This is a working overview of aggregation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-06-06 and is reviewed periodically as new material appears.
该化合物的名称与结构由国际非专利名称体系统一维持,不同文献中出现的同义写法主要在拼写顺序或盐形式描述上不同。研究者通常通过受体结合实验、细胞内环磷酸腺苷积累测定以及动物模型来确认其双激动活性。相当一部分分子层面的细节——例如两条受体通路之间的信号交叉作用——尚处于开放问题状态。
当前公开资料把 tirzepatide 归为肠促胰素类受体双重激动剂。它并非激素天然变体,而是经过序列改造的工程化肽。其分子量、等电点与疏水性等基础参数已在药典和化学数据库中收录,可作为分析检测和质量研究的参照。
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, with mass confirmation by electrospray ionisation mass spectrometry. Peptide mapping after enzymatic digestion verifies the primary sequence. Size-exclusion chromatography quantifies aggregates, while circular dichroism provides a secondary-structure fingerprint. Bioanalytical quantification in plasma uses immunoassay or LC-MS/MS. Reported purity for research-grade lots is commonly 95 percent or higher, and residual water content is checked by Karl Fischer titration.
As a peptide, tirzepatide is handled as a lyophilised solid in research settings and as a preserved solution in finished products. Aqueous solubility is pH dependent and reaches a minimum near the isoelectric point, which lies close to pH 5.4. Stock solutions are typically prepared in neutral or slightly basic buffer to limit precipitation. The solid is hygroscopic and should be equilibrated to room temperature before opening so that condensation does not form on the powder surface.
| Property | Value | Notes |
|---|---|---|
| 分子类型 | 合成修饰肽 | 39 个氨基酸,含脂肪酸侧链 |
| 受体靶点 | GIP 与 GLP-1 受体 | 双重激动剂 |
| 分子量 | 约 4.8 kDa | 以游离肽计 |
| 外观 | 白色至类白色粉末 | 冻干形态常见 |
| 溶解性 | 可溶于水及水性缓冲液 | 溶解后宜低温保存 |
Development began in the 2010s, when researchers modified a GIP-based scaffold to add GLP-1 activity and then attached the fatty diacid to lengthen its half-life. Clinical evaluation proceeded through large phase 3 programmes in type 2 diabetes and in obesity, and regulators in the United States cleared the compound for type 2 diabetes in 2022 and for chronic weight management in 2023. Several cardiovascular and metabolic outcome studies are still reporting, so the picture of long-term benefit and risk is incomplete. Approvals in other regions followed on different timelines.
Tirzepatide is a synthetic peptide of 39 amino acids that carries a C20 fatty diacid side chain attached through a linker. Its molecular formula is C225H348N48O68, and its molecular weight is about 4813 daltons. The compound belongs to the incretin mimetic class and is administered by subcutaneous injection. The fatty acid chain promotes binding to serum albumin, which slows renal clearance and extends the circulation time of the molecule. It was identified during screening of sequences derived from glucose-dependent insulinotropic polypeptide.
The peptide activates two G protein-coupled receptors, GIPR and GLP-1R. Binding triggers adenylyl cyclase activity and raises intracellular cyclic AMP in pancreatic beta cells, which potentiates insulin release when glucose is elevated. Signaling in the central nervous system is associated with reduced appetite and lower energy intake, while effects on gastric emptying and glucagon secretion are also reported. Because activity at both receptors is retained, the pharmacological profile is often described as incretin-based rather than selective for a single receptor.
After subcutaneous injection, absorption is gradual, and peak plasma levels are generally reached within one to three days. Albumin binding extends the apparent half-life to roughly five days, which supports a weekly administration schedule. Metabolism proceeds mainly through proteolytic cleavage of the peptide backbone and beta-oxidation of the fatty acid chain, rather than through cytochrome P450 pathways. Eliminated fragments are largely recycled through general protein turnover, and excretion of intact drug in urine is minimal. These properties distinguish the molecule from short-acting incretin mimetics.
Tirzepatide is a synthetic peptide of 39 amino acids engineered from the native glucose-dependent insulinotropic polypeptide sequence. Its structure incorporates several non-natural residues and a C-terminal segment derived from glucagon-like peptide-1, together with a C20 fatty diacid moiety attached through a linker. The lipophilic side chain promotes binding to serum albumin, which slows renal clearance after administration. The compound is classified as a dual incretin receptor agonist and is supplied as a lyophilized powder for reconstitution or as a preformulated solution, depending on the presentation.
Verification of research-grade material involves checking purity, sequence and counter-ion content against a certificate of analysis. Reported purity figures usually reflect chromatographic area percentage and do not by themselves establish biological activity. Independent laboratories may repeat mass confirmation and peptide mapping to detect substitutions or truncations. Open questions concern how residual solvents, trace metals and subtle conformational variants affect measured behavior, and how consistently different suppliers define their specifications. Documentation of analytical methods matters as much as the headline purity number when results are compared across studies.
