A practical reference on ACTH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-13 and is reviewed periodically as new material appears.
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 化学类别 | 合成七肽 | ACTH(4-10) 结构类似物 |
| 氨基酸序列 | Met-Glu-His-Phe-Pro-Gly-Pro | 单字母写作 MEHFPGP |
| 分子量 | 约 813.9 Da | 随确切形式和盐型略有变化 |
| 常见同义词 | ACTH(4-10) 类似物 | 俄语文献称 Семакс |
| 开发来源 | 俄罗斯 | 二十世纪八十年代 |
The stereoisomer D-phenylalanine (DPA) can be produced by conventional organic synthesis, either as a single enantiomer or as a component of the racemic mixture. It does not participate in protein biosynthesis although it is found in proteins in small amounts—particularly aged proteins and food proteins that have been processed. The biological functions of D-amino acids remain unclear, although D-phenylalanine has pharmacological activity at niacin receptor 2. DL-Phenylalanine (DLPA) is marketed as a nutritional supplement for its purported analgesic and antidepressant activities, which have been supported by clinical trials. DL-Phenylalanine is a mixture of D-phenylalanine and L-phenylalanine. The reputed analgesic activity of DL-phenylalanine may be explained by the possible blockage by D-phenylalanine of enkephalin degradation by the enzyme carboxypeptidase A. Enkephalins act as agonists of the mu and delta opioid receptors, and agonists of these receptors are known to produce antidepressant effects. The mechanism of DL-phenylalanine's supposed antidepressant activity may also be accounted for in part by the precursor role of L-phenylalanine in the synthesis of the neurotransmitters norepinephrine and dopamine, though clinical trials have not found an antidepressant effect from L-phenylalanine alone. Elevated brain levels of norepinephrine and dopamine are thought to have an antidepressant effect. D-Phenylalanine is absorbed from the small intestine and transported to the liver via the portal circulation.
Duterte was inaugurated as the sixteenth president of the Philippines on June 30, 2016, succeeding Benigno Aquino III. At age 71, Duterte became the oldest person elected to the presidency, the first local chief executive to get elected straight to the Office of the President, the second Cebuano president (after Sergio Osmeña), and the first Visayan president from Mindanao. In 2019, he became the first Philippine president since 1986 not to publicize his statement of assets, liabilities, and net worth (SALN); his SALNs since 2019 would only be revealed post-presidency in November 2025.
=== Relationship with Mackenzie Booth === The character was paired with Mackenzie Booth (Emily Weir) for a romance story arc in April 2020. The pair begin interacting on a regular basis when Ari uses Mac's restaurant Salt as a base to search the newspapers for employment. Ari finds support in Mac as he struggles to find a job, and his closed off nature intrigues her. Weir said that Ari is attractive to Mac because he is "drama-free" compared to her previous partner Colby Thorne. She also said "Ari seems someone who's calm and relaxed with himself." Mac is unaware that Ari served time with her brother Dean Thompson (Patrick O'Connor), so when she mentions that they have been spending time together, he warns Ari to stay away from her. However, Mac notices Ari's absence and goes to his caravan to confront him. Her "blunt approach" amuses Ari and it leads him to tell her about his past, including his stint in prison. Weir pointed out that Mac is unlikely to judge him for having "a complicated past" since she also has one. Mac makes it clear that she is still interested in Ari and the pair spend the night together. As Mackenzie leaves Ari's van in the morning, she greets John, who immediately visits Marilyn to gossip about what has gone on. An Inside Soap columnist wondered if Ari's "night of passion" had just cost his family a place to live. Ari later has "serious beef" with Tane over Mac. A love triangle was introduced into the storyline when Mac develops a strong attraction to Tane.
Sources: en.wikipedia.org
=== China, Russia === In 2013, Russia and China banned ractopamine in pork, and Russia also in beef, deeming it unfit for human consumption. Because the traditional Chinese diet embraces pig offal, and because ractopamine is concentrated by the gastro-intestinal system of animals, Chinese officials have banned ractopamine. Other countries in Asia, whose traditional diet is similar to that of the Chinese, have had similar concerns, but the American use of tied trade access as a proxy for conflict has somewhat mitigated their reactions.
