The short version of lyophilised powder fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-15 and is reviewed periodically as new material appears.
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.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
| 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 |
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.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
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.
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.
== History == β-Endorphin was discovered in camel pituitary extracts by C.H. Li and David Chung. The primary structure of β-endorphin was unknowingly determined 10 years earlier, when Li and colleagues analyzed the sequence of another neuropeptide produced in the pituitary gland, γ-lipotropin. They noticed that the C-terminus region of this neuropeptide was similar to that of some enkephalins, suggesting that it may have a similar function to these neuropeptides. The C-terminal sequence of γ-lipotropin turned out to be the primary sequence of the β-endorphin.
== History == The GCCA was formed in 2007 through the merger of two processor organizations and was joined by a number of other core partners that became part of the alliance. The merger was between the International Association of Refrigerated Warehouses (IARW) formed in 1891, the International Refrigerated Transportation Association (IRTA) formed in 1994.
=== Nanotechnology === The Culture has highly advanced nanotechnology, though descriptions of such technology in the books is limited. Many of the described uses are by or for Special Circumstances, but there are no indications that the use of nanotechnology is limited in any way. (In a passage in one of the books, there is a brief reference to the question of sentience when comparing the human brain or a "pico-level substrate".) One of the primary clandestine uses of nanotechnology is information gathering. The Culture likes to be in the know, and as described in Matter "they tend to know everything." Aside from its vast network of sympathetic allies and wandering Culture citizens one of the primary ways that the Culture keeps track of important events is by the use of practically invisible nanobots capable of recording and transmitting their observations. This technique is described as especially useful to track potentially dangerous people (such as ex-Special Circumstances agents). Via such nanotechnology, it is potentially possible for the Culture (or similarly advanced societies) to see everything happening on a given planet, orbital or any other habitat. The usage of such devices is limited by various treaties and agreements among the Involved. In addition, EDust assassins are potent Culture terror weapons, composed entirely of nano machines called EDust, or "Everything Dust." They are capable of taking almost any shape or form, including swarms of insects or entire humans or aliens, and possess powerful weaponry capable of levelling entire buildings.
==== Methods of biomedical waste incineration ==== The three type of medical waste incinerators are controlled air, excess air, and rotary kiln. Controlled air is also known as starved-air incineration, two-stage incineration, or modular combustion. This is the process of which waste is fed to a combustion chamber and combustion air begins to dry and facilitates volatilization of the waste. As a result, carbon dioxide and other excess gases are released into the atmosphere. The second type of incineration is the excess air process. This is similar to the controlled air process, such as the waste being dried, ignited, and combusted by heat provided by the primary chamber burner. However, the main difference is that moisture and volatile components in the waste are vaporized. In a rotary kiln, the process is similar to the two mention above, however, it is more versatile in terms of being able to mix wet and dry waste components and viewed by many waste engineers as being the most environmentally friendly.
Sources: en.wikipedia.org
Curare is an alkaloid poison extracted from native South American plants in the Chondrondendron genus. They were initially used by indigenous groups as a paralyzing agent for hunting. European scientists later discovered that tubocurarine was the major constituent responsible for the paralyzing effect by acting on the neuromuscular junction. Anasthesiologists Harold Griffith and Enid Johnson first documented the successful use of curare, in a clinical trial to facilitate muscle relaxation in a healthy patient undergoing appendicectomy in 1942. Before the use of curare, anesthesiologist required large doses of anesthetic such as chloroform to achieve similar paralyzing effects, hence increased the risk of life-threatening effects in elderly patients who had cardiac complications. Ever since, neuromuscular agents have been commonly used in practice during anesthetic procedures. The clinical trial conducted by Griffith and Johnson also paved the way for discovery of many more neuromuscular drugs for surgical use.
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.
A construct in chemistry is molecular symmetry, as embodied in Group theory. Inorganic compounds display a particularly diverse symmetries, so it is logical that Group Theory is intimately associated with inorganic chemistry. Group theory provides the language to describe the shapes of molecules according to their point group symmetry. Group theory also enables factoring and simplification of theoretical calculations. Spectroscopic features are analyzed and described with respect to the symmetry properties of the, inter alia, vibrational or electronic states. Knowledge of the symmetry properties of the ground and excited states allows one to predict the numbers and intensities of absorptions in vibrational and electronic spectra. A classic application of group theory is the prediction of the number of C–O vibrations in substituted metal carbonyl complexes. The most common applications of symmetry to spectroscopy involve vibrational and electronic spectra. Group theory highlights commonalities and differences in the bonding of otherwise disparate species. For example, the metal-based orbitals transform identically for WF6 and W(CO)6, but the energies and populations of these orbitals differ significantly. A similar relationship exists between CO2 and molecular beryllium difluoride.
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 described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.