This is a working overview of deamidation, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-18. Anything still debated is marked as such rather than presented as settled.
Lyophilized material is generally held at minus 20 degrees Celsius or colder for long-term storage, protected from moisture and light. Solutions are handled under refrigeration, typically between 2 and 8 degrees Celsius, and used within a short window because degradation and microbial growth both accelerate in liquid. Repeated freeze-thaw cycles are avoided, and vials are equilibrated to room temperature before opening to reduce condensation. These are general laboratory conventions for peptides of this size rather than product-specific directions.
Characterization panels may add amino acid analysis for compositional confirmation, circular dichroism for secondary structure in solution, and light scattering for aggregation tendency. Aggregation is a central concern for peptides bearing hydrophobic side chains, since it can lower measured potency and complicate accurate dosing. Stability studies examine temperature, humidity, pH, and light exposure over defined intervals, reporting the percentage of intact peptide remaining. Results depend strongly on the assay used, so comparing values across studies requires matching method details.
Peptide content and purity are commonly measured by reversed-phase high-performance liquid chromatography with ultraviolet detection, using gradient elution over a C18 column. Identity is confirmed by mass spectrometry, because the theoretical monoisotopic mass allows unambiguous assignment of the main component. Impurity profiling resolves deletion sequences, oxidized residues, and truncated fragments. Since the molecule carries a lipophilic side chain, mobile phases often include ion-pairing agents and organic modifiers to keep peaks symmetric.
Clinical development has advanced through phase 2 trials in adults with obesity and type 2 diabetes. Reported phase 2 results described substantial average weight reduction over roughly forty-eight weeks of weekly dosing. A phase 3 program is ongoing to confirm efficacy and assess long-term safety. Because the compound has not received regulatory approval, it is not available as a prescription product. Public discussion of retatrutide often conflates trial findings with marketed status, an important distinction when interpreting coverage of the topic.
Retatrutide is a synthetic peptide developed as a single molecule that activates three distinct hormone receptors: GLP-1, GIP, and glucagon. The compound carries the internal designation LY3437943 and was engineered by modifying the backbone of glucose-dependent insulinotropic polypeptide. Its sequence incorporates non-natural amino acids and a fatty acid side chain that extends circulation time. The triple-agonist design aims to combine appetite suppression, improved insulin response, and increased energy expenditure in one agent. Published reports describe it as an investigational product rather than an approved medicine.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid, appearance varies by batch |
| Solubility | Soluble in water | Also dissolves in aqueous buffer; side chain alters behavior |
| Storage, dry powder | Minus 20 degrees Celsius or below | Desiccated and protected from light |
| Storage, in solution | 2 to 8 degrees Celsius | Short term only; avoid repeated freeze-thaw |
| Primary assay | Reversed-phase HPLC | Frequently paired with mass spectrometry |
Identity and purity are established with reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatographic profiles reveal related impurities, truncated sequences, and oxidation products, while mass measurement confirms the expected molecular mass. Purity values for research material are typically reported as a percentage by peak area. Reference standards help calibrate retention behavior across instruments. Independent laboratories emphasize method suitability because results depend heavily on column chemistry, gradient, and detection wavelength. Batch-to-batch comparison relies on the same validated method.
Investigational peptide material is commonly distributed as a lyophilized powder in sealed vials. The solid form appears as a white to off-white cake or powder and is hygroscopic once opened. Peptides of this size are sensitive to moisture, repeated freeze-thaw cycles, and prolonged exposure to ambient light. Handling practices therefore emphasize desiccation, minimal vial opening, and cold storage. Working aliquots are often prepared to avoid repeatedly warming the bulk container.
Pharmacologically the compound activates three receptors: GLP-1, GIP, and glucagon. GLP-1 and GIP signaling contribute to glucose-dependent insulin release, delayed gastric emptying, and reduced appetite, while glucagon receptor activation is associated with increased energy expenditure and hepatic fat oxidation. The single-molecule design is intended to keep these activities in one peptide rather than combining separate agents. Relative activity at each receptor differs, and the balance between them is a central question in interpretation. The glucagon component is partly offset by incretin-mediated insulin secretion, an interaction that remains incompletely characterized.
