If you have been reading about synthetic heptapeptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2025-12-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C37H51N9O10S | 游离碱形式 |
| 等电点 | 约 6.5 | 估算值，随缓冲体系变化 |
| 主要降解途径 | 水解与氧化 | 侧链氧化最为常见 |
| 溶液储存 | 2 至 8 摄氏度避光 | 避免反复冻融 |
| 常规分析手段 | 反相色谱与质谱联用 | 氨基酸分析辅助核对 |
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
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.
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
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.
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.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
"Chains of Love" is a song by English synth-pop duo Erasure, released in May 1988 as their ninth single overall. It was written by Vince Clarke and Andy Bell, and released by Mute Records as the second single from Erasure's third studio album, The Innocents (1988). In the United States, Sire Records released it as the first single. The chorus is memorable for Bell's use of falsetto. The album version was produced by Stephen Hague and was slightly remixed for its single release (most notably the album version starts cold, while the radio version contains a short synthesizer pattern as an intro). The accompanying music video featured Clarke and Bell performing the song while being hoisted through the air by thick, metal chains.
=== Secretion of Interleukin-10 === Genetically engineered L. lactis can secrete the cytokine interleukin-10 (IL-10) for the treatment of inflammatory bowel diseases (IBD), since IL-10 has a central role in downregulating inflammatory cascades and matrix metalloproteinases. A study by Lothar Steidler and Wolfgang Hans shows that in situ synthesis of IL-10 by genetically engineered L. lactis requires much lower doses than systemic treatments like antibodies to tumor necrosis factor (TNF) or recombinant IL-10. The authors propose two possible routes by which IL-10 can reach its therapeutic target. Genetically engineered L. lactis may produce murine IL-10 in the lumen, and the protein may diffuse to responsive cells in the epithelium or the lamina propria. Another route involves L. lactis being taken up by M cells because of its bacterial size and shape, and the major part of the effect may be due to recombinant IL-10 production in situ in intestinal lymphoid tissue. Both routes may involve paracellular transport mechanisms that are enhanced in inflammation. After transport, IL-10 may directly downregulate inflammation. In principle, this method may be useful for intestinal delivery of other protein therapeutics that are unstable or difficult to produce in large quantities and an alternative to the systemic treatment of IBD.
=== Scientific era === In 1500 polymath Leonardo da Vinci provided the first illustration of the thyroid. In 1543 anatomist Andreas Vesalius gave the first anatomic description and illustration of the gland. In 1656 the thyroid received its modern name, by the anatomist Thomas Wharton. The gland was named thyroid, meaning shield, as its shape resembled the shields commonly used in Ancient Greece. The English name thyroid gland is derived from the medical Latin used by Wharton – glandula thyreoidea. Glandula means 'gland' in Latin, and thyreoidea can be traced back to the Ancient Greek word θυρεοειδής, meaning 'shield-like/shield-shaped'. French chemist Bernard Courtois discovered iodine in 1811, and in 1896 Eugen Baumann documented it as the central ingredient in the thyroid gland. He did this by boiling the thyroid glands of a thousand sheep, and named the precipitate, a combination of the thyroid hormones, 'iodothyrin'. David Marine in 1907 proved that iodine is necessary for thyroid function. Graves' disease was described by Robert James Graves in 1834. The role of the thyroid gland in metabolism was demonstrated in 1895 by Adolf Magnus-Levy. Thyroxine was first isolated in 1914 and synthesized in 1927, and triiodothyroxine in 1952. The conversion of T4 to T3 was discovered in 1970. The process of discovering TSH took place over the early to mid twentieth century. TRH was discovered by Polish endocrinologist Andrew Schally in 1970, contributing in part to his Nobel Prize in Medicine in 1977.
== Applications and detection methods == FFF is applicable in the sub-micron range (from 1 nm to several microns) in the "normal" mode or up to 50 microns in the so-called steric mode. The transition from normal to steric mode takes place when diffusion becomes negligible at sizes above a micron. FFF is unique in its wide dynamic range of sizes covering both soluble macromolecules and particles or colloids which can be separated in one analysis. Typical applications are high molar mass polymers and polymer composites, nanoparticles, both industrial and environmental, viruses and virus like particles, lipid nanoparticles, extracellular vesicles and other types of biological samples. FFF can be coupled to all types of detectors known, from high-performance liquid chromatography (HPLC) to size-exclusion chromatography (SEC). Due to FFF's similarity to liquid chromatography (LC), a liquid mobile phase passing through the channel, the most common detectors are those that are also used for liquid chromatography. The most frequently used is an ultraviolet-visible spectroscopy (UV-VIS) detector, because of its non-destructive nature. Coupling with multi angle light scattering which allows the calculation of the size of eluting fractions and comparison to values obtained via FFF theory. Another popular detector is inductively coupled plasma mass spectrometry to characterize metallic nanoparticles with high specificity and sensitivity.
