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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.
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.
Reconstituted solutions are less stable than the dry powder, and stability depends on concentration, pH, buffer composition, and container material. Low-protein-binding tubes reduce loss of peptide to plastic surfaces. Some researchers add a carrier protein to limit adsorption at low concentrations. The exact shelf life of a given solution is best determined empirically through a stability study rather than assumed from general guidance, because published data cover only a limited set of conditions.
Storage conditions for semaglutide depend heavily on the presentation. Lyophilized research powder is generally kept at two to eight degrees Celsius in a sealed container, protected from light and moisture. Manufacturer labeling for finished injectable products specifies refrigeration before first use, with defined in-use periods at room temperature afterward. The oral tablet form is stored at controlled room temperature and is more tolerant of short excursions. Temperature excursions should be documented rather than inferred.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Acylated GLP-1 receptor agonist | 31-residue synthetic peptide |
| Molecular formula | C187H291N45O59 | established for the free peptide |
| Appearance | White to off-white powder | as supplied before formulation |
| Solubility | Freely soluble in water | aqueous buffers near neutral pH |
| Typical storage | 2 to 8 degrees Celsius, protected from light | powder and solution forms differ in shelf life |
Identity and purity are usually assessed by reverse-phase high-performance liquid chromatography coupled to mass spectrometry. Retention time and observed mass are compared against a reference standard run under identical conditions. Impurity profiles reveal deamidation products, oxidized methionine variants, and truncated fragments that arise during synthesis or storage. Peptide mapping through enzymatic digestion confirms the primary sequence, while amino acid analysis offers an independent check on overall composition.
Stability studies examine how temperature, pH, and moisture influence degradation rates over time. In aqueous solution, hydrolysis and deamidation accelerate as pH moves away from mildly acidic conditions. Light exposure and residual metal ions can also trigger oxidation of susceptible residues. Accelerated aging at elevated temperature is used to estimate shelf life, though extrapolation to room temperature carries uncertainty because individual degradation pathways do not always scale predictably.
Semaglutide is a synthetic peptide analog of human glucagon-like peptide-1, developed by Novo Nordisk and first approved in 2017 for type 2 diabetes. It belongs to the incretin mimetic class, a group of agents that reproduce the glucose-dependent actions of endogenous GLP-1. The molecule was engineered to resist degradation by dipeptidyl peptidase-4 and to bind serum albumin, extending its half-life from minutes to roughly one week. Approval for chronic weight management followed in 2021, based on large cardiovascular and obesity outcome trials.
GLP-1 receptors are expressed on pancreatic beta cells, in the gut, and in several brain regions. Receptor activation raises cyclic AMP, enhances glucose-dependent insulin secretion, and suppresses glucagon release when blood glucose is high. Effects on gastric emptying and on hypothalamic appetite circuits reduce energy intake. Because insulin release remains glucose-dependent, the risk of hypoglycemia is low when the drug is used alone. The precise contribution of each pathway to body weight change in humans remains an area of active investigation.
Clinical studies of semaglutide generally measure glycated hemoglobin, fasting plasma glucose, body weight, and composite cardiovascular endpoints. The SUSTAIN program enrolled adults with type 2 diabetes, while the STEP program focused on obesity without diabetes. Administration follows a stepwise escalation schedule designed to limit gastrointestinal effects during the first weeks. Reported outcomes include mean percentage weight change, the proportion of participants reaching defined weight-loss thresholds, and rates of nausea, vomiting, and diarrhea. Long-term data on durability after treatment stops are still limited and remain a topic of ongoing research.
