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Pulvinone
Pulvinone, an organic compound belonging to the esters, lactones, alcohols and butenolides classes, is a yellow crystalline solid. Although the pulvinone is not a natural product, several naturally occurring hydroxylated derivatives are known. These hydroxylated pulvinones are produced by fungal species, such as the in Europe common Larch Bolete (''Boletus elegans'', also known as ''Suillus grevillei''), or by moulds such as ''Aspergillus terreus''. History Fungi (such as boleti), moulds and lichens produce a wide range of pigments made up of one (monomer) or several (oligomers) units of pulvinic acid. In 1831, in the course of a study of the constituents of lichens (''Cetraria Vulpina''), the French chemist and pharmacist Antoine Bebert discovered a compound named ''vulpinic acid'', the first known naturally occurring methyl ester of pulvinic acid. More details about the structure of this pigment were disclosed in 1860 by the German chemists Franz Möller and Adolph Strecker.'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulvinic Acid
Pulvinic acids are natural chemical pigments found in some lichens, derived biosynthetically from the aromatic amino acids phenylalanine and tyrosine, via dimerization and oxidative ring-cleavage of aryl pyruvic acids, a process that also produces the related pulvinones. Hydroxypulvinic acid pigments (pulvinic acid type family of pigments) have been found in ''Boletus'' (e.g. '' Boletus erythropus''), '' Boletinus'', ''Chalciporus'', ''Gyrodon'', ''Leccinum'', '' Pulveroboletus'', ''Suillus'' (e.g. ''Suillus luteus'', ''Suillus bovinus'', and ''Suillus grevillei''), ''Paxillus'' (e.g. ''Paxillus involutus''), ''Serpula'' (e.g. '' Serpula lacrymans''), '' Xerocomus'' (e.g. '' Xerocomus chrysenteron''), ''Hygrophoropsis'' (e.g. ''Hygrophoropsis aurantiaca''), '' Retiboletus'' (e.g. '' Retiboletus nigerrimus''), '' Pulveroboletus'' (e.g. '' Pulveroboletus auriflammeus''), and are generally characteristic of Boletales. In addition to pulvinone, derivatives and related pigments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Elsevier
Elsevier () is a Dutch academic publishing company specializing in scientific, technical, and medical content. Its products include journals such as ''The Lancet'', ''Cell'', the ScienceDirect collection of electronic journals, '' Trends'', the '' Current Opinion'' series, the online citation database Scopus, the SciVal tool for measuring research performance, the ClinicalKey search engine for clinicians, and the ClinicalPath evidence-based cancer care service. Elsevier's products and services also include digital tools for data management, instruction, research analytics and assessment. Elsevier is part of the RELX Group (known until 2015 as Reed Elsevier), a publicly traded company. According to RELX reports, in 2021 Elsevier published more than 600,000 articles annually in over 2,700 journals; as of 2018 its archives contained over 17 million documents and 40,000 e-books, with over one billion annual downloads. Researchers have criticized Elsevier for its high profit marg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suillus Grevillei
''Suillus grevillei'' ( commonly known as Greville's bolete and larch bolete) is a mycorrhizal mushroom with a tight, brilliantly coloured cap, shiny and wet looking with its mucous slime layer. The hymenium easily separates from the flesh of the cap, with a central stalk that is quite slender. The species has a ring or a tight-fitting annular zone. Description ''Suillus grevillei'' is a mushroom with a 5–10 cm (2–4 in) cap colored from citrus yellow to burnt orange, that is at first hemispherical, then bell-shaped, and finally flattened. It has a sticky skin, often with veil remnants on the edge, short tubes of yellow (possibly staining brownish) which descend down to the bottom of its cylindrical stalk (6–10 x 1–2 cm), which is yellowish above the ring area with streaks of reddish brown below. The flesh is yellow, staining brown. The thin meat has consistency at first but then quickly becomes soft. It has an odor reminiscent of rumpled ''Pelar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Claisen
