The short version of lyophilisation fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-04-06. Anything still debated is marked as such rather than presented as settled.
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。
Tirzepatide 是一种由 39 个氨基酸组成的合成肽,分子结构上以 GIP 序列为骨架并引入脂肪酸侧链修饰,使其能够同时与葡萄糖依赖性促胰岛素多肽(GIP)受体和胰高血糖素样肽-1(GLP-1)受体结合。这种双重激动特性使它在同类肽类药物中区别于选择性 GLP-1 受体激动剂。该分子最早由一家制药公司在 2010 年代报道,随后进入糖尿病与体重管理领域的临床研究。
在生理层面,GIP 与 GLP-1 均为肠道内分泌细胞分泌的肠促胰素,进食后参与胰岛素分泌调节与胃排空抑制。Tirzepatide 通过同时激活这两条信号通路,使胰岛素分泌的葡萄糖依赖性增强,并延缓冲胃排空、降低食欲信号。与单一 GLP-1 激动相比,双靶点作用在血糖控制和体重变化上的效应幅度更大,但具体贡献比例仍在研究之中。
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.
Recommended storage for reference material is a freezer at approximately -20 degrees Celsius, protected from light and moisture. Commercial injectable presentations are stored refrigerated between 2 and 8 degrees Celsius and must not be frozen. Product labelling generally permits a limited period at controlled room temperature once dispensed, with the exact window depending on the presentation. Repeated temperature cycling is avoided because it can promote aggregation or deamidation of the peptide chain.
| 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 |
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.
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.
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.
The compound first appeared in the scientific literature as an investigational agent for type 2 diabetes. Clinical development proceeded through phase 1, phase 2, and phase 3 programs that measured glycemic control as a primary endpoint while recording body weight as a secondary outcome. Regulatory approval in the United States followed in 2022 for glycemic control, and a separate indication for chronic weight management was added later. Subsequent trials have examined cardiovascular outcomes in adults with elevated cardiovascular risk. Debates continue over how much of the observed effect derives from each receptor arm.
Structural work on the molecule centers on a C20 fatty diacid moiety attached through a linker to the peptide backbone. This side chain promotes reversible binding to serum albumin, which slows renal clearance and supports a prolonged action profile. The peptide backbone incorporates aminoisobutyric acid substitutions that limit recognition by digestive enzymes. Together these modifications produce a molecule that is stable enough for subcutaneous delivery but still dependent on careful manufacturing control. Analytical characterization of the active pharmaceutical ingredient typically follows the conventions used for other synthetic peptides.
Tirzepatide is a synthetic peptide composed of 39 amino acids. It acts as a dual agonist at two incretin receptors, the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide-1 receptor. The molecule was designed by modifying the native sequence of glucose-dependent insulinotropic polypeptide to improve metabolic stability and extend its circulation time. Its structure includes several non-natural amino acid residues and a fatty acid side chain. These features distinguish it from earlier single-receptor incretin analogs studied in the same period.
is the net fluid movement between compartments. By convention, outward force is defined as positive, and inward force is defined as negative. The solution to the equation is known as the net filtration or net fluid movement (Jv). If positive, fluid will tend to leave the capillary (filtration). If negative, fluid will tend to enter the capillary (absorption). This equation has a number of important physiologic implications, especially when pathologic processes grossly alter one or more of the variables. According to Starling's equation, the movement of fluid depends on six variables:
Additionally, PELs lack the inherent amplification capabilities of DELs and rely on current mass spectrometric analysis for decoding. Since peptide decoding requires complex mass spectrometry and computational power, this means that current detection sensitivity limits practical PEL sizes.
Carfentanil or carfentanyl, formerly sold under the brand name Wildnil, is an extremely potent opioid analgesic formerly used in veterinary medicine to anesthetize large animals such as elephants and rhinoceroses. It is a structural analogue of the synthetic opioid analgesic fentanyl. It is typically administered in this context by tranquilizer dart. Carfentanil has also been used in humans to image opioid receptors. It has additionally been used as a recreational drug, typically by injection, insufflation, or inhalation. Deaths have been reported in association with carfentanil. Effects and side effects of carfentanil in humans are similar to those of other opioids and include euphoria, relaxation, pain relief, pupil constriction, drowsiness, sedation, slowed heart rate, low blood pressure, lowered body temperature, loss of consciousness, and suppression of breathing. The effects of carfentanil, including overdose, can be reversed by the opioid antagonists naloxone and naltrexone, though higher doses than usual may be necessary compared to other opioids. It acts as an ultrapotent and highly selective agonist of the μ-opioid receptor. Carfentanil was first synthesized in 1974 by a team of chemists at Janssen Pharmaceuticals which included Paul Janssen. It was introduced into veterinary medicine in 1986. Carfentanil is legally controlled in most jurisdictions.
