Everything below concerns 反相色谱. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-12-04. Numbers and descriptions here follow the published literature rather than marketing material.
固体状态的 tirzepatide 通常以冻干粉形式保存，推荐在低温、避光、干燥条件下存放，常见区间为 2 至 8 摄氏度，长期保存可考虑更低温度并避免反复冻融。冻融循环会导致肽链聚集或析出，从而影响后续定量结果。容器密封性与湿度控制同样是稳定性研究中反复强调的因素。
溶解操作一般使用注射用水或适宜的水性缓冲液，必要时加入少量助溶剂以改善溶解速度，但应避免剧烈涡旋振荡，因为剪切力可能促进聚集。配制后的溶液在冷藏条件下的稳定时间通常短于固体形态，具体时限取决于浓度、缓冲体系与容器材质。是否加入防腐成分，则取决于用途是否为多次取样。
Tirzepatide is a synthetic linear peptide of 39 amino acids that acts as a dual agonist at the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. Its sequence derives from native GIP but incorporates non-natural residues and a C20 fatty diacid moiety linked to a lysine side chain. The lipophilic chain promotes albumin binding, which slows renal clearance and extends circulation time. The unmodified peptide has a molecular formula of C225H348N48O68 and a molecular mass near 4,813 daltons.
Receptor activation by tirzepatide raises intracellular cyclic AMP through Gs-coupled signalling at both targets. At the GLP-1 receptor the downstream effect includes glucose-dependent insulin release, suppressed glucagon secretion, delayed gastric emptying, and reduced appetite signalling in the hypothalamus. GIP receptor engagement adds insulinotropic activity and appears to influence lipid handling in adipose tissue. Because both receptors are stimulated at the same time, the pharmacological profile differs from that of selective GLP-1 receptor agonists, and the relative contribution of each arm remains an area of active investigation.
Clinical development proceeded through large phase 3 programmes in type 2 diabetes and in obesity or overweight with at least one weight-related comorbidity. Regulatory approvals followed in several jurisdictions for both indications. Weekly subcutaneous dosing reflects an elimination half-life of roughly five days. Open questions include the durability of metabolic effects after treatment stops, long-term cardiovascular and hepatic outcomes beyond completed trials, and whether the dual mechanism confers benefits independent of total receptor occupancy. Published literature continues to expand on these points. Substantial uncertainty remains about interindividual variability in response.
| Property | Value | Notes |
|---|---|---|
| 储存温度 | 2 至 8 摄氏度 | 固体粉末，避光密封 |
| 外观 | 白色至类白色冻干粉 | 溶解后为澄清至微乳光 |
| 溶解性 | 易溶于水性缓冲液 | 避免剧烈振荡 |
| 常规纯度方法 | 反相高效液相色谱 | 紫外或质谱检测 |
| 定量方法 | 液相色谱串联质谱 | 配合固相萃取前处理 |
Bulk peptide material is normally characterised by reversed-phase high-performance liquid chromatography, which separates the target sequence from truncation products and other closely related impurities. Ultraviolet detection near 214 nanometres is common because the peptide backbone absorbs in that region. Mass spectrometry, usually electrospray ionisation coupled to a mass analyser, is used to confirm the molecular mass. Because the molecule carries a lipophilic side chain, gradient methods often need a relatively high organic modifier fraction to elute it within a practical retention window.
Like most synthetic peptides of this size, the material is commonly supplied as a lyophilised powder that appears white to off-white. It dissolves in aqueous buffers and in mixtures of water with a small proportion of organic solvent, though the fatty acid portion reduces solubility in pure water relative to short peptides. Hygroscopic behaviour is reported for many peptide powders, so weighing is usually performed quickly and under controlled humidity. Working solutions are typically prepared fresh and kept cold.
Tirzepatide activates both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor, making it a dual agonist rather than a selective agent. Engagement of the GLP-1 receptor is linked to glucose-dependent insulin release, slower gastric emptying, and reduced appetite signalling. The relative contribution of the GIP arm remains an active research question; proposed roles include improved insulin sensitivity and altered adipose tissue handling. Receptor occupancy studies suggest the molecule interacts with both targets at circulating concentrations achieved during therapy.
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.
Identity and purity of tirzepatide are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Because the molecule carries several modifications, gradient conditions are adjusted to resolve the intact peptide from deamidation and oxidation products. Enzymatic digestion followed by peptide mapping confirms the primary sequence and locates specific modifications. Quantitation in biological matrices typically uses liquid chromatography with tandem mass spectrometry after solid-phase extraction. Immunoassays are used less often, since antibody cross-reactivity with closely related peptides can bias results.