[RO−P(O)2−O−P(O)2−O−PO3]4− + H2O → [RO−P(O)2−O−PO3]3− + [HPO4]2− + H+ [RO−P(O)2−O−P(O)2−O−PO3]4− + H2O → [RO−PO3]2− + [HO3P−O−PO3]3− + H+ For ATP hydrolysis that takes place with the physiological concentrations of ATP, ADP, and inorganic phosphate (Pi) within the living cell, the change in Gibbs free energy is given by:
There was also a 1.7-litre diesel version available with 58 PS (43 kW) at 4300 rpm and 112 N⋅m (83 lb⋅ft) at 2800 rpm. Introduced in July 1985, it is a naturally aspirated, indirect injection engine. As with the earlier 323 Wagon/Familia Van, the wagon (BW) skipped the succeeding generational change and continued to be available alongside the next generation in most markets. It was later updated with a new grille and continued to be available until 1994/95. When the saloons and hatchbacks received new engines in late 1987, the vans continued to use the old E-series units for a little longer. A factory-built convertible body was introduced in March 1986 in both Mazda 323 and Ford Laser (323 panels from firewall back) versions, initially running the 1.5-litre turbocharged E5T engine but later switching to the 1.6-litre DOHC B6D. Engines (Japanese domestic market):
=== Re–Ru === Lynne Regan (Ph.D. 1987). British biochemist and biotechnologist at the University of Edinburgh which studies interactions between proteins and nucleic acids. Jens Reich (b. 1939). German biophysicist at the Central Institute of Molecular Biology of the Academy of Sciences in Berlin-Buch, pioneer in systems biology. Founder of the New Forum (civil rights movement). Jacques Ricard (1929–2018). French biochemist at the Institut Jacques Monod known for studies of plant enzymes and for developing the concept of enzyme memory. David Rittenberg (1906–1970). American biochemist at Columbia, a pioneer in the use of radioactive tracers to study metabolism. Member Natl. Acad. Sci. USA. Alexander Rich (1924–2015). American biophysicist at MIT, whose many contributions included elucidation of the structure of collagen (with Francis Crick). Member Natl. Acad. Sci. USA. Jane S. Richardson (b. 1941). American biophysicist at Duke University, known for the ribbon diagram, a method of representing the 3D structures of proteins. Member Natl. Acad. Sci. USA. Thorburn Brailsford Robertson (1884–1930), Australian physiologist and biochemist, known for promoting the use of insulin for diabetes in Australia. Dame Carol V. Robinson (b. 1956), British chemist and mass spectroscopist at the University of Oxford known for studies of protein folding. Robert G. Roeder (b. 1942), American biochemist, pioneer in eukaryotic transcription. Irwin Rose (1926–2015). American biochemist at the University of Pennsylvania, noted for the discovery of ubiquitin-mediated protein degradation.
Sources: en.wikipedia.org
==== Declined ==== Jasmine Crockett, incumbent U.S. representative from the 30th district (ran for U.S. Senate, endorsed Haynes III) Marc Veasey, incumbent U.S. representative from the 25th district (ran for Tarrant County judge)
NGF bound to the receptors on Schwann cells provides the growing neurons that are contacted with a trophic factor to promote further growth and regeneration Ciliary neurotrophic factor (CNTF) typically has a high level of expression in Schwann cells associated with nerves that are healthy, but in response to nerve injury CNTF expression decreases in Schwann cells distal to the injury site and remains relatively low unless the injured axon begins to regrow. CNTF has numerous trophic roles in motor neurons in the peripheral nervous system including the prevention of atrophy of dennervated tissue and the prevention of degeneration and death of motor neurons after nerve injury. (frostick) In sciatic motor neurons both CNTF receptor mRNA expression and CNTF receptor is increased after injury for a prolonged time frame compared to the short time frame in the central nervous system suggesting a role for CNTF in nerve regeneration. Insulin-like growth factors (IGFs) have been shown to increase the rate of peripheral nervous system axon regeneration. IGF-I and IGF-II mRNA levels are significantly increased distal to the site of crush injury in rat sciatic nerves. At the site of nerve repair, locally delivered IGF-I can significantly increase the rate of axon regeneration within a nerve graft and help expedite functional recovery of a paralyzed muscle.
==== Red-dome Cave 67: more royal dedications ==== Another nearby cave, the Red-domed Cave A (Cave 67) also has inscriptions mentioning a list of donors including a queen and six kings, among them Suvarnapuspa (ruled 600–625 CE) and his son Suvarnadeva (ruled 625–648 CE). Also included in the inscriptions are the names of King Tottika and his wife Svayamprabha (a Sanskrit name), who also appear in the Maya Cave of the Second Group (Cave 205), suggesting proximity in time of these two caves. The epigraphy also suggest dates later than the Cave of the Painters, with its more ancient inscription about the "painter Tutuka". The Red-dome cave contained a library in which were found very old manuscripts, including one of the oldest known manuscripts in Sanskrit.
Uranium was also used in photographic chemicals (especially uranium nitrate as a toner), in lamp filaments for stage lighting bulbs, to improve the appearance of dentures, and in the leather and wood industries for stains and dyes. Uranium salts are mordants of silk or wool. Uranyl acetate and uranyl formate are used as electron-dense "stains" in transmission electron microscopy, to increase the contrast of biological specimens in ultrathin sections and in negative staining of viruses, isolated cell organelles and macromolecules. The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long half-life of uranium-238 (4.47×109 years) makes it well-suited for use in estimating the age of the earliest igneous rocks and for other types of radiometric dating, including uranium–thorium dating, uranium–lead dating and uranium–uranium dating. Uranium metal is used for X-ray targets in the making of high-energy X-rays.
