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Barbital
Barbital (or barbitone), marketed under the brand names Veronal for the pure acid and Medinal for the sodium salt, was the first commercially available barbiturate. It was used as a sleeping aid (hypnotic) from 1903 until the mid-1950s. The chemical names for barbital are diethylmalonyl urea or diethylbarbituric acid; hence, the sodium salt (known as medinal, a genericised trademark in the United Kingdom) is known also as sodium diethylbarbiturate. Synthesis Barbital, then called "Veronal", was first synthesized in 1902 by German chemists Emil Fischer and Joseph von Mering, who published their discovery in 1903. Barbital was prepared by condensing diethylmalonic ester with urea in the presence of sodium ethoxide, or by adding at least two molar equivalents of ethyl iodide to the silver salt of malonylurea (barbituric acid) or possibly to a basic solution of the acid. The result was an odorless, slightly bitter, white crystalline powder. Its introduction followed the investig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbiturate
Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as well as overdose potential among other possible adverse effects. They have been used recreationally for their anxiolytic and sedative effects, and are thus controlled in most countries due to the risks associated with such use. Barbiturates have largely been replaced by benzodiazepines and nonbenzodiazepines ("Z-drugs") in routine medical practice, particularly in the treatment of anxiety disorders and insomnia, because of the significantly lower risk of overdose, and the lack of an antidote for barbiturate overdose. Despite this, barbiturates are still in use for various purposes: in general anesthesia, epilepsy, treatment of acute migraines or cluster headaches, acute tension headaches, euthanasia, capital punishment, and assisted suicid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbital Synthese
Barbital (or barbitone), marketed under the brand names Veronal for the pure acid and Medinal for the sodium salt, was the first commercially available barbiturate. It was used as a sleeping aid (hypnotic) from 1903 until the mid-1950s. The chemical names for barbital are diethylmalonyl urea or diethylbarbituric acid; hence, the sodium salt (known as medinal, a genericised trademark in the United Kingdom) is known also as sodium diethylbarbiturate. Synthesis Barbital, then called "Veronal", was first synthesized in 1902 by German chemists Emil Fischer and Joseph von Mering, who published their discovery in 1903. Barbital was prepared by condensing diethylmalonic ester with urea in the presence of sodium ethoxide, or by adding at least two molar equivalents of ethyl iodide to the silver salt of malonylurea (barbituric acid) or possibly to a basic solution of the acid. The result was an odorless, slightly bitter, white crystalline powder. Its introduction followed the investiga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer
Bayer AG (, commonly pronounced ; ) is a German multinational corporation, multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceuticals; consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the Euro Stoxx 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer and dyer Friedrich Weskott. As was common in this era, the company was established as a dyestuffs producer. The versatility of aniline chemistry led Bayer to expand their business into other areas, and in 1899 Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. In 1904 Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypnotic
Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia to produce and maintain unconsciousness, "sleep" is metaphorical as there are no regular sleep stages or cyclical natural states; patients rarely recover from anesthesia feeling refreshed and with renewed energy. The word is also used in art.) and to treat insomnia (sleeplessness). This group of drugs is related to sedatives''. ''Whereas the term sedative describes drugs that serve to calm or relieve anxiety, the term hypnotic generally describes drugs whose main purpose is to initiate, sustain, or lengthen sleep. Because these two functions frequently overlap, and because drugs in this class generally produce dose-dependent effects (ranging from anxiolysis to loss of consciousness), they are often referred to collectively as sedative-h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Von Mering
Josef, Baron von Mering (28 February 1849, in Cologne – 5 January 1908, at Halle an der Saale, Germany) was a German physician. Working at the University of Strasbourg, Mering was the first person to discover (in conjunction with Oskar Minkowski) that one of the pancreatic functions is the production of insulin, a hormone which controls blood sugar levels. Mering was curious about the pancreas, a comma shaped organ, situated between the stomach and the small intestine. In an effort to discover its function, he removed the organ from a dog. The dog was then noticed frequently urinating on the floor, although it was house trained. Mering realised that this was a symptom of diabetes and tested the urine, which was found to be high in sugar, confirming his suspicion. Josef von Mering helped to discover barbiturates, a class of sedative drugs used for insomnia, epilepsy, anxiety, and anesthesia. In 1903, he published observations that barbital (then known as diethyl-barbituric a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbituric Acid