The peptide shares degradation routes common to modified peptides: deamidation of asparagine and glutamine residues, oxidation of methionine, and backbone hydrolysis under extreme pH. Lyophilized material is generally more stable than a solution, and residual water content directly affects the rate of hydrolysis. In liquid form, aggregation and visible particles can appear after agitation or repeated freeze-thaw cycles. Stability studies therefore track monomer content, aggregate content, and potency over months under defined temperature and humidity.
Cold-chain handling is standard for formulated product, with dry powder stored frozen and ready-to-use solutions refrigerated. Light exposure is minimized because photodegradation of certain amino acid side chains is possible. Shipping and temperature-excursion studies are used to establish whether short deviations affect quality attributes. Documentation supplied with research material usually includes a certificate of analysis listing purity, identity confirmation, and water or residual solvent content. Users are expected to confirm that material meets the stated specification before use.
Characterization of the peptide relies on reversed-phase high-performance liquid chromatography for purity and related-substance profiling, with ultraviolet detection near 214 nanometers. Mass spectrometry confirms molecular mass and reveals modifications such as oxidation or deamidation. Peptide mapping after enzymatic digestion verifies the amino acid sequence, while amino acid analysis supplies compositional data. Circular dichroism and infrared spectroscopy are used to assess secondary structure, particularly the alpha-helical content that influences aggregation behavior in solution.
Common degradation routes include hydrolysis of labile amide bonds, deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation. Aggregates can form during freeze-thaw cycling, at elevated pH, or when peptide concentration is high. Each route produces characteristic chromatographic or mass shifts that are tracked during stability studies. Whether a given minor impurity alters biological activity is often an open question, and specification limits are typically set on identity and purity rather than on functional data for trace species.
Lyophilized material is generally held at -20 degrees Celsius or lower, desiccated and protected from light, where it remains stable for extended periods. Reconstituted or ready-to-use solution is usually kept at 2 to 8 degrees Celsius with minimal agitation. Repeated freeze-thaw cycles should be avoided because they promote aggregation and reduce the soluble monomer fraction. Shipment of frozen solid commonly uses dry ice, while refrigerated liquid moves with validated cold packs. Stability beyond documented periods is not established.
Current or previous treatment with anti-resorptive or anti-angiogenic therapy Expose bone or bone that can be probed through intra-oral or extra-oral fistula in the maxillofacial region that has persisted for longer than 8 weeks. No history of radiation therapy or metastatic disease to the jaw. Osteonecrosis, or localized death of bone tissue, of the jaws, is a rare potential complication in cancer patients receiving treatments including radiation, chemotherapy, or in patients with tumors or infectious embolic events. In 2003, reports surfaced of the increased risk of osteonecrosis in patients receiving these therapies concomitant with intravenous bisphosphonate. Matrix metalloproteinase-2 may be a candidate gene for bisphosphonate-associated osteonecrosis of the jaws, since it is the only gene known to be associated with both bone abnormalities and atrial fibrillation, another side effect of bisphosphonates. In response to the growing base of literature on this association, the United States Food and Drug Administration issued a broad drug class warning of this complication for all bisphosphonates in 2005.
The photosynthetic amoeboids in the genus Paulinella—P. chromatophora, P. micropora, and marine P. longichromatophora—have the only known independently evolved chloroplast, often called a chromatophore. While all other chloroplasts originate from a single ancient endosymbiotic event, Paulinella independently acquired an endosymbiotic cyanobacterium from the genus Synechococcus around 90 – 140 million years ago. Each Paulinella cell contains one or two sausage-shaped chloroplasts; they were first described in 1894 by German biologist Robert Lauterborn. The chromatophore is highly reduced compared to its free-living cyanobacterial relatives and has limited functions. For example, it has a genome of about 1 million base pairs, one third the size of Synechococcus genomes, and only encodes around 850 proteins. However, this is still much larger than other chloroplast genomes, which are typically around 150,000 base pairs. Chromatophores have also transferred much less of their DNA to the nucleus of their hosts. About 0.3–0.8% of the nuclear DNA in Paulinella is from the chromatophore, compared with 11–14% from the chloroplast in plants. Similar to other chloroplasts, Paulinella provides specific proteins to the chromatophore using a specific targeting sequence. Because chromatophores are much younger compared to the canonical chloroplasts, Paulinella chromatophora is studied to understand how early chloroplasts evolved.
