A practical reference on lyophilized powder: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-20. Anything still debated is marked as such rather than presented as settled.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
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.
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.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
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.
=== Fortification === Some countries require or recommend fortification of foods. As of January 2022, 37 countries, mostly in Sub-Saharan Africa, require food fortification of cooking oil, rice, wheat flour or maize (corn) flour with vitamin A, usually as retinyl palmitate or retinyl acetate. Examples include Pakistan, oil, 11.7 mg/kg and Nigeria, oil, 6 mg/kg; wheat and maize flour, 2 mg/kg. An additional 12 countries, mostly in southeast Asia, have a voluntary fortification program. For example, the government of India recommends 7.95 mg/kg in oil and 0.626 mg/kg for wheat flour and rice. However, compliance in countries with voluntary fortification is lower than countries with mandatory fortification. No countries in Europe or North America fortify foods with vitamin A.
== Chemistry == BmKAEP is an inhibitory β-toxin and thus, a Na+ channel inhibitor. As with other mammal and insect toxins, BmKAEP is classified according to species and mechanism of action. BmKAEP is a 61-amino-acid protein derived from an 85-amino-acid precursor. The mature protein contains 8 cysteine residues that establish 4 disulfide bridges (4C-C). Despite its high homology with other depressant toxins, BmKAEP differs from them at residues 6, 7 and 39, which is thought to be important in determining its unique function. Its lysine residue, at position 51, also has a special feature: it interacts with mammalian Na+ channels.
The primary function of the breasts, as mammary glands, is the nourishing of an infant with breast milk. Milk is produced in milk-secreting cells in the alveoli. When the breasts are stimulated by the suckling of her baby, the mother's brain secretes oxytocin. High levels of oxytocin trigger the contraction of muscle cells surrounding the alveoli, causing milk to flow along the ducts that connect the alveoli to the nipple. Full-term newborns have an instinct and a need to suck on a nipple, and breastfed babies nurse for both nutrition and for comfort. Breast milk provides all necessary nutrients for the first six months of life, and then remains an important source of nutrition, alongside solid foods, until at least one or two years of age.
=== Imaging === Radiological studies of the abdomen, such as CT scans and magnetic resonance imaging are useful for identifying the site of the tumor, differentiating it from other diseases, such as adrenocortical adenoma, and determining the extent of invasion of the tumor into surrounding organs and tissues. On CT, it shows heterogeneous appearance due to necrosis, calcifications, and haemorrhage. After contrast injection, it shows peripheral enhancement. Invasion of adjacent structures such as kidney, vena cava, liver, and retroperitoneal lymph nodes are also common. Online open-access datasets of adrenocortical carcinoma CT examinations are available. On MRI, it shows low intensity on T1-weighted images, and high T2 signal with strong heterogeneous contrast enhancement and slow washout. Haemorrhagic areas may show high T1-signal. Imaging with positron emission tomography (PET) is useful during initial investigation of potentially malignant adrenal tumors and for detecting metastasis. Fluorodeoxyglucose ([18F]FDG or FDG) has high sensitivity but cannot distinguish ACC from other malignancies. 11C-labelled metomidate binds to enzymes expressed in adrenocortical cells and has been used as a radiotracer with high specificity for adrenal tumors.
==== Psychosis ==== Isotretinoin has also been linked to psychosis. Many of the side effects of isotretinoin mimic hypervitaminosis A, which has been associated with psychotic symptoms. The dopamine hypothesis of schizophrenia and psychosis suggests that an increase in dopaminergic stimulation or sensitivity in the limbic system causes psychotic symptoms. It has been suggested that dysregulation of retinoid receptors by retinoids such as isotretinoin may cause schizophrenia. The evidence for this is threefold: transcriptional activation of the dopamine D2 receptor – in addition to serotonin and glutamate receptors – is regulated by retinoic acid; schizophrenia and the retinoid cascade have been linked to the same gene loci; and retinoid dysfunction causes congenital anomalies identical to those observed in people with schizophrenia. Further, the expression of dopamine receptors has indeed been shown to be regulated by retinoic acid.