Sources: en.wikipedia.org
== Diagnosis == There are some laboratory tests that may aid in the diagnosis of GSD-V. A muscle biopsy will note the absence of myophosphorylase in muscle fibers. In some cases, abnormal glycogen accumulation stained by periodic acid-Schiff can be seen with microscopy. Genetic sequencing of the PYGM gene (which codes for the muscle isoform of glycogen phosphorylase) may be done to determine the presence of gene mutations, determining if McArdle's is present. This type of testing is considerably less invasive than a muscle biopsy. The physician can also perform an ischemic forearm exercise test as described below (see History). Some findings suggest a nonischemic test could be performed with similar results. The nonischemic version of this test would involve not cutting off the blood flow to the exercising arm. Findings consistent with McArdle's disease would include a failure of lactate to rise in venous blood and exaggerated ammonia levels. These findings would indicate a severe muscle glycolytic block. Serum lactate may fail to rise in part because of increased uptake via the monocarboxylate transporter (MCT1), which is upregulated in skeletal muscle in McArdle disease. Lactate may be used as a fuel source once converted to pyruvate. Ammonia levels may rise given ammonia is a by-product of AMP deaminase which follows after the production of AMP by adenylate kinase, an alternative pathway for ATP production.
The only feature that differentiates one brand from another is the product name in a standard color, position, font size, and style. In response to these regulations, Philip Morris International, Japan Tobacco Inc., British American Tobacco Plc., and Imperial Tobacco attempted to sue the Australian government. On August 15, 2012, the High Court of Australia dismissed the suit and made Australia the first country to introduce brand-free plain cigarette packaging with health warnings covering 90% of the back and 70% of the front packaging. This took effect on December 1, 2012. Similar policies have since been introduced in the United Kingdom, where standardised packaging of tobacco products regulations (SPOT) were introduced in 2015. These regulations were also challenged by cigarette manufacturers.
Balances for accurately measuring materials. Laboratory glassware, such as burettes and pipettes, for performing titrations. Colorimeters for solution tests which apply the Beer–Lambert law. Spectrophotometer to measure the concentrations of the key parameter nitrate and other nutrients, such as phosphate, sulfate or iron. Containers for growing and storing the plants. Using chemical equipment for hydroponic solutions can be beneficial to growers of any background because nutrient solutions are often reusable. Because nutrient solutions are virtually never completely depleted, and should never be due to the unacceptably low osmotic pressure that would result, re-fortification of old solutions with new nutrients can save growers money and can control point source pollution, a common source for the eutrophication of nearby lakes and streams.
Sources: en.wikipedia.org
By 1562 the tulip trade had reached Europe with the first shipment to Antwerp, where they were mistaken for vegetables, although they had been cultivated in Portugal since 1530, and first appeared in illustration in 1559, and the first tulip flowers were seen in the Netherlands in 1625. Tulips spread rapidly across Europe in the seventeenth century, and became an important trading item, initially in France before concentrating in the Netherlands. Eventually speculative trading in tulips became so intense as to cause a financial bubble which eventually collapsed, a period known as tulip mania (tulipomania), from 1634 to 1637, similar to the Ottoman Empire's Tulip era. Nevertheless, since then the tulip has become indelibly associated with the Netherlands and all things Dutch. it was during this period that the tulipiere, a ceramic vase for growing tulips indoors was devised, and the Golden Age of Dutch Painting was replete with images of tulips. Although tulip festivals are held around the world in the spring, the most famous of these is the display at Keukenhof. One of the better-known novels on tulips is The Black Tulip by Alexandre Dumas, père in 1850, dealing with a contest to grow a black tulip in late seventeenth-century Haarlem.
Gene Expression Omnibus (GEO) A database of high-throughput functional genomics and gene expression data derived from experimental assays and next-generation sequencing and managed by the National Center for Biotechnology Information.
In November 1965, when asked to comment by Time after the number of Americans killed in Vietnam passed 1,000, Kissinger praised Johnson for having to make "difficult and lonely decisions". Kissinger compared Johnson to the sheriff played by Gary Cooper in the 1952 film High Noon, depicting Johnson as a heroic figure making necessary, but unpopular decisions. In a 1967 peace initiative, he would mediate between Washington and Hanoi. In June 1967, at an academic conference in Paris, Kissinger met a French biologist, Herbert Marcovitch, who mentioned that one of his friends was Raymond Aubrac, a Communist hero of the French resistance, who in turn was one of the few Westerners who were friends with Ho Chi Minh. Ho had something of an aversion to Westerners and tried to avoid meeting them as much as possible, and Aubrac was unique in being allowed to correspond with Ho. Wanting to play a role in diplomacy, Kissinger contacted the State Department with a plan for Marovitch and Aubrac to go to Hanoi with a peace offer. The Secretary of State, Dean Rusk, was opposed to Kissinger's plan. However, W. Averell Harriman of the "peace shop" was interested and got President Johnson to approve the approach, which was code-named Operation Pennsylvania. In July 1967, Aubrac and Marcovitch went to Hanoi to see Ho, who told him that he was willing to open peace talks with the United States, provided that the Americans "unconditionally" stopped bombing North Vietnam.
Sources: en.wikipedia.org
电喷雾或基质辅助激光解吸电离质谱是常用手段，测得的质子化离子质荷比可换算为分子量。结果与理论值落在合理误差内，才支持结构一致的判断。
甲硫氨酸侧链含硫醚，在氧气、光照或金属离子存在时容易被氧化。氧化产物极性略增，常在色谱图上表现为主峰之前的肩峰或前伸峰。
通常建议冷藏避光，并在较短时间内使用。不存在适用于所有配方的统一期限，具体取决于浓度、缓冲体系与容器材质。
It is a short synthetic peptide built from seven amino acids: methionine, glutamic acid, histidine, phenylalanine and three prolines. The sequence derives from the 4-10 fragment of adrenocorticotropic hormone with an added proline-glycine-proline tail. No plant or animal extract is involved; the material is produced by solid-phase peptide synthesis.