For a better understanding of the stiffness and strain of resilin, Hooke's law should be taken into consideration. For linear springs, Hooke's law states that the force required to deform the spring is directly proportional to the amount of deformation by a constant which is the characteristic of the spring. A material is viewed as elastic when it can be deformed to a large extend with a limited amount of force. Hydrated resilin has a tensile modulus of 640–2000 kPa, an unconfined compressive modulus of 600–700 kPa, and a strain to break of 300%.
== External links == Annotated bibliography for Francis Aston from the Alsos Digital Library for Nuclear Issues Francis William Aston on Nobelprize.org including the Nobel Lecture, 12 December 1922 Mass Spectra and Isotopes Aston biography from Cambridge History of Mass Spectrometry - Pioneers
Sources: en.wikipedia.org
=== World War II === From the start of World War II in 1939, German ships used the gap to break out from their bases in northern Germany (and from occupied Norway after April 1940) with a view to attacking Allied shipping convoys, but Allied blocking efforts in the North Sea and in the GIUK gap impeded such break-outs. British forces occupied the Faroe Islands in April 1940, and Iceland in May 1940; the United States took over effective control of Greenland in 1940. But the German Kriegsmarine profited greatly from the fall of France in June 1940, after which German submarines could operate from bases on the French coast. The origin of the term "gap" dates to this period, when there was a gap in air coverage known as the Mid-Atlantic gap or the "Greenland air gap". This gap was an area that land-based aircraft could not reach and where, as a result, they could not carry out their anti-submarine duties.
== Entrepreneurship == Mrksich has been an active entrepreneur over the past twenty years. He co-founded SAMDI Tech in 2011, which uses his label-free assay technology to perform high throughput screens for pharmaceutical companies. SAMDI Tech entered into a partnership with Charles River Laboratories in 2018 and was purchased by CRL in 2023. Mrksich also co-founded WMR Biomedical in 2008, with George Whitesides and Carmichael Roberts to develop resorbable stent materials; this company was renamed Lyra Therapeutics and had an IPO in 2020 (NASDAQ LYRA) and has drug-eluting stents in clinical trials for ear, nose and throat disease, including chronic rhinosinusitis. Mrksich has recently founded ModuMab Therapeutics, which applies his megamolecule technology to creating antibody mimics for a broad range of diseases.
== Pre-atomic chemistry == Working in the late 17th century, Robert Boyle developed the concept of a chemical element as substance different from a compound. Near the end of the 18th century, a number of important developments in chemistry emerged without referring to the notion of an atomic theory. The first was Antoine Lavoisier who showed that compounds consist of elements in constant proportion, redefining an element as a substance which scientists could not decompose into simpler substances by experimentation. This brought an end to the ancient idea of the elements of matter being fire, earth, air, and water, which had no experimental support. Lavoisier showed that water can be decomposed into hydrogen and oxygen, which in turn he could not decompose into anything simpler, thereby proving these are elements. Lavoisier also defined the law of conservation of mass, which states that in a chemical reaction, matter does not appear nor disappear into thin air; the total mass remains the same even if the substances involved were transformed. In 1797 the French chemist Joseph Proust established the law of definite proportions, which states that if a compound is broken down into its constituent chemical elements, then the masses of those constituents will always have the same proportions by weight, regardless of the quantity or source of the original compound. This definition distinguished compounds from mixtures.
== Nomenclature == Stop codons were historically given many different names, as they each corresponded to a distinct class of mutants that all behaved in a similar manner. These mutants were first isolated within bacteriophages (T4 and lambda), viruses that infect the bacteria Escherichia coli. Mutations in viral genes weakened their infectious ability, sometimes creating viruses that were able to infect and grow within only certain varieties of E. coli.
