This is a working overview of receptor agonist, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-14 and is reviewed periodically as new material appears.
Semaglutide dissolves readily in water and in aqueous buffers near neutral pH. Solubility decreases near the isoelectric point, where net charge is minimal. Common laboratory solvents include phosphate-buffered saline and dilute ammonium bicarbonate. Strongly acidic or basic conditions may accelerate hydrolysis. Working concentrations are usually prepared by diluting a concentrated stock. Vial surfaces can adsorb small amounts of peptide at low concentrations, so carrier proteins or low-binding tubes are sometimes used.
Reverse-phase high-performance liquid chromatography is the standard method for purity assessment, separating the peptide from truncated or oxidized variants. Mass spectrometry confirms molecular mass and detects modifications, while ultraviolet absorbance near 280 nanometers supports concentration measurement through tryptophan and tyrosine residues. Circular dichroism can indicate secondary structure, though the peptide is largely helical in solution, and ion-exchange chromatography resolves charge variants. Purity values above 95 percent are typical for research-grade material. Stability studies track degradation over time under defined conditions.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Water and aqueous buffers | Near neutral pH |
| Storage temperature | Minus 20 to minus 80 C | Long-term, lyophilized |
| Analytical method | RP-HPLC | Purity assessment |
| Typical purity | Greater than 95 percent | Research-grade material |
Semaglutide 是一种经结构修饰的胰高血糖素样肽-1 类似物，其主链与内源性 GLP-1(7-36) 约有百分之九十四的序列一致性。第 8 位丙氨酸被 α-氨基异丁酸取代，使二肽基肽酶-4 无法识别原有切割位点。第 34 位赖氨酸换为精氨酸，进一步降低酶解速率。第 26 位赖氨酸经间隔基连接一条含十八个碳的二酸脂肪链，该侧链赋予分子与血浆白蛋白结合的能力。
该分子作为 GLP-1 受体的选择性激动剂发挥作用，受体属于 B 类 G 蛋白偶联受体家族，激活后经 Gs 通路提升细胞内环腺苷酸水平。在胰腺 β 细胞，信号促进葡萄糖依赖性的胰岛素释放，血糖偏低时该作用明显减弱。在胰岛 α 细胞，胰高血糖素分泌受到抑制。中枢神经系统与胃肠道同样存在受体表达，相应信号参与食欲调节以及胃排空速率的降低。
The primary target is the GLP-1 receptor, a class B G protein-coupled receptor expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises intracellular cyclic AMP, which potentiates glucose-dependent insulin secretion and lowers glucagon release when blood glucose is elevated. Signalling in the hypothalamus and brainstem is associated with reduced appetite and slower gastric emptying. Because the insulinotropic effect depends on prevailing glucose levels, the hypoglycaemic risk of the peptide alone is described as low in most study settings. The relative contribution of peripheral and central actions remains an active research question.
Large randomised trials in adults with type 2 diabetes and in adults with obesity have reported reductions in body weight and improvements in several cardiovascular risk markers. One outcome trial found a lower incidence of major adverse cardiovascular events in participants with diabetes and established cardiovascular disease. Gastrointestinal effects such as nausea and vomiting are the most frequently reported adverse events and often diminish over time. Changes in lean body mass during weight loss are an area of ongoing investigation. Effects in adolescents and in pregnancy are less well characterised, and current labelling advises against use during pregnancy.
Semaglutide is a synthetic peptide analogue of glucagon-like peptide-1, a gut hormone released after nutrient intake. The molecule contains 31 amino acid residues and differs from the native sequence at several positions. A non-natural residue at position eight resists the enzyme that normally truncates the hormone, while a lysine-linked fatty diacid side chain promotes binding to serum albumin. These two modifications extend the circulating half-life from minutes to roughly one week. The peptide is produced by solid-phase synthesis followed by selective acylation, and its identity and purity are confirmed by spectrometric and chromatographic techniques.