Barbituric acid or malonylurea or 6-hydroxyuracil is an organic compound based on a pyrimidine heterocyclic skeleton. It is an odorless powder soluble in water. Barbituric acid is the parent compound of barbiturate drugs, although barbituric acid itself is not pharmacologically active. The compound was first synthesised by Adolf von Baeyer. Naming It remains unclear why Baeyer chose to name the compound that he discovered "barbituric acid". In his textbook ''Organic Chemistry'', the American organic chemist Louis Frederick Fieser (1899–1977) initially speculated that the name stemmed from the German word ''Schlüsselbart'' (literally, the beard (''Bart Latin: ''barba'') of a key (''Schlüssel'')' that is, the bit of a key), because Baeyer had regarded barbituric acid as central (or "key") to understanding uric acid and its derivatives. However, Fieser subsequently decided that Baeyer had named the compound after a young lady whom he had met and who was called "Barbara"' hence t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propylbarbital
Propylbarbital (Propal, Propanal, Proponal), also known as 5,5-dipropylbarbituric acid, is a barbiturate derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ... used as a hypnotic drug. References Barbiturates Hypnotics GABAA receptor positive allosteric modulators {{sedative-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grain (measure)
A grain is a unit of measurement of mass, and in the troy weight, avoirdupois, and apothecaries' systems, equal to exactly milligrams. It is nominally based upon the mass of a single ideal seed of a cereal. From the Bronze Age into the Renaissance, the average masses of wheat and barley grains were part of the legal definitions of units of mass. Expressions such as "thirty-two grains of wheat, taken from the middle of the ear" appear to have been ritualistic formulas, essentially the premodern equivalent of legal boilerplate. Another source states that it was defined such that 252.458 units would balance of distilled water at an ambient air-water pressure and temperature of and respectively. Another book states that Captain Henry Kater, of the British Standards Commission, arrived at this value experimentally. The grain was the legal foundation of traditional English weight systems, and is the only unit that is equal throughout the troy, avoirdupois, and apothecaries' sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor
The GABAA receptor (GABAAR) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions (Cl−) and, to a lesser extent, bicarbonate ions (HCO3−). Depending on the membrane potential and the ionic concentration difference, this can result in ionic fluxes across the pore. If the membrane potential is higher than the equilibrium potential (also known as the reversal potential) for chloride ions, when the receptor is activated Cl− will flow into the cell. This causes an inhibitory effect on neurotransmission by diminishing the chance of a successful action potential occurring at the postsynaptic cell. The reversal potential of the GABAA-mediated inhibitory postsynaptic potential (IPSP) in normal solution is −70 mV, contrasting the GABAB IPSP (-100 mV). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Emil Fischer
Hermann Emil Louis Fischer (; 9 October 1852 – 15 July 1919) was a German chemist and 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fischer projection, a symbolic way of drawing asymmetric carbon atoms. He also hypothesized lock and key mechanism of enzyme action. He never used his first given name, and was known throughout his life simply as Emil Fischer. Early years and career Fischer was born in Euskirchen, near Cologne, the son of Laurenz Fischer, a businessman, and his wife Julie Poensgen. After graduating he wished to study natural sciences, but his father compelled him to work in the family business until determining that his son was unsuitable. Fischer then attended the University of Bonn in 1871, but switched to the University of Strasbourg in 1872. He earned his doctorate in 1874 under Adolf von Baeyer with his study of phthaleins, and was appointed to a position at the university. After eight ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Solution
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean. Principles of buffering Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−: When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen io ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclodextrin
Cyclodextrins are a family of cyclic oligosaccharides, consisting of a macrocyclic ring of glucose subunits joined by α-1,4 glycosidic bonds. Cyclodextrins are produced from starch by enzymatic conversion. They are used in food, pharmaceutical, drug delivery, and chemical industries, as well as agriculture and environmental engineering. Cyclodextrins are composed of 5 or more α-D-glucopyranoside units linked 1->4, as in amylose (a fragment of starch). Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape: * α (alpha)-cyclodextrin: 6 glucose subunits * β (beta)-cyclodextrin: 7 glucose subunits * γ (gamma)-cyclodextrin: 8 glucose subunits The largest well-characterized cyclodextrin contains 32 1,4-anhydroglucopyranoside units. Poorly-characterized mixtures, containing at least 150-membered cyclic oligosaccharides are also known. Applications Drug delivery Cyclodextrins are ingredients in more than 30 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
