This is a working overview of deamidation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-23 and is reviewed periodically as new material appears.
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.
Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.
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.
Reversed-phase high-performance liquid chromatography is the standard tool for assessing purity. Detection near 214 nanometers captures the peptide backbone, and the resulting chromatogram shows the main peak alongside related impurities. Electrospray ionization mass spectrometry confirms molecular mass and supports sequence verification. Common degradation products include oxidized residues, deamidated forms, and truncated fragments, each appearing as a distinct peak or shoulder in the trace.
| 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 |
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, a structure that differs from natural ghrelin in length and in the presence of non-natural amino acid residues. Early laboratory work described it as a comparatively selective agent that stimulates growth hormone release with limited effect on other pituitary hormones. The compound is supplied as a lyophilized solid for research use and has no identified natural source in the body.
Activity is mediated mainly through the growth hormone secretagogue receptor, now generally called the ghrelin receptor or GHS-R1a. Binding at this G-protein-coupled receptor triggers phospholipase C signaling, calcium mobilization, and release of growth hormone from pituitary somatotrophs. Reports describe less pronounced stimulation of adrenocorticotropic hormone and prolactin compared with earlier secretagogues such as hexarelin or GHRP-6. Selectivity figures vary between assay systems, so the degree of separation from other secretagogues is an area of ongoing comparison rather than a fixed constant.
Only 249Bk is available in large quantities; it has a relatively short half-life of 330 days and emits mostly soft β-particles, which are inconvenient for detection. Its alpha radiation is rather weak (1.45×10−3% with respect to β-radiation), but is sometimes used to detect this isotope. 247Bk is an alpha-emitter with a long half-life of 1,380 years, but it is hard to obtain in appreciable quantities; it is not formed upon neutron irradiation of plutonium because β-decay of curium isotopes with mass number below 248 is not known. (247Cm would actually release energy by β-decaying to 247Bk, but this has never been seen.) The 20 isotopes of californium with mass numbers 237–256 are formed in nuclear reactors; californium-253 is a β-emitter and the rest are α-emitters. The isotopes with even mass numbers (250Cf, 252Cf and 254Cf) have a high rate of spontaneous fission, especially 254Cf of which 99.7% decays by spontaneous fission. Californium-249 has a relatively long half-life (352 years), weak spontaneous fission and strong γ-emission that facilitates its identification. 249Cf is not formed in large quantities in a nuclear reactor because of the slow β-decay of the parent isotope 249Bk and a large cross section of interaction with neutrons, but it can be accumulated in the isotopically pure form as the β-decay product of (pre-selected) 249Bk. Californium produced by reactor-irradiation of plutonium mostly consists of 250Cf and 252Cf, the latter being predominant for large neutron fluences, and its study is hindered by the strong neutron radiation.
=== Infectious hypotheses === One hypothesis suggests that prenatal viral infection may contribute to the development of autism. Prenatal exposure to rubella or cytomegalovirus activates the mother's immune response and may greatly increase the risk for autism in mice. Congenital rubella syndrome is the most convincing environmental cause of autism. Infection-associated immunological events in early pregnancy may affect neural development more than infections in late pregnancy, not only for autism, but also for psychiatric disorders of presumed neurodevelopmental origin, notably schizophrenia. A 2021 meta-analysis of 36 studies suggested a relationship between mothers recalling an infection during pregnancy and having children with autism.
In the United States domestic market, the chain fell to third place in terms of same-store sales behind Ohio-based Wendy's. The decline was the result of 11 consecutive quarters of same store sales decline. In August 2014, 3G announced that it planned to acquire the Canadian restaurant and coffee shop chain Tim Hortons and merge it with Burger King with backing from Warren Buffett's Berkshire Hathaway. The two chains retained separate operations post-merger, with Burger King remaining in its Miami headquarters. A Tim Hortons representative stated that the proposed merger would allow Tim Hortons to leverage Burger King's resources for international growth. The combined company became the third-largest international chain of fast food restaurants. The deal led to a controversy over the practice of tax inversions, in which a company decreases the amount of taxes it pays by moving its headquarters to a tax haven, a country with lower rates, but maintains the majority of their operations in their previous location. As a high-profile instance of tax inversion, news of the merger was criticized by U.S. politicians, who felt that the move would result in a loss of tax revenue to foreign interests, and could result in further government pressure against inversions. In 2019, Burger King reported that it planned to close up to 250 low-volume locations per year, with closures coming into effect in 2020. In February 2021, Burger King began testing a customer loyalty rewards program called "Royal Perks" in Los Angeles, Miami, New York City, New Jersey, and Long Island, New York.
