A practical reference on reversed-phase HPLC: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-15 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Contains one methionine sulfur atom |
| Molecular mass | Approximately 814 Da | Consistent with a seven-residue peptide |
| Appearance | White to off-white powder | Typical lyophilized form |
| Solubility | Freely soluble in water | Also soluble in dimethyl sulfoxide |
| Typical storage | -20 °C, desiccated | Limits methionine oxidation |
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
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。
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.
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.
It has been suspected that the Bolivian police themselves have a responsibility in promoting anti-Peruvian xenophobia, trying to blame Peruvians for the increase in crime (in instead of Bolivia's internal problems), as well as not efficiently preserving the human rights of Peruvian migrants in the face of outrages. For example, Colonel Javier Gómez Bustillos of the Bolivian Police (markedly anti-Peruvian) would have carried out attacks to Peruvian citizens in May 2001, and despite this, he continued to receive the protection of his government and his institution, who would have promoted him to the best positions in his institution instead of making him answer to the law. The Bolivian press and The media would have helped the development of this current of anti-Peruvian opinion, getting it to position itself in the Bolivian masses, by giving great emphasis in its programs to criminal acts carried out by Peruvian migrants, including the most serious crimes such as drug trafficking and those related to subversion. The death of a Peruvian soldier, the sailor Juan Vega Llana, also contributed to the latter, due to the fact that he was assassinated, in a central street of La Paz, by Peruvian people (classified as subversive) who were members of the terrorist group Sendero Luminoso, who They sought revenge for the Massacre in the prisons of Peru.
Skin cancer can be categorized into two groups: melanoma, which is considered more severe, and nonmelanoma skin cancer, which includes basal cell carcinoma and cutaneous squamous cell carcinoma. Mohs micrographic surgery is used for high-risk nonmelanoma skin cancers located in cosmetically critical or sensitive areas like the face, ears, scalp, neck, genitalia, hands, and feet, where tissue conservation is of utmost importance. It is also indicated when the tumor is recurrent, aggressive, large, or painful, which tells us there is invasion of the nerve or vasculature.
=== Soviet disintegration === Political scientist Alex Pravda frames the Soviet collapse as unfolding in two acts: an initial phase, from 1989 to 1990, driven by smaller republics in the Baltic and Caucasus seeking sovereignty, followed by a second, from late 1990 through 1991, in which the defection of larger republics—Ukraine and, decisively, Russia under Boris Yeltsin—eroded the center's capacity to hold the union together. For Pravda, the USSR's demise was overwhelmingly domestic in origin, driven by ethnic nationalist movements that flourished under perestroika's liberalized conditions and were seized upon by republican elites contesting a Kremlin weakened by economic crisis; the international dimension of the Cold War's end played, in his assessment, only a secondary role. The collapse of the Eastern European governments with Gorbachev's tacit consent inadvertently encouraged several Soviet republics to seek greater independence from Moscow's rule. Agitation for independence in the Baltic states led to first Lithuania, and then Estonia and Latvia, declaring their independence. Disaffection in the other republics was met by promises of greater decentralization. More open ballots led to the election of candidates opposed to the Communist Party of the Soviet Union, but it also contributed to party fragmentation and presidentialism, which complicated democratic transition. Washington's confidence in the Soviet Union's survival outlasted Moscow's own. Visiting Kiev on 1 August 1991, George Bush Sr.
Jerky is made from domesticated animals as well as game animals. Jerky from domesticated animals includes llama, beef, pork, goat and mutton or lamb and game animals such as guanaco, deer, kudu, springbok, kangaroo, and bison are also used. Other animals such as turkey, ostrich, calamari, salmon, chicken, duck, goose, shrimps, oxen, squids, octopuses, alligator, pigeon, crocodile, tuna, emu, horse, camel, lion, bear, snake and earthworm have entered the global, national, regional or local market with varying degrees of success. Most fat must be trimmed from the meat prior to drying, as fat increases the chances of spoilage (modern vacuum packing and chemical preservatives have served to help prevent these risks). The meat must be dried quickly to limit bacterial growth during the critical period when the meat is not yet dry. To dry quickly without high temperature, which would cook the meat, the meat must be sliced or pressed thin. Salt is the most commonly added ingredient and is used to improve flavor, enhance the storage life and remove moisture from the product. Spices such as black pepper or garlic are other common ingredients. Ingredients such as soy sauce, Worcestershire sauce, sugar, teriyaki or barbecue spice can be added to change the flavor and are usually employed in homemade beef jerky recipes. In industrial settings, large low-temperature drying ovens with many heater elements and fans use exhaust ports to remove moisture-laden air. The combination of fast-moving air and low heat dries the meat to the desired moisture content within a few hours.
