Certificate of analysis comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-12-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| 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 |
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.
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.
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
==== Effect of size, shape, composition and environment ==== As a general rule, the wavelength of light absorbed increases as a function of increasing nanoparticle size. Both the surface plasmon resonance frequency and scattering intensity depend on the size, shape composition and environment of the nanoparticles. This phenomenon may be quantified by use of the Mie scattering theory for spherical nanoparticles. Nanoparticles with diameters of 30–100 nm may be detected easily by a microscope, and particles with a size of 40 nm may even be detected by the naked eye when the concentration of the particles is 10−4 M or greater. The scattering from a 60 nm nanoparticle is about 105 times stronger than the emission from a fluorescein molecule.
The territorial organisation of the Republic of Serbia was regulated by the Law on Territorial Organisation and Local Self-Government, adopted in the Assembly of Serbia on 24 July 1991. Under the Law, the municipalities, cities and settlements make the bases of the territorial organization. Serbia was divided into 195 municipalities and 4 cities, which were the basic units of local autonomy. It had two autonomous provinces: Kosovo and Metohija in the south (with 30 municipalities), which was under the administration of UNMIK after 1999, and Vojvodina in the north (with 46 municipalities and 1 city). The territory between Kosovo and Vojvodina was called Central Serbia. Central Serbia was not an administrative division on its own and had no regional government of its own. In addition, there were four cities: Belgrade, Niš, Novi Sad and Kragujevac, each having an assembly and budget of its own. The cities comprised several municipalities, divided into "urban" (in the city proper) and "other" (suburban). Competences of cities and their municipalities were divided. Municipalities were gathered into districts, which are regional centres of state authority, but have no assemblies of their own; they present purely administrative divisions, and host various state institutions such as funds, office branches and courts. The Republic of Serbia was then and is still today divided into 29 districts (17 in Central Serbia, 7 in Vojvodina and 5 in Kosovo, which are now defunct), while the city of Belgrade presents a district of its own.
TCM "holds that the body's vital energy (chi or qi) circulates through channels, called jingluo ("meridians and collaterals"), that have branches connected to bodily organs and functions." Its view of the human body is only marginally concerned with anatomical structures, but focuses primarily on the body's functions (such as digestion, breathing, temperature maintenance, etc.): These functions are aggregated and then associated with a primary functional entity – for instance, nourishment of the tissues and maintenance of their moisture are seen as connected functions, and the entity postulated to be responsible for these functions is xiě (blood). These functional entities thus constitute concepts rather than something with biochemical or anatomical properties. The primary functional entities used by traditional Chinese medicine are qì, xuě, the five zàng organs, the six fǔ organs, and the meridians which extend through the organ systems. These are all theoretically interconnected: each zàng organ is paired with a fǔ organ, which are nourished by the blood and concentrate qi for a particular function, with meridians being extensions of those functional systems throughout the body. Concepts of the body and of disease used in TCM are pseudoscientific, similar to Mediterranean humoral theory. TCM's model of the body is characterized as full of pseudoscience. Some practitioners no longer consider yin and yang and the idea of an energy flow to apply.
In immunology, an antigen (Ag) is a molecule, or portion thereof, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungi, and bacteria. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are antigen-specific, meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react to bind more than one antigen. The reaction between an antigen and an antibody is called the antigen-antibody reaction. Antigen can originate either from within the body ("self-protein" or "self antigens") or from the external environment ("non-self"). The immune system identifies and attacks "non-self" external antigens. Antibodies usually do not react with self-antigens due to negative selection of T cells in the thymus and B cells in the bone marrow. The diseases in which antibodies react with self antigens and damage the body's own cells are called autoimmune diseases.
Sources: en.wikipedia.org
== FSH preparations == Preparations of follicle-stimulating hormone (FSH) mainly include those derived from the urine of menopausal women, as well as recombinant preparations. The recombinant preparations are more pure and more easily administered, but they are more expensive. The urinary preparations are equally effective and less expensive, but are not as convenient to administer as they are available in vials versus injection pens. One study reported that users of the purified urinary FSH preparation Bravelle experienced less injection site pain compared to the recombinant preparation Follistim.
heterogeneous nuclear RNA (hnRNA) Also H-RNA. Any of a set of RNA molecules of widely variable size occurring in the nucleus and united by their rapid turnover rate during protein synthesis. HnRNA represents all of the various transcriptional products of protein-coding genes, including both of exons and introns, from raw, unprocessed primary transcripts to spliced, capped, and polyadenylated mature messenger RNAs and all of the intermediate forms in between.
