If you have been reading about 五肽 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 2025-09-01. Numbers and descriptions here follow the published literature rather than marketing material.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Researchers at a pharmaceutical company first described it in the 1990s while screening small peptides for growth hormone releasing activity. Its chain contains five amino acid residues, two of which are non-natural building blocks, including 2-aminoisobutyric acid and a naphthylalanine derivative. The molecule was designed to act at the ghrelin receptor while avoiding several effects observed with earlier secretagogues.
At the cellular level, ipamorelin binds the growth hormone secretagogue receptor, also called the ghrelin receptor. Activation of this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to release of growth hormone into circulation. Because release follows a pulsatile pattern, studies often report peak concentration and total area under the curve rather than a single time point. Selectivity for this receptor is the property most frequently discussed in comparative work.
在机制层面，ipamorelin 与生长激素促分泌受体 1a 型结合，该受体也介导胃饥饿素的多种效应。受体激活后，细胞内信号促进生长激素从垂体前叶释放。由于对促肾上腺皮质激素和皮质醇的刺激较弱，它被视为选择性较高的促分泌剂。这种选择性在动物模型和少量人体研究中被观察到，但人体数据仍然有限。
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic pentapeptide | Growth hormone secretagogue family |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Contains two non-natural residues |
| Molecular formula | C38H49N9O5 | Free base form |
| Molecular weight | 711.85 g/mol | Calculated from formula |
| Primary target | GHS-R1a ghrelin receptor | Agonist activity |
Quality claims for research peptides vary widely across suppliers. A certificate of analysis should list purity by chromatography, the mass found by spectrometry, and the analytical conditions used. Independent testing at a third-party laboratory is a common way to check identity and purity, because documents alone cannot confirm what is inside a vial. Purity figures describe the proportion of the target peptide among detected species, and they say nothing about biological activity or sterility.
Lyophilized ipamorelin powder is the form usually supplied for laboratory work. Kept dry, protected from light, and held at minus 20 degrees Celsius or below, it remains stable for extended periods, often measured in years. Once dissolved, the peptide degrades faster through hydrolysis, oxidation, and deamidation, so solutions are typically refrigerated and used within weeks. Repeated freeze-thaw cycles and exposure to alkaline conditions accelerate loss of the parent compound.
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.
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。
在 GHS 家族中，早期肽类如 GHRP-6 与 GHRP-2 会同时促进生长激素、皮质醇与催乳素的释放，并明显增加食欲。Ipamorelin 在动物与早期人体研究中表现出对生长激素释放的相对选择性，对上述其他激素的影响较小。这种差异通常归因于受体结合模式与下游信号偏向的不同，而完整的分子解释仍有待补充。需要区分的是，选择性是研究观察中的相对程度，并非绝对界限。
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
Quality control for research-grade ipamorelin is not governed by a single harmonized pharmacopeial monograph, so certificates of analysis vary between suppliers. Common tests include appearance, solubility, water content, peptide content by quantitative amino acid analysis, and residual counterion measurement. Independent verification by an outside laboratory is often used to confirm identity and purity claims. Salt form, counterion content, and residual solvent levels are frequently unspecified, which complicates direct comparison between lots and leaves reproducibility partly unresolved.
== Career and research == Williams then spent another period back at Merton, having won a junior research fellowship, Then, “out of the blue, in 1954, Cyril Hinshelwood, then Oxford Professor of Chemistry, asked to see Bob.” He was told that three colleges—Christ Church, Pembroke and Wadham—needed a tutor in chemistry. “Each one will invite you to dine. Come back again in two weeks to give me your decision.” Williams joined Wadham College, Oxford in 1955 and remained there for the rest of his life. His doctoral students include Peter Day, Carole Perry and Michael Thor Pope. William's work in pure inorganic chemistry led to a two-volume textbook of inorganic chemistry, written with Courtenay Phillips, He became increasingly interested in enzyme catalysis, and in particular the role of metal ions, as for example the role of copper in proteins. He and Bert Vallee proposed of the concept of the entatic state whereby atoms and groups in enzyme active sites are maintained by binding to the apoenzyme in positions and states appropriate to catalyse reactions. In the first paper ever published in the Journal of Theoretical Biology Williams argued that spatial separation of the H+ and OH– ions produced in the conversion of ATP to ADP would be necessary for the catalysis. In the same year Peter Mitchell proposed a similar idea in the form of the chemiosmotic hypothesis. In a special issue of the Journal of Theoretical Biology in celebration of 50 years of its existence Williams described the correspondence between Mitchell and himself.
