A practical reference on receptor agonist: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-05-11. Anything still debated is marked as such rather than presented as settled.
肽类的主要降解路径包括天冬酰胺脱酰胺、甲硫氨酸氧化、天冬氨酸异构化以及由 β-折叠驱动的聚集，这些反应对 pH 与缓冲液种类较为敏感。磷酸盐、丙二醇与苯酚等辅料会影响局部微环境与界面行为。强制降解研究借助高温、强光、氧化剂与极端 pH 暴露来预测产物谱。关于长期室温存放的数据相对有限，超出标签条件的稳定性仍属开放问题，需要在具体制剂中通过实时与加速试验加以确认。
容器与密封系统同样参与稳定性表现。硅油涂层、胶塞材质与顶空氧含量可能改变聚集速率与氧化水平。分析结果因此需要在完整包装形式下评估，而不能仅凭原料药数据推断。法规文件通常要求同时提交批次数据与代表性容器中的稳定性趋势。
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.
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.
| Property | Value | Notes |
|---|---|---|
| 保存温度 | 2 至 8 摄氏度 | 避免冻结，部分制剂允许短期室温 |
| 粉末外观 | 白色至类白色固体 | 吸湿后易结块 |
| 纯度检测方法 | 反相高效液相色谱 | 紫外检测，常用 214 纳米 |
| 分子量确认方法 | 液相色谱串联质谱 | 偏差通常以 ppm 表示 |
| 常见降解产物 | 氧化与脱酰胺变体 | 源自甲硫氨酸与天冬酰胺残基 |
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1, a hormone released from intestinal L-cells after food intake. It contains 31 amino acids and differs from native GLP-1 through modifications that slow enzymatic breakdown. The peptide was developed to extend the short circulating half-life of endogenous GLP-1, which is measured in minutes. Researchers introduced the compound in the early 2010s. Two backbone changes and a fatty acid side chain define its structure, distinguishing it from earlier GLP-1 receptor agonists.
The compound binds the GLP-1 receptor on pancreatic beta cells and other tissues, activating a G-protein signaling cascade that raises intracellular cyclic AMP. This action increases glucose-dependent insulin secretion when blood glucose is elevated, while binding also slows gastric emptying and reduces glucagon release. In the central nervous system, receptor activation in the hypothalamus and brainstem contributes to reduced appetite. The fatty acid chain binds albumin, which protects the peptide from renal filtration and enzymatic degradation. This albumin binding is central to its extended circulation time.
Native GLP-1 is degraded rapidly by dipeptidyl peptidase-4. Semaglutide resists this cleavage because alanine at position 8 is replaced by alpha-aminoisobutyric acid. A second substitution at position 34 introduces arginine, which further stabilizes the peptide. The most distinctive modification is a spacer and C18 fatty diacid attached at lysine 26, enabling strong albumin affinity. These three changes together produce a half-life measured in days rather than minutes, and the same structural logic underlies other long-acting analogs in this class.
Semaglutide is a synthetic peptide analog of glucagon-like peptide-1 (GLP-1), a hormone released from intestinal L-cells after food intake. The compound belongs to the incretin mimetic class and acts at GLP-1 receptors distributed across pancreatic, gastrointestinal, cardiovascular, and central nervous system tissues. Compared with native GLP-1, the molecule carries structural changes that extend its activity from minutes to roughly one week. It is studied for glycemic control in type 2 diabetes and for weight management, and its effects on cardiovascular and other outcomes remain active research areas.
Receptor binding triggers G protein signaling that raises intracellular cyclic AMP in pancreatic beta cells. Insulin release follows in a glucose-dependent manner, so secretion increases when blood glucose is elevated and diminishes when it is not. The same signaling suppresses glucagon release from alpha cells and slows gastric emptying, which blunts the post-meal glucose rise. In the brain, receptor activation in regions such as the arcuate nucleus is associated with reduced appetite and lower energy intake. How much each of these effects contributes to overall weight change is not fully settled.
=== Types === 2-keto compounds: clorazepate, diazepam, flurazepam, halazepam, prazepam, and others 3-hydroxy compounds: lorazepam, lormetazepam, oxazepam, temazepam 7-nitro compounds: clonazepam, flunitrazepam, nimetazepam, nitrazepam Triazolo compounds: adinazolam, alprazolam, estazolam, triazolam Imidazo compounds: climazolam, loprazolam, midazolam 1,5-benzodiazepines: clobazam
== Medical uses == Isavuconazonium is used to treat invasive aspergillosis and invasive mucormycosis in adults aged eighteen years and older. It is available in a capsule for administration by mouth and as a powder for administration via infusion.
The acetolactate synthase (ALS) enzyme (also known as acetohydroxy acid or acetohydroxyacid synthase, abbr. AHAS) is a protein found in plants and micro-organisms. ALS catalyzes the first step in the synthesis of the branched-chain amino acids (valine, leucine, and isoleucine).