Sources: en.wikipedia.org
== Legal and judicial figures == Richard Harison (1764), first U.S. attorney for the District of New York Peter van Schaack (1767), loyalist and attorney Abraham Van Vechten (1780s), two-time New York attorney general Anthony Bleecker (1791), lawyer and founding member of the New-York Historical Society Samuel Jones Jr. (1793), recorder of New York City; chancellor of New York; chief justice of the New York City Superior Court Augustus B. Woodward (1793), first chief justice of the Michigan Territory; one of the founders of the University of Michigan Thomas Phoenix (1795), New York County district attorney Pierre C. Van Wyck (1795), New York County district attorney; recorder of New York City William P. Van Ness (1797), judge on the United States District Court for the Southern District of New York Sampson Simson (1800), attorney, philanthropist, remembered as the "father of Mount Sinai Hospital" Alexander Hamilton Jr. (1804), son of Alexander Hamilton, attorney, soldier, and member of the New York State Assembly Hugh Maxwell (1808), New York County district attorney and Collector of the Port of New York Matthew C. Paterson (1809), New York County district attorney Ogden Hoffman (1812), former New York State attorney general, U.S. attorney for the Southern District of New York, and U.S. congressman from New York Frederic de Peyster (1819), New York attorney Theodore Sedgwick III (1829), U.S. attorney for the Southern District of New York Samuel Blatchford (1837), associate justice of the U.S.
=== Preventing and treating infection === To lower the bacterial count in wounds, therapists may use topical antibiotics, which kill bacteria and can also help by keeping the wound environment moist, which is important for speeding the healing of chronic wounds. Some researchers have experimented with the use of tea tree oil, an antibacterial agent which also has anti-inflammatory effects. Disinfectants are contraindicated because they damage tissues and delay wound contraction. Further, they are rendered ineffective by organic matter in wounds like blood and exudate and are thus not useful in open wounds. A greater amount of exudate and necrotic tissue in a wound increases likelihood of infection by serving as a medium for bacterial growth away from the host's defenses. Since bacteria thrive on dead tissue, wounds are often surgically debrided to remove the devitalized tissue. Debridement and drainage of wound fluid are an especially important part of the treatment for diabetic ulcers, which may create the need for amputation if infection gets out of control. Mechanical removal of bacteria and devitalized tissue is also the idea behind wound irrigation, which is accomplished using pulsed lavage. Removing necrotic or devitalized tissue is also the aim of maggot therapy, the intentional introduction by a health care practitioner of live, disinfected maggots into non-healing wounds. Maggots dissolve only necrotic, infected tissue; disinfect the wound by killing bacteria; and stimulate wound healing.
== Side-effects == Many of the side effects of abciximab are due to its anti-platelet effects which increase the risk of bleeding. The most common type of bleeding due to abciximab is gastrointestinal hemorrhage. Thrombocytopenia is a rare but known serious risk characterized by a severe drop in platelets circulating in the blood. Abciximab induced thrombocytopenia is usually rapid occurring hours after administration but may occur up to 16 days later. Transfusing platelets is the only known treatment for abciximab-induced thrombocytopenia, but this therapy may have limited effectiveness because the drug may bind and inhibit the receptors on the newly transfused platelets.
Sources: en.wikipedia.org
On July 16, 1945, the first atomic bomb test took place near the town of Alamogordo (New Mexico, USA). As a result of the atmospheric nuclear weapons tests carried out by the United States, the Soviet Union, France, Great Britain, and China, the Earth's atmosphere became increasingly contaminated with fission products from these tests from the 1950s onwards. The radioactive fallout landed on the earth's surface and ended up in plants and, via animal feed, in food of animal origin. Ultimately, they entered the human body and could be detected in bones and teeth as strontium-90, among other things. The radioactivity in the field was measured with a gamma scope, as shown at the air raid equipment exhibition in Bad Godesberg in 1954. Around 180 tests were carried out in 1962 alone. The extent of the radioactive contamination of the food sparked worldwide protests in the early 1960s.
== Conservation == Parmotrema perlatum has been identified as a species of concern in some regions due to its rarity and declining populations. In Hungary, it has been proposed for 'endangered' status in the Hungarian lichen red list, reflecting its limited distribution and the pressures it faces in its natural habitats there. Similarly, in Ukraine, the species is listed in the Red Data Book of Ukraine with the status of "Rare". Additionally, Parmotrema perlatum is red-listed in Sweden In northern North America, its NatureServe conservation status is designated as "G4", meaning "apparently secure" at the global level. In the United States, it has been assessed as secure in Kentucky and presumed extirpated in Wisconsin, while in Canada, it is considered as vulnerable in British Columbia and Ontario, and critically imperiled in New Brunswick.
== Pharmacokinetics == Following single or multiple intravenous infusions, the majority of drug elimination occurred within 24 hours of intravenous administration. Elimination half-life of eteplirsen was 3 to 4 hours.
Nick Coatsworth is an Australian infectious diseases expert. He was Australia's deputy chief medical officer during the early years of the COVID-19 pandemic, when he regularly appeared in print and on radio and television to provide the public with information. He is Nine Network's medical expert and presents the television show Do You Want to Live Forever? with Tracy Grimshaw.
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.
Keep the powder dry, protected from light, and at minus 20 degrees Celsius or lower. A desiccant and a sealed vial limit moisture uptake. Let the vial reach room temperature before opening to reduce condensation.