ACTH(4-10) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-09-10 and is reviewed periodically as new material appears.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
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.
| Property | Value | Notes |
|---|---|---|
| Typical purity | ≥95% by HPLC | Research-grade material |
| Detection wavelength | 214 nm | Peptide bond absorbance |
| Reconstitution medium | Sterile water or saline | Prepare fresh or aliquot immediately |
| Storage (solution) | -80 °C, single-use aliquots | Avoid repeated freeze-thaw cycles |
| Common salt form | Acetate or trifluoroacetate | Affects mass and solubility |
Published research has focused mainly on neurological and cognitive endpoints in animal models, with proposed mechanisms involving brain-derived neurotrophic factor and related signalling pathways. A substantial share of the human data originates from a limited number of research groups, and independent replication in other countries remains sparse. Regulatory status reflects that distribution: the peptide is registered as a medicine in Russia and appears in some neighbouring markets, while elsewhere it is handled as a research chemical without approved therapeutic labelling. Questions about dose-response relationships, long-term effects, and comparability across studies are still open.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
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.
There are pharmacies in Europe that have been in operation since medieval times. In Florence, Italy, the director of the museum in the former Santa Maria Novella pharmacy says that the pharmacy there dates back to 1221. In Trier (Germany), the Löwen-Apotheke is in operation since 1241, the oldest pharmacy in Europe in continuous operation. In Dubrovnik (Croatia), a pharmacy that first opened in 1317 is located inside the Franciscan monastery: it is the 2nd oldest pharmacy in Europe that is still operating. In the Town Hall Square of Tallinn (Estonia), there is a pharmacy dating from at least 1422. The medieval Esteve Pharmacy, located in Llívia, a Catalan enclave close to Puigcerdà, is a museum: the building dates back to the 15th century and the museum keeps albarellos from the 16th and 17th centuries, old prescription books and antique drugs.
== Safety == Responsibility for the safety of the subjects in a clinical trial is shared between the sponsor, the local site investigators (if different from the sponsor), the various IRBs that supervise the study, and (in some cases, if the study involves a marketable drug or device), the regulatory agency for the country where the drug or device will be sold. A systematic concurrent safety review is frequently employed to assure research participant safety. The conduct and on-going review is designed to be proportional to the risk of the trial. Typically this role is filled by a Data and Safety Committee, an externally appointed Medical Safety Monitor, an Independent Safety Officer, or for small or low-risk studies the principal investigator. For safety reasons, many clinical trials of drugs are designed to exclude women of childbearing age, pregnant women, or women who become pregnant during the study. In some cases, the male partners of these women are also excluded or required to take birth control measures.
=== Enzyme activity === An enzyme's name is often derived from its substrate or the chemical reaction it catalyzes, with the word ending in -ase. Examples are lactase, alcohol dehydrogenase and DNA polymerase. Different enzymes that catalyze the same chemical reaction are called isozymes. The International Union of Biochemistry and Molecular Biology have developed a nomenclature for enzymes, the EC numbers (for "Enzyme Commission"). Each enzyme is described by "EC" followed by a sequence of four numbers which represent the hierarchy of enzymatic activity (from very general to very specific). That is, the first number broadly classifies the enzyme based on its mechanism while the other digits add more and more specificity. The top-level classification is:
Oxycodone was allegedly chosen over other common opiates for this product because it had been shown to produce less sedation at equianalgesic doses compared to morphine, hydromorphone (Dilaudid), and hydrocodone (Dicodid). During Operation Himmler, Skophedal was also reportedly injected in massive overdose into the prisoners dressed in Polish Army uniforms in the staged incident on 1 September 1939 which opened the Second World War. The personal notes of Adolf Hitler's physician, Theodor Morell, indicate Hitler received repeated injections of "Eukodal" (oxycodone; produced by Merck) and Scophedal, as well as Dolantin (pethidine), codeine, and morphine less frequently; oxycodone could not be obtained after late January 1945. In the United States, the Controlled Substances Act (CSA) was passed by the United States Congress and signed into law by President Richard Nixon on 27 October 1970. The passing of the CSA resulted in all products containing oxycodone being classified as a Schedule II controlled substance. In the early 1990s, Purdue Pharma, a privately held company based in Stamford, Connecticut, developed a controlled-release version of oxycodone: the prescription painkiller OxyContin ("contin" being short for "continuous", reflecting a longer duration of pain relief). It was approved by the FDA in 1995 after no long-term studies and no assessment of its addictive capabilities. David Kessler, the FDA commissioner at the time, later said of the approval of OxyContin: "No doubt it was a mistake.
