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Alloxan
Alloxan, sometimes referred to as ''alloxan hydrate'', is the name of the organic compound with the formula OC(N(H)CO)2C(OH)2. It is classified as a derivative of pyrimidine. The anhydrous derivative OC(N(H)CO)2CO is also known, as well as a dimeric derivative. These are some of the earliest known organic compounds. They exhibit a variety of biological activities. History and literature The compound was discovered by Justus von Liebig and Friedrich Wöhler. It is one of the oldest named organic compounds. It was originally prepared in 1818 by Luigi Valentino Brugnatelli (1761-1818) and was named in 1838 by Wöhler and Liebig. The name "Alloxan" emerged from an amalgamation of the words "allantoin" and "Oxalsäure" ( oxalic acid). The alloxan model of diabetes was first described in rabbits by Dunn, Sheehan and McLetchie in 1943. The name is derived from allantoin, a product of uric acid excreted by the fetus into the allantois, and oxaluric acid derived from oxalic acid a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloxane Chemistry
Alloxan, sometimes referred to as ''alloxan hydrate'', is the name of the organic compound with the formula OC(N(H)CO)2C(OH)2. It is classified as a derivative of pyrimidine. The anhydrous derivative OC(N(H)CO)2CO is also known, as well as a dimeric derivative. These are some of the earliest known organic compounds. They exhibit a variety of biological activities. History and literature The compound was discovered by Justus von Liebig and Friedrich Wöhler. It is one of the oldest named organic compounds. It was originally prepared in 1818 by Luigi Valentino Brugnatelli (1761-1818) and was named in 1838 by Wöhler and Liebig. The name "Alloxan" emerged from an amalgamation of the words "allantoin" and "Oxalsäure" ( oxalic acid). The alloxan model of diabetes was first described in rabbits by Dunn, Sheehan and McLetchie in 1943. The name is derived from allantoin, a product of uric acid excreted by the fetus into the allantois, and oxaluric acid derived from oxalic acid a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrimidine
Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other diazines are pyrazine (nitrogen atoms at the 1 and 4 positions) and pyridazine (nitrogen atoms at the 1 and 2 positions). In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U). Occurrence and history The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives, including the nucleotides cytosine, thymine and uracil, thiamine (vitamin B1) and alloxan. It is also found in many synthetic compounds such as barbiturates and the HIV drug, zidovudine. Although pyrimidine derivatives such as alloxan were known in the early 19th century, a laboratory synthesis of a pyrimidine was not carried out until 1879, when Grimaux reporte ... [...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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murexide
Murexide (NH4C8H4N5O6, or C8H5N5O6·NH3), also called ammonium purpurate or MX, is the ammonium salt of purpuric acid. It is a purple solid that is soluble in water. The compound was once used as an indicator reagent. Aqueous solutions are yellow at low pH, reddish-purple in weakly acidic solutions, and blue-purple in alkaline solutions. Preparation Murexide is prepared by treating alloxantin with ammonia to 100 °C, or by treating uramil (5-aminobarbituric acid) with mercury oxide. It may also be prepared by digesting alloxan with alcoholic ammonia. History Justus von Liebig and Friedrich Wöhler in Giessen, Germany, had investigated the purple product, murexide, obtained from snake excrement in the 1830s, but this was not an abundant raw material, and a method of using it as a dyestuff was not established at that time. In the 1850s, French colourists and dye-producers, such as Depoully in Paris, succeeded in making murexide from abundant South American guano and of app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murexide Dye
Murexide (NH4C8H4N5O6, or C8H5N5O6·NH3), also called ammonium purpurate or MX, is the ammonium salt of purpuric acid. It is a purple solid that is soluble in water. The compound was once used as an indicator reagent. Aqueous solutions are yellow at low pH, reddish-purple in weakly acidic solutions, and blue-purple in alkaline solutions. Preparation Murexide is prepared by treating alloxantin with ammonia to 100 °C, or by treating uramil (5-aminobarbituric acid) with mercury oxide. It may also be prepared by digesting alloxan with alcoholic ammonia. History Justus von Liebig and Friedrich Wöhler in Giessen, Germany, had investigated the purple product, murexide, obtained from snake excrement in the 1830s, but this was not an abundant raw material, and a method of using it as a dyestuff was not established at that time. In the 1850s, French colourists and dye-producers, such as Depoully in Paris, succeeded in making murexide from abundant South American guano and of app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luigi Valentino Brugnatelli
Luigi Valentino Brugnatelli (also Luigi Gaspare Brugnatelli or Luigi Vincenzo Brugnatelli) (14 February 1761 in Pavia – 24 October 1818 in Pavia) was an Italian chemist and inventor who discovered the process for electroplating in 1805. Early life Born in Pavia, he attended the Pharmacy School created by Count Karl Joseph von Firmian at the University of Pavia where he was a pupil of Giovanni Antonio Scopoli who urged him to practice the medical profession, which he did without neglecting his interests in chemistry. Brugnatelli graduated in medicine in 1784 with a thesis on the chemical analysis of gastric juices. He was also a pupil of Lazzaro Spallanzani. Academic career and discoveries He occasionally taught at the University of Pavia where he became the head of chemistry teaching in 1796. In 1813 he became its Rector. In 1798 Brugnatelli discovered the silver salt fulminic acid when he found that if silver was dissolved in nitric acid and the solution added to spiri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Periodic Table (short Story Collection)
