If you have been reading about Melanocortin receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-06-15. Numbers and descriptions here follow the published literature rather than marketing material.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
| Property | Value | Notes |
|---|---|---|
| Solid storage temperature | -20 °C or below | Desiccated and protected from light |
| Solution storage temperature | -80 °C as single-use aliquots | Avoid repeated freeze-thaw cycles |
| Purity assessment method | RP-HPLC, around 214 nm | Reported as main-peak area percent |
| Identity confirmation method | ESI-MS or MALDI-TOF | Measured mass compared with calculated mass |
| Common synonyms | ACTH(4-10) analog; Met-Glu-His-Phe-Pro-Gly-Pro | Also written as Semaxum in some sources |
Published studies are dominated by animal models of stroke, ischemia, and cognitive impairment, with a smaller number of human trials conducted in Russia. Many of the human reports are small, single-center, and published in Russian-language journals, which limits independent scrutiny. Outcome measures vary between studies and often rely on clinician-rated scales rather than objective biomarkers. Systematic reviews have noted the methodological weaknesses and called for larger, preregistered trials before firm conclusions can be drawn.
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
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。
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。
Tomato – in culinary terms, the tomato is regarded as a vegetable, but it is botanically classified as a fruit and a berry. Banana – the fruit has been described as a "leathery berry". In cultivated varieties, the seeds are diminished nearly to non-existence. Pepo – berries with skin that is hardened: cucurbits, including gourds, squash, melons. Hesperidium – berries with a rind and a juicy interior: most citrus fruit. Cranberry, gooseberry, redcurrant, grape. The strawberry, regardless of its appearance, is classified as a dry, not a fleshy fruit. Botanically, it is not a berry; it is an aggregate-accessory fruit, the latter term meaning the fleshy part is derived not from the plant's ovaries but from the receptacle that holds the ovaries. Numerous dry achenes are attached to the outside of the fruit-flesh; they appear to be seeds but each is actually an ovary of a flower, with a seed inside. Schizocarps are dry fruits, though some appear to be fleshy. They originate from syncarpous ovaries but do not actually dehisce; rather, they split into segments with one or more seeds. They include a number of different forms from a wide range of families, including carrot, parsnip, parsley, cumin.
Grandidier, A. (1899). Guide de l'immigrant à Madagascar (in French). Paris: A Colin et cie. Kurlansky, Mark (1997). Cod: A Biography of the Fish That Changed the World. New York: Walker. ISBN 0-8027-1326-2.
Other types of car windows can reduce transmission of UV that is greater than 335 nm. Fused quartz, depending on quality, can be transparent even to vacuum UV wavelengths. Crystalline quartz and some crystals such as CaF2 and MgF2 transmit well down to 150 nm or 160 nm wavelengths. Wood's glass is a deep violet-blue barium-sodium silicate glass with about 9% nickel(II) oxide developed during World War I to block visible light for covert communications. It allows both infrared daylight and ultraviolet night-time communications by being transparent between 320 nm and 400 nm and also the longer infrared and far-red light. Its maximum UV transmission is at 365 nm, one of the wavelengths of mercury lamps.
Sources: en.wikipedia.org
One exception is that thyroid hormones may aggravate heart conditions, especially in older patients; therefore, physicians may start these patients on a lower dose and work up to a larger one to avoid the risk of a heart attack.
=== Nutritional supplement === Despite the lack of any recognized syndromes of PABA deficiency in humans, except for those who lack the colonic bacteria that generate PABA, many claims of benefit are made by commercial suppliers of PABA as a nutritional supplement. The benefit is claimed for fatigue, irritability, depression, weeping eczema (moist eczema), scleroderma (premature hardening of the skin), patchy pigment loss in the skin (vitiligo), and premature grey hair.
June: Jupiter IRBM deployment to Turkey begins, joining the Jupiters deployed to Italy as well as the Thor IRBMs deployed to the UK as nuclear missiles placed within striking distance of Moscow. July 11: North Korea and China sign a defensive treaty, the Sino-North Korean Mutual Aid and Cooperation Friendship Treaty. July 19: The Nicaraguan Revolution begins. August 13: The Berlin Wall is built by the Soviets following the breakdown in talks to decide the future of Germany. August 17: Alliance for Progress aid to Latin America from the United States begins. September 1: The Soviet Union resumed testing of nuclear weapons in the atmosphere. The Eritrean War of Independence begins. September 4: John F. Kennedy signs the Foreign Assistance Act. September 18: UN Secretary General Dag Hammarskjöld dies in a plane crash on his way to negotiate a ceasefire in Katanga amidst the Congo Crisis September 28: Syria withdraws from the United Arab Republic. October 17: 22nd Soviet Party Congress held in USSR. October 27: Checkpoint Charlie standoff between US and Soviet tanks begins. October 31: The Soviet Union detonates the Tsar Bomba, the most powerful thermonuclear weapon ever tested, with an explosive yield of some 50 megatons. November 18: John F. Kennedy authorizes the deployment of 18,000 military advisors to support the struggle against communist insurgents in South Vietnam. December 2: Fidel Castro openly describes himself as a Marxist–Leninist. December 18: Republic of India invades the former Portuguese territory of Goa.
One should expect that, within a few thousand years of its entering the stage of industrial development, any intelligent species should be found occupying an artificial biosphere which surrounds its parent star. Dyson conceived that such structures would be clouds of asteroid-sized space habitats, though science fiction writers have preferred a solid structure: either way, such an artifact is often called a Dyson sphere, although Dyson used the term "shell". Dyson said that he used the term "artificial biosphere" in the article to mean a habitat, not a shape. The general concept of such an energy-transferring shell had been created decades earlier by science fiction writer Olaf Stapledon in his 1937 novel Star Maker, a source which Dyson credited publicly. Freeman Dyson was interviewed by Robert Wright in 2003 and the Dyson Sphere topic was broached. In response he stated that the paper he wrote on this concept was intended to be a joke and had nothing to do with work. He added that it amused him that he had become famous only for the things he didn't think were serious.