At the same time, Kissinger met with Dobrynin to warn him that Nixon was a dangerous man who wanted to escalate the Vietnam war. In April 1969, North Korea shot down a U.S. Navy plane on a spy mission, killing 31 airmen. Kissinger wanted to bomb a North Korean air base in retaliation, being opposed by the Defense Secretary Melvin Laird, the Secretary of State William Rogers and General Earle Wheeler, the chairman of the joint chiefs of staff, who all warned that to bomb North Korea might start a second war in Asia. Kissinger argued that bombing North Korea would help end the Vietnam war, saying: "Hanoi might say, 'This guy [Nixon] is becoming irrational'-and we'd better settle with him". Unable to gain support at the National Security Council, Kissinger appealed to Nixon's Domestic Affairs Adviser, John Ehrlichman, saying that, though striking in North Korea might cause a second Korean war, it might also help with the Vietnam war. When Ehrlichman asked Kissinger how far things might escalate if the U.S. bombed North Korea, he was told: "Well, it could go nuclear". Ehrlichman came away convinced that Kissinger with his thick German accent, academic titles, advocacy of a ruthless foreign policy and a role as a senior presidential adviser seemed too much like the eponymous character of the 1964 black comedy Dr. Strangelove and advised Nixon not to strike North Korea, advice that was accepted. Starting in April 1969, Kissinger pressed for a plan code-named Operation Duck Hook, which would see the United States return to bombing North Vietnam and possibly use nuclear weapons.
=== Salt balance === Dermal macrophages facilitate skin homeostasis by regulating the skin's salt composition. For instance, an increase in salt concentration after a salt-heavy meal attracts dermal macrophages that express TonEBP, a transcriptional factor responding to osmotic pressure changes. This process triggers VEGF-C transcription, resulting in the growth of lymph capillaries and blood vessels dilation, regulating salt-sensitive hypertension by lowering the blood pressure. An increase in sodium ions concentration also facilitates the polymerisation of glycosaminoglycans, which helps the storage of sodium ions in the skin. A salt solution such as sodium chloride in the skin can trigger hypertonic stress, which acts as a stimulus for attracting macrophages. A higher salt concentration also causes macrophages activation. It induces the expression of pro-inflammatory genes such as CXCL-1, CCL2, and IL-1 and inhibits anti-inflammatory genes such as CCL18 and CCL22. Hence, the activation of dermal macrophages can be achieved by the local salt concentration, independent of the salt ingested. The expression of such genes could contribute to the skin's defence against parasitic infections.
=== Mycotoxins and alimentary mycotoxicoses === The term alimentary mycotoxicosis refers to the effect of poisoning by mycotoxins through food consumption. The term mycotoxin is usually reserved for the toxic chemical compounds naturally produced by fungi that readily colonize crops under specific temperature and moisture conditions. Mycotoxins can have severe effects on human and animal health. For example, an outbreak which occurred in the UK during 1960 caused the death of 100,000 turkeys which had consumed aflatoxin-contaminated peanut meal. In the USSR in World War II, 5,000 people died due to alimentary toxic aleukia (ALA). In Kenya, mycotoxins led to the death of 125 people in 2004, after consumption of contaminated grain. In animals, mycotoxicosis targets organ systems such as the liver and digestive system. Other effects can include reduced productivity and suppression of the immune system, thus pre-disposing the animals to other secondary infections. Common foodborne mycotoxins include:
Sources: en.wikipedia.org
Provisioning for sea was crucial in the 19th century due to the lack of modern conveniences such as refrigeration, freeze-drying and canning. Most foodstuffs and liquids such as spirits, molasses, vinegar, and water, were shipped in casks, the balance in wooden crates and other suitable packing materials. It was also commonplace to carry live chickens, both for their eggs and meat, and some small livestock such as sheep, which were butchered when their feed ran out, providing fresh meat before barreled stores such as beef and salt pork were consumed. The fare for officers and rations for the crew were distinct, as were dining accommodations, with each reflecting their relative stations in society and the navy. Due to the inability to maintain water fresh for extended periods of time prior to the advent of modern hygiene, shipboard plumbing, and disinfectants, it was common to ship large quantities of beer to provide both hydration and nourishment in times when water aboard fouled. The beer's alcoholic content served as a preservative. In contrast, grog, a mix of rum and water, was provided and consumed daily (with officers provided their rum straight). The rum allotment per man was retained in the United States Navy until the latter part of the 19th century, and all the way until 1970 in the British Royal Navy.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system. However, not all people with insulin resistance develop diabetes since an impairment of insulin secretion by pancreatic beta cells is also required. In the early stages of insulin resistance, the mass of beta cells expands, increasing the output of insulin to compensate for the insulin insensitivity, so that the disposition index remains constant. But when type 2 diabetes has become manifest, the person will have lost about half of their beta cells. The causes of the aging-related insulin resistance seen in obesity and in type 2 diabetes are uncertain. Effects of intracellular lipid metabolism and ATP production in liver and muscle cells may contribute to insulin resistance.