''The Periodic Table'' ( it, Il sistema periodico) is a 1975 short story collection by Primo Levi, named after the periodic table in chemistry. In 2006, the Royal Institution of Great Britain named it the best science book ever. Content The stories are autobiographical episodes based on the author's experiences as a Jewish-Italian doctoral-level chemist under the Fascist regime in Italy and afterwards. They include various themes that follow a chronological sequence: his ancestry, his study of chemistry and practising the profession in wartime Italy, a pair of imaginative tales he wrote at that time, and his subsequent experiences as an anti-Fascist partisan, his arrest and imprisonment, interrogation, and internment in the Fossoli di Carpi and Auschwitz camps, and postwar life as an industrial chemist. Each of the twenty-one stories in the book bears the name of a chemical element as its title and has a connection to the element in some way. Chapters #"Argon" – The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney Stone
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine stream. A small stone may pass without causing symptoms. If a stone grows to more than , it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A stone may also result in blood in the urine, vomiting, or painful urination. About half of people who have had a kidney stone will have another within ten years. Most stones form by a combination of genetics and environmental factors. Risk factors include high urine calcium levels, obesity, certain foods, some medications, calcium supplements, hyperparathyroidism, gout and not drinking enough fluids. Stones form in the kidney when minerals in urine are at high concentration. The diagnosis is usually based on symptoms, urine testing, and medical i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Prout
William Prout FRS (; 15 January 1785 – 9 April 1850) was an English chemist, physician, and natural theologian. He is remembered today mainly for what is called Prout's hypothesis. Biography Prout was born in Horton, Gloucestershire in 1785 and educated at 17 years of age by a clergyman, followed by the Redland Academy at Bristol and Edinburgh University, where he graduated in 1811 with an MD. His professional life was spent as a practising physician in London, but he also occupied himself with chemical research. He was an active worker in biological chemistry and carried out many analyses of the secretions of living organisms, which he believed were produced by the breakdown of bodily tissues. In 1823, he discovered that stomach juices contain hydrochloric acid, which can be separated from gastric juice by distillation. In 1827, he proposed the classification of substances in food into sugars and starches, oily bodies, and albumen, which would later become known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boa (genus)
''Boa'' is a genus of non-venomous boas found in Mexico, the Caribbean, and Central and South America. Five species are currently recognized. Etymology The Online Etymology Dictionary says that the word comes from the "late 14c., "large snake," from Latin boa, type of large serpent mentioned in Pliny's "Natural History;" origin unknown (in medieval folk etymology the name was associated with Greek bous "ox")." Species Boa is a polytypic genus and so contains more than one species. The boa constrictor has been reported to grow to a maximum of 14 feet (4.3 m) in length.Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. . Numerous subspecies are currently recognised. A now extinct species, the Marie-Galante boa (''Boa blanchardensis''), lived during the Pleistocene on Marie Galante in the Lesser Antilles. Distribution and habitat ''Boa'' species are found in northern Mexico through Central America (Belize, Guatemala, Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turin
Turin ( , Piedmontese language, Piedmontese: ; it, Torino ) is a city and an important business and cultural centre in Northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is mainly on the western bank of the Po (river), Po River, below its Susa Valley, and is surrounded by the western Alps, Alpine arch and Superga Hill. The population of the city proper is 847,287 (31 January 2022) while the population of the urban area is estimated by Larger Urban Zones, Eurostat to be 1.7 million inhabitants. The Turin metropolitan area is estimated by the Organisation for Economic Co-operation and Development, OECD to have a population of 2.2 million. The city used to be a major European political centre. From 1563, it was the capital of the Duchy of Savoy, then of the Kingdom of Sardinia ruled by the House of Savoy, and the first capital of the Kingdom of Italy from 1861 to 1865. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primo Levi
Primo Michele Levi (; 31 July 1919 – 11 April 1987) was an Italian chemist, partisan, writer, and Jewish Holocaust survivor. He was the author of several books, collections of short stories, essays, poems and one novel. His best-known works include '' If This Is a Man'' (1947, published as ''Survival in Auschwitz'' in the United States), his account of the year he spent as a prisoner in the Auschwitz concentration camp in Nazi-occupied Poland; and '' The Periodic Table'' (1975), linked to qualities of the elements, which the Royal Institution named the best science book ever written. Levi died in 1987 from injuries sustained in a fall from a third-story apartment landing. His death was officially ruled a suicide, but some, after careful consideration, have suggested that the fall was accidental because he left no suicide note, there were no witnesses, and he was on medication that could have affected his blood pressure and caused him to fall accidentally. Biography E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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