dual agonist raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-10-12 and is reviewed periodically as new material appears.
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。
定量分析的主流方法是反相高效液相色谱联用紫外或质谱检测，利用肽在疏水固定相上的保留行为确定纯度与含量。对于生物基质中的浓度测定，常采用液相色谱串联质谱，并配合固相萃取或蛋白沉淀进行样品前处理。免疫分析法也可使用，但可能受到结构相关肽的交叉反应干扰。
Clinical research programs have evaluated tirzepatide in adults with type 2 diabetes and in adults with obesity or excess weight. Trials generally reported reductions in glycated hemoglobin and body weight across treatment periods of several months. Since these studies enrolled defined populations under controlled conditions, the findings describe group averages rather than individual outcomes. Open questions include the durability of effects after treatment stops, variation among subgroups, and the long-term consequences of sustained dual receptor stimulation. Published trial summaries should be consulted for exact measurements rather than secondary accounts.
Tirzepatide is a synthetic peptide built from 39 amino acid residues. Its backbone derives from the native glucose-dependent insulinotropic polypeptide sequence, altered at several positions to resist enzymatic cleavage. A fatty diacid group attached through a linker extends plasma residence time by promoting reversible binding to serum albumin. The molecule carries a net negative charge near physiological pH and has a reported molecular weight close to 4813 daltons. These features separate it from shorter incretin analogs and account for its prolonged dosing interval.
Pharmacologically, tirzepatide activates two distinct G protein-coupled receptors: the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. Binding at each target triggers cyclic AMP accumulation and downstream signaling in pancreatic beta cells, adipose tissue and the central nervous system. Because the two pathways overlap only partially, the combined effect on insulin secretion, glucagon suppression and appetite signaling differs from that of selective single-receptor compounds. Affinity is not equal across the two targets, and the clinical meaning of that imbalance remains an area of active study.
| 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 |
Structure-activity work shows that fatty acid length, linker chemistry and the position of acylation all influence albumin affinity and receptor potency. Plasma protein binding exceeds 99 percent, which restricts distribution and slows renal clearance. Degradation proceeds largely through general proteolysis and fatty acid oxidation rather than cytochrome P450 metabolism, so exposure to common oxidative drug interactions is limited. Whether these clearance routes vary meaningfully between individuals is not fully established.
The molecule is a synthetic 39-amino-acid peptide whose backbone derives from the sequence of human glucose-dependent insulinotropic polypeptide, with several substitutions that raise metabolic stability and shift receptor preference. A C20 fatty diacid is attached through a short linker to a lysine side chain, a modification that increases binding to serum albumin. The reported monoisotopic mass is approximately 4813 Da. Near neutral pH the peptide carries a net negative charge, and the lipid tail makes the molecule markedly more hydrophobic than the unmodified parent sequence.
Storage recommendations for tirzepatide generally specify refrigeration at 2–8 °C to maintain stability. The peptide should be protected from light and kept in its original packaging to prevent aggregation or adsorption. Freezing is not recommended because freeze-thaw cycles can cause aggregation or precipitation. Once dispensed, storage conditions and in-use periods follow product-specific labeling, which may allow room temperature storage for a limited time.
Degradation pathways for tirzepatide include deamidation, oxidation, and aggregation, which are common for therapeutic peptides. These processes can be monitored by size-exclusion chromatography (SEC) for aggregates and ion-exchange chromatography for charge variants. Forced degradation studies under acidic, basic, oxidative, and thermal stress help identify potential impurities. The exact stability profile depends on formulation, concentration, and container-closure system.
Analytical characterization of tirzepatide typically employs reversed-phase high-performance liquid chromatography (RP-HPLC) for purity assessment and peptide mapping. Mass spectrometry, often coupled with electrospray ionization, confirms molecular weight and sequence integrity. Amino acid analysis and capillary electrophoresis may also be used to detect impurities or degradation products. These methods are essential for batch release and stability studies.
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.
Apiin (apigenin 7-O-apioglucoside), isolated from parsley and celery Apigetrin (apigenin 7-glucoside), found in dandelion coffee Vitexin (apigenin 8-C-glucoside) Isovitexin (apigenin 6-C-glucoside) Rhoifolin (apigenin 7-O-neohesperidoside) Schaftoside (apigenin 6-C-glucoside 8-C-arabinoside)
An example is the usage of the word in the religious landscape of early modern Europe. "Addiction" at the time meant "to attach" to something, giving it both positive and negative connotations. The object of this attachment could be characterized as "good or bad". The meaning of addiction during the early modern period was mostly associated with positivity and goodness; during this early modern and highly religious era of Christian revivalism and Pietistic tendencies, it was seen as a way of "devoting oneself to another".
