If you have been reading about fatty diacid 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 2026-07-21. Numbers and descriptions here follow the published literature rather than marketing material.
Large randomised trials in adults with type 2 diabetes and in adults with obesity have reported reductions in body weight and improvements in several cardiovascular risk markers. One outcome trial found a lower incidence of major adverse cardiovascular events in participants with diabetes and established cardiovascular disease. Gastrointestinal effects such as nausea and vomiting are the most frequently reported adverse events and often diminish over time. Changes in lean body mass during weight loss are an area of ongoing investigation. Effects in adolescents and in pregnancy are less well characterised, and current labelling advises against use during pregnancy.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released after nutrient intake. The molecule contains 31 amino acid residues and differs from the native sequence at several positions. A non-natural residue at position eight resists the enzyme that normally truncates the hormone, while a lysine-linked fatty diacid side chain promotes binding to serum albumin. These two modifications extend the circulating half-life from minutes to roughly one week. The peptide is produced by solid-phase synthesis followed by selective acylation, and its identity and purity are confirmed by spectrometric and chromatographic techniques.
Development began in the early 2010s with the goal of extending GLP-1 activity beyond the brief window achieved by native peptide infusion. The earliest approved formulation was a subcutaneous injection given once weekly. A later oral tablet pairs the peptide with an absorption enhancer, sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, usually shortened to SNAC. That carrier lowers local pH and helps the peptide cross gastric tissue. Both routes deliver the same active molecule.
Semaglutide is a synthetic peptide analog of human glucagon-like peptide-1, a gut hormone released after meals. Its backbone retains the GLP-1 sequence but incorporates two substitutions that slow enzymatic breakdown by dipeptidyl peptidase-4. A short polyethylene glycol linker and a C18 fatty diacid are attached to the peptide chain, allowing the molecule to bind serum albumin and remain in circulation far longer than the native hormone. The result is a circulating half-life measured in days rather than the minutes typical of endogenous GLP-1.
Receptor activation occurs at GLP-1 receptors distributed across pancreatic islets, the hypothalamus, and the gastrointestinal tract. Binding triggers G protein signaling that raises cyclic AMP and enhances glucose-dependent insulin release. Because the effect depends on prevailing glucose levels, insulin secretion does not rise when blood sugar is already low. Signaling in the brain and gut also influences appetite and gastric emptying, which is why the compound appears in both metabolic and weight-related research literature.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Acylated GLP-1 receptor agonist | 31-residue synthetic peptide |
| Molecular formula | C187H291N45O59 | established for the free peptide |
| Appearance | White to off-white powder | as supplied before formulation |
| Solubility | Freely soluble in water | aqueous buffers near neutral pH |
| Typical storage | 2 to 8 degrees Celsius, protected from light | powder and solution forms differ in shelf life |
序列层面的改动同时解决了两个问题，即酶解稳定性与肾脏清除速度。天然 GLP-1 在循环中的半衰期仅约两分钟，主要被二肽基肽酶-4 迅速灭活。酰化侧链与白蛋白的可逆结合形成循环储库，使分子缓慢释放并持续激活受体。这种设计思路后来被广泛用于同类长效肽的开发，属于该类药物化学改造的典型范式。
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
该分子作为 GLP-1 受体的选择性激动剂发挥作用，受体属于 B 类 G 蛋白偶联受体家族，激活后经 Gs 通路提升细胞内环腺苷酸水平。在胰腺 β 细胞，信号促进葡萄糖依赖性的胰岛素释放，血糖偏低时该作用明显减弱。在胰岛 α 细胞，胰高血糖素分泌受到抑制。中枢神经系统与胃肠道同样存在受体表达，相应信号参与食欲调节以及胃排空速率的降低。
Degradation proceeds along several parallel routes. Deamidation of asparagine and glutamine residues generates charged variants that shift retention time in chromatographic analysis. Oxidation targets methionine and can be accelerated by trace metals or dissolved oxygen. Non-covalent aggregation produces dimers, oligomers, and larger species that are difficult to reverse. Isomerisation at aspartate residues is slower but measurable under thermal stress. The distribution among these pathways depends on pH, buffer composition, ionic strength, and the presence of excipients such as sugars or surfactants.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nm is the standard purity method, reported as area percent. Mass spectrometry, usually with electrospray ionisation, confirms identity and reveals covalent modifications. Size-exclusion chromatography quantifies aggregates and fragments. Peptide mapping after enzymatic digestion localises changes to specific sequence regions. Circular dichroism and infrared spectroscopy report on secondary structure, while light scattering tracks particle formation in liquid formulations. No single technique captures every quality attribute.