Development has progressed from single- and multiple-ascending-dose studies in healthy volunteers into larger randomized trials in adults with obesity, type 2 diabetes, and fatty liver disease. Early reports describe dose-dependent reductions in body weight and improvements in glycemic markers over treatment periods of several months. Whether the glucagon arm adds tolerability cost without added benefit is still debated. Long-term cardiovascular outcomes, effects after treatment stops, and performance in older or comorbid populations are open questions rather than settled findings. Approval status may change, so the current investigational label should be confirmed against regulatory sources.
Retatrutide is an investigational synthetic peptide developed under the code LY3437943, with a backbone derived from glucose-dependent insulinotropic polypeptide. Several non-proteinogenic residues, including alpha-aminoisobutyric acid, appear in that backbone, and a fatty diacid side chain attached through a linker extends circulation time. The molecule carries roughly thirty-nine amino acid units and a total mass near 4.7 kilodaltons. Administration is by subcutaneous injection once weekly. Published work uses both the name retatrutide and the code LY3437943.
Quality control of research material relies on several complementary checks. Purity testing confirms the absence of truncated or oxidized peptide species, while water content and counterion analysis show how much mass comes from salts rather than the peptide itself. Sequence verification through tandem mass spectrometry ensures the correct amino acid chain. Because unregulated suppliers vary widely, independent verification of identity and purity is often necessary before a sample enters experiments.
Documentation plays a practical role in maintaining consistent results across laboratories. Certificates of analysis list purity, identity, and testing methods, and batch numbers allow comparisons between lots. Records of storage temperature and handling history help investigators interpret unexpected findings. When a sample behaves anomalously, reviewing that documentation often reveals whether the cause lies in the material or in the assay conditions.
Peptides in this class degrade mainly through hydrolysis, oxidation, and aggregation. The lipid modification improves plasma residence time but can also promote self-association in aqueous solution at higher concentrations. Oxidation of methionine and deamidation of asparagine residues are common chemical liabilities that accumulate during storage. Stability studies therefore track purity loss, aggregate formation, and changes in receptor-binding potency over time under defined temperature and humidity conditions.
Solid peptide is generally held as a lyophilised powder at low temperature to slow degradation, with desiccant to limit moisture uptake. Reconstituted solutions are less stable and are usually kept refrigerated and protected from light for short periods. Repeated freeze-thaw cycles are avoided because they encourage aggregation. Laboratory handling includes work in a fume hood or laminar flow cabinet to limit inhalation and contamination. Weighing and transfer steps are performed with antistatic tools to reduce static-driven loss of fine powder.
==== Comparison ==== Spironolactone, the 5α-reductase inhibitor finasteride, and the nonsteroidal antiandrogen flutamide all appear to have similar effectiveness in the treatment of hirsutism. Some clinical research, though, has found that the effectiveness of spironolactone for hirsutism is greater than that of finasteride, but is less than that of flutamide. The combination of spironolactone with finasteride is more effective than either alone for hirsutism and the combination of spironolactone with a birth-control pill is more effective than a birth-control pill alone. One study showed that spironolactone or the steroidal antiandrogen cyproterone acetate both in combination with a birth-control pill had equivalent effectiveness for hirsutism. Spironolactone is considered to be a first-line treatment for hirsutism, finasteride and the steroidal antiandrogen cyproterone acetate are considered to be second-line treatments, and flutamide is no longer recommended for hirsutism due to liver toxicity concerns. The nonsteroidal antiandrogen bicalutamide is an alternative option to flutamide with improved safety. The combination of spironolactone with a birth-control pill in the treatment of acne appears to have similar effectiveness to a birth-control pill alone and the combination of a birth-control pill with cyproterone acetate, flutamide, or finasteride. However, this was based on low- to very low-quality evidence.
=== 24 April === Russian forces stopped an attack on the Black Sea Fleet base at Sevastopol. The Russian defence ministry said that "three unmanned high-speed boats" were destroyed. Ukraine did not comment on the attack.
