pentapeptide is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-12-10. Numbers and descriptions here follow the published literature rather than marketing material.
Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.
The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.
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。
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。
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with C-terminal amide |
| Average mass | Approximately 711.9 Da | Value derived from the formula |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and aqueous acetonitrile | Dissolution aided by acidic diluents |
| Common synonyms | Ipamorelin; NNC 26-0161 | Code name used in early reports |
Signal transduction begins when the peptide binds GHSR-1a on pituitary somatotrophs. The receptor couples to Gq/11 proteins, activating phospholipase C, which cleaves phosphatidylinositol bisphosphate into inositol trisphosphate and diacylglycerol. Inositol trisphosphate releases calcium from intracellular stores, and the resulting rise in cytosolic calcium drives growth hormone vesicle fusion. Concurrent Gs coupling and cyclic AMP elevation have also been reported, and the relative contribution of each arm to the overall secretory response is not fully settled.
Structural features distinguish the molecule from earlier secretagogues. An alpha-aminoisobutyric acid residue near the N-terminus and a D-naphthylalanine substitution increase receptor affinity, while C-terminal amidation improves resistance to exopeptidases. These modifications are associated with reduced stimulation of appetite and of the hypothalamic-pituitary-adrenal axis compared with hexarelin or growth hormone releasing peptide-6. Whether the same profile applies at every dose level studied is a matter of ongoing investigation rather than settled consensus.
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.
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.
Vegetable oils such as castor oil are typically unattractive alternatives to petroleum-derived lubricants because of their poor oxidative stability. Castor oil has better low-temperature viscosity properties and high-temperature lubrication than most vegetable oils, making it useful as a lubricant in jet, diesel, and racing engines. The viscosity of castor oil at 10 °C (50 °F) is 2,420 centipoise, but it tends to form gums in a short time, so its usefulness is limited to engines that are regularly rebuilt, such as racing engines. Lubricant company Castrol took its name from castor oil. Castor oil has been suggested as a lubricant for bicycle pumps because it does not degrade natural rubber seals.
=== Uses and importance to humans === Food crops Some aquatic plants are used by humans as a food source. Examples include wild rice (Zizania), water caltrop (Trapa natans), Chinese water chestnut (Eleocharis dulcis), Indian lotus (Nelumbo nucifera), water spinach (Ipomoea aquatica), prickly waterlily (Euryale ferox), and watercress (Rorippa nasturtium-aquaticum).
bioenergetics The branch of biochemistry and cell biology that studies the flow of energy through living systems, in particular how organisms acquire, produce, transform, and utilize energy in order to perform biochemical work such as metabolic reactions.
Sources: en.wikipedia.org
This reaction was hailed as a "revolution" and essentially started the distinct field of synthetic peptide chemistry. It remained unsurpassed in utility for peptide synthesis until the early 1950s when mixed anhydride and active ester methodologies were developed. Although the reaction is no longer commonly used for peptides, it is nonetheless very widespread for amine protection in other applications within organic synthesis and total synthesis. Common procedures to achieve protection starting from benzyl chloroformate include:
Glycine is not widely used in foods for its nutritional value, except in infusions. Instead, glycine's role in food chemistry is as a flavorant. It is mildly sweet, and it counters the aftertaste of saccharine. It also has preservative properties, perhaps owing to its complexation to metal ions. Metal glycinate complexes, e.g. copper(II) glycinate are used as supplements for animal feeds. As of 1971, the U.S. Food and Drug Administration "no longer regards glycine and its salts as generally recognized as safe for use in human food", and only permits food uses of glycine under certain conditions. Glycine has been researched for its potential to extend life. The proposed mechanisms of this effect are its ability to clear methionine from the body, and activating autophagy.
== Businesses and companies == SNOCAP, a content control technology company MHS Aviation (Germany) (ICAO airline code: MHV; IATA airline code: M2; callsign: SNOWCAP) German charter airline Snowcap Inn, Newry, Maine, USA; a hotel at the Sunday River (ski resort)
== Eighteenth century == During the 17th century, silk production in Calabria begin to suffer from competition by rising competitors elsewhere on the Italian Peninsula, France, and increasing imports from the Ottoman Empire and Persia. Following the War of the Spanish Succession, the Kingdom of Naples passed in 1707 to Austria, whose Emperor Charles VI of Habsburg added King of Naples to his titles: the Habsburgs, ruling for a short period, sought to modernize the kingdom's political structures. In 1732 Pope Clement XII founded the Italo-Albanian College and Library, transferred from San Benedetto Ullano to San Demetrio Corone in 1794.