Routine characterization relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry, to confirm identity and estimate purity. Peptide mapping after enzymatic digestion verifies the amino acid sequence and locates appended groups such as the fatty acid chain. Size-exclusion chromatography detects aggregates and fragments, while ion-exchange chromatography resolves charge variants. Circular dichroism and nuclear magnetic resonance supply secondary and higher-order structural information in research settings. No single technique covers every attribute, so laboratories combine orthogonal methods and compare outcomes against a reference standard where one exists.
=== Electrokinetic injection === In this method a high voltage is applied to the sample solution and molecules are loaded to the CE capillary by electromigration and electroosmotic flow of the sample. Electrokinetic injection improves the sensitivity comparing to hydrodynamic injection while using lower voltage and longer injection time, but reproducibility of peak areas and migration times is lower. However, method is biased to analytes with high electrophoretic mobility: high mobility molecules are injected better. As a result, electrokinetic injection is susceptible to matrix effects and changes in sample ionic strength.
Ambala district: Centre of Excellence for Litchi, announced in FY2025-26. Yamunanagar district: Centre of Excellence for strawberry, announced in FY2025-26. Karnal district: Centre of Excellence for Vegetables, Gharaunda, established 7.01.2011. Karnal district: Potato Technology Centre, Shamgarh, established 06.04.2016. Kurukshetra district: Centre for Subtropical Fruits, Ladwa, established 06.04.2016. Kurukshetra district: Horticulture Integrated Bee Keeping, Ram Nagar, post office Chaduni Jattan, established 10.11.2017. Rohtak district: Hi-tech Greenhouse Seedling Centre, established 17.12.2013. Jhajjar district: Center of Excellence for Flowers, Munimpur, established 2022. Gurugram district: Hi-tech Greenhouse Seedling Centre, established 17.12.2013. Nuh district: Center of Excellence for Onions, Pinangwan, established 2022. Palwal district: Integrated Horticulture Development, Centre, Hodal, established 13.10.2018. Mahendergarh district: Integrated Horticulture Development Centre, Sundrah village on Ateli-Kanina road, established 01.09.2019. Bhiwani district: Centre of excellence for semi-arid horticulture, Gignaw, established 2022. Hisar district: Multi Crops Demonstration Centre, Barwala, established 2022. Hisar district: Date Palm and Guava Demonstration Centre, announced in FY2025-26. Fatehabad district: Guava Demonstration Centre at Government Garden Nursery on Uklana road, Bhuna, established 27.10.2020. Sirsa district: Centre of Excellence for fruits (Citrus & Pomegranate), Mangiana, established 22.06.2013.
Yeast taxonomy includes classification of yeast species depending on the presence or absence of a sexual phase. Therefore, some winemaking yeasts are classified by their asexual anamorph (or "imperfect" form) while others may be classified by their sexual teleomorph (or "perfect" form). A common example of this is Brettanomyces (or "Brett") that is usually referenced in wine and viticulture text under its asexual classification though some scientific and winemaking texts may describe specific species (such as Dekkera bruxellensis) under its sporulating sexual classification of Dekkera. Unless otherwise noted, this article will commonly refer to the asexual form of wine yeast. The most common yeast generally associated with winemaking is Saccharomyces cerevisiae which is also used in bread making and brewing. Other genera of yeast that can be involved in winemaking (either beneficially or as the cause of potential wine faults) include:
An integral component of the Mannich reaction, in addition to an amine and a carbonyl compound, is a carbanion, which plays the role of the nucleophile in the nucleophilic addition to the ion formed by the reaction of the amine and the carbonyl.
In fact, penicillin is soluble in ethanol, ether and chloroform. Further research was undertaken in the early 1930s by others including Harold Raistrick who confirmed the chemical instability of penicillin in 1932. While Fleming continued to send samples of the mould to researchers, the requests for samples tapered off.
Sources: en.wikipedia.org
The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. This pericardial sac is filled with a serous fluid for lubrication. The heart itself is divided into a right and left half, each with an atrium and ventricle. The atrium and ventricles of each side are separated by atrioventricular valves which prevent back flow from one chamber to the next during contraction. Being myogenic, the heart's pace is maintained by pacemaker cells found in the sinoatrial node, located on the right atrium. The sinoatrial node uses calcium to cause depolarisation of the signal transduction pathway from the atrium through right and left atrioventricular bundle which communicates contraction to the ventricles. The avian heart also consists of muscular arches that are made up of thick bundles of muscular layers. Much like a mammalian heart, the avian heart is composed of endocardial, myocardial and epicardial layers. The atrium walls tend to be thinner than the ventricle walls, due to the intense ventricular contraction used to pump oxygenated blood throughout the body. Avian hearts are generally larger than mammalian hearts when compared to body mass. This adaptation allows more blood to be pumped to meet the high metabolic need associated with flight.