In 1959 Ernst Freese coined the terms "transitions" or "transversions" to categorize different types of point mutations. Transitions are replacement of a purine base with another purine or replacement of a pyrimidine with another pyrimidine. Transversions are replacement of a purine with a pyrimidine or vice versa. There is a systematic difference in mutation rates for transitions (Alpha) and transversions (Beta). Transition mutations are about ten times more common than transversions.
== Principle == Capillary electrochromatography (CEC) combines the principles used in HPLC and CE. The mobile phase is driven across the chromatographic bed using electroosmosis instead of pressure (as in HPLC). Electroosmosis is the motion of liquid induced by an applied potential across a porous material, capillary tube, membrane or any other fluid conduit. Electroosmotic flow is caused by the Coulomb force induced by an electric field on net mobile electric charge in a solution. Under alkaline conditions, the surface silanol groups of the fused silica will become ionised leading to a negatively charged surface. This surface will have a layer of positively charged ions in close proximity which are relatively immobilised. This layer of ions is called the Stern layer. The thickness of the double layer is given by the formula:
Sources: en.wikipedia.org
== Structure and mechanism == Although the respiratory function of hemocyanin is similar to that of hemoglobin, there are a significant number of differences in its molecular structure and mechanism. Whereas hemoglobin carries its iron atoms in porphyrin rings (heme groups), the copper atoms of hemocyanin are bound as prosthetic groups coordinated by histidine residues. Each hemocyanin monomer holds a pair of copper(I) cations in place via interactions with the imidazole rings of six histidine residues. It has been noted that species using hemocyanin for oxygen transportation include crustaceans living in cold environments with low oxygen pressure. Under these circumstances hemoglobin oxygen transportation is less efficient than hemocyanin oxygen transportation. Nevertheless, there are also terrestrial arthropods using hemocyanin, notably spiders and scorpions, that live in warm climates. The molecule is conformationally stable and fully functioning at temperatures up to 90 degrees C. Most hemocyanins bind with oxygen non-cooperatively and are roughly one-fourth as efficient as hemoglobin at transporting oxygen per amount of blood. Hemoglobin binds oxygen cooperatively due to steric conformation changes in the protein complex, which increases hemoglobin's affinity for oxygen when partially oxygenated. In some hemocyanins of horseshoe crabs and some other species of arthropods, cooperative binding is observed, with Hill coefficients of 1.6–3.0. Hill coefficients vary depending on species and laboratory measurement settings.
== Chemistry == The bark is known to be rich in tannins, saponins, alkaloids, lipids, phytosterols, glucosides, xylose, rhamnose, arabinose, lupeol, methoxychalcones, and kukulkanins. Additionally, Mimosa tenuiflora contains labdane diterpenoids.
With the recent advances of noninvasive imaging, living liver donors usually have to undergo imaging examinations for liver anatomy to decide if the anatomy is feasible for donation. The evaluation is usually performed by multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI). MDCT is good in vascular anatomy and volumetry. MRI is used for biliary tree anatomy. Donors with very unusual vascular anatomy, which makes them unsuitable for donation, could be screened out to avoid unnecessary operations.
=== Minimum wage === As a candidate for governor, Pritzker campaigned on raising the minimum wage in Illinois to $15 an hour. He enacted a plan to do so, raising the minimum wage to $9.25 an hour on January 1, 2020, and then to $10 an hour on July 1 of that year. The minimum wage has risen by $1 per hour each year on January 1. It was $15 as of January 1, 2025.
Sources: en.wikipedia.org
不是。Semax 是完全人工合成的七肽，自然界中没有对应的已知肽段。它的设计灵感来自促肾上腺皮质激素片段 ACTH(4-10)，但序列经过了替换和延长。
Semax 被描述为 ACTH(4-10) 的结构类似物，两者共享部分序列特征。它保留了该片段的部分神经相关活性方向，但去除了完整片段带来的激素释放效应。二者并非同一物质，也不能互相替代。
加入的 Pro-Gly-Pro 三肽被普遍认为能提升分子对蛋白水解酶的稳定性。这种设计让短肽在体内维持时间更长。具体延长的程度以及不同组织中是否一致，文献中仍存在不同报告。
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.