== Medical uses == In the European Union, melphalan is indicated for the treatment of multiple myeloma; malignant lymphoma (Hodgkin, non-Hodgkin lymphoma); acute lymphoblastic and myeloblastic leukemia; childhood neuroblastoma; ovarian cancer; and mammary adenocarcinoma. In the United States, melphalan is used as a high-dose conditioning treatment prior to hematopoietic progenitor (stem) cell transplantation in people with multiple myeloma. In the European Union, it is indicated, in combination with other cytotoxic medicinal products, as reduced intensity conditioning treatment prior to allogeneic haematopoietic stem cell transplantation in malignant haematological diseases in adults. In August 2023, the US Food and Drug Administration approved melphalan (Hepzato) as a liver-directed treatment for adults with uveal melanoma with unresectable hepatic metastases affecting less than 50% of the liver and no extrahepatic disease, or extrahepatic disease limited to the bone, lymph nodes, subcutaneous tissues, or lung that is amenable to resection or radiation.
Sources: en.wikipedia.org
Gamow was not entirely wrong. Although his concept about the direct synthesis of amino acid from the DNA double strands was proven false, his prediction on the nature of amino acids and how they were coded by the DNA sequences (triplet nucleotides) were confirmed the key components of protein synthesis. This broad concept is now known as the genetic code. It was Crick, along with J.S. Griffith and Leslie Orgel (member of the RNA Tie Club), describing the 20-amino acid prediction as the "magic number," introduced the proper concept in 1957:[The] order of the amino acids is determined by the order of the nucleotides of the nucleic acid. There are some twenty naturally occurring amino acids commonly found in proteins, but (usually) only four different nucleotides. The problem of how a sequence of four things (nucleotides) can determine a sequence of twenty things (amino acids) is known as the 'coding' problem.As Crick was lecturing on his hypothesis, such adaptors do exist in nature was already discovered by the team of Mahlon Hoagland and Paul Zamecnik, whose paper was published the following year in March 1958. These "soluble RNAs" are now called transfer RNAs and mediate the translation of messenger RNAs on ribosomes according to the rules contained in the genetic code. Crick imagined that his adaptors would be small, perhaps 5-10 nucleotides long. In fact, they are much larger, having a more complex role to play in protein synthesis, and are closer to 100 nucleotides in length.
Lockheed implemented it into the L-1011 TriStar in 1973 at the request of Pacific Southwest Airlines (who used the baggage compartment as an entertainment lounge) and possibly also to suit potential Soviet buyers (see below). In October 1967, the Soviet government approved a Ministry of Civil Aviation (Aeroflot) specification for an aerobus. This called for 350 seats and a range of 3,600 kilometres (1,900 nautical miles) with a 40-tonne payload or 5,800 km (3,100 nmi) with seats taken but no freight. The airliner had to operate from smaller airports (classified as Klass "B" and "V" [Russian: класс "Б", "В"] or "Class B/C" by the Soviets) 2,600-metre (8,500 ft) runways. In the second half of the 1960s, OKB-240 (as the Ilyushin bureau was formally known) was restoring positions lost (with Yakovlev, in favour of Tupolev and Antonov) during the Khrushchev era and was well placed to secure design of the aerobus. When the Soviet cabinet's defence industry committee promoted the Aeroflot specification on September 8, 1969, to a preliminary project, (Russian: аванпроект; transliterated: avanproyekt), it entrusted it to Ilyushin. The bureau received specific operational requirements for the aerobus on February 22, 1970. In developing the concept which had been agreed, Ilyushin faced four challenges: configuration (layout or "shape"), powerplant, automation (avionics) and manufacturing capacity.
S-adenosyl-L-homocysteine + protein Ntau-methyl-L-histidine Thus, the two substrates of this enzyme are S-adenosyl methionine and protein L-histidine, whereas its two products are S-adenosylhomocysteine and protein Ntau-methyl-L-histidine. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:protein-L-histidine N-tele-methyltransferase. Other names in common use include protein methylase IV, protein (histidine) methyltransferase, actin-specific histidine methyltransferase, and S-adenosyl methionine:protein-histidine N-methyltransferase.
Hydroxycarbamide, also known as hydroxyurea, is an antimetabolite medication used in sickle-cell disease, essential thrombocythemia, chronic myelogenous leukemia, polycythemia vera, and cervical cancer. In sickle-cells disease it increases fetal hemoglobin and decreases the number of attacks. It is taken by mouth. Common side effects include bone marrow suppression, fevers, loss of appetite, psychiatric problems, shortness of breath, and headaches. There is also concern that it increases the risk of later cancer. Use during pregnancy is typically harmful to the fetus. Hydroxycarbamide is in the antineoplastic family of medications. It is believed to work by blocking the making of DNA. Hydroxycarbamide was approved for medical use in the United States in 1967. It is on the World Health Organization's List of Essential Medicines. Hydroxycarbamide is available as a generic medication.
