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�Œ–学性质与分析表征 — Quick Reference

By Editorial Desk · published 2026-03-08 · last reviewed 2026-03-28 · Faq

The short version of ACTH(4-10) fits in a sentence. The long version — which is the one that helps — is below.

Reviewed 2026-03-28. Anything still debated is marked as such rather than presented as settled.

化学性质与分析表征

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。

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。

Background and Development

Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.

Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.

Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.

Semax at a glance

PropertyValueNotes
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

Handling, Storage, and Research Status

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.

Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.

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.

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Semax Structure and Research Background

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.

Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.

Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.

Analytical Testing And Storage

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.

Semax Peptide Background and Identity

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.

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.

Notes from published material

=== Consequences on Regional Stability === The Accords had far-reaching implications for the broader Sahel region, although the agreement's limited implementation failed to bring long-term stability. Northern Mali, despite the peace deal, remained volatile due to a combination of inter-ethnic tensions and the rise of jihadist groups, including the Islamic State in the Greater Sahara (ISGS) and affiliates of al-Qaeda. The incomplete implementation of the accords, particularly the failure to effectively decentralise power and integrate former rebels into the national army, created a vacuum in governance. This allowed jihadist factions to expand their operations not only in Mali but also in neighbouring Niger and Burkina Faso. Moreover, ongoing disputes over local governance and the distribution of resources led to further fragmentation among signatories of the accord. The Sahel's security situation worsened as international forces, including the United Nations Multidimensional Integrated Stabilization Mission in Mali (MINUSMA), were stretched thin. By 2023, MINUSMA had been pushed out of Mali following deteriorating relations between the transitional government in Bamako and international actors.

Acitretin, sold under the brand names Neotigason and Soriatane, is a second-generation retinoid. It is taken orally, and is typically used for psoriasis. It was patented in Germany in 1974 and approved for medical use in the United States in 1996. Acitretin is an oral retinoid used in the treatment of severe resistant psoriasis. Because of the potential for problems and severe side effects it is generally used in only very severe cases of psoriasis that have been unresponsive to other treatments. It binds to nuclear receptors that regulates gene transcription. They induce keratinocyte differentiation and reduce epidermal hyperplasia, leading to the slowing of cell reproduction. Acitretin is readily absorbed and widely distributed after oral administration. A therapeutic effect occurs after two to four weeks or longer. Patients who have received the medication are advised against giving blood for at least three years due to the risk of birth defects.

=== Draft and minor leagues === The Boston Red Sox selected Bagwell in the fourth round (110th overall) of the 1989 Major League Baseball draft. Throughout his career, Barry Axelrod served as his agent. For his first professional assignment, the Red Sox appointed Bagwell to the Single-A Winter Haven Red Sox of the Florida State League in 1989, where he batted .310 with two home runs. In 1990, while playing for the Double-A New Britain Red Sox, Bagwell won the Eastern League Most Valuable Player Award. In 136 games with New Britain, he batted .333 with 160 hits, four home runs (HR), 61 runs batted in (RBI), 34 doubles, seven triples, 73 bases on balls (BB or walks), 57 strikeouts (SO), .422 on-base percentage (OBP), .457 slugging percentage (SLG) and .880 on-base plus slugging percentage (OPS). He finished first in the league in hits and doubles, second in batting, OBP and OPS, fourth in walks, fifth in SLG, ninth in runs scored and tenth in RBI. Late in the 1990 season, the Red Sox, who were in search of relief pitching to improve their chances of making the playoffs, contacted the Houston Astros about Larry Andersen. Stan Benjamin, who scouted the New England region for the Astros, recommended that they ask for Bagwell in return. The Astros initially hesitated owing to his sparse home run production, but Benjamin persuaded them, quipping that New Britain's Beehive Field was so large that "Babe Ruth couldn't hit home runs in that ballpark."[a] On August 30, 1990, the Red Sox took the Astros' offer.

(one-letter sequence: NDECELCVNVACTGCL). Plecanatide is nearly structurally identical to human uroguanylin, apart from the substitution of Asp3 with Glu3. Disulfide bonds exist between Cys4 and Cys12, as well as Cys7 and Cys15. Plecanatide has two important motifs. The first being the acidic residues Asp2 and Glu3 which modulate the affinity for its receptor in response to environmental pH. Simulations predict the optimal activity of Plecanatide to occur at pH 5, making it suitable for targeting cells within the proximal intestine, which has a pH of between 5 and 6. The second is the ACTGC motif (residues Ala11 to Cys15) which is the region responsible for its binding to the receptor, guanylate cyclase-C.