Quality control relies on pharmacopoeial monographs where they exist, combined with in-house specifications for identity, purity, water content, and counter-ion composition. Reference standards allow calibration across laboratories, although certified materials for every analogue are not universally obtainable. Batch records, chromatograms, and mass spectra form the documentation trail. Regulatory classification varies by jurisdiction and intended use, and research-grade material differs from pharmaceutical-grade material in testing scope. Analytical uncertainty is often expressed as relative standard deviation across replicate injections.
The company that developed the compound filed it as a long-acting analogue, and it gained first approval in 2017 for type 2 diabetes. Later authorisations from several regulators extended the indication to chronic weight management, and the World Health Organization added the glucagon-like peptide-1 receptor agonist drug class to its model list of essential medicines in 2023. Production uses solid-phase peptide synthesis followed by side-chain conjugation and chromatographic purification. Supply constraints and cost differences across regions are well documented. Literature on long-term outcomes continues to grow, with many trials reporting surrogate endpoints rather than hard clinical endpoints.
Semaglutide is a synthetic peptide of thirty-one amino acids that shares roughly ninety-four percent sequence identity with human glucagon-like peptide-1. Two substitutions resist enzymatic cleavage by dipeptidyl peptidase-4, and a fatty diacid side chain attached through a linker promotes binding to serum albumin. That albumin binding slows renal clearance and extends the circulating half-life from minutes to approximately one week. The structural changes are well established in the published literature. Whether the same modifications affect receptor signalling bias in ways that matter clinically remains an open question.
Pharmacological activity arises from agonism at the glucagon-like peptide-1 receptor, a G protein-coupled receptor expressed in the pancreas, the gastrointestinal tract, and the brainstem. Receptor activation raises intracellular cyclic adenosine monophosphate and enhances insulin release in a glucose-dependent manner, an effect that diminishes when blood glucose concentration is low. Other effects include slowed gastric emptying and hypothalamic satiety signalling. These pathways are described well. Receptor desensitisation rates across tissues, relative to the endogenous hormone, are still under investigation, and reported findings differ between laboratories.
==== Food and flavor authentication ==== Foods, flavorings and scents are often sold with the guarantee that chemical additives come from natural sources. This claim becomes hard to test when the chemical compound has a known structure and is readily synthesized in a lab. Authentication of claims about the origins of these chemicals has made good use of various stable isotopes, including those of hydrogen. Combined carbon and hydrogen isotope analysis has been used to test the authenticity of (E)-methyl cinnamate, γ-decalactone and δ-decalactone. Hydrogen and nitrogen isotope ratios have been used for the authentication of alkylpyrazines used as "natural" coffee flavorings.
In the elections of 1982, the PSOE won a resounding victory by obtaining an absolute majority in the Congress of Deputies (202 deputies) and in the Senate. The second most voted political force was the coalition formed by Alianza Popular and the Partido Demócrata Popular, which became with its 106 deputies the conservative alternative to the socialist power. The PCE (with 4 deputies) and UCD (with 12) were practically erased, as well as Suárez's Democratic and Social Center (which only obtained 2 deputies). With this result, described as an authentic "electoral earthquake", the party system underwent a radical change from the imperfect two-party system (UCD/PSOE) of 1977 and 1979 to a dominant party system (the PSOE). The 1982 elections have been considered by most historians as the end of the political transition process initiated in 1975. Firstly, because of the high turnout, the highest ever recorded until then (79.8%), which reaffirmed the commitment of the citizens to the democratic system and showed that the "turn back" advocated by the involutionary sectors did not have the support of the people. Secondly, because for the first time the political alternation typical of democracies took place, thanks to the free exercise of the vote by the citizens. Thirdly, because a party that had nothing to do with Francoism was acceding to the government, since it was one of the defeated parties in the civil war.
