstenedione, boldione (androstadienedione), bolandiol (norandrostenediol), bolandione (norandrostenedione), dienedione, mentabolan (MENT dione, trestione), and methoxydienone (methoxygonadiene) (although these are relatively weak AAS). AAS that are not orally active are used almost exclusively in the form of esters administered by intramuscular injection, which act as depots and are long-acting prodrugs. Examples include testosterone, as testosterone cypionate, testosterone enanthate, and testosterone propionate, and nandrolone, as nandrolone phenylpropionate and nandrolone decanoate, among many others (see here for a full list of testosterone and nandrolone esters). An exception is the long-chain ester testosterone undecanoate, which is orally active, albeit with only low oral bioavailability (approximately 3%). In contrast to most other AAS, 17α-alkylated testosterone derivatives show resistance to metabolism due to steric hindrance and are orally active, though they may be esterified and administered via intramuscular injection as well.
Louis, Missouri; Integrative Technologies for Advancing Scientific Cores ABRF 2014, 23–25 March, Albuquerque, New Mexico; Team Science and Big Data: Cores at the Frontier ABRF 2013, 2–5 March, Palm Springs, California; Tools for the Advancement of Convergence Science ABRF 2012, 17–20 March, Orlando, Florida; Learning From Biomolecules ABRF 2011, 19–22 February, San Antonio, Texas; Technologies to Enable Personalized Medicine ABRF 2010, 20–23 March, Sacramento, California; Translating Basic Research With Advances in Biomolecular Technology ABRF 2009, 7–10 February, Memphis, Tennessee; Application and Optimization of Existing and Emerging Biotechnologies ABRF 2008, 9–12 February, Salt Lake City, Utah; Enabling Technologies in the Life Sciences ABRF 2007, 31 March- 3 April, Tampa, Florida; Creating the Biological Roadmap ABRF 2006, 11–14 February, Long Beach, California; Integrating Science, Tools and Technologies with Systems Biology ABRF 2005, 5–8 February, Savannah, Georgia; BioMolecular Technologies: Discovery to Hypothesis ABRF 2004, 28 February – 2 March, Portland, Oregon; Integrating Technologies in Proteomics and Genomics ABRF 2003, 10–13 February, Denver, Colorado; Translating Biology Using Proteomics and Functional Genomics ABRF 2002, 9–12 March, Austin, Texas; Biomolecular Technologies: Tools for Discovery in Proteomics and Genomics ABRF 2001, 24–27 February, San Diego, CA; The New Biology: Technology for resolving Macromolecular Communications ABRF 2000, 19–22 February, Bellevue, Washington; From Singular to Global Analyses of Biological Systems ABRF 1999, 19–22 March, Durham, North Carolina; Bioinformatics and Biomolecular Technologies: Linking Genomes, Proteomes and Biochemistry ABRF 1998, 21–24 March, San Diego, California; From Genomes to Function – Technical Challenges of the Post-Genome Era ABRF 1997, 9–12 February, Baltimore, Maryland; Techniques at the Genome-Proteome Interface ABRF 1996, 30 March – 2 April, San Francisco, California; Biomolecular Techniques
It has been indicated that one Mn2+ ion is tightly bound to His370, while the second is loosely bound to Asp276. Human prolidase has four crystal structures, HsProl-Mn, HsProl-Na-GlyPro, HsProl-Mg-LeuPro, and HsProl-Mn-Pro. The first of these structures, HsProl-Mn, pertains to the activity of serum prolidase before binding the substrate. Furthermore, HsProl-Na-GlyPro results from substrate degradation caused by the exchange of the Mn2+ ion with Na+. This is caused by the substrate GlyPro binding to the enzyme. The third crystal structure of serum prolidase is HsProl-Mg-LeuPro. This structure functions similarly to HsProl-Na-GlyPro; however, the substrate utilized in this structure is LeuPro. Additionally, Mn2+ is replaced by Mg2+. These differences cause the structure to be more stable with a lower turnover rate. The final crystal structure of serum prolidase is HsProl-Mn-Pro, which employs Pro as the substrate. This Pro comes from the reaction being catalyzed by this enzyme. The crystal structure of prolidase is well-researched and recorded in the Protein Data Bank.
Serotonin syndrome is typically caused by the use of two or more serotonergic drugs, including SSRIs. Serotonin syndrome is a condition that can range from mild (most common) to deadly. Mild symptoms may consist of increased heart rate, fever, shivering, sweating, dilated pupils, myoclonus (intermittent jerking or twitching), as well as hyperreflexia. Concomitant use of SSRIs or SNRIs for depression with a triptan for migraine does not appear to heighten the risk of the serotonin syndrome. Taking monoamine oxidase inhibitors (MAOIs) in combination with SSRIs can be fatal, since MAOIs disrupt monoamine oxidase, an enzyme which is needed to break down serotonin and other neurotransmitters. Without monoamine oxidase, the body is unable to eliminate excess neurotransmitters, allowing them to build up to dangerous levels. The prognosis for recovery in a hospital setting is generally good if serotonin syndrome is correctly identified. Treatment consists of discontinuing any serotonergic drugs and providing supportive care to manage agitation and hyperthermia, usually with benzodiazepines.
== Host/implant interactions == Wound healing of the skin and tendons is a complex coordinated process in the body that happens slowly over weeks or even years. A number of products in the market today aim to affect this process positively, although little data is available on their success. The majority of products are still in the development phases where the (often inflammatory) interactions between the host and the implanted devices are being assessed. Implanted ECM biomaterials fall into two general categories based on how they interact with the host. Incorporating devices eventually allow the growth of cells and passage of blood vessels through the matrix, whereas nonincorporating biomaterials are encapsulated by a wall of fused macrophages. In nonincorporating biomaterials such as Permacol, an acellular porcine dermal implant for hernia repair, it is important that the material is not degraded or infiltrated by the immune system. Encapsulated biomaterials that are recognized as foreign can be degraded and/or rejected by the body and migrate to the outside of the body. In incorporated ECM biomaterials, infiltration by the immune system can occur in as few as seven days, leading to rapid degradation of the device volume. In the case of Graftjacket, an allograft from human dermis, the matrix is quickly populated by host cells as vasculature. The device itself decreased more than 60% in volume, and is replaced with host fibroblasts and macrophages.
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.
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.