This is a working overview of 反相色谱, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-12-05 and is reviewed periodically as new material appears.
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.
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 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.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
| 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 |
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.
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.
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。
== Reactions == The cycle comprises three enzyme-catalysed reactions. The first stage is the deamination of the purine nucleotide adenosine monophosphate (AMP) to form inosine monophosphate (IMP), catalysed by the enzyme AMP deaminase:
== Organization == The Hukbalahap was regarded by the PKP as its "citizen's army" against the Japanese. It was headed by the Central Luzon Bureau, with Vicente Lava as its secretary, and a secretariat, ostensibly a party apparatus meant to keep the Huks in line with PKP ideology. There were five committees which composed the Huk structure:
==== 1.B. β-Barrel porins and other outer membrane proteins ==== 1.B.1 General bacterial porin family 1.B.2 Chlamydial porin (CP) family 1.B.3 Sugar porin (SP) family 1.B.4 Brucella-Rhizobium porin (BRP) family 1.B.5 Pseudomonas OprP porin (POP) family 1.B.6 OmpA-OmpF porin (OOP) family 1.B.7 Rhodobacter PorCa porin (RPP) family 1.B.8 Mitochondrial and plastid porin (MPP) family 1.B.9 FadL outer membrane protein (FadL) family 1.B.10 Nucleoside-specific channel-forming outer membrane porin (Tsx) family 1.B.11 Outer membrane fimbrial usher porin (FUP) family 1.B.12 Autotransporter-1 (AT-1) family 1.B.13 Alginate export porin (AEP) family 1.B.14 Outer membrane receptor (OMR) family 1.B.15 Raffinose porin (RafY) family 1.B.16 Short chain amide and urea porin (SAP) family 1.B.17 Outer membrane factor (OMF) family 1.B.18 Outer membrane auxiliary (OMA) protein family 1.B.19 Glucose-selective OprB porin (OprB) family 1.B.20 Two-partner secretion (TPS) family 1.B.21 OmpG porin (OmpG) family 1.B.22 Outer bacterial membrane secretin (secretin) family 1.B.23 Cyanobacterial porin (CBP) family 1.B.24 Mycobacterial porin 1.B.25 Outer membrane porin (Opr) family 1.B.26 Cyclodextrin porin (CDP) family 1.B.31 Campylobacter jejuni major outer membrane porin (MomP) family 1.B.32 Fusobacterial outer membrane porin (FomP) family 1.B.33 Outer membrane protein insertion porin (Bam complex) (OmpIP) family 1.B.34 Corynebacterial porins 1.B.35 Oligogalacturonate-specific porin (KdgM) family 1.B.39 Bacterial porin, OmpW (OmpW) family 1.B.42 Outer membrane lipopolysaccharide export porin (LPS-EP) family 1.B.43 Coxiella porin P1 (CPP1) family 1.B.44 Probable protein translocating porphyromonas gingivalis porin (PorT) family 1.B.49 Anaplasma P44 (A-P44) porin family 1.B.48 Curli-like transporters 1.B.54 Intimin/Invasin (Int/Inv) or Autotransporter-3 family 1.B.55 Poly-acetyl-D-glucosamine porin (PgaA) family 1.B.57 Legionella major-outer membrane protein (LM-OMP) family 1.B.60 Omp50 porin (Omp50 Porin) family 1.B.61 Delta-proteobacterial porin (Delta-porin) family 1.B.62 Putative bacterial porin (PBP) family 1.B.66 Putative beta-barrel porin-2 (BBP2) family 1.B.67 Putative beta barrel porin-4 (BBP4) family 1.B.68 Putative beta barrel porin-5 (BBP5) superfamily 1.B.70 Outer membrane channel (OMC) family 1.B.71 Proteobacterial/verrucomicrobial porin (PVP) family 1.B.72 Protochlamydial outer membrane porin (PomS/T) family 1.B.73 Capsule biogenesis/assembly (CBA) family 1.B.78 DUF3374 electron transport-associated porin (ETPorin) family
In 1908, the Russian foreign minister, Alexander Izvolsky, offered Russian support, for the third time, for the annexation of Bosnia and Herzegovina by Austria-Hungary, in exchange for Austrian support for the opening of the Bosporus Strait and the Dardanelles to Russian warships. Austria's foreign minister, Alois von Aehrenthal, pursued this offer vigorously, resulting in the quid pro quo understanding with Izvolsky, reached on 16 September 1908 at the Buchlau Conference. However, Izvolsky made this agreement with Aehrenthal without the knowledge of Tsar Nicholas II or his government in St. Petersburg, or any of the other foreign powers including Britain, France and Serbia. Based upon the assurances of the Buchlau Conference and the treaties that preceded it, Franz Joseph signed the proclamation announcing the annexation of Bosnia-Herzegovina into the Empire on 6 October 1908. However a diplomatic crisis erupted, as both the Serbs and the Italians demanded compensation for the annexation, which the Austro-Hungarian government refused to entertain. The incident was not resolved until the revision of the Treaty of Berlin in April 1909, exacerbating tensions between Austria-Hungary and the Serbs.