Inhalants are gases, aerosols, or solvents that are breathed in and absorbed through the lungs. While some "inhalant" drugs are used for medical purposes, as in the case of nitrous oxide, a dental anesthetic, inhalants are used as recreational drugs for their intoxicating effect. Most inhalant drugs that are used non-medically are ingredients in household or industrial chemical products that are not intended to be concentrated and inhaled, including organic solvents (found in cleaning products, fast-drying glues, and nail polish removers), fuels (gasoline (petrol) and kerosene), and propellant gases such as Freon and compressed hydrofluorocarbons that are used in aerosol cans such as hairspray, whipped cream, and non-stick cooking spray. A small number of recreational inhalant drugs are pharmaceutical products that are used illicitly, such as anesthetics (ether and nitrous oxide) and volatile anti-angina drugs (alkyl nitrites, more commonly known as "poppers"). The most serious inhalant abuse occurs among children and teens who "[...] live on the streets completely without family ties". Inhalant users inhale vapor or aerosol propellant gases using plastic bags held over the mouth or by breathing from a solvent-soaked rag or an open container. The effects of inhalants range from an alcohol-like intoxication and intense euphoria to vivid hallucinations, depending on the substance and the dosage. Some inhalant users are injured due to the harmful effects of the solvents or gases, or due to other chemicals used in the products inhaled.
Mass spectral interpretation is the method employed to identify the chemical formula, characteristic fragment patterns and possible fragment ions from the mass spectra. Mass spectra is a plot of relative abundance against mass-to-charge ratio. It is commonly used for the identification of organic compounds from electron ionization mass spectrometry. Organic chemists obtain mass spectra of chemical compounds as part of structure elucidation and the analysis is part of many organic chemistry curricula.
== History == The brewery started as a small, casual pub in the alleyways of Gyeongnidan in Seoul. The idea to start the pub was inspired by Tudor's article in The Economist, which claimed: "brewing remains just about the only useful activity at which North Korea beats the South." The pub began selling Bill's Pale Ale, The Booth's first brew, along with a small selection of pizza. After realizing how crucial the cold chain transportation system was to maintaining the quality and flavor of beer, the owners established the first cold chain import and distribution system, The Booth Cold Chain. This was soon importing beers from Mikkeller, Evil Twin, To Øl, and 8 Wired. Two crowdfunding campaigns titled Equity for Booth were launched, in September 2015 and February 2017.
=== The degree of crystallinity and crystal structure of nanocellulose. === Nanocellulose exhibits cellulose crystal I organization and the degree of crystallinity is unchanged by the preparation of the nanocellulose. Typical values for the degree of crystallinity were around 63%.
Pleasure promotes well-being as a positive feeling about what is attractive. Pain, by contrast, diminishes well-being as a negative feeling about what is aversive. Pleasure and pain are closely tied to the brain's reward system, influencing motivation and behavior by reinforcing beneficial actions and discouraging harmful ones. They shape how individuals perceive their lives and interact with their social and physical environments. Pleasure and pain are commonly seen as opposites that counterbalance each other. This view suggests that the negative value of experiencing intense pain can be compensated by the positive value of experiencing intense pleasure. A different perspective argues that their relation is more complex because they influence experience, motivation, and well-being in distinct ways that are not always symmetrical. Following this idea, one view holds that avoiding pain is more important than seeking pleasure. Pleasure and pain are often tied to emotions, which are temporary states of arousal, such as joy, hope, anger, and fear. Emotions include subjective experiences of pleasure and pain alongside other psychological phenomena, such as the evaluative assessment of a situation and a disposition to engage in certain types of behavior. For example, fear evaluates a situation as dangerous and is associated with a behavioral disposition to flee. Additionally, emotions are linked to physiological changes, like sweating, and bodily expressions that signal the emotional state to others.