However, package models do not solve the error threshold problem that originally motivated the idea of the hypercycle. A few years later, Maarten Boerlijst and Paulien Hogeweg, and later Nobuto Takeuchi, studied the replicator equations with the use of partial differential equations and cellular automata models, methods that already proved to be successful in other applications. They demonstrated that spatial self-structuring of the system completely solves the problem of global extinction for large systems and, partially, the problem of parasites. The latter was also analysed by Robert May, who noticed that an emergent rotating spiral wave pattern, which was observed during computational simulations performed on cellular automata, proved to be stable and able to survive the invasion of parasites if they appear at some distance from the wave core. Unfortunately, in this case, rotation decelerates as the number of hypercycle members increases, meaning that selection tends toward decreasing the amount of information stored in the hypercycle. Moreover, there is also a problem with adding new information into the system. In order to be preserved, the new information has to appear near to the core of the spiral wave. However, this would make the system vulnerable to parasites, and, as a consequence, the hypercycle would not be stable.
Sources: en.wikipedia.org
He framed Latino immigrants, particularly those from Mexico, as threats to the nation's social and genetic "fitness." He promoted sterilization as a means of racial and social improvement. Some of the factors that may catapulted the movement behind the sterilization abuse in Latina women in the state of California, began with one of the earliest organizations in eugenic sterilizations in the U.S., the Human Betterment Foundation (HBF), the Sterilization Act of 1909, and the Immigration Act of 1924. The California Act of 1909 was one of the major legal and political influences that established authority for doctors and psychiatrists of state hospitals and mental institutions to perform sterilizations on the people unfit to function in society because of their intelligence levels, presumed future deviant behavior and sexual activity. With that established, organizations such as the Human Betterment Foundation came to be the organization that held these ideologies and promote eugenic sterilizations and the Immigration Act of 1924 further developed the idea that labor-migrants were needed, but women and children were not as there was a fear of Latino and Immigrant invasion.
Bioequivalence is a term in pharmacokinetics used to assess the expected in vivo biological equivalence of two proprietary preparations of a drug. If two products are said to be bioequivalent it means that they would be expected to be, for all intents and purposes, the same. One article defined bioequivalence by stating that, "two pharmaceutical products are bioequivalent if they are pharmaceutically equivalent and their bioavailabilities (rate and extent of availability) after administration in the same molar dose are similar to such a degree that their effects, with respect to both efficacy and safety, can be expected to be essentially the same. Pharmaceutical equivalence implies the same amount of the same active substance(s), in the same dosage form, for the same route of administration and meeting the same or comparable standards." For The World Health Organization (WHO) "two pharmaceutical products are bioequivalent if they are pharmaceutically equivalent or pharmaceutical alternatives, and their bioavailabilities, in terms of rate (Cmax and tmax) and extent of absorption (area under the curve), after administration of the same molar dose under the same conditions, are similar to such a degree that their effects can be expected to be essentially the same".
In a poor, shallow latch, the infant may latch close to, or at, the nipple, which can cause the mother pain. While the infant is at the breast, the first indicators of a shallow latch are having the areola be largely visible outside the infant's mouth and a narrow infant mouth angle. Additional signs result from poor positioning when the infant comes toward the breast to latch. If the infant leads with their brow or forehead, they are likely to flex their neck; this latching mechanism causes the nipple to point down and then hit the hard palate during sucking. From an external view, this manifests as the nose and forehead being close to the breast and the chin far from the breast. This neck flexion also obstructs the normal swallowing mechanism, preventing the infant from drinking efficiently. In addition to not being able to swallow properly, this shallow latch prevents the infant from adequately compressing the glandular tissue behind the nipple and stimulating milk flow; thus, they may begin to apply more suction, which manifests externally as cheek dimpling, or sucking their cheeks in.
=== Aerosol === In aerosol mass spectrometry, one of the ionization techniques consists in firing a laser to individual droplets. These systems are called single particle mass spectrometers (SPMS). The sample may optionally be mixed with a MALDI matrix prior to aerosolization.
Sources: en.wikipedia.org
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.
Reversed-phase liquid chromatography establishes purity, while mass spectrometry confirms molecular mass. The two techniques are normally used together. Retention time alone is not sufficient evidence of identity.
Different counterions change the mass per unit of peptide and can shift chromatographic behavior. Two samples of equal stated purity may therefore not be directly comparable. Reports should specify the counterion whenever quantitative comparisons are made.
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.