Sources: en.wikipedia.org

Further detail

As Western imports became popular, demand for Japanese art declined within Japan itself. In Europe and America, the new availability of Japanese art led to a fascination for Japanese culture; a craze known in Europe as Japonisme. Imperial patronage, government sponsorship, promotion to new audiences, and Western technology combined to foster an era of Japanese artistic innovation. In the decorative arts, Japanese artists reached new levels of technical sophistication. Today, Masayuki Murata owns more than 10,000 Meiji art works and is one of the most enthusiastic collectors. From that time, most of the excellent works of Meiji Art were bought by foreign collectors and only a few of them remained in Japan, but because he bought back many works from foreign countries and opened the Kiyomizu Sannenzaka Museum, the study and reevaluation of Meiji Art rapidly advanced in Japan from the 21st century. Nasser Khalili is also one of the world's most dedicated collectors of Meiji art, and his collection encompasses many categories of Meiji art. The Japanese Imperial Family also owns excellent works of Meiji Art, some of which were donated to the state and are now stored in the Museum of the Imperial Collections.

=== Skin === Deficiencies in vitamin A have been linked to an increased susceptibility to skin infection and inflammation. Vitamin A appears to modulate the innate immune response and maintains homeostasis of epithelial tissues and mucosa through its metabolite, retinoic acid (RA). As part of the innate immune system, toll-like receptors in skin cells respond to pathogens and cell damage by inducing a pro-inflammatory immune response which includes increased RA production. The epithelium of the skin encounters bacteria, fungi and viruses. Keratinocytes of the epidermal layer of the skin produce and secrete antimicrobial peptides (AMPs). Production of AMPs resistin and cathelicidin, are promoted by RA.

Britain was irritated by several French actions following the Treaty of Amiens. Bonaparte annexed Piedmont and Elba, made himself President of the Italian Republic, a state in northern Italy that France had set up, and failed to evacuate Holland, as it had agreed to do in the treaty. France then continued to interfere with British trade despite peace having been made and complained about Britain harbouring certain individuals and not cracking down on the anti-French press. Malta was captured by Britain during the war and was subject to a complex arrangement in the 10th article of the Treaty of Amiens, where it was to be restored to the Knights of St. John with a Neapolitan garrison and placed under the guarantee of third powers. The weakening of the Knights of St. John by the confiscation of their assets in France and Spain along with delays in obtaining guarantees prevented the British from evacuating it after three months as stipulated in the treaty.

Sources: en.wikipedia.org

Supporting material

Helianthus tuberosus – Plants for a Future database Jerusalem artichoke – Ohio Perennial & Biennial Weed Guide NutritionData, Complete nutritional info. Purdue University Alternative Field Crops Manual: Jerusalem Artichoke

=== Structure-activity-relationship (SAR) === An important part of designing a compound, that is an ideal inhibitor to a certain target, is to understand the amino acid sequence of the target site for the compound to bind to. Modelling both prothrombin and FXa makes it possible to deduct the difference and identify the amino acids at each binding site. At the bottom of the S1 pocket on FXa the binding amino acid is Asp-189 which amidine moieties can bind to. After X-raying the binding site of FXa, it was revealed that the S1 pocket had a planar shape, meaning that a flat amidinoaryl group should bind to it without steric hindrance. Modern direct Xa inhibitors are L-shaped molecules whose ends fit perfectly in the S1 and S4 pockets. The long side of the L-shape has to conform to a highly-specific tunnel within the targets active site. To accomplish that, this part of the molecules is designed to have little formal interactions with FXa in that region. As there is no specific bonding, the fit of these agents between the pockets of FXa increases the total specificity of the drugs to the FXa molecule. The interaction between the S1 pocket of FXa and the inhibitor can be both ionic or non-ionic, which is important because it allows the design of the moiety to be adjusted to increase oral bioavailability. Previously designed compounds were charged molecules that are not absorbed well in the gastrointestinal tract and therefore did not reach high serum concentrations.

Bioanalyzer: The bioanalyzer is an instrument that uses electrophoresis to separate and analyze DNA, RNA, and protein samples. It can provide detailed information about the size, integrity, and purity of a DNA sample.

Sources: en.wikipedia.org

Frequently asked questions

用什么方法确认分子量?

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。

为什么甲硫氨酸容易出问题?

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。

溶液配制后如何保存?

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。

Where was Semax developed?

It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.

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