Sources: en.wikipedia.org
=== Paintings, drawings and plans === Plan de l’Institut pour la Construction Séricicole de Brousse (Plan for the Institute for sericulture development in Bursa) (1893) Plan des Travaux de Parachèvement de l’Agence d’Angora (Working drawings for the completion of the Ankara Office) (1895) Plan de Construction de l’Agence à Ada Bazar (Construction plans for the Ottoman Public Debt Office in Adapazari) (1896) Sanctuaires Byzantins (Byzantine Sanctuaries) L’Art Islamique dans le Vilayet de Brousse (18 cartes et croquis) (Islamic Art in the Bursa Vilayet (18 cards and sketches) L’Art Islamique en Orient (première partie) ou Vieilles Faïences Turques (36 dessins), première édition : Alttürkishe Keramik, (Islamic Art in the East (part one) or Ancient Turkish Faience (36 drawings), first edition: Alttürkishe Keramik, Published by Apollo, Bologna, 1923, (with an introduction by Charles Wulzinger, 36 drawings (40 Plates) printed by Schulz on behalf of Librairie Raymond (bookshop) (Péra, Constantinople); second edition printed in France in Montauban. A large book planned to be the first of a set of three books with the general title L’Art Islamique en Orient (Islamic Art in the East). L’Art Islamique en Orient (deuxième partie) ou Fragments d’Architecture Religieuse et Civile (Islamic Art in the East (part two) or Fragments of Religious and Civil Architecture) printed in Prague, 1924, 52 CMY drawings, Librairie Raymond, oriental art and archaeology publications, Péra – Constantinople – Dedicated to Charles Richard Crane with a preface by the author dated 15 July 1923.
The maximum yield in such kinetic resolutions is 50%, since a yield of more than 50% means that some of wrong isomer also has reacted, giving a lower enantiomeric excess. Such reactions must therefore be terminated before equilibrium is reached. If it is possible to perform such resolutions under conditions where the two substrate- enantiomers are racemizing continuously, all substrate may in theory be converted into enantiopure product. This is called dynamic resolution. In biocatalyzed asymmetric synthesis, a non-chiral unit becomes chiral in such a way that the different possible stereoisomers are formed in different quantities. The chirality is introduced into the substrate by influence of enzyme, which is chiral. Yeast is a biocatalyst for the enantioselective reduction of ketones.
=== Synthesis === Dezocine [(−)-13β-amino-5,6,7,8,9,10,11,12-octahydro-5α-methyl-5,11-methanobenzocyclodecen-31-ol, hydrobromide] is a pale white crystal powder. It has no apparent odor. The salt is soluble at 20 mg/ml, and a 2% solution has a pH of 4.6. The synthesis of dezocine begins with the condensation of 1-methyl-7-methoxy-2-tetralone with 1,5-dibromopentane through use of NaH or potassium tert-butoxide. This yields 1-(5-bromopentyl)-1-methyl-7-methoxy-2-tetralone, which is then cyclized with NaH to produce 5-methyl-3-methoxy-5,6,7,8,9,10,11,12-octahydro-5,11-methanobenzocyclodecen-13-one. The product is then treated with hydroxylamine hydrochloride, to yield an oxime. A reduction reaction in hydrogen gas produces an isomeric mixture, from which the final product is crystallized and cleaved with HBr.
Sources: en.wikipedia.org
Native GLP-1 is degraded within minutes by dipeptidyl peptidase-4 and neutral endopeptidases. Semaglutide carries a non-natural amino acid at position eight that blocks that cleavage, and a fatty diacid side chain that binds albumin. The result is a much longer duration of action than the native hormone.
The fatty diacid chain associates strongly with serum albumin, which keeps the peptide in circulation and shields it from rapid renal clearance. Bound peptide is released gradually, producing a sustained receptor signal. This mechanism also reduces the peak-to-trough variation seen with shorter-acting analogues.
The balance between peripheral receptor activation and signalling in the central nervous system is not fully resolved. The extent to which slowed gastric emptying accounts for reduced energy intake, compared with direct effects on appetite circuits, is debated. Long-term effects on lean mass and on tissues outside the gut and brain are still under study.
Sealed, protected from light, and refrigerated at two to eight degrees Celsius for most research material. Desiccated storage limits moisture uptake. Allow the vial to reach room temperature before opening to prevent condensation.