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Chromones
Chromone (or 1,4-benzopyrone) is a derivative of benzopyran 4H-1-Benzopyran is an organic compound with the formula . It is one of two isomers of benzopyran, the other being 2H-1-Benzopyran, 2H-1-benzopyran, which is more prevalent. It can be viewed as the fusion of a benzene ring to a heterocyclic pyra ... with a substituted keto group on the pyran ring. It is an isomer of coumarin. Derivatives of chromone are collectively known as ''chromones''. Most, though not all, chromones are also phenylpropanoids. Examples * 6,7-dimethoxy-2,3-dihydrochromone has been isolated from '' Sarcolobus globosus''. * Eucryphin, a chromone rhamnoside, can be isolated from the bark of '' Eucryphia cordifolia''. * Cromolyn (disodium cromoglicate) was found to inhibit antigen challenge as well as stress induced symptoms.HOWELL, J.B. & ALTOUNYAN, R.E. (1967). A double-blind trial of disodium cromoglycate in the treatment of allergic bronchial asthma. Lancet, 2, 539–542Abstract/ref> Cro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cromolyn
Cromoglicic acid (International Nonproprietary Name, INN)—also referred to as cromolyn (United States Adopted Name, USAN), cromoglycate (former British Approved Name, BAN), or cromoglicate—is traditionally described as a mast cell stabilizer, and is commonly marketed as the sodium salt sodium cromoglicate or cromolyn sodium. This drug prevents the release of inflammation, inflammatory chemicals such as histamine from mast cells. It is considered a breakthrough drug in management of asthma, as the patients can be freed from steroids in many cases; however, it is mainly effective as a prophylaxis for allergic and exercise-induced asthma, not as a treatment for acute asthma attacks. Cromoglicic acid has been the non-corticosteroid treatment of choice in the treatment of asthma, for which it has largely been replaced by leukotriene receptor antagonists because of their safety and convenience. Cromoglicic acid requires administration four times daily, and does not provide additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mast Cell Stabilizer
Mast cell stabilizers are medications used to prevent or treat certain allergic disorders. They block mast cell degranulation, stabilizing the cell and thereby preventing the release of histamine and related mediators. One suspected pharmacodynamic mechanism is the blocking of IgE-regulated calcium channels. Without intracellular calcium, the histamine vesicles cannot fuse to the cell membrane and degranulate. As inhalers they are used to treat asthma, as nasal sprays to treat hay fever (allergic rhinitis) and as eye drops for allergic conjunctivitis. Finally, in oral form, they are used to treat the rare condition of mastocytosis. Examples Mast cell stabilizer medications include: * cromoglicic acid (cromolyn/cromoglycate) * ketotifen * lodoxamide * nedocromil * pemirolast * olopatadine Research The following substances are studied on their potential mast cell stabilizing effects, but the current results are inconclusive: * vitamin D * quercetin Quercetin is a plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by an unsaturated lactone ring , forming a second six-membered heterocycle that shares two carbons with the benzene ring. It belongs to the benzopyrone chemical class and is considered a lactone. Coumarin is a colorless crystalline solid with a sweet odor resembling the scent of vanilla and a bitter taste. It is found in many plants, where it may serve as a chemical defense against predators. While coumarin is not an anticoagulant, its 3-alkyl-4-hydroxy derivatives, such as the fungal metabolite dicoumarol, inhibit synthesis of vitamin K, a key component in blood clotting. A related compound, the prescription drug anticoagulant warfarin, is used to inhibit formation of blood clots, deep vein thrombosis, and pulmonary embolism. Etymology Coumarin is derived from , the French word for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthone
Xanthone is an organic compound with the molecular formula C13H8O2. It is a white solid. In 1939, xanthone was introduced as an insecticide and it currently finds uses as ovicide for codling moth eggs and as a larvicide. Xanthone is also used in the preparation of xanthydrol, which is used in the determination of urea levels in the blood. It can also be used as a photocatalyst. Synthesis Xanthone can be prepared by the heating of phenyl salicylate: Six methods have been reported for synthesizing xanthone derivatives: *The Michael-Kostanecki method uses an equimolar mix of a polyphenol and an ''O''-hydroxybenzoic acid, which are heated with a dehydrating agent. *The Friedel-Crafts method has a benzophenone intermediate. *The Robinson-Nishikawa method is a variant of the Hoesch synthesis but with low yields. *The Asahina-Tanase method synthesizes some methoxylated xanthones, and xanthones with acid-sensitive substituents. *The Tanase method is used to synthesize po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nedocromil
