Everything below concerns mass spectrometry. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-01-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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 |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
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。
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.
Thrombotic thrombocytopenic purpura - uncommon and potentially fatal thrombotic microangiopathy characterized by severe thrombocytopenia, organ ischemia connected to diffuse microvascular platelet rich-thrombi, and microangiopathic hemolytic anemia. Relapsing polychondritis - uncommon multisystem autoimmune disease with an unclear etiology that is marked by progressive cartilaginous tissue loss and recurring episodes of inflammation. Mixed connective tissue disease - systemic autoimmune disease that shares characteristics with two or more other systemic autoimmune diseases, such as rheumatoid arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus, and systemic sclerosis. It is an example of overlap syndrome. Undifferentiated connective tissue disease - unclassifiable systemic autoimmune disorders that do not meet any of the current classification requirements for connective tissue diseases, yet have clinical and serological signs similar to connective tissue diseases. Psoriatic arthritis - inflammatory musculoskeletal condition linked to psoriasis. Cryoglobulinemia - condition sometimes associated with systemic lupus erythematosus or rheumatoid arthritis in which there are abnormal proteins in the blood. IgG4-related disease - chronic inflammatory condition in which there is deposition of connective tissue (fibrosis) in different organs. Potentially life-threatening. Periaortitis - a group of rare vascular inflammatory diseases in which fibrous inflammatory tissue develops around the aorta or other structures such as the ureters.
The Legend of Zelda: Breath of the Wild Dark Souls (video game) Grand Theft Auto V The Last of Us Bloodborne Half-Life 2 Tetris Super Mario Galaxy 2 The Legend of Zelda: Ocarina of Time Resident Evil 4 An Edge Special Edition - "the 30th anniversary special edition" - 100 greatest games of Edge's lifetime (2023)
Ciglitazone (INN) is a thiazolidinedione. Developed by Takeda Pharmaceuticals in the early 1980s, it is considered the prototypical compound for the thiazolidinedione class. Ciglitazone was never used as a medication, but it sparked interest in the effects of thiazolidinediones. Several analogues were later developed, some of which—such as pioglitazone and troglitazone—made it to the market. Ciglitazone significantly decreases VEGF production by human granulosa cells in an in vitro study, and may potentially be used in ovarian hyperstimulation syndrome. Ciglitazone is a potent and selective PPARγ ligand. It binds to the PPARγ ligand-binding domain with an EC50 of 3.0 μM. Ciglitazone is active in vivo as an anti-hyperglycemic agent in the ob/ob murine model. Inhibits HUVEC differentiation and angiogenesis and also stimulates adipogenesis and decreases osteoblastogenesis in human mesenchymal stem cells.
Sources: en.wikipedia.org
The condensation between ethyl cyanoacetate (1) and acetone gives ethylisopropylidenecyanoacetate [759-58-0] (2). This product is reacted with N-butylcyanoacetamide [39581-21-0] (3) in sodium methoxide solution to give N-butyl-2,4-dicyano-3,3-dimethylglutarimide, CID:10681941 (4). The glutarimide is cyclized with phosphoric acid to yield 3-butyl-9,9-dimethyl-3,7-diazabicyclo[3.3.1]nonane-2,4,6,8-tetraone, https://pubchem.ncbi.nlm.nih.gov/compound/10825633 CID:10825633 (5). The reaction between 1-(o-anisyl)piperazine [35386-24-4] (6) and 1,4-dibromobutane [110-52-1] (7) gives the Quat salt CID:15895413(8). Convergent synthesis (in the presence of potassium carbonate) affords Umespirone (KC-9172) (9).
=== Pharmacodynamics === DOM-NBOMe is a potent agonist of the serotonin 5-HT2 receptors, including the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors. Its affinity (Ki) for the serotonin 5-HT2A receptor was reported to be 45.8 nM. In terms of functional activity, DOM-NBOMe showed an EC50Tooltip half-maximal effective concentration of 4.25 nM and EmaxTooltip maximal efficacy of 88.8% at the serotonin 5-HT2A receptor, an EC50 of 54.6 nM and Emax of 20.1% at the serotonin 5-HT2B receptor, and an EC50 of 9.96 nM and Emax of 87.6% at the serotonin 5-HT2C receptor. It was inactive as an agonist of the serotonin 5-HT1A receptor, with an EC50 of >10,000 nM. DOM-NBOMe showed 17-fold lower potency as a serotonin 5-HT2A receptor agonist compared to 25D-NBOMe in vitro, while DOM was not assessed in the same study and thus DOM-NBOMe could not be compared to that compound. Whereas the potency of 2Cs can be dramatically increased by N-(2-methoxybenzyl) substitution, this has not been the case with the DOx series of psychedelics, where activity has been negatively impacted. DOM-NBOMe has been assessed and found to produce the head-twitch response, a behavioral proxy of psychedelic effects, in rodents. However, DOM-NBOMe showed a weak maximal head-twitch response compared to DOI. Whereas DOI induced a maximum of 36 head twitches in a 20-minute period, DOM-NBOMe produced a maximum of 12 head twitches in the same amount of time (i.e., about 33% of that of DOI).
=== Addiction remission === The term fen-phen was created in 1994 when Pietr Hitzig and Richard B. Rothman reported that this combination could presumptively remit alcohol and cocaine craving. The authors suggested that other combined dopamine and serotonin agonists or precursors might share this therapeutic potential. Subsequent experiments in rats supported these preliminary reports. In 2006 it was confirmed that the combination of phentermine and the serotonin precursor 5-hydroxytryptophan (5-HTP), in place of fenfluramine, significantly decreased alcohol withdrawal seizures in rats. Intramural National Institutes of Health (NIH) double-blind protocols to demonstrate the efficacy of fen-phen in alcohol and cocaine addiction were designed, but never performed.
The detector also marks the time of emergence, the retention time, which serves for initial identification of the component. More advanced detectors, provide also additional information, specific to the analyte's characteristics, such as UV-VIS spectrum or mass spectrum, which can provide insight on its structural features. These detectors are in common use, such as UV/Vis, photodiode array (PDA) / diode array detector and mass spectrometry detector. A digital microprocessor and user software control the HPLC instrument and provide data analysis. Some models of mechanical pumps in an HPLC instrument can mix multiple solvents together at a ratios changing in time, generating a composition gradient in the mobile phase. Newer HPLC instruments have a column oven that allows for adjusting the temperature at which the separation is performed. The sample mixture to be separated and analyzed is introduced, in a discrete small volume (typically microliters), into the stream of mobile phase percolating through the column. The components of the sample move through the column, each at a different velocity, which are a function of specific physical interactions with the adsorbent, the stationary phase. The velocity of each component depends on its chemical nature, on the nature of the stationary phase (inside the column) and on the composition of the mobile phase. The time at which a specific analyte elutes (emerges from the column) is called its retention time. The retention time, measured under particular conditions, is an identifying characteristic of a given analyte.
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
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.