Aib substitution is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Development began in the early 2010s with the goal of extending GLP-1 activity beyond the brief window achieved by native peptide infusion. The earliest approved formulation was a subcutaneous injection given once weekly. A later oral tablet pairs the peptide with an absorption enhancer, sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, usually shortened to SNAC. That carrier lowers local pH and helps the peptide cross gastric tissue. Both routes deliver the same active molecule.
Semaglutide is a synthetic peptide analog of human glucagon-like peptide-1, a gut hormone released after meals. Its backbone retains the GLP-1 sequence but incorporates two substitutions that slow enzymatic breakdown by dipeptidyl peptidase-4. A short polyethylene glycol linker and a C18 fatty diacid are attached to the peptide chain, allowing the molecule to bind serum albumin and remain in circulation far longer than the native hormone. The result is a circulating half-life measured in days rather than the minutes typical of endogenous GLP-1.
Receptor activation occurs at GLP-1 receptors distributed across pancreatic islets, the hypothalamus, and the gastrointestinal tract. Binding triggers G protein signaling that raises cyclic AMP and enhances glucose-dependent insulin release. Because the effect depends on prevailing glucose levels, insulin secretion does not rise when blood sugar is already low. Signaling in the brain and gut also influences appetite and gastric emptying, which is why the compound appears in both metabolic and weight-related research literature.
| Property | Value | Notes |
|---|---|---|
| Molecular class | 31-amino-acid peptide | Modified glucagon-like peptide-1 analogue |
| Molecular mass | approximately 4114 Da | Calculated for the free peptide backbone |
| Appearance | white to off-white powder | Typical of purified lyophilised peptide batches |
| Solubility class | freely soluble in water | Aqueous solubility improves at slightly alkaline pH |
| Typical storage | -20 degrees Celsius, dry, dark | Protect from repeated freeze-thaw cycles |
Clinical development of this compound followed earlier short-acting GLP-1 analogues that required frequent injection. Once-weekly subcutaneous formulations entered use after 2017, and an oral formulation using a permeation enhancer later became available. The oral version pairs the peptide with sodium N-(8-[2-hydroxybenzoyl] amino) caprylate, a carrier that improves uptake across the gastric epithelium. Interest has expanded from glycaemic control into weight management and metabolic liver disease. Regulatory status and approved indications differ between countries, and the product remains subject to ongoing safety monitoring.
Semaglutide is a synthetic peptide that acts as an agonist at the glucagon-like peptide-1 receptor. It is a structural analogue of human GLP-1(7-37), modified to resist enzymatic degradation by dipeptidyl peptidase-4. The peptide backbone contains alpha-aminoisobutyric acid at position 8, a substitution that stabilises the helix and slows cleavage. A fatty diacid side chain attached through a linker at lysine 34 promotes binding to serum albumin, which extends the circulating half-life. These two modifications together allow less frequent administration than native GLP-1 requires.
Storage guidance for the finished injectable product distinguishes the unused state from the in-use state. Before first use, pens are kept refrigerated between 2 and 8 degrees Celsius, protected from light, and never frozen, since freezing can disrupt the peptide or the device. After first use, label instructions in several markets permit storage at room temperature up to about 30 degrees Celsius for a limited number of days. Solid research-grade material is normally held at or below minus 20 degrees Celsius, often with desiccant, and allowed to equilibrate before opening.
Quantification and purity assessment rely on separation methods coupled to optical or mass detection. Reversed-phase high-performance liquid chromatography resolves the intact peptide from related impurities and is the standard assay technique. Size-exclusion chromatography measures aggregates, while ion-exchange chromatography separates charge variants produced by deamidation. Mass spectrometry confirms identity and detects mass shifts of a few daltons. In biological matrices, liquid chromatography with tandem mass spectrometry is often used because immunoassays can cross-react with endogenous GLP-1 or with circulating fragments.
As a peptide, semaglutide is sensitive to conditions that break amide bonds or modify side chains. Deamidation of asparagine and glutamine residues, oxidation of methionine and tryptophan, and non-covalent aggregation are the main degradation routes described in published stability work. Rate depends strongly on pH, buffer species, ionic strength, temperature and exposure to light. Formulators therefore choose a defined solution pH and often add excipients such as phosphate buffer, propylene glycol and phenol, each of which plays a separate role in pH control, tonicity or preservation.