Sources: en.wikipedia.org
Sensation: The oral mucosa is richly innervated, meaning it is a very good at sensing pain, touch, temperature and taste. A number of cranial nerves are involved in sensations in the mouth including trigeminal (V), facial (VII), glossopharyngeal (IX) and vagus (X) nerves. The dorsum of the tongue is covered in specialised mucosa. This contains the presence of taste buds allowing taste, and it accounts for around 15% of oral mucosa. Reflexes such as swallowing, gagging and thirst are also initiated in the mouth. Thermal regulation: Although not significant in humans, some animals such as dogs rely on panting to regulate their temperature, as sweat glands are only present in their paws.
patent, Preparation of a Whey Protein Concentrate, combined pretreatment and ultrafiltration with water injection and cation exchange to produce a low-mineral, acid-soluble whey protein concentrate suitable for beverage formulations. The water-injection step, or diafiltration, adds water during ultrafiltration so that additional lactose, minerals, and other permeable constituents are removed, while retaining the protein. Diafiltration subsequently became an important method for manufacturing higher-protein whey protein concentrates and whey protein isolates. The New Zealand Dairy Board received a non-exclusive, royalty-free license to use the Coca-Cola process with New Zealand whey. The Dairy Board and NZDRI continued investing in whey-protein processing and product development. The work initiated for Coca-Cola generated deep expertise and provided a technological base for developing whey protein concentrates for other applications and markets. In 1982, the industry established the Whey Products Corporation to coordinate whey processing, investment, and marketing across the cooperative dairy sector. This approach enabled New Zealand to become a leading supplier of technically demanding whey-protein products during the 1980s and 1990s. The industry's centralized whey-products operations were later folded back into the Dairy Board, which merged with Kiwi Co-operative Dairies and New Zealand Dairy Group in 2001 to form Fonterra.
20 April Nixon announced that he would order the withdrawal of 150,000 U.S. troops from South Vietnam over the next 12 months in a gradual policy of Vietnamization, putting more responsibility on the South Vietnamese.
=== Controversy === Newborn screening tests have become a subject of political controversy in the last decade. Lawsuits, media attention, and advocacy groups have surfaced a number of different, and possibly countervailing, positions on the use of screening tests. Some have asked for government mandates to widen the extent of the screening to find detectable and treatable birth defects. Others have opposed mandatory screening concerned that effective follow-up and treatment may not be available, or that false positive screening tests may cause harm to infants and their families. Others have learned that government agencies were often secretly storing the results in databases for future genetic research, often without consent of the parents nor limits on how the data could be used in the future . In the UK a campaign called the Newborn Screening Collaborative, 17 small rare disease organisations including Genetic Alliance UK, have joined together to raise awareness surrounding this issue and promote the positives of early diagnosis.
Sources: en.wikipedia.org
=== European Union === In the European Union, many blue cheeses, such as Cabrales, Danablu, Gorgonzola, Roquefort and Blue Stilton, carry a protected designation of origin, meaning they can bear the name only if they have been made in a particular region. Similarly, individual countries have protections of their own such as France's Appellation d'Origine Contrôlée and Italy's Denominazione di Origine Protetta. Blue cheeses with no protected origin name are designated simply "blue cheese".
=== Modified Miller–Urey experiments === Much work has been done since the 1950s toward understanding how Miller–Urey chemistry behaves in various environmental settings. Different atmospheric compositions. In 1983, testing different atmospheric compositions, Miller and another researcher repeated experiments with varying proportions of H2, H2O, N2, CO2 or CH4, and sometimes NH3. They found that the presence or absence of NH3 in the mixture did not significantly impact amino acid yield, as NH3 was generated from N2 during the spark discharge. Additionally, CH4 proved to be one of the most important atmospheric ingredients for high yields, likely due to its role in HCN formation. Much lower yields were obtained with more oxidized carbon species in place of CH4, but similar yields could be reached with a high H2/CO2 ratio. Thus, Miller–Urey reactions work in atmospheres of other compositions as well, depending on the ratio of reducing and oxidizing gases. Role of nitrites and calcium carbonate. More recently, Jeffrey Bada and H. James Cleaves, graduate students of Miller, hypothesized that the production of nitrites, which destroy amino acids, in CO2 and N2-rich atmospheres may explain low amino acids yields. In a Miller–Urey setup with a less-reducing (CO2 + N2 + H2O) atmosphere, when they added calcium carbonate to buffer the aqueous solution and ascorbic acid to inhibit oxidation, yields of amino acids greatly increased, demonstrating that amino acids can still be formed in more neutral atmospheres under the right geochemical conditions.