Thiotepa, as well as its more reactive metabolite, tepa, work as an alkylating agent via its aziridine ring. Due to the basic nature of aziridine and the physiological pH, aziridine is protonated to form the aziridinium ion, resulting in an electrophilic moiety that is highly susceptible to nucleophiles. DNA reacts through the nucleophilic N-7 position of guanine onto the electrophilic aziridine ring, rendering alkylated nucleobases. Thiotepa contains three reactive aziridine rings, allowing a single molecule to alkylate multiple nucleobases. Hence, it is a polyfunctional alkylating agent. This property also gives rise to its ability to cross-link DNA strands. Apart from its mechanism of action, it is suggested that thiotepa can function as a prodrug. Due to its moderate lipophilicity, it first penetrates the cell membrane, followed by hydrolysis to release the more hydrophilic aziridine ring. The aziridine ring can once again alkylate the DNA. The highly reactive metabolite tepa can be considered as an active metabolite and alkylates DNA similar to its parent drug. Ultimately, the alkylation of DNA leads to cell damage and can lead to cell death. Cross-linking blocks the separation of DNA strands, inhibiting replication and the proliferation of cells.
=== Combinatorial extension === The combinatorial extension (CE) method is similar to DALI in that it too breaks each structure in the query set into a series of fragments that it then attempts to reassemble into a complete alignment. A series of pairwise combinations of fragments called aligned fragment pairs, or AFPs, are used to define a similarity matrix through which an optimal path is generated to identify the final alignment. Only AFPs that meet given criteria for local similarity are included in the matrix as a means of reducing the necessary search space and thereby increasing efficiency. A number of similarity metrics are possible; the original definition of the CE method included only structural superpositions and inter-residue distances but has since been expanded to include local environmental properties such as secondary structure, solvent exposure, hydrogen-bonding patterns, and dihedral angles. An alignment path is calculated as the optimal path through the similarity matrix by linearly progressing through the sequences and extending the alignment with the next possible high-scoring AFP pair. The initial AFP pair that nucleates the alignment can occur at any point in the sequence matrix. Extensions then proceed with the next AFP that meets given distance criteria restricting the alignment to low gap sizes. The size of each AFP and the maximum gap size are required input parameters but are usually set to empirically determined values of 8 and 30 respectively.
==== Distribution of inefficient medicine and harms to health ==== One of the first acts under Melo's administration was to buy, among other medicines, azithromycin, ivermectin, and hydroxychloroquine and chloroquine – the latter of two which had been approved for the treatment of malaria – to supposedly combat COVID-19, despite multiple studies showing that all the medicines bought were ineffective towards treating the virus. The controversial decision was brought to suit by PSOL, which alleged that his administration was using public money to buy the medicine. The measure was also criticized by the council of the Faculty of Medicine at the Federal University of Rio Grande do Sul that asked for the immediate suspension of their distribution. Melo justified the purchase with the Ministry of Medicine by stating that people in the middle and upper-middle classes, and their friends, were taking the medicine. In total, the city government bought 239,000 reais worth of the medications, which they packaged into what they called the "COVID kit". Along with their ineffectiveness, it has been reported that the use of the medications combined over a long period and in high doses could lead to liver and renal damage, leading to the need for a liver transplant or possibly death. In February, the Justice ministry prohibited, in a liminary decision, the city from distributing the kit. In the decision, the judge argued that the prohibition would be necessary while robust evidence, based on clinical studies and recognized by the scientific community, did not exist.
Sources: en.wikipedia.org
Despite having suitable crystals, however, the structure of tRNAPHE was not immediately solved at high resolution; rather it took pioneering work in the use of heavy metal derivatives and a good deal more time to produce a high-quality density map of the entire molecule. In 1973, Kim et al. produced a 4 Ångström map of the tRNA molecule in which they could unambiguously trace the entire backbone. This solution would be followed by many more, as various investigators worked to refine the structure and thereby more thoroughly elucidate the details of base pairing and stacking interactions, and validate the published architecture of the molecule. The tRNAPHE structure is notable in the field of nucleic acid structure in general, as it represented the first solution of a long-chain nucleic acid structure of any kind—RNA or DNA—preceding Richard E. Dickerson's solution of a B-form dodecamer by nearly a decade. Also, tRNAPHE demonstrated many of the tertiary interactions observed in RNA architecture which would not be categorized and more thoroughly understood for years to come, providing a foundation for all future RNA structural research.
Cerebrosides (monoglycosylceramides) are a group of glycosphingolipids which are important components of animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1-hydroxyl moiety. The sugar residue can be either glucose or galactose; the two major types are therefore called glucocerebrosides (a.k.a. glucosylceramides) and galactocerebrosides (a.k.a. galactosylceramides). Galactocerebrosides are typically found in neural tissue, while glucocerebrosides are found in other tissues.
=== 2018 American consulate bombing === On 2 December 2018, at approximately 7:30 CST, two grenades were thrown onto consular grounds in Guadalajara, with one of them exploding and causing a 16-inch (approximately 40 cm) hole in the wall of the building. At the time of the bombing, the consulate general office was closed and no injuries were sustained. It is unconfirmed if the attack was carried out by a cartel.
