The short version of 合成七肽 fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic heptapeptide | Analog of an ACTH fragment |
| Amino acid length | Seven residues | Met-Glu-His-Phe-Pro-Gly-Pro |
| Origin | Moscow, 1980s | Institute of Molecular Genetics |
| Approved regions | Russia and some neighboring states | Not cleared in Western markets |
| Common trade names | Multiple national brands | Sold as a nasal formulation |
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
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.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
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。
GAHT may limit fertility potential. Should a transgender individual choose to undergo gender-affirming surgery, their fertility potential is lost completely. Before starting any treatment, individuals may consider fertility issues and fertility preservation. Options include semen cryopreservation, oocyte cryopreservation, and ovarian tissue cryopreservation. A study presented at ENDO 2019 (the Endocrine Society's conference) shows that even after one year of treatment with testosterone, a transgender man can preserve his fertility potential. A 2015 study demonstrated normal spermatogenesis in some transgender women who were long-term estrogen therapy patients. In other cases, there is some research showing effective restoration of fertility by alternative means than HRT cessation alone. Dr. Will Powers has demonstrated the effectiveness of clomifene in restoring spermatogenesis in trans women. His study also includes an in-depth description of other methods for fertility restoration.
Alexandre Marc Raymond (22 January 1872 – 16 May 1941) was a French Orientalist architect and artist. After working in Islamic art, he turned to Byzantine art. During the last twenty years of his life he undertook substantial work, in particular on Hagia Sophia.
Various enzymes or transporters involved in vasodilation are differentially expressed in those with pulmonary arterial hypertension. PAH is associated with reduced prostacyclin synthase activity in the vascular smooth muscle cells, resulting in decreased prostacyclin (PGI2) levels (prostacyclin acts as a vasodilator and inhibitor of vascular smooth muscle proliferation). The vasoconstrictor and cell proliferation activator endothelin-1 is also more active in those with PAH. And those with PAH also have evidence of reduce Nitric oxide synthetase activity, resulting in lower levels of the vasodilator nitric oxide. And those with PAH also more commonly express the L-allelic variant of the 5-HTT gene promoter, resulting in increased expression of the serotonin transporter (5-HTT), and leading to vasoconstriction via pulmonary artery smooth muscle proliferation.
Sources: en.wikipedia.org
=== Sheep wool === Wool from shearing sheep is a little-used yet promising renewable growing medium. In a study comparing wool with peat slabs, coconut fibre slabs, perlite and rockwool slabs to grow cucumber plants, sheep wool had a greater air capacity of 70%, which decreased with use to a comparable 43%, and water capacity that increased from 23% to 44% with use. Using sheep wool resulted in the greatest yield out of the tested substrates, while application of a biostimulator consisting of humic acid, lactic acid and Bacillus subtilis improved yields in all substrates.
=== Pharmacokinetics === Ciclosporin is a cyclic peptide composed of 11 amino acids. It has an unusually high molecular weight (1,202 Da) for an oral medication, but still achieves a bioavailability of up to ~30% due to its N-methylated cyclic structure, which confers both metabolic stability and a pronounced chameleonic properties, which allow it to pass through membranes such as those of the intestinal epithelium. It contains a single D-amino acid (D-alanine), which is rarely encountered in nature. Unlike most peptides, ciclosporin is not synthesized by ribosomes. Ciclosporin is highly metabolized by the CYP3A4 enzyme in humans and animals after ingestion. The metabolites, which include cyclosporin B, C, D, E, H, and L, have less than 10% of ciclosporin's immunosuppressant activity and are associated with higher kidney toxicity.
In 1968, Mahathir had expressed concern over escalating racial tensions in two newspaper articles, and feared preventative measures would be needed to avoid violence. Outside parliament, he openly criticised the government, also sending an open dissenting letter to Tunku for failing to uphold Malay interests and calling for his resignation. By the end of the year, Mahathir was fired from UMNO's Supreme Council and expelled from the party. Tunku had to be persuaded not to have him arrested. Expelled from UMNO, Mahathir wrote his first book, The Malay Dilemma, in which he set out his vision for the Malay community. The book argued that a balance had to be achieved between government support for Malays, so that their economic interests would not be dominated by the Chinese, and exposing Malays to sufficient competition. Mahathir saw Malays as typically avoiding hard work and failing to "appreciate the real value of money and property", and hoped this balance would rectify this. Mahathir criticised Tunku's government in the book, which led to it being banned in Malaysia. The ban was only lifted in 1981 under Mahathir's premiership.
Sources: en.wikipedia.org
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.
It is registered as a medicine in Russia and has been used clinically there for decades. No regulatory agency in Western Europe or North America has approved it for any indication.
Semax corresponds to the four-to-ten fragment of adrenocorticotropic hormone. Because it omits the first three residues, it lacks the adrenal-stimulating action of the full hormone.
Suppliers normally quote a percentage of total chromatographic peak area, most often from reversed-phase HPLC. That figure says nothing about what the remaining percentage contains, and it depends on the detection wavelength used. A mass spectrometry result is a separate and stronger check on identity.