Information found in PPIs databases supports the construction of interaction networks. Although the PPI network of a given query protein can be represented in textbooks, diagrams of whole cell PPIs are frankly complex and difficult to generate. One example of a manually produced molecular interaction map is the Kurt Kohn's 1999 map of cell cycle control. Drawing on Kohn's map, Schwikowski et al. in 2000 published a paper on PPIs in yeast, linking 1,548 interacting proteins determined by two-hybrid screening. They used a layered graph drawing method to find an initial placement of the nodes and then improved the layout using a force-based algorithm. Bioinformatic tools have been developed to simplify the difficult task of visualizing molecular interaction networks and complement them with other types of data. For instance, Cytoscape is an open-source software widely used and many plugins are currently available. Pajek software is advantageous for the visualization and analysis of very large networks. Identification of functional modules in PPI networks is an important challenge in bioinformatics. Functional modules means a set of proteins that are highly connected to each other in PPI network. It is almost similar problem as community detection in social networks. There are some methods such as Jactive modules and MoBaS. Jactive modules integrate PPI network and gene expression data where as MoBaS integrate PPI network and Genome Wide association Studies.
Sources: en.wikipedia.org
=== Phase I - modification === In phase I, a variety of enzymes acts to introduce reactive and polar groups into their substrates. One of the most common modifications is hydroxylation catalysed by the cytochrome P-450-dependent mixed-function oxidase system. These enzyme complexes act to incorporate an atom of oxygen into nonactivated hydrocarbons, which can result in either the introduction of hydroxyl groups or N-, O- and S-dealkylation of substrates. The reaction mechanism of the P-450 oxidases proceeds through the reduction of cytochrome-bound oxygen and the generation of a highly-reactive oxyferryl species, according to the following scheme:
=== Absorption and distribution in the body === Following oral administration, alitretinoin exhibits variable absorption, which is increased when taken with food. It is extensively bound to plasma proteins. Metabolism occurs in the liver via CYP3A4, forming 4-oxoalitretinoin. The half-life ranges from 2 to 10 hours, and elimination occurs primarily renally. No significant systemic distribution is observed after dermal application.
=== Heart disease === Tricuspid regurgitation is usually secondary to right ventricular dilation which may be due to left ventricular failure (the most common cause), right ventricular infarction, inferior myocardial infarction, or cor pulmonale Other causes of tricuspid regurgitation include carcinoid syndrome and myxomatous degeneration.
Sources: en.wikipedia.org
=== Pharmacokinetics === The pharmacokinetic characteristics of reslizumab are similar across the children and adults. Peak serum concentrations are observed at the end of infusion and declines in a biphasic manner. The mean observed accumulation ratio of reslizumab following multiple doses of administration ranged from 1.5 to 1.9-fold. Reslizumab has a volume of distribution of approximately 5 L, clearance of approximately 7 mL/hour, and a half-life of about 24 days. Reslizumab is degraded by enzymatic proteolysis into small peptides and amino acids, as are other monoclonal antibodies.
John D. Rockefeller, 3rd, 1906-1978, About the Rockefellers, Rockefeller Archive Center John D Rockefeller 3rd papers, 1905-1980, DIMES: The Online Collection and Catalog of Rockefeller Archive Center. Rockefeller Brothers Fund website FBI Records: The Vault – John D. Rockefeller III at fbi.gov Asia Society – founded by Rockefeller.
ClCH2CO2H + Na2S2O3 → Na[O3S2CH2CO2H] + NaCl Na[O3S2CH2CO2H] + H2O → HSCH2CO2H + NaHSO4 Organolithium compounds and Grignard reagents react with sulfur to give the thiolates, which are readily hydrolyzed:
==== Serotonin ==== Amphetamine exerts analogous, yet less pronounced, effects on serotonin as on dopamine and norepinephrine. Amphetamine affects serotonin via VMAT2 inhibition and SERT phosphorylation. Like dopamine, amphetamine has low, micromolar affinity at the human 5-HT1A receptor.
Sources: en.wikipedia.org
建议在低温、避光、干燥环境中密封保存，常见条件为 2 至 8 摄氏度，长期存放可置于更低温度。应避免反复冻融，并尽量减少容器开启次数。
溶解后的稳定时间通常短于固体形态，受浓度、缓冲液和容器材质影响。冷藏条件下一般只能维持较短时间，具体期限应通过实际稳定性实验确认。
反相高效液相色谱用于纯度与含量测定，液相色谱串联质谱用于生物基质中的定量，体积排阻色谱用于检测聚集体。多种方法结合才能较完整地表征样品。
It is a dual GIP and GLP-1 receptor agonist, frequently grouped with incretin-based peptide therapeutics. It is a peptide rather than a small molecule and is given by subcutaneous injection.