Sources: en.wikipedia.org
== Development == Macrophages that reside in adult healthy tissues either derive from circulating monocytes or are established before birth and then maintained during adult life independently of monocytes. By contrast, most of the macrophages that accumulate at diseased sites typically derive from circulating monocytes. Leukocyte extravasation describes monocyte entry into damaged tissue through the endothelium of blood vessels as they become macrophages. Monocytes are attracted to a damaged site by chemical substances through chemotaxis, triggered by a range of stimuli including damaged cells, pathogens and cytokines released by macrophages already at the site. At some sites such as the testis, macrophages have been shown to populate the organ through proliferation. Unlike short-lived neutrophils, macrophages survive longer in the body, up to several months.
The diagnostic tests of ptaquiloside inside cells include gene mutation detection, immunohistochemical detection of tumor biomarkers, chromosomal aberrations, oxidative stress for EBH, PCR, real-time PCR and DNase-SISPA (sequence-independent single primer amplification).
== Other early lodges == On April 15, 1820, Cubans received news that Rafael del Riego and his Liberal constitutionalist movement was triumphant in Spain. Juan Manuel de Cagigal publicly swore his allegiance to the 1812 Constitution, after being forced to do so by regiments of the Spanish Army from Málaga and Catalonia. Only days after the announcement of the new situation in Spain, several Masonic Lodges and other secret societies that had been operating in secret began operating openly. They had large numbers, and during the era of the Liberal Triennium, they took advantage of the situation to establish more lodges.
== Cultural analogues == Akira Kurosawa's 1948 film Drunken Angel centers upon the efforts of Doctor Sanada, himself an alcoholic, to sustain a young gangster against tuberculosis, counseling him to abandon his self-destructive lifestyle. The character Dr. House, from the television series of the same name, can be considered as an example of this archetype in modern pop culture; his physical and emotional scars are both a burden and a driving force in his need to fix the problems of others while destroying himself. In East Coker, T. S. Eliot wrote "The wounded surgeon plies the steel/That questions the distempered part".
Cannabis (), commonly known as marijuana (), weed, pot, Mary Jane, and ganja, among other names, is a non-chemically uniform psychoactive drug from the Cannabis plant. Native to Central or South Asia, cannabis has been used as a drug for both recreational and entheogenic purposes and in various traditional medicines for centuries. Tetrahydrocannabinol (THC) is the main psychoactive component of cannabis, which is one of the 483 known compounds in the plant, including at least 65 other cannabinoids, such as cannabidiol (CBD). Cannabis can be used by smoking, vaporizing, within food, or as an extract. Cannabis has various mental and physical effects, which include euphoria, altered states of mind and sense of time, difficulty concentrating, impaired short-term memory, impaired body movement (balance and fine psychomotor control), relaxation, and an increase in appetite. Onset of effects is felt within minutes when smoked, but may take up to 90 minutes when eaten (as orally consumed drugs must be digested and absorbed). The effects last for two to six hours, depending on the amount used. At high doses, mental effects can include anxiety, delusions (including ideas of reference), hallucinations, panic, paranoia, and cannabis-induced psychotic disorder (CIPD). There is a strong relation between cannabis use and the risk of psychosis, though the direction of causality is debated.
Sources: en.wikipedia.org
It is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue. Three of its residues are non-standard amino acids, and the chain ends in an amide rather than a free acid. The molecule is small enough that it can be characterised by routine peptide analytical techniques.
It has not received marketing approval as a medicine in the United States or the European Union. Supplied material is generally described and handled as a research chemical. Regulatory treatment varies by jurisdiction, and some countries restrict growth hormone secretagogues under sports or medicines legislation.
Earlier secretagogues were associated with broader hormonal responses, including measurable changes in cortisol and prolactin. Reports on this peptide describe a narrower profile in which growth hormone release is the most prominent effect. The observation is influential because it shapes how the compound is compared with other members of the same receptor family.
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。