Sources: en.wikipedia.org
=== Mining and oil, and gas industry === Antiscalants are used in mining operations and oil & gas production to prevent scale deposition in pipelines, drilling equipment, and processing facilities. Scaling in these industries can lead to decreased flow rates, equipment damage, and production downtime. Preventing the formation of scale from blocking or hindering fluid flow through pipelines, valves, and pumps used in oil production and processing. Oilfield scaling is the precipitation and accumulation of insoluble crystals (salts) from a mixture of incompatible aqueous phases in oil processing systems.
=== 21 April === Russia claimed to have taken Bohdanivka, three kilometers from Chasiv Yar. The Russian-installed governor of Sevastopol said that a Neptune missile was launched at a vessel of the Russian Black Sea Fleet, causing a small fire. The Ukrainian Navy claimed that it struck the salvage ship Kommuna. Subsequent satellite images did not reveal any damage. Ukrainian military observer Kostyantyn Mashovets claimed that the Russian Central Grouping of Forces, which operates in the Pokrovsk and Toretsk directions (northwest and northeast of Avdiivka), had over 86,000 personnel, 280 tanks, 760 armored vehicles, and around 1,100 tube and rocket artillery systems.
=== Storyteller === Conway styles himself "Furrydom's Storyteller", making annual appearances at Anthrocon in what has come to be known as Uncle Kage's Story Hour. The entertainment typically consists of four or five extended personal anecdotes. His stage name resulted from his first storytelling experience at ConFurence in 1994, and derives from his fandom name Kagemushi Goro (Shadow Bug Goro), a reference to Kagemusha. Conway is regularly invited to tell his stories at other fan conventions, including I-CON, Eurofurence, ConClave, and Camp Feral!. Gross sales from recordings of his Story Hours were over US$2600 in 2004; no profit was realized, as the intention was to increase membership and awareness of Anthrocon.
Sources: en.wikipedia.org
When used for analysis of mixtures, the eluant is usually collected in fractions of 1–5 ml which can be further analyzed. When used for protein purification there may be only two collection containers: one for the purified product and one for waste.
Scintigraphy is a nuclear medicine procedure in which low-level radioactive substances are injected into the patient for diagnostic purposes. These include bone scintigraphy, thyroid scintigraphy, octreotide scintigraphy, and, as a further development of the procedure, single photon emission computed tomography (SPECT). For example, 201Tl thallium(I) chloride, technetium compounds (99mTc tracer, 99mtechnetium tetrofosmin), PET tracers (with radiation exposure of 1100 MBq each with 15O-water, 555 MBq with 13N ammonia, or 1850 MBq with 82Rb rubidium chloride) are used in myocardial scintigraphy to diagnose blood flow conditions and function of the heart muscle (myocardium). The examination with 74 MBq 201Thallium Chloride causes a radiation exposure of about 16 mSv (effective dose equivalent), the examination with 740 MBq 99mTechnetium-MIBI about 7 mSv. Metastable 99mTc is by far the most important nuclide used as a tracer in scintigraphy because of its short half-life, the 140 keV gamma radiation it emits, and its ability to bind to many active biomolecules. Most of this radiation is excreted after the examination. The remaining 99mTc decays rapidly to 99Tc with a half-life of 6 hours. This has a long half-life of 212,000 years and, because of the relatively weak beta radiation released during its decay, contributes only a small amount of additional radiation exposure over the remaining lifetime. In the United States alone, approximately seven million individual doses of 99mTc are administered each year for diagnostic purposes.
== Biosynthesis == The peptidoglycan monomers are synthesized in the cytosol and are then attached to a membrane carrier bactoprenol. Bactoprenol transports peptidoglycan monomers across the cell membrane where they are inserted into the existing peptidoglycan.
Sources: en.wikipedia.org
冻融过程中冰晶形成与局部浓度升高会促使肽链发生界面吸附和聚集。聚集不仅降低有效含量，还会改变可见异物与不溶性微粒的计数结果。将溶液分装为单次使用的小体积等份可减少循环次数。
该方法依据疏水性差异分离主峰与相关杂质，对缺失序列、氧化产物和脱酰胺变体具有较好分辨能力。流动相中加入离子对试剂可改善峰形。紫外检测在肽键吸收区工作，灵敏度足以支持常规放行检验。
加速条件可以放大多数化学降解，但聚集与界面诱导的变化对容器、摇动和温度历史更敏感。某些固态转变在短时高温下不一定出现。因此实时稳定性数据仍不可替代，加速结果一般只作为趋势参考。
It is a glucagon-like peptide-1 receptor agonist, often grouped with the incretin mimetics. Its backbone is modified from the human hormone to resist enzymatic degradation and to bind albumin. These two features distinguish it from the native peptide.