Sources: en.wikipedia.org
== Clinical significance == The ACTH receptor plays a role in glucose metabolism when expressed in white adipose cells. When bound to ACTH, a short-term insulin-resistance occurs, and it stimulates lipolysis via hormone sensitive lipase. Demonstrated in mice, ACTH promotes lipolysis in response to increased energy demand, notably in times of stress. Lipolytic activity due to melanocortin receptors has been demonstrated in several types of test animals: rats and hamsters primarily respond to ACTH, rabbits respond to alpha and beta MSH's (therefore not using the ACTH receptor), and guinea pigs responding to both ACTH and other MSH's. In humans, ACTH has little lipolytic effect on adipose tissue. ACTH receptor activation also influences immune function. Melanocortins, including ACTH, have anti-inflammatory effects which can be exerted via GC-dependent and -independent pathways. The GC-dependent pathway activates ACTH receptors to increase levels of cortisol which bind GC receptors. Via genomic and faster non-genomic pathways, this causes, among other immune responses, a reduction in leukocyte and neutrophil infiltration, cytokine production, especially of cytokine CXCL-1, and increased phagocytosis of apoptotic neutrophils. These profound anti-inflammatory effects and the ability to increase GC's are why ACTH therapy is still used today. It is often used as treatment for infantile spasms, multiple sclerosis, nephrotic syndrome, gout, ulcerative colitis, Crohn's disease, rheumatoid arthritis, and systemic lupus erythematosus.
resigned as corporation chairman, and was replaced by childhood friend, Roger Harvin. In March 1996, Hala Moddelmog was appointed president of Church's Chicken, making her the first female president of a fast food restaurant chain.
On 9 November 1918, Philipp Scheidemann, a Social Democrat, proclaimed the German Republic, marking Germany's transition to a federal democratic state. Germany's new leadership signed the Treaty of Versailles in 1919, accepting defeat by the Allies. Germans perceived the treaty as humiliating, which was seen by historians as influential in the rise of Adolf Hitler. Germany lost around 13% of its European territory and ceded all of its colonial possessions. On 11 August 1919, President Friedrich Ebert signed the democratic Weimar Constitution. Communists briefly seized power in Bavaria and a few larger cities, while conservative elements failed to overthrow the central government in the 1920 Kapp Putsch. The occupation of the Ruhr by Belgian and French troops and a period of hyperinflation followed. A plan to restructure Germany's war reparations and the creation of a new currency in 1924 helped stabilise the government and ushered in the Golden Twenties, an era of artistic innovation and liberal cultural life. In 1929, the Great Depression hit Germany, and by 1932 the unemployment rate had risen to nearly 30%. The Nazi Party led by Adolf Hitler became the largest party in the Reichstag after the election of July 1932, and President Hindenburg appointed Hitler as chancellor on 30 January 1933. After the Reichstag fire, a decree abrogated basic civil rights, and the first Nazi concentration camp opened. On 23 March 1933, the Enabling Act gave Hitler unrestricted legislative power, overriding the constitution, and marked the beginning of Nazi Germany.
==== Pollybeak ==== The "pollybeak" deformity, characterized by excessive supratip fullness usually involving a cartilaginous hump or loss of tip projection, is the indication for approximately 50% of all revision rhinoplasties. If too much of the osseo-cartilaginous framework is removed, the consequent weakening can cause the external nasal skin to become shapeless, resulting in a "pollybeak" deformity, resembling the beak of a parrot.
=== NADPH-hemoprotein reductase activity === The domain is associated with the oxidoreductase family and acts on NADH or NADPH, using a heme protein as an electron acceptor. Requires FAD and FMN as cofactors to catalyse the reaction: NADPH + H+ + n oxidised hemoprotein = NADP+ + n reduced hemoprotein.
