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Keller's Reagent (organic)
In organic chemistry, Keller's reagent is a mixture of anhydrous (glacial) acetic acid, concentrated sulfuric acid, and small amounts of ferric chloride, used to detect alkaloids. Keller's reagent can also be used to detect other kinds of alkaloids via reactions in which it produces products with a wide range of colors.. An extract of heartwood reacts with the reagent to produce a yellow-brown color.. Certain compounds "can be detected by means of a bright blue color formed with Keller's reagent".. "With Keller's reagent there is first a pale red, later a blue violet color." Cohn describes its use to detect the principal components of digitalis (note that they may not be alkaloids). The reaction with this reagent is also known as the Keller–Kiliani reaction, after C. C. Keller and H. Kiliani, who both used it to study digitalis in the late 19th century. It can be used for digitoxin's quantitative analysis.Another method of visualizing the Keller-Kiliani reaction is to treat the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes Physical property, physical and Chemical property, chemical properties, and evaluation of Reactivity (chemistry), chemical reactivity to understand their behavior. The study of organic reactions includes the organic synthesis, chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical (in silico) study. The range of chemicals studied chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxin
Digoxin (better known as digitalis), sold under the brand name Lanoxin among others, is a medication used to treat various heart disease, heart conditions. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Digoxin is one of the oldest medications used in the field of cardiology. It works by increasing myocardial contractility, increasing stroke volume and blood pressure, reducing heart rate, and somewhat extending the time frame of the Muscle contraction, contraction. Digoxin is taken by mouth or by intravenous, injection into a vein. Digoxin has a half life of approximately 36 hours given at average doses in patients with normal renal function. It is excreted mostly unchanged in the urine. Common side effects include gynecomastia, breast enlargement with other side effects generally due to an excessive dose. These side effects may include loss of appetite, nausea, trouble seeing, confusion, and an Heart arrhythmia, irregular heartbeat. Gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baljet Reaction
The Baljet reaction is a qualitative and quantitative method of analysis published by Henri Baljet in 1918. This chemical reaction is used for the detection and Colorimetric analysis, colorimetric determination of Cardenolide, cardenolides. To the sample, an aqueous hydroxide solution and an Ethanol, ethanolic picric acid solution is combined and added, with a positive test turning orange or red. The mechanism involves cardenolides 1 reacting in alkaline solution with picric acid 2 to form stabilized Meisenheimer complex, Meisenheimer complexes, as shown with the resonance form 3a to 3c: See also * Keller's reagent (organic) * Dische test References Chemical reactions Analytical chemistry {{Reaction-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dische Test
The Dische test, or Dische reaction, is used to distinguish DNA from RNA. It was invented by Zacharias Dische. Method Dische's diphenylamine reagent consists of diphenylamine, glacial acetic acid, sulfuric acid, and ethanol. When heated with DNA, it turns blue in the presence of DNA. A more intense blue color indicates a greater concentration of DNA. Mechanism The acid converts deoxyribose to a molecule that binds with diphenylamine to form a blue substance. The reagent does not interact with RNA, so can be used to distinguish DNA from RNA. See also *Bial's test Bial's test is a chemical test for the presence of pentoses originally developed for the diagnosis of pentosuria. It is named after Manfred Bial, a German physician. The components include orcinol, hydrochloric acid, and ferric chloride. A pentos ... References {{reflist Analytical reagents Genetics techniques ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunteria Eburnea
''Hunteria umbellata'' grows as either a shrub or small tree up to tall, with a trunk diameter of up to . Its flowers feature a white, creamy or pale yellow corolla. The fruit is yellow and smooth. Its habitat is forests from sea level to altitude. Its numerous local medicinal uses include for fever, leprosy sores, stomach and liver problems and as an anthelmintic, especially against internal worms. ''Hunteria umbellata'' has been used as arrow poison. The plant's hard wood is used in carving and to make small tools. The species is native to an area of tropical Africa from Guinea-Bissau Guinea-Bissau, officially the Republic of Guinea-Bissau, is a country in West Africa that covers with an estimated population of 2,026,778. It borders Senegal to Guinea-Bissau–Senegal border, its north and Guinea to Guinea–Guinea-Bissau b ... in the west to Angola in the south. References umbellata Plants used in traditional African medicine Flora of Angola Flora of West Tropi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digoxigenin
Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants ''Digitalis purpurea'', ''Digitalis orientalis'' and ''Digitalis lanata'' (foxgloves), where it is attached to sugars, to form the glycosides (e.g. digoxin, lanatoside C). Uses in biotechnology Digoxigenin is a hapten, a small molecule with high antigenicity, that is used in many molecular biology applications similarly to other popular haptens such as 2,4-Dinitrophenol, biotin, and fluorescein. Typically, digoxigenin is introduced chemically (conjugation) into biomolecules (proteins, nucleic acids) to be detected in further assays. Kd of the digoxigenin-antibody interaction has been estimated at ~12 nM (compare to Kd~0.1pM for the biotin-streptavidin interaction). ;DIG-binding proteins Tinberg et al. designed artificial proteins that bind DIG. Their best binder, DIG10.3, was a 141 amino acid protein that bound DIG with a dissociation constant (Kd) of 541 (+/- 193) pM. Anti-digoxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitoxin
Digitoxin is a cardiac glycoside used for the treatment of heart failure and certain kinds of heart arrhythmia. It is a phytosteroid and is similar in structure and effects to digoxin, though the effects are longer-lasting. Unlike digoxin, which is eliminated from the body via the kidneys, it is eliminated via the liver, and so can be used in patients with poor or erratic kidney function. While several controlled trials have shown digoxin to be effective in a proportion of patients treated for heart failure, the evidence base for digitoxin is not as strong, although it is presumed to be similarly effective. Medical uses Digitoxin is used for the treatment of heart failure, especially in people with impaired kidney function. It is also used to treat certain kinds of heart arrhythmia, such as atrial fibrillation. Contraindications Contraindications include * problems with the heart rhythm, such as severe bradycardia (slow heartbeat), ventricular tachycardia (fast heartbeat caused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anhydrous
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achieve perfect dryness; anhydrous compounds gradually absorb water from the atmosphere so they must be stored carefully. Solids Many salts and solids can be dried using heat, or under vacuum. Desiccators can also be used to store reagents in dry conditions. Common desiccants include phosphorus pentoxide and silica gel. Chemists may also require dry glassware for sensitive reactions. This can be achieved by drying glassware in an oven, by flame, or under vacuum. Dry solids can be produced by freeze-drying, which is also known as lyophilization. Liquids or solvents In many cases, the presence of water can prevent a reaction from happening, or cause undesirable products to form. To prevent this, anhydrous solvents must be used when perform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardenolide
A cardenolide is a type of steroid. Many plants contain derivatives, collectively known as cardenolides, including many in the form of cardenolide glycosides (cardenolides that contain structural groups derived from sugars). Cardenolide glycosides are often toxic; specifically, they are cardiac arrest, heart-arresting. Cardenolides are toxic to animals through inhibition of the enzyme Na+/K+-ATPase, Na+/K+-ATPase, which is responsible for maintaining the sodium and Potassium in biology, potassium ion gradients across the cell membranes. Etymology The term derives from ''card-'' "heart" (from Greek language, Greek καρδία ''kardiā'') and the suffix , referring to the lactone ring with double bond at C17. Cardenolides are a class of steroids (or aglycones if viewed as cardiac glycoside constituents), and cardenolides are a subtype of this class (see Wikipedia:MeSH D04#MeSH D04.808.155 --- cardenolides, MeSH D codes list). Structure Cardenolides are C(23)-steroids with methyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