Testosterone is used as a medication for the treatment of male hypogonadism, gender dysphoria, and certain types of breast cancer. This is known as hormone replacement therapy (HRT) or testosterone replacement therapy (TRT), which maintains serum testosterone levels in the normal range. Decline of testosterone production with age has led to interest in androgen replacement therapy. It is unclear if the use of testosterone for low levels due to aging is beneficial or harmful. Testosterone is included in the World Health Organization's list of essential medicines, which are the most important medications needed in a basic health system. It is available as a generic medication. It can be administered as a cream or transdermal patch that is applied to the skin, by injection into a muscle, as a tablet that is placed in the cheek, or by ingestion. Common side effects from testosterone medication include acne, swelling, and breast enlargement in males. Serious side effects may include liver toxicity, heart disease (though a randomized trial found no evidence of major adverse cardiac events compared to placebo in men with low testosterone), and behavioral changes. Women and children who are exposed may develop virilization. It is recommended that individuals with prostate cancer not use the medication. It can cause harm if used during pregnancy or breastfeeding. 2020 guidelines from the American College of Physicians support the discussion of testosterone treatment in adult men with age-related low levels of testosterone who have sexual dysfunction.
=== Sleeping sickness === Sleeping sickness, or trypanosomiasis, is treated with pentamidine or suramin (depending on subspecies of parasite) delivered by intramuscular injection in the first phase of the disease, and with melarsoprol and eflornithine intravenous injection in the second phase of the disease. Eflornithine is commonly given in combination with nifurtimox, which reduces the treatment time to 7 days of eflornithine infusions plus 10 days of oral nifurtimox tablets. Eflornithine is also effective in combination with other drugs, such as melarsoprol and nifurtimox. A study in 2005 compared the safety of eflornithine alone to melarsoprol and found eflornithine to be more effective and safe in treating second-stage sleeping sickness Trypanosoma brucei gambiense. Eflornithine is not effective in the treatment of Trypanosoma brucei rhodesiense due to the parasite's low sensitivity to the drug. Instead, melarsoprol is used to treat Trypanosoma brucei rhodesiense. Another randomized control trial in Uganda compared the efficacy of various combinations of these drugs and found that the nifurtimox-eflornithine combination was the most promising first-line theory regimen. A randomized control trial was conducted in Congo, Côte d'Ivoire, the Democratic Republic of the Congo, and Uganda to determine if a 7-day intravenous regimen was as efficient as the standard 14-day regimen for new and relapsing cases. The results showed that the shortened regimen was efficacious in relapse cases, but was inferior to the standard regimen for new cases of the disease.
Food irradiation (sometimes called radurization in American English, and radurisation in British English) is the process of exposing food and food packaging to ionizing radiation, such as from gamma rays, x-rays, or electron beams. Food irradiation improves food safety and extends product shelf life (preservation) by effectively destroying organisms responsible for spoilage and foodborne illness, inhibits sprouting or ripening, and is a means of controlling insects and invasive pests. Globally, consumer acceptance of irradiated foods grew from 33% to 67% from 1992 to 2024. The U.S. Food and Drug Administration (FDA), the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and U.S. Department of Agriculture (USDA) have performed studies that confirm irradiation to be safe. In order for a food to be irradiated in the U.S., the FDA will still require that the specific food be thoroughly tested for irradiation safety. Food irradiation is permitted in over 60 countries, and about 500,000 metric tons of such food are processed annually worldwide. The regulations for how food is to be irradiated, as well as the foods allowed to be irradiated, vary greatly from country to country. In Austria, Germany, and many other countries of the European Union only dried herbs, spices, and seasonings can be processed with irradiation and only at a specific dose, while in Brazil all foods are allowed at any dose.
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.
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.