Sources: en.wikipedia.org
During mitosis, SUMO-2/3 localize to centromeres and condensed chromosomes, whereas SUMO-1 localizes to the mitotic spindle and spindle midzone, indicating that SUMO paralogs regulate distinct mitotic processes in mammalian cells. One of the major SUMO conjugation products associated with mitotic chromosomes arose from SUMO-2/3 conjugation of topoisomerase II, which is modified exclusively by SUMO-2/3 during mitosis. SUMO-2/3 modifications seem to be involved specifically in the stress response. SUMO-1 and SUMO-2/3 can form mixed chains, however, because SUMO-1 does not contain the internal SUMO consensus sites found in SUMO-2/3, it is thought to terminate these poly-SUMO chains. Serine 2 of SUMO-1 is phosphorylated, raising the concept of a 'modified modifier'.
== Chromatographic methods == Reversed phase liquid chromatography (RPLC) is the most important chromatographic method for measuring solute hydrophobicity. The non polar stationary phase mimics biological membranes. Peptide usage has many advantages because partition is not extended by the terminal charges in RPLC. Also, secondary structures formation is avoided by using short sequence peptides. Derivatization of amino acids is necessary to ease its partition into a C18 bonded phase. Another scale had been developed in 1971 and used peptide retention on hydrophilic gel. 1-butanol and pyridine were used as the mobile phase in this particular scale and glycine was used as the reference value. Pliska and his coworkers used thin layer chromatography to relate mobility values of free amino acids to their hydrophobicities. About a decade ago, another hydrophilicity scale was published, this scale used normal phase liquid chromatography and showed the retention of 121 peptides on an amide-80 column. The absolute values and relative rankings of hydrophobicity determined by chromatographic methods can be affected by a number of parameters. These parameters include the silica surface area and pore diameter, the choice and pH of aqueous buffer, temperature and the bonding density of stationary phase chains.
Ingestion is one of the primary pathways of MNP exposure due to the omnipresence of these particles in food, beverages, and drinking water. Studies show that MNPs are detected in a variety of consumables, including drinking water, beer, honey, sugar, table salt, and even airborne particles that settle on food. Indirect ingestion also occurs via toothpaste, face wash, scrubs, and soap. Marine products are particularly concerning sources of ingestion-related exposure due to the accumulation of MNPs in aquatic environments. Fish, bivalves, and other seafood are frequently contaminated with MNPs that are ingested through water and food and build up through the process of bioaccumulation. Humans consuming these animals are thus directly exposed to microplastics embedded in tissue; for instance, humans eat the entire soft tissue of bivalves, along with their digestive systems, which increases the direct transfer of MNPs. In a study along the Mediterranean coast of Turkey, 1822 MNPs were extracted from the stomachs and intestines of 1337 fish specimens, with fibers accounting for 70% of these particles. Contamination is further compounded by plastic packaging and storage materials, which can leach MNPs over time, leading to additional ingestion from common foods and drinks. Concerns have also been raised about exposure due to plastic cookware and utensils, with one study estimating that using plastic cookware may introduce up to 4,900 microplastics into homecooked food each year.
Endocytosis is another mechanism for cellular internalization. Endocytosis is the process of cellular ingestion by which the plasma membrane folds inward to bring substances into the cell. During this process cells absorb material from the outside of the cell by imbibing it with their cell membrane. The classification of cellular localization using fluorescence or by endocytosis inhibitors is the basis of most examination. However, the procedure used during preparation of these samples creates questionable information regarding endocytosis. Moreover, studies show that cellular entry of penetratin by endocytosis is an energy-dependent process. This process is initiated by polyarginines interacting with heparan sulphates that promote endocytosis. Research has shown that TAT is internalized through a form of endocytosis called macropinocytosis. Studies have illustrated that endocytosis is involved in the internalization of CPPs, but it has been suggested that different mechanisms could transpire at the same time. This is established by the behavior reported for penetratin and transportan wherein both membrane translocation and endocytosis occur concurrently.
=== Iron deficiency === One of the causes of iron-deficiency anemia is reduced absorption of iron. Iron absorption can be enhanced through ingestion of vitamin C alongside iron-containing food or supplements. Vitamin C helps to keep iron in the reduced ferrous state, which is more soluble and more easily absorbed. It also chelates iron into a soluble complex. It specifically helps the absorption of non-heme iron, which is found in non-meat sources and absorbed via DMT1.
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 is associated with the melanocortin receptor family, particularly subtypes found in the central nervous system. This interaction is separate from the adrenal pathway activated by full-length ACTH.