Sources: en.wikipedia.org
== Function == It is known that it participates in some specific immune responses. It plays a part in tissue inflammation as well as the engulfing of pathogens by phagocytes. In addition it is known to help to neutralize some viruses. The properdin promotes the association of C3b with Factor B and provides a focal point for the assembly of C3bBb on a surface. It binds to preformed alternative pathway C3-convertases. Properdin also inhibits the Factor H – mediated cleavage of C3b by Factor I. Properdin, in addition to Factor H, can bind to glycosaminoglycan (GAG) epitopes by renal tubular heparin sulfates. Additionally, the binding of properdin to Salmonella typhosa lipopolysaccharide (LPS) and Neisseria meningitidis lipopolysaccharide result in activation of the complementary alternative pathway. Furthermore, it binds to various microbial surfaces, resulting in the assembly of the alternative pathway C3 convertase.
Since December 1989, Romania has pursued a policy of strengthening relations with the West in general, more specifically with the United States and the EU, albeit with limited relations involving the Russian Federation. It joined NATO on 29 March 2004, the EU on 1 January 2007, while it joined the International Monetary Fund and the World Bank in 1972, and is a founding member of the World Trade Organization. Romania is recognised as a middle power for its military capabilities, as well as its active diplomatic engagement on the global stage. Recent governments have stated that their goals include strengthening ties with and helping other countries (in particular Moldova, Ukraine, and Georgia) with better integration with the rest of the West. Romania has also made clear since the late 1990s that it supports NATO and EU membership for the democratic former Soviet republics in Eastern Europe and the Caucasus. Romania applied to join to the Schengen Area in 2007, acquiring full membership in 2025 along with Bulgaria. In December 2005, President Traian Băsescu and United States Secretary of State Condoleezza Rice signed an agreement that would allow a U.S. military presence at several Romanian facilities primarily in the eastern part of the country. In 2009, US Secretary of State Hillary Clinton referred to Romania as "one of the most trustworthy and respectable US allies".
Historically, many of the prestigious universities in Peru have been public, including the National University of San Marcos. Founded in May 1551, it is the top university in Peru and the oldest university in the Americas. To be admitted into one of the national public universities, students must have a high score on the admission test. In 2002, the most prestigious public universities joined and created the Strategic Alliance of Peruvian Universities, including National University of San Marcos, La Molina – National Agrarian University, National University of Engineering, Federico Villarreal University, and the National University of Callao. Other public and private universities joined as an associate or advisory members.
=== Peroxide stress response === In response to an increased flux of hydrogen peroxide and other organic peroxides such as tert-butyl hydroperoxide and cumene hydroperoxide, peroxide stimulon gets activated. Studies of E. coli response to H2O2 have shown that exposure to H2O2 elevated mRNA levels of 140 genes, of which 30 genes are members of the OxyR regulon. The genes include many genes coding for metabolic enzymes and antioxidant enzymes demonstrating the role of these enzymes in reorganization of metabolism under stress conditions.
== Ribozymes and the origin of life == RNA can also act as a hereditary molecule, which encouraged Walter Gilbert to propose that in the distant past, the cell used RNA as both the genetic material and the structural and catalytic molecule rather than dividing these functions between DNA and protein as they are today; this hypothesis is known as the "RNA world hypothesis" of the origin of life. Since nucleotides and RNA (and thus ribozymes) can arise by inorganic chemicals, they are candidates for the first enzymes, and in fact, the first "replicators" (i.e., information-containing macro-molecules that replicate themselves). An example of a self-replicating ribozyme that ligates two substrates to generate an exact copy of itself was described in 2002. The discovery of the catalytic activity of RNA solved the "chicken and egg" paradox of the origin of life, solving the problem of origin of peptide and nucleic acid central dogma. According to this scenario, at the origin of life, all enzymatic activity and genetic information encoding was done by one molecule: RNA. Ribozymes have been produced in the laboratory that are capable of catalyzing the synthesis of other RNA molecules from activated monomers under very specific conditions, these molecules being known as RNA polymerase ribozymes. The first RNA polymerase ribozyme was reported in 1996, and was capable of synthesizing RNA polymers up to 6 nucleotides in length.
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.