Nedocromil sodium is a medication considered a mast cell stabilizer which acts to prevent wheezing, shortness of breath, and other breathing problems caused by asthma. It is administered by an inhaler under the brand name Tilade, and as an eye drop under the brand name Alocril. The effects of nedocromil versus asthma are gradual rather than fast-acting and it is not indicated for acute respiratory distress compared to fast acting bronchodilators like albuterol or other well-known inhaler medications. Liquid preparations of nedocromil are available in the UK under the name Rapitil for use for allergic eye reactions. Nedocromil sodium has been shown to be effective in alleviating symptoms of allergic conjunctivitis. Nedocromil is classified as a benzopyrone. Nedocromil acts as a mast cell stabilizer, inhibits the degranulation of mast cells, prevents release of histamine and tryptase, so preventing the synthesis of prostaglandins and leukotrienes. US Production of inhaled nedoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergic Conjunctivitis
Allergic conjunctivitis (AC) is Allergic Inflammation, inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist of redness (mainly due to vasodilation of the peripheral small blood vessels), edema (swelling) of the conjunctiva, itching, and increased lacrimation (production of tears). If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis (ARC). The symptoms are due to release of histamine and other active substances by mast cells, which stimulate dilation of blood vessels, irritate nerve endings, and increase secretion of tears. Treatment of allergic conjunctivitis is by avoiding the allergen (''e.g.'', avoiding grass in bloom during "hay fever season") and treatment with antihistamines, either topical (in the form of eye drops), or systemic (in the form of tablets). Antihistamines, medications that stabilize mast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthma
Asthma is a common long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. A sudden worsening of asthma symptoms sometimes called an 'asthma attack' or an 'asthma exacerbation' can occur when allergens, pollen, dust, or other particles, are inhaled into the lungs, causing the bronchioles to constrict and produce mucus, which then restricts oxygen flow to the alveoli. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise. Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. Diag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergic Rhinitis
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a type I hypersensitivity reaction. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis. Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust, or mold. Inherited genetics and environmental exposures contribute to the development of allergies. Growing up on a farm and having multiple older siblings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzopyran
4H-1-Benzopyran is an organic compound with the formula . It is one of two isomers of benzopyran, the other being 2H-1-Benzopyran, 2H-1-benzopyran, which is more prevalent. It can be viewed as the fusion of a benzene ring to a heterocyclic pyran ring. Some benzopyrans have shown anticancerous activity ''in vitro''. The radical (chemistry), radical form of benzopyran is paramagnetic. The unpaired electron is delocalized over the whole benzopyran molecule, rendering it less reactive than one would expect otherwise. A similar example is the cyclopentadienyl radical. Commonly, benzopyran is encountered in the reduced state, in which it is partially saturated with one hydrogen atom, introducing a tetrahedral CH2 group in the pyran ring. Therefore, there are many structural isomers owing to the multiple possible positions of the oxygen atom and the tetrahedral carbon atom: Nomenclature According to current IUPAC nomenclature, the name chromene used in previous recommendations i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' are methyl), with the formula . Many ketones are of great importance in biology and industry. Examples include many sugars (ketoses), many steroids, ''e.g.'', testosterone, and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considered retained IUPAC names, although some introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucryphia Cordifolia
''Eucryphia cordifolia'', the ulmo, is a species of tree in the family Cunoniaceae. It is found in Chile and Argentina. It is threatened by logging and habitat loss. The natural habitat is along the Andes Range from 38 to 43°S, and up to 700 meters (2300 ft) above sea level. It is an exquisite tree with a thick trunk and broad crown and can become over 12 m (39 ft) high. It blooms in February and March, depending on latitude and altitude. The fruit is a capsule about 1.5 cm (0.6 in) in length. Cultivation and uses Its flowers contain a highly appreciated aromatic nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ..., harvested by introduced European bees and commercialized as ulmo honey (''miel de Ulmo''). The wood is light brown to brown, heavy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