In the UK, Lih Mei Liao and Sarah M. Creighton of the University College London Institute for Women's Health wrote in the British Medical Journal in 2007 that "the few reports that exist on patients' satisfaction with labial reductions are generally positive, but assessments are short-term and lack methodological rigour." They wrote that the increased demand for cosmetic genitoplasty (labiaplasty) may reflect a "narrow social definition of normal." The National Health Service performed double the number of genitoplasty procedures in the year 2006 than in the 2001–2005 period. The authors noted that "the patients consistently wanted their vulvas to be flat, with no protrusion beyond the labia majora ... some women brought along images to illustrate the desired appearance, usually from adverts or pornography that may have been digitally altered." The Royal Australian and New Zealand College of Obstetricians and Gynæcologists published the same concern about the exploitation of psychologically insecure women. The International Society for the Study of Women's Sexual Medicine produced a report in 2007 concluding that "vulvar plastic surgery may be warranted only after counseling if it is still the patient's preference, provided that it is conducted in a safe manner and not solely for the purpose of performing surgery".
==== Ethiopia ==== According to a 2013 study on agricultural value chains, approximately 90% of households in Ethiopia across all income groups purchase their beef through local butchers in traditional markets.
Hemp juice is produced in a patented industrial procedure directly following harvest whereby the leafy upper part of the plant, including the flower heads, are being cold-pressed after harvest. These parts of the hemp plant have been entirely neglected so far in industrial hemp fabric production. Hence, through the procedure of pressing juice, a previously neglected highly valuable part of the plant is now being used for human consumption. All active ingredients remain fully intact without drying the hemp. The juice does not compete with the production of fibers and shives instead both add up to double revenue of the farmer. The average yield of hemp juice is approximately 3 tons per hectare. This newly developed production procedure allows for a significantly higher financial efficiency as well as sustainability in the cultivation of drug-free industrial hemp. Furthermore, the cold-pressing procedure preserves all of the plant-based active ingredients. There are two common harvesting procedures: "Cutting" the upper parts of the hemp plant or "stripping" the leaves off the uppermost part of the hemp plant. Both these procedures result in varying quantities of cannabinoids in the hemp juice. Consequently, the harvesting procedure in itself already influences the quality of the resulting hemp juice. If one only uses the uppermost, leafy part of the hemp plant for hemp juice production, the remaining part of the hemp plant can still be used for the industrial production of its fibers or any other industrial uses.
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes tends to progress in severity, and is due to either a reduced production of the hormone insulin by the pancreas or unresponsiveness of bodily cells to insulin's effects. Classic symptoms include the three Ps: polydipsia (excessive thirst), polyuria (excessive urination), and polyphagia (excessive hunger), together with weight loss and blurred vision. If left untreated, the disease can lead to many health complications, including disorders of the cardiovascular system, eye, kidney, and nerves. The major types of diabetes are type 1 and type 2. The most common type is type 2. The most common treatment for type 1 is insulin replacement therapy (insulin injections), while anti-diabetic medications (such as metformin and semaglutide or tirzepatide) and lifestyle modifications can be used to manage type 2. Gestational diabetes, a form that sometimes arises during pregnancy, normally resolves shortly after delivery. Type 1 diabetes is an autoimmune condition in which the body's immune system attacks the beta cells (β-cell) in the pancreas, preventing the production of insulin. This condition typically is present from birth or develops early in life. Type 2 diabetes occurs when the body becomes resistant to insulin and thus glucose remains in the bloodstream instead of being absorbed by the cells.