The formyl peptide receptors (FPR) belong to a class of G protein-coupled receptors involved in chemotaxis. In humans, there are three formyl peptide receptor isoforms, each encoded by a separate gene that are named FPR1, FPR2, and FPR3. These receptors were originally identified by their ability to bind N-formyl peptides such as N-formylmethionine produced by the degradation of either bacterial or host cells. Hence formyl peptide receptors are involved in mediating immune cell response to infection. These receptors may also act to suppress the immune system under certain conditions. The close phylogenetic relation of signaling in chemotaxis and olfaction was recently proved by detection formyl peptide receptor like proteins as a distinct family of vomeronasal organ chemosensors in mice. FPR is now properly accepted as termed FPR1 by the International Union of Basic and Clinical Pharmacology.
Vitamin C megadosage is a term describing the consumption or injection of vitamin C in doses comparable to or higher than the amounts produced by the livers of mammals which are able to synthesize vitamin C. An argument for this, although not the actual term, was described in 1970 in an article by Linus Pauling. Briefly, his position was that for optimal health, humans should be consuming at least 2,300 mg/day to compensate for the inability to synthesize vitamin C. The recommendation also fell into the consumption range for gorillas—a non-synthesizing near-relative to humans. A second argument for high intake is that serum ascorbic acid concentrations increase as intake increases until it plateaus at about 190 to 200 micromoles per liter (μmol/L) once consumption exceeds 1,250 milligrams. As noted, government recommendations are a range of 40 to 110 mg/day and normal plasma is approximately 50 μmol/L, so "normal" is about 25% of what can be achieved when oral consumption is in the proposed megadose range. Pauling popularized the concept of high dose vitamin C as prevention and treatment of the common cold in 1970. A few years later he proposed that vitamin C would prevent cardiovascular disease, and that 10 grams/day, initially administered intravenously and thereafter orally, would cure late-stage cancer. Mega-dosing with ascorbic acid has other champions, among them chemist Irwin Stone and the controversial Matthias Rath and Patrick Holford, who both have been accused of making unsubstantiated treatment claims for treating cancer and HIV infection.
Sources: en.wikipedia.org
==== Adherence ==== Poor compliance with medications and follow-up visits are a major reason for treatment failure and disease progression in glaucoma patients. Poor adherence could lead to increased complication rates, thus increasing the need for non-pharmacological interventions, including surgery. Patient education and communication must be ongoing to sustain successful treatment plans for this lifelong disease with no early symptoms.
=== Screening for GBS colonization === Though the GBS colonization status of women can change during pregnancy, cultures to detect GBS carried out ≤5 weeks before delivery predict quite accurately the GBS carrier status at delivery. In contrast, if the prenatal culture is performed more than five weeks before delivery, it is unreliable for predicting the GBS carrier status at delivery. The clinical specimens recommended for culture of GBS at 36–37 weeks' gestation provide a 5-week window for valid culture results that includes births that occur up to a gestational age of at least 41 weeks (32–34 weeks of gestation for women with twins) are swabs collected from the lower vagina (near the introitus) and then from the rectum (through the anal sphincter) without use of a speculum. Vaginal-rectal samples should be collected using a flocked swab, preferably, since flocked swabs release samples and microorganisms more effectively than fiber swabs. Following the recommendations of the Centers for Disease Control and Prevention of the United States (CDC) these swabs should be placed into a non-nutritive transport medium and later inoculated into a selective enrichment broth, Todd Hewitt broth with selective antibiotics (enrichment culture). After incubation, the enrichment broth is subcultured to blood agar plates, and GBS-like colonies are identified by the CAMP test or using latex agglutination with GBS antisera.
Sir Ninian Martin Stephen was selected by Queen Elizabeth II to become the next Governor-General of Australia, to take the place of Sir Zelman Cowen at the latter's retirement in July. Died: Marcel Camus, 69, French film director known for Black Orpheus (Orfeu Negro), winner of the 1959 Palme d'Or and the 1960 Academy Award for Best Foreign Language Film, died following open heart surgery.
Nine variables were identified as effective predictors for 90-day mortality after a discharge from a cirrhosis-related hospital admission. The variables include all Model for End-Stage Liver Disease (MELD)'s components, as well as sodium, albumin, total cholesterol, white blood cell count, age, and length of stay. The hepatic venous pressure gradient (difference in venous pressure between incoming and outgoing blood to the liver) also determines the severity of cirrhosis, although it is hard to measure. A value of 16 mm or more means a greatly increased risk of death.
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 synthetic peptide that activates both the GIP and GLP-1 receptors, making it a dual agonist. Approved products are given by injection rather than by mouth. It is not a small molecule and does not belong to the older sulfonylurea or thiazolidinedione families.