Sources: en.wikipedia.org
Beta cells in the islets of Langerhans release insulin in two phases. The first-phase release is rapidly triggered in response to increased blood glucose levels, and lasts about 10 minutes. The second phase is a sustained, slow release of newly formed vesicles triggered independently of sugar, peaking in 2 to 3 hours. The two phases of the insulin release suggest that insulin granules are present in diverse stated populations or "pools". During the first phase of insulin exocytosis, most of the granules predispose for exocytosis are released after the calcium internalization. This pool is known as Readily Releasable Pool (RRP). The RRP granules represent 0.3-0.7% of the total insulin-containing granule population, and they are found immediately adjacent to the plasma membrane. During the second phase of exocytosis, insulin granules require mobilization of granules to the plasma membrane and a previous preparation to undergo their release. Thus, the second phase of insulin release is governed by the rate at which granules get ready for release. This pool is known as a Reserve Pool (RP). The RP is released slower than the RRP (RRP: 18 granules/min; RP: 6 granules/min). Reduced first-phase insulin release may be the earliest detectable beta cell defect predicting onset of type 2 diabetes. First-phase release and insulin sensitivity are independent predictors of diabetes. The description of first phase release is as follows:
While there are many rehabilitation centres for wealthy people struggling with addiction in South Africa there are very few facilities for the poor. Some have argued that people struggling with heroin addiction are treated as the 'undeserving poor' and subject to policing rather than medical interventions. In the populous province of KwaZulu-Natal there are only two government rehab centres accessible by poor people.
The physics of FTICR is similar to that of a cyclotron at least in the first approximation. In the simplest idealized form, the relationship between the cyclotron frequency and the mass-to-charge ratio is given by
It is the sedating ingredient of NyQuil (generally in combination with dextromethorphan and acetaminophen). In Commonwealth countries, such as Australia, Canada, South Africa, and the United Kingdom, doxylamine is available prepared with paracetamol (acetaminophen) and codeine under the brand name Dolased, Propain Plus, Syndol, or Mersyndol, as treatment for tension headache and other types of pain. Doxylamine succinate is used in general over-the-counter sleep-aids branded as Somnil (South Africa), Dozile, Donormyl, Lidène (France, Russian Federation), Dormidina (Spain, Portugal), Restavit, Unisom-2, Sominar (Thailand), Sleep Aid (generic, Australia), Dorminox (Poland) and Noctiben Mea (Slovenia). In the United States: Doxylamine succinate is the active ingredient in many over-the-counter sleep aids branded under various names. Doxylamine succinate and pyridoxine (vitamin B6) are the ingredients of Diclegis, approved by the FDA in April 2013 becoming the only drug approved for morning sickness with a class A safety rating for pregnancy (no evidence of risk). In Canada: Doxylamine succinate and pyridoxine (vitamin B6) are the ingredients of Diclectin, which is used to prevent morning sickness. It is also available in combination with vitamin B6 and folic acid under the brand name Evanorm (marketed by Ion Healthcare). In India Doxylamine preparations are available typically in combination with pyridoxine and may also contain folic acid. Doxylamine usage is thus restricted for pregnant women.
A recent DNA analysis reported in media outlets, based on a preprint study from the University of Padova, identified a proportion of genetic material, DNA traces, found on the Shroud of Turin, suggest the extensive exposure of the cloth in the Mediterranean region and the possibility that the yarn was produced in India. The researchers stated that this may reflect historical trade connections, such as the import of linen or material from regions near the Indus Valley, rather than indicating a geographic origin of the cloth. The study also noted that the detected DNA reflects material accumulated over periods of handling and environmental exposure, and does not establish the age or history of the shroud. In 2016, Italian palynologist Marzia Boi proposed based on published pictures of pollen from the shroud that the most abundant pollen on the shroud was from genus Helichrysum and suggested that the former could have come from balms and ointments used in first century AD burial rituals. However, the researchers who studied the pollen directly had identified it as from Gundelia tournefortii.
Sources: en.wikipedia.org
Long-term storage is usually at minus 20 to minus 80 degrees Celsius in a sealed, desiccated container. Working aliquots can be held briefly at 2 to 8 degrees Celsius.
Repeated temperature cycling can promote aggregation and peptide degradation. Dividing material into single-use aliquots limits this risk.
Mass spectrometry is commonly used to confirm molecular mass and detect structural modifications. It is often paired with chromatographic purity assessment.
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.