Fujirebio is a Japanese multinational in vitro diagnostics (IVD) company, founded in 1950 and headquartered in Tokyo, Japan. The company develops, manufactures, and markets IVD testing products — including reagents, instruments, and software — for clinical diagnostics and research use. Fujirebio operates offices in Asia, Europe, and the United States, and maintains a broad international distribution network, with manufacturing facilities in Japan, Europe, and the United States. The company employs more than 1,400 people globally. Fujirebio operates an open business model in which it develops novel biomarkers and diagnostic content, validates them using its own fully-automated Lumipulse® chemiluminescent enzyme immunoassay (CLEIA) platform, and distributes them globally through partnerships and a Contract Development and Manufacturing Organization (CDMO) model — providing development, manufacturing, and regulatory services to third-party diagnostic companies. The company’s principal areas of expertise include oncology, infectious diseases, and neurological disorders. In May 2025, Fujirebio received FDA 510(k) clearance for the Lumipulse® G pTau 217/β-Amyloid 1-42 Plasma Ratio test, the first FDA-cleared blood-based IVD test to aid in identifying amyloid pathology associated with Alzheimer’s disease. In 2022, Fujirebio acquired ADx NeuroSciences, a Belgian biotech company specializing in neurological biomarker research, for €40 million. Fujirebio is a consolidated subsidiary of H.U. Group Holdings, Inc.
Levorphanol's exceptionally high analgesic efficacy in the treatment of neuropathic pain is also conferred by its action on serotonin and norepinephrine transporters, similar to the opioids tramadol and tapentadol, and mutually complements the analgesic effect of its NMDA receptor antagonism. Levorphanol shows a high rate of psychotomimetic side effects such as hallucinations and delirium, which have been attributed to its binding to and activation of the KOR. At the same time however, activation of this receptor as well as of the DOR have been determined to contribute to its analgesic effects.
==== Gas foaming ==== To overcome the need to use organic solvents and solid porogens, a technique using gas as a porogen has been developed. First, disc-shaped structures made of the desired polymer are prepared by means of compression molding using a heated mold. The discs are then placed in a chamber where they are exposed to high pressure CO2 for several days. The pressure inside the chamber is gradually restored to atmospheric levels. During this procedure the pores are formed by the carbon dioxide molecules that abandon the polymer, resulting in a sponge-like structure. The main problems resulting from such a technique are caused by the excessive heat used during compression molding (which prohibits the incorporation of any temperature labile material into the polymer matrix) and by the fact that the pores do not form an interconnected structure.
Sources: en.wikipedia.org
A July 2016 study in The Lancet Psychiatry reported that nearly half of transgender people surveyed undertook body-altering procedures without medical supervision. Transition-related care is not covered under Mexico's national health plan. Only one public health institution in Mexico provides free hormones for transgender people. Health care for transgender Mexicans focuses on HIV and prevention of other sexually transmitted diseases. The Lancet study also found that many transgender Mexicans have physical health problems due to living on the margins of society. The authors of the study recommended that the World Health Organization declassify transgender identity as a mental disorder, to reduce stigma against this population. In June 2020, the Mexican federal government released "The Protocol for Access without Discrimination to Health Care Services for Lesbian, Gay, Bisexual, Transsexual, Transvestite, Transgender, and Intersex Persons and Specific Care Guidelines." The guidelines are used in healthcare facilities administered by the government. The guidelines state that the process of identifying one's sexual orientation, gender identify and/or expression can occur at early ages. Thus, the guidelines recommend that medical facilities and doctors consider the use of puberty blockers and cross-sex hormones as a treatment for transgender minors when appropriate. In addition to the guidelines, multiple Mexican states have modified their civil codes to recognize gender-affirming healthcare as a right for transgender people under the age of eighteen.
Surveillance studies from 2005 and later show the estimated global incidence is 1–2 cases per million population per year. Sporadic CJD (sCJD) incidence increased from the years 1990–2018 in the UK. Probable or definite sCJD deaths also increased from the years 1996–2018 in twelve additional countries. CJD incidence is greatest in those over the age of 55 years old, with an average age of 67 years old. The intensity of CJD surveillance increases the number of reported cases, often in countries where CJD epidemics have occurred in the past and where surveillance resources are greatest. An increase in surveillance and reporting of CJD is most likely in response to BSE and vCJD. Possible factors contributing to an increase in CJD incidence are an aging population, population increase, clinician awareness, and more accurate diagnostic methods. Since CJD symptoms are similar to other neurological conditions, it is also possible that CJD is mistaken for stroke, acute nephropathy, general dementia, and hyperparathyroidism.
