Everything below concerns lyophilization. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-05-24. Where a claim depends on a specific study, the study is described rather than over-claimed.
从用途定位看，ipamorelin 目前主要以研究用肽的身份被讨论，未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用，不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小，因此对其效应强度与一致性的描述应保持谨慎。
Ipamorelin 是一种合成五肽，序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2，分子式 C38H49N9O5，游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素（GHS）家族，作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道，设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。
Storage recommendations for the dry solid center on low temperature and low moisture, most often -20 °C in a sealed, desiccated container protected from light. Solutions are less stable than the powder and are usually kept cold and used within a short window. Freeze-thaw cycling is a recognized source of loss, and aliquoting before freezing is a standard precaution. These practices derive from general peptide handling principles rather than from a single published stability trial, so exact shelf lives should be treated as approximate.
Analytical confirmation relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry for identity and purity assessment. Mass spectrometry distinguishes the intact molecule from truncation products and from oxidation or deamidation variants that share similar chromatographic retention. Immunoassays appear in some biological studies but can cross-react with related peptides, so they are weaker tools for identity work. Reported purity figures depend heavily on the gradient, detector, and integration method used, which complicates direct comparison between laboratories.
Research quantities of ipamorelin are typically distributed as a white to off-white lyophilized powder. The solid dissolves readily in water and in aqueous buffers, and stock solutions are commonly prepared in sterile water or a mildly acidic diluent. Adsorption to plastic and glass surfaces can reduce the concentration of very dilute solutions, so containers and transfer steps deserve attention when accurate concentrations matter. Reconstituted material is generally used promptly rather than held for extended periods.
| Property | Value | Notes |
|---|---|---|
| 分子式 | C38H49N9O5 | 五肽，C 端酰胺化 |
| 分子量 | 约 711.85 g/mol | 游离碱形式 |
| 外观 | 白色至类白色冻干粉 | 研究用材料的常见形态 |
| 溶解性 | 溶于水及 DMSO 等极性溶剂 | 建议现配现用 |
| 储存温度 | -20 °C 或更低 | 干燥、避光、限制冻融次数 |
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
Storage recommendations for ipamorelin usually focus on temperature, moisture, and light. Lyophilized powder is typically held at or below minus twenty degrees Celsius in a desiccated container protected from light. Reconstituted solutions are often aliquoted and stored at minus eighty degrees Celsius to reduce repeated freeze-thaw cycles, which can promote aggregation or degradation. The optimal buffer and pH depend on the specific assay, and no single condition applies to every experimental context. Peptide stability should be assessed with time-point measurements rather than assumed from general handling rules.
In the scientific literature, ipamorelin appears mainly in preclinical studies, receptor binding assays, and reviews of growth hormone secretagogues. Authors often discuss its selectivity profile alongside limitations such as small sample sizes, short study durations, and differences between species. Some papers examine pharmacokinetics and clearance, but human data are limited and not sufficient to define general clinical effects. Regulatory discussion treats the compound as an investigational or research substance rather than an approved therapy in most jurisdictions. Open questions include oral bioavailability, long-term endocrine effects, and whether selectivity observed in animals persists in humans.
Research peptides such as ipamorelin are commonly supplied as lyophilized powder and characterized by analytical certificates. Reversed-phase high-performance liquid chromatography is used to estimate purity by ultraviolet absorbance, while mass spectrometry confirms molecular identity and detects sequence-related impurities. Counterion content, water content, and residual synthesis reagents can affect the reported mass balance. A certificate of analysis may list a purity percentage, but that number depends on the analytical method and the definition of impurity peaks. Independent verification is often recommended because research supply chains vary in quality control practices.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue family. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues that resist enzymatic breakdown. Researchers at Novo Nordisk described the compound in the 1990s while searching for agents that release growth hormone with fewer side effects than earlier secretagogues. The molecule acts as an agonist at the ghrelin receptor, also called GHS-R1a, which is expressed in the pituitary and in several peripheral tissues.
Selectivity distinguishes ipamorelin from first-generation secretagogues such as GHRP-6. At doses that reliably raise growth hormone, it shows little stimulation of adrenocorticotropic hormone or cortisol release in animal models, and it does not markedly raise prolactin or appetite. Binding at GHS-R1a on pituitary somatotrophs triggers calcium influx and pulsatile growth hormone secretion. Because the compound mimics the natural ghrelin signal, the release pattern tends to follow the body's own rhythm rather than producing a sustained elevation.
Most published work on ipamorelin comes from rodent studies and small early-phase human trials. Subcutaneous and intravenous routes have been used, while oral delivery is limited by poor absorption and rapid breakdown in the gut. The reported plasma half-life is short, on the order of two hours, and varies with species and assay method. Whether chronic use produces meaningful clinical benefit remains unresolved, and long-term safety data in humans are sparse. No major regulatory agency has approved the compound as a therapeutic drug.