Blood volume measurement may be used in people with congestive heart failure, chronic hypertension, kidney failure and critical care. The use of relative blood volume changes during dialysis is of questionable utility. Total Blood Volume can be measured manually via the Dual Isotope or Dual Tracer Technique, a classic technique, available since the 1950s. This technique requires double labeling of the blood; that is 2 injections and 2 standards (51Cr-RBC for tagging red blood cells and I-HAS for tagging plasma volume) as well as withdrawing and re-infusing patients with their own blood for blood volume analysis results. This method may take up to 6 hours for accurate results. The blood volume is 70 ml/kg body weight in adult males, 65 ml/kg in adult females and 70-75 ml/kg in children (1 year old and over). Total Blood Volume has been measured manually by the use of carbon monoxide (CO) as a tracer for more than 100 years and was first proposed by French scientists Grehant and Quinquaud in 1882. Soon after a usable set-up for human use was developed by Oxford scientists John Haldane and Lorrain Smith and presented in the Journal of Physiology in 1900.
RN=C=NR ↔ RN+≡C-N−R ↔ RN−-C≡N+R The N=C=N core is relatively linear and the C-N=C angles approach 120°. In the case of C(NCHPh2)2, the central N=C=N angle is 170° and the C-N=C angles are within 1° of 126°. The C=N distances are short, nearly 120 pm, as is characteristic of double bonds. Carbodiimides are chiral, possessing C2-symmetry and therefore axial chirality. However, due to the low energy barrier to the molecule rotating and thereby converting quickly between its isomers, the actual isolation of one optical isomer of a carbodiimide is extremely difficult. It has been demonstrated at least once, in the case of conformationally restricted cyclic carbodiimides; though there are other reports of one-handed axially chiral carbodiimides, their validity has since been called into question on experimental and computational grounds. The parent compound, methanediimine, (HN=C=NH), is a tautomer of cyanamide.
=== Calcification and lipids === Calcification forms among vascular smooth muscle cells of the surrounding muscular layer, specifically in the muscle cells adjacent to atheromas and on the surface of atheroma plaques and tissue. In time, as cells die, this leads to extracellular calcium deposits between the muscular wall and outer portion of the atheromatous plaques. With the atheromatous plaque interfering with the regulation of calcium deposition, it accumulates and crystallizes. A similar form of intramural calcification, presenting the picture of an early phase of arteriosclerosis, appears to be induced by many drugs with an antiproliferative mechanism of action (Rainer Liedtke 2008). Cholesterol is delivered into the vessel wall by cholesterol-containing low-density lipoprotein (LDL) particles. To attract and stimulate macrophages, the cholesterol must be released from the LDL particles and oxidized, a key step in the ongoing inflammatory process. The process is worsened if there is insufficient high-density lipoprotein (HDL), the lipoprotein particle that removes cholesterol from tissues and carries it back to the liver. The foam cells and platelets encourage the migration and proliferation of smooth muscle cells, which in turn ingest lipids, become replaced by collagen, and transform into foam cells themselves. A protective fibrous cap normally forms between the fatty deposits and the artery lining (the intima). These capped fatty deposits (now called 'atheromas') produce enzymes that cause the artery to enlarge over time.
Sources: en.wikipedia.org
== Professional activities == Tippett's work in cybersecurity has led to roles as speaker, contributor and advisor to government and private sector organizations. From 2003 to 2005, he served on the President's Information Technology Committee (PITAC), established by Congress in 1997 under the High Performance Computing Act of 1991 to "guide the Administration's efforts to accelerate the development and adoption of information technologies vital for American prosperity in the 21st century." The U.S. Chamber of Commerce awarded Tippett its first Leadership in Health Care Award at the Chamber's first annual Health Care Summit (2012) for his leadership of Verizon's incubator. Tippett was also Chief Scientist for ICSA Labs and previously served as president of the International Computer Security Association. Tippett is currently an adjunct professor in the Division of General Medical Sciences at Case Western Reserve University School of Medicine. In November 2017, T.E.N., a technology and information security executive networking and relationship-marketing firm, announced that Tippett received the 2017 ISE® Luminary Leadership Award.