The key intermediate, normeperidine, is obtained by a scheme closely akin to the parent molecule. Thus, alkylation of benzyl cyanide (1) with the tosyl analog of the bischloroethylamine (2) leads to the substituted piperidine (3). Basic hydrolysis serves to convert the nitrile to the acid (4). Treatment of this last with sulfuric acid in ethanol serves both to esterify the acid and to remove the tosyl group to yield the secondary amine (5). Alkylation of that amine by means of N-(2-chloroethyl)morpholine gives morpheridine.
=== Antimineralocorticoid activity === Progesterone is a potent antimineralocorticoid. It has 1000% of the affinity of aldosterone, the major endogenous agonist, for the human MR, and 100% of the affinity of aldosterone for the rat MR. Progesterone produces antimineralocorticoid effects such as natriuresis (excretion of sodium in the urine) at normal physiological concentrations. A 200 mg dose of oral progesterone is considered to be approximately equivalent in antimineralocorticoid effect to a 25 to 50 mg dose of the potent antimineralocorticoid spironolactone, which itself is a derivative of progesterone. Doses of progesterone of 50 to 200 mg by intramuscular injection, which are similar to progesterone exposure in the third trimester of pregnancy, have also been reported to produce antimineralocorticoid-like effects. The antimineralocorticoid effects of progesterone underlie its ability to lower blood pressure and reduce water and salt retention and its potential application in the treatment of hypertension. An active metabolite of progesterone, 11-deoxycorticosterone (21-hydroxyprogesterone), is a precursor of aldosterone and has strong mineralocorticoid activity (i.e., is a strong agonist of the MR). However, it is formed in relatively small amounts, and any such effects produced by it are usually outweighed by the antimineralocorticoid activity of progesterone. Progesterone may be a relatively weak antimineralocorticoid in vivo.
Dominion Voting Systems announces that they have sued Fox Corporation and Fox Broadcasting Company, the parent company of Fox News, for defamation and for failing to preserve documents relating to the role Rupert Murdoch played in spreading false claims about Dominion. November 9 – The South Dakota Legislature votes to consider the impeachment of Attorney General Jason Ravnsborg. November 11 – Vice President Harris travels to Paris to deliver a speech at the Paris Peace Forum. November 12 – United States Attorney General Merrick Garland announces that former White House Chief Strategist Steve Bannon has been charged by the Department of Justice for refusing to testify to the January 6 select committee investigating the Capitol riot and refusing to provide documents requested by the committee. Bannon turned himself in to the FBI three days later. November 13 – While speaking before a "ReAwaken America" audience in November 2021, Former Trump National Security Advisor Michael Flynn said, "If we are going to have one nation under God, which we must, we have to have one religion. One nation under God, and one religion under God." causing some outrage. November 15 Radio host and conspiracy theorist Alex Jones is found liable for damages in lawsuits brought by parents of children killed in the Sandy Hook elementary school shooting, over Jones's false claim the massacre was a hoax. President Biden signs the Infrastructure Investment and Jobs Act into law. November 16 – Maryland reports their first case of monkeypox in a resident who traveled from Nigeria. November 17 – The U.S.
Sources: en.wikipedia.org
X-ray crystallography: This technique allows for the 3D determination of molecular structures. Various forms of spectroscopy: Ultraviolet-visible spectroscopy: Historically, this has been an important tool, since many inorganic compounds are strongly colored NMR spectroscopy: Besides 1H and 13C many other NMR-active nuclei (e.g., 11B, 19F, 31P, and 195Pt) can give important information on compound properties and structure. The NMR of paramagnetic species can provide important structural information. Proton (1H) NMR is also important because the light hydrogen nucleus is not easily detected by X-ray crystallography. Infrared spectroscopy: Mostly for absorptions from carbonyl ligands Electron nuclear double resonance (ENDOR) spectroscopy Mössbauer spectroscopy Electron-spin resonance: ESR (or EPR) allows for the measurement of the environment of paramagnetic metal centres. Electrochemistry: Cyclic voltammetry and related techniques probe the redox characteristics of compounds.