The mechanism of melatonin biosynthesis initiates with the hydroxylation of L-tryptophan, a process that requires the cofactor tetrahydrobiopterin (THB) to react with oxygen and the active site iron of tryptophan hydroxylase. Although the complete mechanism is not entirely understood, two main mechanisms have been proposed: The first mechanism involves a slow transfer of one electron from THB to molecular oxygen (O2), potentially producing a superoxide (O−2). This superoxide could then recombine with the THB radical to form 4a-peroxypterin. 4a-peroxypterin may either react with the active site iron (II) to create an iron-peroxypterin intermediate or directly transfer an oxygen atom to the iron, facilitating the hydroxylation of L-tryptophan. Alternatively, the second mechanism proposes that oxygen interacts with the active site iron (II) first, forming iron (III) superoxide. This molecule could then react with THB to form an iron-peroxypterin intermediate. Following the formation of iron (IV) oxide from the iron-peroxypterin intermediate, this oxide selectively attacks a double bond to yield a carbocation at the C5 position of the indole ring. A subsequent 1,2-shift of the hydrogen and the loss of one of the two hydrogen atoms on C5 would restore aromaticity, producing 5-hydroxy-L-tryptophan. The decarboxylation of 5-hydroxy-L-tryptophan to produce 5-hydroxytryptamine is then facilitated by a decarboxylase enzyme with pyridoxal phosphate (PLP) as a cofactor.
Sources: en.wikipedia.org
=== Benign prostatic hyperplasia === A meta-analysis found that tadalafil is an effective treatment for lower urinary tract symptoms due to benign prostatic hyperplasia and that such treatment had a low rate of adverse effects. Tadalafil is FDA-approved for males as a therapy to treat and prevent symptoms of benign prostatic hyperplasia, such as urinary urgency, hesitancy, weak stream, dribbling, and incontinence. Tadalafil was found to have similar benefits for lower urinary tract symptoms as the usually prescribed tamsulosin.
The three substrates of this enzyme are aromadendrin ((+)-dihydrokaempferol), reduced nicotinamide adenine dinucleotide phosphate (NADPH), and a proton. Its products are leucopelargonidin and oxidised NADP+. This enzyme is an oxidoreductase with the systematic name cis-3,4-leucopelargonidin:NADP+ 4-oxidoreductase. Other names in common use include dihydroflavanol 4-reductase (DFR), dihydromyricetin reductase, NADPH-dihydromyricetin reductase, and dihydroquercetin reductase. It participates in flavonoid biosynthesis.
When gunfights finally erupted outside and around the television studio, they were almost always the result of miscommunication. One such example is when a group of Patriotic Guardsmen took up a defensive position in a building close to the television centre on the 23rd. It has not been established who took the first shots at around 17:00, but a gunfight soon ensued with those in the television station returning fire onto the position of the Patriotic guards, according to an aid worker who had set up a first aid station at the side of the television station, and who said that, afterwards, the group of Patriotic Guardsmen would later deny that they had fired first. This is only one of many examples of gunfights between pro-revolution forces after the flight of Ceaușescu on the 22nd. Scenes of major gunfights during this period include the television, radio and telephone buildings, as well as Casa Scânteii (the nation's print media center, which serves a similar role today under the name of the "House of the Free Press", Casa Presei Libere) and the post office in the district of Drumul Taberei; Palace Square (site of the Central Committee building, but also of the Central University Library, the national art museum in the former Royal Palace, and the Ateneul Român (Romanian Athenaeum), Bucharest's leading concert hall); the university and the adjoining University Square (one of the city's main intersections); Otopeni and Băneasa airports; hospitals; and the Ministry of Defence.
Hypoglycemia is a condition that occurs when blood glucose levels decrease below normal, causing symptoms including anxiety, tremors, nausea, palpitations, confusion, and coma. Individuals with diabetes or other conditions that result in low blood sugar may carry glucose tablets, oral glucose gel, hard candy, or sugar packets to use when their blood sugar becomes too low. Severe low blood sugar can lead to confusion, coma, neurological damage and other potentially serious complications, making it unsafe to administer glucose by mouth. In these cases, dextrose (D-glucose) can be administered into a vein to quickly and directly raise blood glucose levels.
Risk factors for kidney disease include diabetes, high blood pressure, family history, older age, ethnic group and smoking. For most patients, a GFR over 60 mL/min/1.73 m2 is adequate. But significant decline of the GFR from a previous test result can be an early indicator of kidney disease requiring medical intervention. The sooner kidney dysfunction is diagnosed and treated the greater odds of preserving remaining nephrons, and preventing the need for dialysis.