Rainer Ludwig Claisen (; 14 January 1851 – 5 January 1930) was a German chemist best known for his work with condensations of carbonyls and sigmatropic rearrangements. He was born in Cologne as the son of a jurist and studied chemistry at the university of Bonn (1869), where he became a member of K.St.V. Arminia. He served in the army as a nurse in 1870–1871 and continued his studies at Göttingen University. He returned to the University of Bonn in 1872 and started his academic career at the same university in 1874. He died in 1930 in Godesberg am Rhein (near Bonn). Career Scientific contributions * Described the condensation of aromatic aldehydes with aliphatic aldehydes or ketones in 1881. This variation of the now well-known aldol condensation reaction is called the Claisen–Schmidt condensation. * Discovered (1887) the condensation reaction of an ester with an activated methylene group, now known as the Claisen condensation. * Synthesis of cinnamates by react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacob Volhard
Jacob Volhard (4 June 1834 – 14 January 1910) was the German chemist who discovered, together with his student Hugo Erdmann, the Volhard–Erdmann cyclization reaction. He was also responsible for the improvement of the Hell–Volhard–Zelinsky halogenation. From 1852 to 1855 he studied chemistry at the University of Giessen, and afterwards, furthered his education at the University of Heidelberg. For two years he worked as an assistant under Justus von Liebig at the University of Munich, and in 1860/61 studied with August Wilhelm von Hofmann in London. In 1863 he obtained his habilitation at Munich, where he subsequently became an associate professor. In the meantime, he worked in the Institute of Plant Physiology at the Bavarian Academy of Sciences (1865–76). In 1879 he was named a professor of organic chemistry at the University of Erlangen, then in 1882 relocated to the University of Halle, where he served as a professor up until 1908. Selected works * ''Die Begrün ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saponification
Saponification is a process of converting esters into soaps and alcohols by the action of aqueous alkali (for example, aqueous sodium hydroxide solutions). Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. Sodium stearate is a typical soap. Saponification of fats Vegetable oils and animal fats are the traditional materials that are saponified. These greasy materials, triesters called triglycerides, are mixtures derived from diverse fatty acids. Triglycerides can be converted to soap in either a one- or a two-step process. In the traditional one-step process, the triglyceride is treated with a strong base (e.g. lye), which cleaves the ester bond, releasing fatty acid salts (soaps) and glycerol. This process is also the main industrial method for producing glycerol. In some soap-making, the glycerol is left in the soap. If necessary, soaps may be precipitated by salting it out with sodium chloride. Fat in a corpse converts into adipoce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulpinic Acid
Vulpinic acid is a natural product first found in and important in the symbiosis underlying the biology of lichens. It is a simple methyl ester derivative of its parent compound, pulvinic acid, and a close relative of pulvinone, both of which derive from aromatic amino acids such as phenylalanine via secondary metabolism. The roles of vulpinic acid are not fully established, but may include properties that make it an antifeedant for herbivores. The compound is relatively toxic to mammals. Chemical description Vulpinic acid was first isolated from lichens in 1925. As an isolated, purified substance, it is bright yellow in color. Vulpinic acid is derived biosynthetically by esterification from pulvinic acid; pulvinate itself derives from the aromatic amino acids phenylalanine and tyrosine, via dimerization and oxidative ring-cleavage of arylpyruvic acids, a process that also produces the related pulvinones. There have been several chemical syntheses reported for vulpinic acid. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Spiegel
Adolf (also spelt Adolph or Adolphe, Adolfo and when Latinised Adolphus) is a given name used in German-speaking countries, Scandinavia, the Netherlands and Flanders, France, Italy, Spain, Portugal, Latin America and to a lesser extent in various Central European and East European countries with non-Germanic languages, such as Lithuanian Adolfas and Latvian Ādolfs. Adolphus can also appear as a surname, as in John Adolphus, the English historian. The female forms Adolphine and Adolpha are far more rare than the male names. The name is a compound derived from the Old High German ''Athalwolf'' (or ''Hadulf''), a composition of ''athal'', or ''adal'', meaning "noble" (or '' had(u)''-, meaning "battle, combat"), and ''wolf''. The name is cognate to the Anglo-Saxon name '' Æthelwulf'' (also Eadulf or Eadwulf). The name can also be derived from the ancient Germanic elements "Wald" meaning "power", "brightness" and wolf (Waldwulf). Due to negative associations with Adolf Hitler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