She initially attempts to use her powers on Jasmine, but learns of Jasmine's ESP and tries to make the latter her pet instead. Despite being mortally wounded by Blitz, Succubus dies transferring her lifeforce to him. During the events of the crossover film Tokusou Sentai Dekaranger vs. Abaranger, Saunaginnan revives Succubus, who is subsequently deleted by Deka Pink and Yellow and Abare Yellow. Succubus Hells is portrayed by Mayu Gamō (蒲生 麻由, Gamō Mayu). Reversian Blitz Hells (リバーシア星人ブリッツ・ヘルズ, Ribāshia Seijin Burittsu Heruzu): The oldest, cruelest, and most powerful of the Hells Siblings who possesses energy-based powers, wields a sword and a machine gun-like blaster, is willing to sacrifice his siblings, and earned a reputation as the "Outer Space Grim Reaper" (宇宙の死神, Uchū no Shinigami). After being defeated by the Dekarangers, he attempts to escape in God Pounder, only to be deleted by Riding Dekaranger Robo. Blitz Hells is voiced by Hiroshi Tsuchida (土田 大, Tsuchida Hiroshi). Tylerian Durden (タイラー星人ダーデン, Tairā Seijin Dāden): The owner and fight promoter of an illegal fight club, gambling operation, and illegal steroid ring from Planet Tyler. After recognizing the Dekarangers while they were infiltrating his fight club, he retaliates by piloting a demon-themed Kaijuki called Ultimate Evil (アルティメットイビル, Arutimetto Ibiru), only to be deleted by Super Dekaranger Robo. Durden is voiced by Masaharu Satō (佐藤 正治, Satō Masaharu).
=== Viral trends === The app has spawned numerous viral trends, Internet celebrities, and music trends around the world. Duets, a feature that allows users to add their own video to an existing video with the original content's audio, have sparked many of these trends. Many stars got their start on Musical.ly, which merged with TikTok on 2 August 2018. These include Loren Gray, Baby Ariel, Zach King, Lisa and Lena, Jacob Sartorius, and many others. Loren Gray remained the most-followed individual on TikTok until Charli D'Amelio surpassed her on 25 March 2020. Gray's was the first TikTok account to reach 40 million followers on the platform. She was surpassed with 41.3 million followers. D'Amelio was the first to ever reach 50, 60, and 70 million followers. Charli D'Amelio remained the most-followed individual on the platform until she was surpassed by Khaby Lame on 23 June 2022. Other creators rose to fame after the platform merged with musical.ly on 2 August 2018. TikTok also played a major part in making "Old Town Road" by Lil Nas X one of the biggest songs of 2019 and the longest-running number-one song in the history of the US Billboard Hot 100. TikTok has allowed many music artists to gain a wider audience, often including foreign fans. For example, despite never having toured in Asia, the band Fitz and the Tantrums developed a large following in South Korea following the widespread popularity of their 2016 song "HandClap" on the platform.
=== Category:EC 1.21 (act on X-H and Y-H to form an X-Y bond) === Category:EC 1.21.1 Iodotyrosine deiodinase EC 1.21.1.1 Category:EC 1.21.3 Isopenicillin N synthase EC 1.21.3.1 Tetrahydrocannabinolic acid synthase EC 1.21.3.7 Category:EC 1.21.4 Category:EC 1.21.99 Thyroxine 5-deiodinase EC 1.21.99.3 Iodothyronine deiodinase EC 1.21.99.3 and EC 1.21.99.4
Circular dichroism is one of the most general and basic tools to study protein folding. Circular dichroism spectroscopy measures the absorption of circularly polarized light. In proteins, structures such as alpha helices and beta sheets are chiral, and thus absorb such light. The absorption of this light acts as a marker of the degree of foldedness of the protein ensemble. This technique has been used to measure equilibrium unfolding of the protein by measuring the change in this absorption as a function of denaturant concentration or temperature. A denaturant melt measures the free energy of unfolding as well as the protein's m value, or denaturant dependence. A temperature melt measures the denaturation temperature (Tm) of the protein. As for fluorescence spectroscopy, circular-dichroism spectroscopy can be combined with fast-mixing devices such as stopped flow to measure protein folding kinetics and to generate chevron plots.
