A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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。
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Clinical reports describe use in ischaemic stroke, transient ischaemic attack, optic nerve conditions, and cognitive complaints, but most of these studies are small and were conducted in a single region. Systematic reviews have generally described the evidence base as limited in size and variable in methodological quality. Randomised controlled data suitable for international regulatory assessment are scarce. As a result, major treatment guidelines outside Russia do not include the peptide, and interest in it remains largely research-driven rather than routine clinical.
| 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 |
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
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.
=== T cells === Some T cells (e.g. regulatory T cells) release TGF-β1 to inhibit the actions of other T cells. Specifically, TGF-β1 prevents the interleukin(IL)-1- & interleukin-2-dependent proliferation in activated T cells, as well as the activation of quiescent helper T cells and cytotoxic T cells. Similarly, TGF-β1 can inhibit the secretion and activity of many other cytokines including interferon-γ, tumor necrosis factor-alpha (TNF-α), and various interleukins. It can also decrease the expression levels of cytokine receptors, such as the IL-2 receptor to down-regulate the activity of immune cells. However, TGF-β1 can also increase the expression of certain cytokines in T cells and promote their proliferation, particularly if the cells are immature.
Software models and simulations for SARS-CoV-2, including spread, functional mechanisms and properties, efficacy of potential treatments, transmission risks, vaccination modelling/monitoring, (computational fluid dynamics, computational epidemiology, computational biology/computational systems biology were developed by governments, universities, and companies. Modelling software and related software is also used to evaluate impacts on the environment and the economy.
It contains food bars and a drink mix. Similarly, the Food Packet, Survival, Abandon Ship (FPSAS) and Food Packet, Survival, Aircraft, Life Raft (FPSALR) are fitted into the storage areas on lifeboats. The "Jimmy Dean", a pre-packaged shelf-stable ration containing, among other items, a pre-made Jimmy Dean brand deli-style sandwich, is often issued in the field to U.S. servicemen as an alternative to MREs.
=== Basal rate determination === Basal insulin requirements will vary between individuals and periods of the day. The basal rate for a particular time period is determined by fasting while periodically evaluating the blood sugar level. Neither food nor bolus insulin must be taken for 4 hours before or during the evaluation period. If the blood sugar level changes dramatically during evaluation, then the basal rate can be adjusted to increase or decrease insulin delivery to keep the blood sugar level approximately steady. For instance, to determine an individual's morning basal requirement, they must skip breakfast. On waking, they would test their blood glucose level periodically until lunch. Changes in blood glucose level are compensated with adjustments in the morning basal rate. The process is repeated over several days, varying the fasting period, until a 24-hour basal profile has been built up which keeps fasting blood sugar levels relatively steady. Once the basal rate is matched to the fasting basal insulin need, the pump user will then gain the flexibility to skip or postpone meals such as sleeping late on the weekends or working overtime on a weekday. Many factors can change insulin requirements and require an adjustment to the basal rate:
Sources: en.wikipedia.org
Delayed puberty (and dysmenorrhoea or amenorrhoea in women) in young people Severe kidney damage: high blood sugar can overwork the kidneys, eventually leading to kidney failure and the need for a kidney transplant Severe neuropathy (nerve damage to hands and feet) Extreme fatigue Edema (during blood sugars controlled phases) Heart problems Retinal damage and subsequent vision problems High cholesterol (hypercholesterolaemia) Osteoporosis Death
=== H2 Relaxin === In the human ovary, H2 relaxin is produced by the corpus luteum and by Granulosa cells from large antral follicles. Research has shown that the relaxin gene is expressed once the Granulosa cells have reached a certain luteinised status, by which Granulosa cells differentiate into Luteal cells. Therefore, it can act as a good biomarker in relation to Granulosa cell differentiation status. Relaxin is produced to support early pregnancy until the placenta can take over. Relaxin plays a key role in implantation and placenta formation. The relaxin receptor RXFP1 is found on myometrial cells. In rats, it has been linked playing a role in the spacing between embryos in the uterus. RXFP1 is also located on endometrial stromal cells where it can induce cyclic adenosine monophosphate (cAMP). cAMP is a molecule which is necessary for the functional changes in the endometrium to form the decidual lining, where the blastocyst can implant. This results in neo-angiogenesis and endometrial thickening, both linked to early pregnancy development.
In the EU member states legislation was introduced in 1998 which had a major effect on UK Pharmacy operations. It effectively prohibited the use of tablet counters for counting and dispensing bulk packaged tablets. Both usage and sales of the machines in the UK declined rapidly as a result of the introduction of blister packaging for medicines.
Sources: en.wikipedia.org
manufacturers of processed food, aware of the possible contribution of their products to the obesity epidemic, met together and discussed the problem as early as April 8, 1999; however, a proactive strategy was considered and rejected. As a general rule, optimizing the amount of salt, sugar and fat in a product will improve its palatability, and profitability. Reducing salt, sugar and fat, for the purpose of public health, had the potential to decrease palatability and profitability. Media influence may play an important role in prevention of obesity as it has the ability to boost many of the main prevention/intervention methods used nowadays including lifestyle modification. The media is also highly influential on children and teenagers as it promotes healthy body image and sets societal goals for lifestyle improvement. Examples of media influence are support for the "Let's Move!" campaign and the MyPlate program initiated by Michelle Obama, and the NFL's Play60 campaign. These campaigns promote physical activity in an effort to reduce obesity especially for children. In 2011, the Obama administration introduced a $400 million Healthy Food Financing Initiative, the goal of the program is to "create jobs and economic development, and establish market opportunities for farmers and ranchers," as described by the secretary of agriculture, Tom Vilsack. Population-based approaches have been recommended and pursued in the U.S. Obesity is complex because it affects multiple environments, involves multiple industries and sectors, and affects both energy intake and expenditure.
== Early life and education == Born in Aarberg, Switzerland, Wüthrich was educated in chemistry, physics, and mathematics at the University of Bern before pursuing his PhD supervised by Silvio Fallab at the University of Basel, awarded in 1964.
=== May === 1 May – MSPs vote 70–58 to defeat a motion of no confidence in the Scottish Government. 2 May – John Swinney is set to become the next SNP leader and first minister after Kate Forbes confirms she will not seek the party's leadership. 5 May – John Swinney warns that any bid to challenge his election as leader would delay rebuilding the party amid reports party activist Graeme McCormick is set to put his name forward. He subsequently announces he will not launch a challenge and endorses Swinney. 6 May – John Swinney is confirmed as Leader of the Scottish National Party after being unopposed in the leadership election, and begins his second tenure in the post. 7 May – John Swinney wins the backing of the Scottish Parliament to become Scotland's seventh First Minister, and will be sworn into office the next day. 8 May – John Swinney is sworn in as Scotland's seventh first minister at a ceremony at the Court of Session in Edinburgh. Swinney appoints Kate Forbes as Scotland's Deputy First Minister. Plans to redevelop Glasgow's Met Tower as a digital technology hub are cancelled, with the company behind the redevelopment citing "significant changes" to economic conditions and the construction market. 9 May – Swinney confirms to the BBC that the SNP's strategy of using the next general election as a mandate for a second referendum on Scottish independence remains. 10 May – Food Standards Scotland confirms a case of BSE has been found on a farm in Ayrshire, but says there is no risk to the public as the animal did not enter the food chain.
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 described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.