=== Hydrogen Isotope Analysis === Hydrogen isotope analysis is used to help reconstruct environmental change. Dinosterol is a particularly good target for such analysis because it is commonly found in high concentrations in a variety of aquatic environments and is well preserved in the sediment record. Hydrogen isotope analysis requires a purification method that achieves GC baseline resolution and is high yielding. Dinosterol coelutes with other sterols during GC; therefore a procedure for proper purification that involves reversed phase-high performance liquid chromatography (RP-HPLC) was developed by Atwood et al. The hydrogen isotope ratios in dinosterol can be used to reconstruct salinity semi-quantitatively. In a study by Schwab et al., the hydrogen isotope ratio of dinosterol was measured in suspended particles and surface sediments from the Chesapeake Bay estuary. The D/H ratio was found to decrease by 0.99 ± 0.23% per unit increase in salinity over the salinity range 10–29 PSU. The correlation between hydrogen isotopic response and salinity may result from diminished exchange of water between algal cells and their environment, lower growth rates and/or increased production of osmolytes at high salinities.
==== Officer of the Order of the British Empire (OBE) ==== Military Commander Trefor Morgan Fox, Royal Navy, C037045S. Commander Christopher Robert Hollingworth, Royal Navy, C041543F. Colonel Andrew Glenn David Lock, Royal Marines, N029023U. Commander Lucy Jane Ottley, Royal Navy, V030919T. Commander Ian Hayden Richardson, Royal Navy, C038366T. Commander Jamie Duncan Wells, Royal Navy, C039514F. Captain Allan Thomas Youp, Royal Navy, C038889U. Lieutenant Colonel Nicholas Paul Andrew, Royal Regiment of Artillery, 537949. Lieutenant Colonel Tracy-Louise Appleyard, Royal Army Medical Corps, 540495. Colonel Edward Hugh James Carter, 532335. Lieutenant Colonel Ewan Christian Noble Harris, The Royal Welsh, 545550. Lieutenant Colonel Timothy Matthew Holmes, Corps of Royal Electrical and Mechanical Engineers, 546527. Colonel Matthew Gordon Timothy Lewis, 554319. Lieutenant Colonel (now Acting Colonel) John Andrew Lyons, Royal Corps of Signals, 549561. Lieutenant Colonel Craig David Pope, Royal Army Medical Corps, 549180. Colonel Nigel Offley Crewe-Read, , 545207. Colonel Thomas Woolley, 551152. Colonel Nicholas George Charles Yardley, 544447. Wing Commander Erica Jane Ferguson, Royal Air Force, 2629012K. Wing Commander Matthew Elfed Lewis, Royal Air Force, 5208143G. Wing Commander Stephen McCleery, Royal Air Force, 2635078L. Wing Commander Alison Morton, Royal Air Force, W996632T. Air Commodore Patrick James Shea-Simonds, Royal Air Force, 5208323H. Group Captain Paul Andrew Weaver Smith, Royal Air Force, 8024057B.
Previously, there had been no detailed descriptions of their spectral properties in peer-reviewed general scientific literature. A small amount of agent A-230 was also claimed to have been synthesised in the Czech Republic in 2017 for the purpose of obtaining analytical data to help defend against these novel toxic compounds. The Soviet Union and Russia reportedly developed extremely potent fourth-generation chemical weapons from the 1970s until the early 1990s, according to a publication by two chemists, Lev Fyodorov and Vil Mirzayanov, in Moskovskiye Novosti weekly in 1992. The publication appeared just on the eve of Russia's signing of the Chemical Weapons Convention. According to Mirzayanov, the Russian Military Chemical Complex (MCC) was using defence conversion money received from the West for development of a chemical warfare facility. Mirzayanov made his disclosure out of environmental concerns. He was the head of a counter-intelligence department and performed measurements outside the chemical weapons facilities to make sure that foreign spies could not detect any traces of production. To his horror, the levels of deadly substances were eighty times greater than the maximum safe concentration. The Prosecutor-General of Russia effectively admitted the existence of Novichok agents when he brought a treason case against Mirzayanov. According to expert witness testimonies that three scientists prepared for the KGB, Novichok and other related chemical agents had indeed been produced and therefore Mirzayanov's disclosure represented high treason.