Sources: en.wikipedia.org
==== United Arab Emirates ==== Seven & I Holdings announced in June 2014 that they had agreed a contract with Seven Emirates Investment LLC to open the first Middle Eastern 7-Eleven in Dubai, United Arab Emirates during the summer of 2015. The company also said that they had plans to open about 100 stores in the country by the end of 2017. The first store was opened in October 2015. The country has 13 stores as of January 2018, but as of the 2020s, 7-Eleven has shut down and is now absent in Dubai until further notice.
A 2021 poll conducted by the Levada Center found that 49% of Russians prefer the USSR's political system, while 18% prefer the current political system and 16% would prefer a Western democracy. A further 62% of people polled preferred the Soviet system of central planning, while 24% prefer a market-based system. According to the Levada Center's polls, the primary reasons cited for Soviet nostalgia are the advantages of the shared economic union between the Soviet republics, including perceived financial stability. This was referenced by up to 53% of respondents in 2016. At least 43% also lamented the loss of the Soviet Union's global political superpower status. About 31% cited the loss of social trust and capital. The remainder of the respondents cited a mix of reasons ranging from practical travel difficulties to a sense of national displacement. The 1941–1945 period of World War II is still known in Russia as the 'Great Patriotic War'. The war became a topic of great importance in cinema, literature, history lessons at school, the mass media, and the arts. As a result of the massive losses suffered by the military and civilians during the conflict, Victory Day celebrated on 9 May is still one of the most important and emotional dates in Russia. Catherine Wanner asserts that Victory Day commemorations are a vehicle for Soviet nostalgia, as they "kept alive a mythology of Soviet grandeur, of solidarity among the Sovietskii narod, and of a sense of self as citizen of a superpower state".
Formation of additional capillaries and larger blood vessels (angiogenesis) is a major mechanism by which a cancer may help to enhance its own growth. Disorders of retinal capillaries contribute to the pathogenesis of age-related macular degeneration. Reduced capillary density (capillary rarefaction) occurs in association with cardiovascular risk factors and in patients with coronary heart disease.
=== Before the search === The earliest mention of some matter with the properties of deuterium was a passing mention in Ernest Rutherford's 1919 Bakerian lecture. In this theory, the deuterium nucleus with mass two and charge one would contain two protons and one nuclear electron. Also in 1919, Otto Stern and Max Volmer reported on diffusion experiments with water which they claimed disproved the existence of isotopes of hydrogen; their conclusions were assumed to be correct throughout the 1920s.
==== Pharmacokinetics of Quinoline and quinazoline-derivatives ==== Absorption is variable within the group, with tmax ranging from 1–4 hours for Lenvatinib to 4–10 hours for cabozatinib. Food can slow down the absorption rate but should not affect the extent of the absorption. All drugs have high protein binding, ranging from 90-99%. Vandetanib and cabozatinib are metabolized mainly by CYP3A4, while lenvatinib is metabolized by CYP450 and via other pathways. The drugs are eliminated mostly in faeces, but also in urine. Vandetanib has a half-life of 19 days, while cabozatinib’s half-life is 99 hours.
Sources: en.wikipedia.org
Native GLP-1 is degraded within minutes by dipeptidyl peptidase-4 and neutral endopeptidases. Semaglutide carries a non-natural amino acid at position eight that blocks that cleavage, and a fatty diacid side chain that binds albumin. The result is a much longer duration of action than the native hormone.
The fatty diacid chain associates strongly with serum albumin, which keeps the peptide in circulation and shields it from rapid renal clearance. Bound peptide is released gradually, producing a sustained receptor signal. This mechanism also reduces the peak-to-trough variation seen with shorter-acting analogues.
The balance between peripheral receptor activation and signalling in the central nervous system is not fully resolved. The extent to which slowed gastric emptying accounts for reduced energy intake, compared with direct effects on appetite circuits, is debated. Long-term effects on lean mass and on tissues outside the gut and brain are still under study.
Native GLP-1 is degraded within minutes by circulating enzymes. The synthetic version carries substitutions at positions that block enzymatic cleavage, plus a fatty acid side chain that promotes albumin binding. These two changes together extend circulation time from minutes to roughly a week.