== Mechanism of action == NGF binds with at least two classes of receptors: the tropomyosin receptor kinase A (TrkA) and low-affinity NGF receptor (LNGFR/p75NTR). Both are associated with neurodegenerative disorders. When NGF binds to the TrkA receptor, it drives the homodimerization of the receptor, which in turn causes the autophosphorylation of the tyrosine kinase segment. The tropomyosin receptor kinase A receptor has five extracellular domains, and the fifth domain is sufficient in binding NGF. Once bound, the complex undergoes endocytosis and activates the NGF transcriptional program, following two major pathways, the Ras/MAPK pathway and the PI3K/Akt pathway. The binding of NGF to TrkA also leads to the activation of PI 3-kinase, ras, and PLC signaling pathways. Alternatively, the p75NTR receptor can form a heterodimer with TrkA, which has higher affinity and specificity for NGF. Studies suggest that NGF circulates throughout the entire body via the blood plasma, and is important for the overall maintenance of homeostasis.
==== Capital punishment ==== The use of propofol as part of an execution protocol has been considered, although no person has been executed using this agent. This is largely due to European manufacturers and governments banning the export of propofol for such use.
== Synthesis == The synthesis of metal carbonyls is a widely studied subject of organometallic research. Since the work of Mond and then Hieber, many procedures have been developed for the preparation of mononuclear metal carbonyls as well as homo- and heterometallic carbonyl clusters.
...we have learned with interest and humility that Dr. Karl Beyer, a vice-president of Merck, Sharpe and Dohme, Rahway, New Jersey, U.S.A., and current president of the American Pharmacological Society, "coined the word (Pharmacometrics) in the early '50s and has been using it in internal reports ever since" (J. R. Vane, personal communication). Moreover, one of the laboratories in the pharmacological department of his Company is "labeled 'Pharmacometrics'"! We do not know in exactly what sense Dr. Beyer has been using the word, though we find it difficult to think of any other legitimate one than that advanced above. We can only hope that he also thinks so and that its use in the title of this book may help to give it the wider currency that we believe it to deserve and all the "priority" rights to Dr. Beyer.
Sources: en.wikipedia.org
In El Salvador, Mister Donut has a large cultural presence as the menu includes traditional Salvadoran cuisine and is known for its famous 2X1 promotion during September. It has sponsored local football teams such as CD Águila and Alianza F.C. which are major football teams in the country. As of 2026, there are 24 Mister Donut stores in the country, with a few offering 24-hour service. The rights are held by Sistemas Comestibles.
In 2020, urea derivative 3 (Table 1) was identified via high-throughput screening (HTS), as a competitive inhibitor of ERAP1 aminopeptidase activity (IC50 = 6.9 μM) with increased selectivity over ERAP2 and IRAP. SAR exploration and docking studies showed that the N-acetylpiperazine carbonyl group was critical for the activity via its zinc-binding group properties.
== Structure and reactivity == DBNPA is a halogenated cyanoacetamide compound, characterized by the presence of two bromine atoms at the 2,2-position of the carbon backbone. DBNPA contains a cyano (-CN) group and an amide (-CONH2) group attached to a three-carbon chain. The molecular formula is C3H2Br2N2O, with a molecular weight of 241.87 g/mol. DBNPA is highly reactive due to the two electron-withdrawing bromine atoms and a cyano (-CN) group attached to the central carbon backbone. These substituents form a very electron-deficient core, making it highly vulnerable to nucleophilic attacks. The cyano group increases the reactivity of the compound by stabilizing the electron deficiency while the amide (−CONH2) group affects its water solubility. The electron-deficient carbon adjacent to the bromine atoms plays a critical role in DBNPA’s biocidal properties, leading to the disruption of microbial cellular functions. Since DBNPA is a highly reactive molecule, it is prone to pH-dependent hydrolysis at neutral and alkaline conditions because of the weak carbon-bromide bonds. DBNPA is also susceptible to be broken down in reducing environments by stepwise debromination. Additionally, DBNPA is highly sensitive to ultraviolet (UV) exposure, which accelerates its degradation in aqueous environments. Due to its reactive nature, DBNPA must be stabilized in products to prevent premature degradation before application.
Sources: en.wikipedia.org
两者都是 GHS-R1a 激动剂，但 ipamorelin 在研究中显示出更高的生长激素释放选择性。早期资料显示它对皮质醇、催乳素与食欲的刺激弱于 GHRP-6。这些差异是相对程度，而非绝对区分。
公开资料中它主要以研究用肽的形式出现，未获主要监管机构批准用于治疗。可得材料通常标注仅供研究使用。任何临床用途的宣称都缺少监管依据。
序列中的 Aib 与 D-2-Nal 等非天然残基可提高对肽酶的抵抗能力，并影响受体结合的构象。这类修饰在合成肽设计中较为常见。它们也使常规氨基酸分析需要额外步骤才能确认序列。
Aib 即 α-氨基异丁酸，是一种非蛋白质源氨基酸，其侧链为两个甲基。它在肽链中倾向于诱导螺旋构象并限制骨架的柔性。这种刚性被认为有助于抵抗蛋白酶切割。