Pro-Gly-Pro tail is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-01-08. Numbers and descriptions here follow the published literature rather than marketing material.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid from research suppliers |
| Solubility | Freely soluble in water | Also dissolves in aqueous buffers; solutions are used fresh |
| Typical storage temperature | -20 °C for lyophilized powder | Short-term transport at 2-8 °C is common |
| Common analytical method | Reverse-phase HPLC | Paired with mass spectrometry for identity confirmation |
| Common synonyms | ACTH(4-10) analogue; MEHFPGP | N-terminal methionine retained in the chain |
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。
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。
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。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
These can then be used to re-cellularise a three-dimensional lung tissue scaffold. A 2010 investigation used the ECM scaffold to produce entire lungs in vitro to be transplanted into living rats. These successfully enabled gas exchange but for short time intervals only. Nevertheless, this was a huge leap towards whole lung regeneration and transplants for humans, which has already taken another step forward with the lung regeneration of a non-human primate. Cystic fibrosis is another disease of the lungs, which is highly fatal and genetically linked to a mutation in the CFTR gene. Through growing patient-specific lung epithelium in vitro, lung tissue expressing the cystic fibrosis phenotype has been achieved. This is so that modelling and drug testing of the disease pathology can be carried out with the hope of regenerative medical applications.
=== Hypertension === As with other angiotensin II receptor antagonists, candesartan is indicated for the treatment of hypertension. Candesartan has an additive antihypertensive effect when combined with a diuretic, such as chlorthalidone. It is available in a fixed-combination formulation with a low dose of the thiazide diuretic hydrochlorothiazide. Candesartan/hydrochlorothiazide combination preparations are marketed under various trade names including Atacand Plus, Hytacand, Blopress Plus, Advantec and Ratacand Plus.
== Kosmotropes and chaotropes == Highly charged ions interact strongly with water, breaking hydrogen bonds and inducing electrostatic structuring of nearby water, and are thus called "structure-makers" or "kosmotropes". Conversely, weak ions can disrupt the structure of water, and are thus called "structure-breakers" or "chaotropes". The order of the tendency of ions to make or break water structure is the basis of the Hofmeister series. Hofmeister discovered a series of salts that have consistent effects on the solubility of proteins and, as it was discovered later, on the stability of their secondary and tertiary structures. Anions appear to have a larger effect than cations, and are usually ordered as follows:
Sources: en.wikipedia.org
In 2010, the United States produced more sulfuric acid than any other inorganic industrial chemical. The principal use for the acid is the extraction of phosphate ores for the production of fertilizer manufacturing. Other applications of sulfuric acid include oil refining, wastewater processing, and mineral extraction.
The 9/11 attacks resulted in immediate responses, including domestic reactions; closings and cancellations; hate crimes; international responses; and military responses. Shortly after the attacks, the September 11th Victim Compensation Fund was created by an Act of Congress. The purpose of the fund was to compensate the victims of the attacks and their families with their agreement not to file lawsuits against the airlines involved. Legislation authorizes the fund to disburse a maximum of $7.375 billion, including operational and administrative costs, of U.S. government funds. The fund was set to expire by 2020 but was prolonged in 2019 to allow claims to be filed until October 2090.
R-CH=CH-CO-SCoA + H2O2 Hydrogen peroxide arises by the degradation of adenosine monophosphate, which yields hypoxanthine. Hypoxanthine is then oxidatively catabolized first to xanthine and then to uric acid, and the reaction is catalyzed by the enzyme xanthine oxidase:
This recognition positioned AUC as the first university in Egypt to offer an ISCEA-accredited program that not only grants a professional certificate but also prepares participants to sit for the globally respected Certified Supply Chain Manager (CSCM) exam. Other countries in EMEA in which supply chain professionals are acquiring their supply chain certification credentials from ISCEA include Iraq, Egypt, Jordan, Kenya, South Africa and Spain.
Sources: en.wikipedia.org
The Dexcom CGM is a continuous glucose monitoring system developed by Dexcom, Inc., a company specializing in glucose monitoring technology for individuals with diabetes. Several iterations of the Dexcom CGM wearable device have been released, beginning with the Dexcom Short-Term Sensor (STS), followed by the Dexcom Seven and Dexcom Seven Plus. Later models include the Dexcom G4, Dexcom G5, Dexcom G6, and Dexcom G7. The most recently released model, Stelo by Dexcom, is a more affordable option designed for individuals with type 2 diabetes. Dexcom was founded in 1999 by John Burd and released its first CGM, the Dexcom STS, in 2006 following U.S. Food and Drug Administration (FDA) approval. As of 2025, only the Dexcom G6, Dexcom G7, and Stelo remain available.
the exact colour of the spore powder (white/cream/ochre), the taste (mild/bitter/acrid), colour changes in the flesh, the distance from the centre to which the cap skin can be pulled off: (peeling percentage). cap colour (but this is often very variable within one species), reaction of the flesh to ferrous sulphate (FeSO4), formalin, alkalis, and other chemicals, ornamentation of the spores, and other microscopic characteristics, such as the appearance of the cystidia in various mounting reagents. Despite the difficulty in positively identifying collected specimens, the possibility to spot the toxic species by their acrid taste makes some of the mild species, such as R. cyanoxantha and R. vesca, popular edible mushrooms. Russula is mostly free of deadly poisonous species, and mild-tasting ones are all edible.
Rhodesia began to lose vital economic and military support from South Africa, which, while sympathetic to the white minority government, never accorded it diplomatic recognition. The South African government placed limits on the fuel and munitions they supplied to the Rhodesian military. They also withdrew the personnel and equipment that they had previously provided to aid the war effort, though covert military support continued. In 1976, the South African government and United States governments worked together to place pressure on Smith to agree to a form of majority rule. In response to the initiative of United States Secretary of State Henry Kissinger, in 1976 Ian Smith accepted the principle of black majority rule within two years. The Rhodesians now offered more concessions, but those concessions, focused on reaching an "internal settlement" with moderate black leaders, were insufficient to end the war. At the time, some Rhodesians said the still embittered history between the British-dominated Rhodesia and the Afrikaner-dominated South Africa partly led the South African government to withdraw its aid to Rhodesia. Ian Smith said in his memoirs that even though many white South Africans supported Rhodesia, South African Prime Minister John Vorster's policy of détente with the black African states ended up with Rhodesia being offered as the "sacrificial lamb" to buy more time for South Africa. Other observers perceived South Africa's distancing itself from Rhodesia as being an early move in the process that led to majority rule in South Africa itself.
Sources: en.wikipedia.org
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.
A fraction of an intranasal dose is thought to reach the central nervous system, and this route is favoured partly for that reason. The proportion is not well characterized. Direct measurement in humans remains difficult with current methods.
Raised BDNF and NGF expression has been reported across several animal studies, which makes the signal fairly consistent. Whether the same change occurs in humans at usable doses is not established. It is best treated as a working hypothesis rather than a confirmed clinical mechanism.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.