Sources: en.wikipedia.org
== Revival of fine teas == Yellow and white teas became difficult to find in the United States and even green tea had become uncommon because of the People's Republic of China's ban on exports to the U.S. After the ban was lifted in 1971, these teas typical to China re-entered the American market for the first time since the first two decades of the 20th century. In the early 1980s, a mini-revival of demand for better quality teas from all origins occurred in the United States. Prior to this time, much of the tea available in 20th century U.S. was blended specifically for gallon and half-gallon sized iced tea bags, with the quality of not "creaming down" (a creamy looking color that imparts to some teas after cooling down) when iced as a needed aspect; "clear-liquoring" teas were required. Most iced tea blends in the U.S. have traditionally been made from the teas of Indonesia, Sri Lanka, Kenya, Argentina and Malawi. A recent rise in the demand for orthodox tea in both gallon and half-gallon iced tea bags, as well as 500 and 1,000 gram loose tea packs has caused manufacturers to reinstate orthodox manufacturing methods. This is a departure from the more common Sri Lankan, Indonesian, Argentinian and other nations' orthodox rotorvane tea-making method which has limitations and can not produce whole leaf black tea. The rotorvane method was adopted primarily to satisfy the demand for the smaller leaf sizes that fit into small (1-2 gram) tea bag blends worldwide starting in the early 20th century.}
Lowering transaction costs in commercial markets: Digital payments, whether integrated in e-commerce platforms or in mobile money accounts, e-wallets, etc., reduce transactions costs within agricultural markets. The need for safe, rapid monetary transactions is particularly apparent in rural areas. Plus, digital payments can provide a gateway to bank accounts, insurance, and credit. Using distributed ledger technologies or smart contracts is another way to reduce trust-related transaction costs in commercial markets. Many retail and food companies have partnered with IBM to develop blockchain pilots related to food safety and traceability, and Alibaba is testing blockchain to reduce fraud in agri-food e-commerce between China and Australia/New Zealand. Lowering transaction costs in government services: Digital payments can also streamline government delivery of agricultural subsidies. In 2011, the Nigerian Federal Ministry of Agriculture and Rural Development started delivering fertilizer subsidy vouchers to e-wallets on mobile phones; by 2013, they had reached 4.3 million smallholders nationwide. Compared to the previous program, the e-vouchers cut costs: from 2011 to 2013, the cost per smallholder farmer receiving fertilizer went from US$225–300 to US$22. The e-vouchers also reached more smallholders, increasing from between 600,000-800,000 in 2011 to 4.3 million in 2013.
=== Laminin G === The laminin globular (G) domain, also known as the LNS (Laminin-alpha, Neurexin and Sex hormone-binding globulin) domain, is on average 177 amino acids in length and can be found in one to six copies in various laminin family members as well as in a large number of other extracellular proteins. For example, all laminin alpha-chains have five laminin G domains, all collagen family proteins have one laminin G domain, the CNTNAP proteins have four laminin G domains, while neurexin 1 and 2 each hold six laminin G domains. On average, approximately one quarter of the proteins that hold laminin G domains is taken up by these laminin G domains themselves. The smallest laminin G domain can be found in one of the collagen proteins (COL24A1; 77 AA) and the largest domain in TSPEAR (219 AA). The exact function of the Laminin G domains has remained elusive, and a variety of binding functions has been ascribed to different Laminin G modules. For example, the laminin alpha1 and alpha2 chains each have five C-terminal laminin G domains, where only domains LG4 and LG5 contain binding sites for heparin, sulphatides and the cell surface receptor dystroglycan. Laminin G-containing proteins appear to have a wide variety of roles in cell adhesion, signalling, migration, assembly and differentiation.
peroxy Also peroxide and sometimes peroxo. A functional group consisting of two oxygen atoms directly connected to each other by a single bond and each also connected to one other atom. Peroxides have the general structural formula –O–O–.
The United States is home to a wide variety of ethnic groups, traditions, and customs. The country has been described as having the values of individualism and personal autonomy, as well as a strong work ethic and competitiveness. Voluntary altruism toward others also plays a major role; according to a 2016 study by the Charities Aid Foundation, Americans donated 1.44% of total GDP to charity—the highest rate in the world by a large margin. Americans have traditionally been characterized by a unifying political belief in an "American Creed" that emphasizes consent of the governed, liberty, equality under the law, democracy, social equality, property rights, and a preference for limited government. The U.S. has acquired significant hard and soft power through its diplomatic influence, economic power, military alliances, and cultural exports such as American movies, music, video games, sports, and food. The influence that the United States exerts on other countries through soft power is referred to as Americanization. Nearly all present Americans or their ancestors came from Europe, Africa, or Asia (the "Old World") within the past five centuries. Mainstream American culture is a Western culture largely derived from the traditions of European immigrants with influences from many other sources, such as traditions brought by slaves from Africa.
Sources: en.wikipedia.org
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.
A high main-peak percentage says little about identity, counter-ion content, or residual solvents. It also does not distinguish an isomer or a closely eluting analog. Mass confirmation and the accompanying documentation cover those gaps.
Salt form changes mass, solubility, and hygroscopicity, and acetate and trifluoroacetate salts behave differently in solution. Storage guidance still centers on -20 °C for powder and lower temperatures for solutions. The certificate should state which salt is present.
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.