Sources: en.wikipedia.org
=== Biotechnology === BASF was cooperating with Monsanto Company in research, development and marketing of biotechnology. In correlation to this work, BASF has licensed many gene editing tools including CRISPR Cas9 and CRISPR Cas12a (Cpf1). The BASF Plant Science subsidiary produces the Amflora and Starch Potato genetically modified potato with reduced amylose. In 2010 BASF conducted Department of Environment, Food and Rural Affairs approved trials of genetically modified potatoes in the United Kingdom. Starch Potato was authorised for use in the USA in 2014. Other GM crops are Phytaseed Canola varieties with phytase, sulfonylurea herbicide tolerant soybean and drought tolerant corn (with cold shock protein B) developed with Monsanto.
Here birds rest on ant nests, or pick and drop ants onto their wings and feathers; this may be a means to remove ectoparasites from the birds. Myrmecophagous mammals such as Anteaters, aardvarks, pangolins, echidnas and numbats have special adaptations for living on a diet of ants. These adaptations include long, sticky tongues to capture ants and strong claws to break into ant nests. They also have gut microbiomes that appear to be similar. Brown bears (Ursus arctos) have been found to feed on ants. About 12%, 16%, and 4% of their faecal volume in spring, summer and autumn, respectively, is composed of ants. Some lacertid lizards are specialist ant-feeders. Assassin bugs in the subfamily Holoptilinae secrete attractants that stupefy ants on which they prey. Several spiders such as in the genera Zodarion, Oecobius, Amyciaea and Aphantochilus are specialist ant predators.
== Side effects == Side effects of ciclosporin can include gum enlargement, increased hair growth, convulsions, peptic ulcers, pancreatitis, fever, vomiting, diarrhea, confusion, increased cholesterol, trouble breathing, numbness and tingling (particularly of the lips), itchiness, high blood pressure, potassium retention (possibly leading to hyperkalemia), kidney and liver dysfunction, burning sensations at finger tips, and an increased vulnerability to opportunistic fungal and viral infections. Ciclosporin causes hypertension by inducing vasoconstriction in the kidneys and increasing sodium reabsorption. The increase in blood pressure can cause cardiovascular events; it is thus recommended that the lowest effective dose for people requiring long-term treatment be used. Ciclosporin use after a kidney transplantation is associated with increased levels of uric acid in the blood and, in some cases, gout. Ciclosporin is listed as an IARC Group 1 carcinogen (i.e. there is sufficient evidence of carcinogenicity in humans), specifically leading to squamous cell skin cancer and non-Hodgkin lymphoma.
The perineal body is a pyramidal structure of muscle and connective tissue and part of it is located between the anus and vagina. It is a tendon that is formed at the point where the bulbospongiosus muscle, superficial transverse perineal muscle, and external anal sphincter muscle converge to form this major supportive structure of the pelvis and vagina. Below this, muscles and their fascia converge and become part of the perineal body. The lower vagina is attached to the perineal body by attachments from the pubococcygeus, perineal muscles, and the anal sphincter. The perineal body is made up of smooth muscle, elastic connective tissue fibers, and nerve endings. Above the perineal body are the vagina and the uterus. Damage and resulting weakness of the perineal body changes the length of the vagina and predisposes it to rectocele and enterocele.
Sources: en.wikipedia.org
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.
No. It shares high sequence identity but carries non-natural modifications that alter its stability and clearance. The naturally occurring hormone is broken down within minutes, while the synthetic analogue circulates far longer.
Attachment to serum albumin reduces renal filtration of the peptide and shields it from enzymatic breakdown. The consequence is a much longer interval between administrations than unmodified peptides allow. The precise contribution of binding affinity to overall duration is still being quantified.
Native GLP-1 is degraded within minutes by circulating enzymes. The synthetic version carries substitutions at positions that block enzymatic cleavage, plus a fatty acid side chain that promotes albumin binding. These two changes together extend circulation time from minutes to roughly a week.