The UK quits the Energy Charter Treaty, which had allowed fossil fuel companies to sue governments over profits lost in the drive towards net zero. Data from the Office for National Statistics shows a surplus in government finances of £16.7bn in January 2024, more than double the figure for January 2023. 22 February More than 60 MPs have signed a House of Commons motion calling for the resignation of Speaker Sir Lindsay Hoyle. A further 50 sanctions against Russia are announced, aimed at restricting those supplying its military with munitions such as rocket launchers, missiles and explosives. Employees of a company contracted by the Home Office are suspended after a baby's birth certificate was returned to the parents with the place of birth, Israel, crossed out. The UK government announces that legislation will be introduced to clear hundreds of sub-postmasters in England and Wales who were wrongly convicted as a result of the Horizon IT scandal. 23 February Thousands of people in the Keyham area of Plymouth, Devon are evacuated as an unexploded World War II bomb is moved by military convoy for disposal at sea. The bomb was discovered in a garden three days prior. This is also the first time that the UK Emergency Alert System is used in a live situation. Ofgem confirms that the average annual energy bill will fall by £238 from April to £1,690, its lowest rate for two years. Shamima Begum loses her legal bid to overturn the decision to revoke her UK citizenship. Ibrahima Bah is sentenced to nine years and six months in prison.
== Relation to humans == Arapaima is exploited in many ways by local human populations. Its tongue is thought to have medicinal qualities in South America. It is dried and combined with guarana bark, which is grated and mixed into water. Doses are given to kill intestinal worms. The bony tongue is used to scrape cylinders of dried guarana, an ingredient in some beverages, and the bony scales are used as nail files. Arapaima produce boneless steaks and are considered a delicacy. In the Amazon region, locals often salt and dry the meat, rolling it into a cigar-style package that is then tied and can be stored without rotting, which is important in a region with little refrigeration. Arapaima are referred to as the "cod of the Amazon", and can be prepared in the same way as traditional salted cod. Designers have begun using the skin of the arapaima as leather to make jackets, shoes, and handbags, and to cover furniture. In July 2009, villagers around Kenyir Lake in Terengganu, Malaysia, reported sighting A. gigas. The "Kenyir monster", or "dragon fish" as the locals call it, was claimed to be responsible for the mysterious drowning of two men on 17 June. In August 2018, India Times reported that arapaima has been spotted in the Chalakudy River, following floods in Kerala; their presence in India is attributed to illegal importation for fish farming. The arapaima is depicted on both the flag and the seal of the Department of Ucayali, Peru.
=== Urinary preparations === Purified urinary FSH (75 IU FSH and ≤ 2 IU of LH) Generic urofollitropin for injection, purified. Brands Bravelle, U.S., (≤ 2 IU LH) Metrodin, U.S. and Canada, (≤ 1 IU LH) Fertinorm Hp, (Canada) Highly purified urinary FSH (75 IU FSH and ≤ 0.1 IU LH/1000 IU FSH) Generic urofollitropin for injection, (highly) purified. Brands Fertinex (≤ 0.1 IU LH/1000 IU FSH)
Sources: en.wikipedia.org
Reversed-phase liquid chromatography with ultraviolet detection is the standard approach, reported as area percent of the main peak. Orthogonal methods such as mass spectrometry confirm that the main peak has the expected mass. Purity figures are only comparable when column, gradient, and wavelength are matched.
Dry powder is usually kept at minus 20 degrees Celsius or below in a sealed, desiccated container. Once dissolved, material is refrigerated and used quickly. These conventions apply to research-grade peptides generally, not to a specific marketed product.
Chromatography separates components but does not confirm what they are. Mass spectrometry assigns a mass to each peak, which identifies the target peptide and flags modifications such as oxidation or truncation. The two techniques together give both a quantity and an identity check.
Retatrutide is an investigational peptide that activates the GLP-1, GIP, and glucagon receptors at the same time. It is being studied for obesity and type 2 diabetes and has not been approved for clinical use. The internal code LY3437943 refers to the same molecule.