Sources: en.wikipedia.org
== Alternative medicine == Triiodothyronine has been used to treat Wilson's syndrome, an alternative medical diagnosis not recognized as a medical condition by mainstream medicine. This diagnosis involves various non-specific symptoms that are attributed to the thyroid, despite normal thyroid function tests. The American Thyroid Association has raised concern that the prescribed treatment with triiodothyronine is potentially harmful.
This was reported in most of mainland Europe and the UK which led to a price increase of approximately 30 percent in the cost of street heroin and increased demand for diverted methadone. The number of addicts seeking treatment also increased significantly during this period. Other heroin droughts (shortages) have been attributed to cartels restricting supply in order to force a price increase and also to a fungus that attacked the opium crop of 2009. Many people thought that the American government had introduced pathogens into the Afghanistan atmosphere in order to destroy the opium crop and thus starve insurgents of income. On 13 March 2012, Haji Bagcho, with ties to the Taliban, was convicted by a US District Court of conspiracy, distribution of heroin for importation into the United States and narco-terrorism. Based on heroin production statistics compiled by the United Nations Office on Drugs and Crime, in 2006, Bagcho's activities accounted for approximately 20 percent of the world's total production for that year.
=== Metamorphism === Monazite geochronology is generally regarded as a powerful tool to reveal metamorphic history. Metamorphism is the mineralogical and textural changes in preexisting rocks in response to a change in environment to different temperatures and pressures. It occurs at a temperature above diagenesis (~200 °C) and below melting (>800 °C). The mineral assemblage formed by metamorphism depends on the composition of the parent rock (protolith) and more importantly, the stability of different minerals at varying temperature and pressure (P-T). A set of mineral assemblages that form under similar temperature and pressure is called a metamorphic facies. Most mineral changes during rock burial, uplift, hydrothermal processes and deformation are associated with metamorphic reactions. Monazite is commonly found in many metamorphic rocks, especially in those formed from pelites and sandstones. The zonation in monazite reflects the successive monazite forming events. They may be formed from reactions along a single pressure-temperature (P-T) loop in a phase diagram, or reactions without changing P-T. For a metamorphic event, monazite is formed by the reactions with more than one P-T loop. The objective of monazite geochronology is to relate these monazite forming events/reactions with P-T conditions. We can then put time constrains on the P-T loops, forming a comprehensive pressure-temperature-time loops revealing the metamorphic history of the rocks.
On 18 November 1956, while addressing Western dignitaries at a reception in Moscow's Polish embassy, Khrushchev infamously declared, "Whether you like it or not, history is on our side. We will bury you", shocking everyone present. He would later clarify he had not been referring to nuclear war, but the "historically fated victory of communism over capitalism." Eisenhower's secretary of state, John Foster Dulles, initiated a "New Look" for the containment strategy, calling for a greater reliance on nuclear weapons against US enemies in wartime. Dulles also enunciated the doctrine of "massive retaliation", threatening a severe US response to any Soviet aggression. Possessing nuclear superiority, for example, allowed Eisenhower to face down Soviet threats to intervene in the Middle East during the 1956 Suez Crisis. The declassified US plans for retaliatory nuclear strikes in the late 1950s included the "systematic destruction" of 1,200 major urban centers in the Soviet Bloc and China, including Moscow, East Berlin and Beijing. In spite of these events, there were substantial hopes for détente when an upswing in diplomacy took place in 1959, including a two-week visit by Khrushchev to the US, and plans for a two-power summit for May 1960. The latter was disturbed by the U-2 spy plane scandal, however, in which Eisenhower was caught lying about the intrusion of American surveillance aircraft into Soviet territory.
=== Pollution remediation === NASA's microencapsulating technology enabled the creation of "Petroleum Remediation Product," (PRP) which safely cleans petroleum-based pollutants from water. PRP uses thousands of microcapsules—tiny balls of beeswax with hollow centers. Water cannot penetrate the microcapsule's cell, but oil is absorbed into the beeswax spheres as they float on the water's surface. Contaminating chemical compounds that originally come from crude oil (such as fuels, motor oils, or petroleum hydrocarbons) are caught before they settle, limiting damage to ocean beds. PRP microcapsules serve as nutrients to assist naturally occurring microbes in soil or water to biodegrade contaminants.
Sources: en.wikipedia.org
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.
Most published work uses intranasal administration, matching the route of the registered Russian formulation. Some animal experiments use intravenous or intraperitoneal injection. The route matters because the intact peptide is cleared rapidly from blood, so exposure differs between methods.
A purity value describes the share of the powder accounted for by the target peptide, usually by high-performance liquid chromatography. It does not confirm that the sequence is correct, which requires mass spectrometry or amino acid analysis. Purity and identity are separate checks.
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.