Sources: en.wikipedia.org
BMR (Males) in Kcals/day = 88.36 + 13.40 (weight in kg) + 4.8 (height in cm) – 5.68 (age in years) BMR (Females) in Kcals/day = 447.59 + 9.25 (weight in kg) + 3.10 (height in cm) – 4.33 (age in years) The Mifflin St. Jeor Equation is as follows:
History of sonochemistry – history of the study of the effect of sonic waves and wave properties on chemical systems. History of stereochemistry – history of the study of the relative spatial arrangement of atoms within molecules. History of supramolecular chemistry – history of the area of chemistry beyond the molecules and focuses on the chemical systems made up of a discrete number of assembled molecular subunits or components. History of thermochemistry – history of the study of energy and heat associated with chemical reactions and/or physical transformations. History of phytochemistry – history of the study of phytochemicals. History of polymer chemistry – history of the multidisciplinary science that deals with the chemical synthesis and chemical properties of polymers or macromolecules. History of solid-state chemistry – history of the study of the synthesis, structure, and properties of solid phase materials, particularly, but not necessarily exclusively of, non-molecular solids History of multidisciplinary fields involving chemistry: History of chemical biology – history of the scientific discipline spanning the fields of chemistry and biology that involves the application of chemical techniques and tools, often compounds produced through synthetic chemistry, to the study and manipulation of biological systems. History of chemical oceanography – history of the study of the behavior of chemical elements within the Earth's oceans.
== Genome and genetics == H. influenzae was the first free-living organism to have its entire genome sequenced. The sequencing was completed in 1995 by Craig Venter and his team at the Institute for Genomic Research, now part of the J. Craig Venter Institute. Haemophilus was chosen because one of the project leaders, Nobel laureate Hamilton Smith, had been working on it for decades and was able to provide high-quality DNA libraries. The sequencing method used was whole-genome shotgun, which was completed and published in Science in 1995. The genome of strain Rd KW20 consists of 1,830,138 base pairs of DNA in a single circular chromosome that contains 1604 protein-coding genes, 117 pseudogenes, 57 tRNA genes, and 23 other RNA genes. About 90% of the genes have homologs in E. coli, another gamma-proteobacterium. In fact, the similarity between genes of the two species ranges from 18% to 98% protein sequence identity, with the majority sharing 40–80% of their amino acids (with an average of 59%). Conjugative plasmids (DNA molecules that are capable of horizontal transfer between different species of bacteria) can frequently be found in H. influenzae. It is common that the F+ plasmid of a competent Escherichia coli bacterium conjugates into the H. influenzae bacterium, which then allows the plasmid to transfer among H. influenzae strands via conjugation.
The electricity production in Colombia comes mainly from Renewable energy sources. 69.93% is obtained from the hydroelectric generation. Colombia's commitment to renewable energy was recognized in the 2014 Global Green Economy Index (GGEI), ranking among the top 10 nations in the world in terms of greening efficiency sectors.
=== Lamellar keratoplasty === Lamellar keratoplasty encompasses several techniques which selectively replace diseased layers of the cornea while leaving healthy layers in place. The chief advantage is improved tectonic integrity of the eye. Disadvantages include the technically challenging nature of these procedures, which replace portions of a structure only 500 μm thick, and reduced optical performance of the donor/recipient interface compared to full-thickness keratoplasty.
Sources: en.wikipedia.org
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.
It acts as an agonist at the growth hormone secretagogue receptor, also known as the ghrelin receptor. Binding at pituitary somatotroph cells promotes growth hormone release.
Early studies report weaker effects on cortisol, prolactin, and appetite than compounds such as GHRP-6. The size of that difference in humans is not firmly established.
不是。它属于人工合成的五肽，设计上模拟胃饥饿素受体的部分作用，但不存在于人体天然激素谱中。