Rentrop did not generalize about the functional significance of these collaterals, which he said was "unknown," but their existence suggests that they may exert a preemptive, protective effect. Subsequently, Rentrop's associate Cohen prospectively evaluated 23 patients undergoing PTCA and observed that during balloon inflation, the mean grade of collateral filling increased dramatically. Nineteen of 23 patients showed improvement (p=0.01) but post-PTCA arteriography revealed no visible collaterals in any patient. The functional effect of filling was dramatic: using an index of ischemia (based on the percent of hypocontractile perimeter of myocardium, sum of ST segment elevation, and time of onset of angina), Cohen found that grade 0 or 1 filling confers only nominal protection from ischemia (i.e., filling is non-existent or of side branches only), but partial filling (i.e. grade 2 or greater) of these segments provides almost complete preservation of the affected myocardium from the asynergy associated with critical coronary stenosis. Pain was observed in all nine patients with 0 or 1 filling, but in only five of 14 patients with grade 2 or 3 filling. Thus, the severity of symptoms correlated inversely with the degree of observed collateral filling. In another often-cited study, Freedman focused on the issue of MI prevention by selecting 121 patients with severe single vessel disease. 64 had Q-wave infarction and 57 did not; 32 had unstable angina or subendocardial infarction.
=== Drug affinity responsive target stability (DARTS) === The Drug Affinity Responsive Target Stability assay follows a similar basic assumption to TPP – that protein stability is increased by ligand binding. In DARTS, however, protein stability is assessed in response to digestion by a protease. Briefly, a sample of cell lysate is incubated with a small molecule of interest, the sample is split into aliquots, and each aliquot goes through limited proteolysis after addition of protease. Limited proteolysis is critical, since complete proteolysis would render even a ligand-bound protein completely digested. Samples are then analyzed via SDS-PAGE to assess differences in extent of digestion, and bands are then excised and analyzed via mass spectrometry to confirm the identities of proteins that are resist proteolysis. Alternatively, if the target is already suspected and is being tested for validation, a western blot protocol can be used to identify protein directly.
== Atomic spectroscopy == Electrons exist in energy levels (i.e. atomic orbitals) within an atom. Atomic orbitals are quantized, meaning they exist as defined values instead of being continuous (see: atomic orbitals). Electrons may move between orbitals, but in doing so they must absorb or emit energy equal to the energy difference between their atom's specific quantized orbital energy levels. In optical spectroscopy, energy absorbed to move an electron to a higher energy level (higher orbital) and/or the energy emitted as the electron moves to a lower energy level is absorbed or emitted in the form of photons (light particles). Because each element has a unique number of electrons, an atom will absorb/release energy in a pattern unique to its elemental identity (e.g. Ca, Na, etc.) and thus will absorb/emit photons in a correspondingly unique pattern. The type of atoms present in a sample, or the amount of atoms present in a sample can be deduced from measuring these changes in light wavelength and light intensity. Atomic spectroscopy is further divided into atomic absorption spectroscopy and atomic emission spectroscopy. In atomic absorption spectroscopy, light of a predetermined wavelength is passed through a collection of atoms. If the wavelength of the source light has energy corresponding to the energy difference between two energy levels in the atoms, a portion of the light will be absorbed. The difference between the intensity of the light emitted from the source (e.g., lamp) and the light collected by the detector yields an absorbance value.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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.