Portugal, officially the Portuguese Republic, is a country in Southwestern Europe. Mainland Portugal is located on the southwestern portion of the Iberian Peninsula, and bordered by Spain to the north and east. Portugal also includes the archipelagos of Madeira and the Azores in the Atlantic Ocean. The country has a population of 11.4 million, and Lisbon, its capital, is the largest city. Portugal's internal waters and territorial sea together account for two-fifths of its territory, and its exclusive economic zone is one of Europe's largest. The country's terrain contains a diverse range of landscapes and regional climates. The western Iberian Peninsula has been inhabited since prehistory, with the earliest signs of settlement dating to between 5500 BC and 5300 BC. Muslims had occupied the Iberian Peninsula since 711. As a result of the Reconquista against them, Portugal was established as a county of the Kingdom of León in 868 and formally as a kingdom in 1179. During the Age of Discovery, the kingdom made several advancements in nautical science and maritime exploration to discover new territories and sea routes, which led to the establishment of the Portuguese Empire. The kingdom became a republic in 1910, before becoming a dictatorship in 1926, whose 1974 overthrow enabled democracy to be established in 1976. Portugal is a unitary republic and multi-party representative democracy with four separate sovereignty organs: president, government, parliament, and judiciary.
=== Insurgents === Natural enemies of the Agents of the Four Seasons. They are divided into Reformists, whose goal is to threaten the Agents' safety to pressure institutions into changing the laws governing their divine powers, and Defeaters, whose goal is to eliminate the Agents out of hatred for the seasons.
Diprenorphine, also known as diprenorfin and sold under the brand name Revivon, is a non-selective, high-affinity, weak partial agonist of the μ- (MOR), κ- (KOR), and δ-opioid receptor (DOR) (with equal affinity) which is used in veterinary medicine as an opioid antagonist. It is used to reverse the effects of super-potent opioid analgesics such as etorphine and carfentanil that are used for tranquilizing large animals. The drug is not approved for use in humans. Diprenorphine was the preferred reversal for etorphine but today naltrexone is preferred due to being a full antagonist. Effects occur within 1–3 minutes when given IV and 15–20 minutes given IM. Diprenorphine is the strongest opioid antagonist that is commercially available (some 100 times more potent than nalorphine), and is used for reversing the effects of very strong opioids for which the binding affinity is so high that naloxone does not effectively or reliably reverse the narcotic effects. Diprenorphine is used as a reversal agent for etorphine and carfentanil, and is normally used to remobilise animals once veterinary procedures have been completed. Since diprenorphine also has partial agonistic properties of its own, it should not be used on humans if they are accidentally exposed to etorphine or carfentanil. Naloxone or naltrexone is the preferred human opioid receptor antagonist. Because diprenorphine is a weak partial agonist of the opioid receptors rather than a silent antagonist, it can produce some opioid effects in the absence of other opioids at sufficient doses.
==== Indirect routes of production of 99Mo ==== Other particle accelerator-based isotope production techniques have been investigated. The supply disruptions of 99Mo in the late 2000s and the ageing of the producing nuclear reactors forced the industry to look into alternative methods of production. The use of cyclotrons or electron accelerators to produce 99Mo from 100Mo via (p,pn) or (γ,n) reactions, respectively, has been further investigated. The (n,2n) reaction on 100Mo yields a higher reaction cross-section for high energy neutrons than of (n,γ) on 98Mo with thermal neutrons. In particular, this method requires accelerators that generate fast neutron spectrums, such as ones using D-T or other fusion-based reactions, or high energy spallation or knock out reactions. A disadvantage of these techniques is the necessity for enriched 100Mo targets, which are significantly more expensive than natural isotopic targets and typically require recycling of the material, which can be costly, time-consuming, and arduous.
Sources: en.wikipedia.org
它属于合成修饰肽,同时激动 GIP 与 GLP-1 两种肠促胰素受体。这类分子通常被称为双重肠促胰素受体激动剂,与选择性 GLP-1 激动剂在靶点范围上不同。
分子上的脂肪酸侧链使其与血浆白蛋白结合增强,显著延长循环半衰期。半衰期延长后,稳定血药浓度可在较长的给药间隔内维持,因此常见用法为每周一次。
同时激活两条肠促胰素通路可能在胰岛素分泌、胃排空和食欲调节上产生叠加效应。与单靶点相比,临床研究中观察到的血糖与体重变化幅度通常更明显,但各通路的具体贡献比例尚无定论。
Solid material is normally kept frozen at about -20 degrees Celsius, desiccated and protected from light. Solutions are held cold and used within a defined window because degradation products accumulate over time.