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Lichen Spot Tests
A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change (or lack thereof) associated with application of the chemical. The tests are routinely encountered in dichotomous keys for lichen species, and they take advantage of the wide array of lichen products produced by lichens and their uniqueness among taxa. As such, spot tests reveal the presence or absence of chemicals in various parts of a lichen. They were first proposed by the botanist William Nylander in 1866. Three common spot tests use either 10% aqueous KOH solution (K test), saturated aqueous solution of bleaching powder or calcium hypochlorite (C test), or 5% alcoholic ''p''-phenylenediamine solution (P test). The colour changes occur due to presence of particular secondary metabolites in the lichen. There are several other less frequently used spot tests of more limited use that are employed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichenology
Lichenology is the branch of mycology that studies the lichens, symbiotic organisms made up of an intimate symbiotic association of a microscopic alga (or a cyanobacterium) with a filamentous fungus. Study of lichens draws knowledge from several disciplines: mycology, phycology, microbiology and botany. Scholars of lichenology are known as lichenologists. History The beginnings Lichens as a group have received less attention in classical treatises on botany than other groups although the relationship between humans and some species has been documented from early times. Several species have appeared in the works of Dioscorides, Pliny the Elder and Theophrastus although the studies are not very deep. During the first centuries of the modern age they were usually put forward as examples of spontaneous generation and their reproductive mechanisms were totally ignored. For centuries naturalists had included lichens in diverse groups until in the early 18th century a French researche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Household Bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad spectrum bactericidal properties, making them useful for disinfecting and sterilizing. They are used in swimming pool sanitation to control bacteria, viruses, and algae, and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the bleaching of wood pulp. Bleaches also have other minor uses like removing mildew, killing weeds, and increasing the longevity of cut flowers. Bleaches work by reacting with many colored organic compounds, such as natural pigments, and turning them into colorless ones. While most bleaches are oxidizing agents (chemicals that can remove electrons from other m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hypochlorite
Sodium hypochlorite (commonly known in a dilute solution as bleach) is an Inorganic chemistry, inorganic chemical compound with the chemical formula, formula NaOCl (or NaClO), comprising a sodium cation () and a hypochlorite anion (or ). It may also be viewed as the sodium salt (chemistry), salt of hypochlorous acid. The anhydrous Chemical compound, compound is unstable and may decompose explosively. It can be crystallized as a hydrate, pentahydrate ·5, a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated. Sodium hypochlorite is most often encountered as a pale greenish-yellow dilute solution referred to as liquid bleach, which is a household chemical widely used (since the 18th century) as a disinfectant or a bleaching agent. In solution, the compound is unstable and easily decomposes, liberating chlorine, which is the active principle of such products. Sodium hypochlorite is the oldest and still most important chlorine-releasing compounds, chl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Usnic Acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933-1937 by Curd and Robertson. Usnic acid was identified in many genera of lichens including ''Usnea'', '' Cladonia'', ''Hypotrachyna'', ''Lecanora'', ''Ramalina'', '' Evernia'', ''Parmelia'' and '' Alectoria''. Although it is generally believed that usnic acid is exclusively restricted to lichens, in a few unconfirmed isolated cases the compound was found in kombucha tea and non-lichenized ascomycetes. At normal conditions, usnic acid is a bitter, yellow, solid substance. It is known to occur in nature in both the d- and l-forms as well as a racemic mixture. Salts of usnic acid are called usnates (e.g. copper usnate). Biological role in lichens Usnic acid is a secondary metabolite in lichens whose role has not been completely elucidated. It is believed that usnic acid prote ... [...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] |
Xanthone
Xanthone is an organic compound with the molecular formula O[C6H4]2CO. It is a white solid. In 1939, xanthone was introduced as an insecticide and it currently finds uses as Insecticide, 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 dehydration reaction, dehydrating agent. *The Friedel–Crafts reaction, Friedel-Crafts method has a benzophenone intermediate. *The Robinson-Nishikawa method is a variant of the Hoesch reaction, Hoesch synthesis but with low yields. *The Asahina-Tanase method synthesizes some methoxylated xanthones, and xanthones with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depsidone
Depsidones (+ "depside" + "one") are chemical compounds that are sometimes found as secondary metabolites in lichens. They are esters that are both depsides and cyclic ethers. An example is norstictic acid Norstictic acid is a depsidone produced as a secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fun .... References {{reflist Biochemistry Carboxylate esters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orcinol
Orcinol is an organic compound with the formula CH3C6H3(OH)2. It occurs in many species of lichens including ''Roccella tinctoria'' and ''Lecanora''. Orcinol has been detected in the "toxic glue" of the ant species ''Camponotus saundersi''. It is a colorless solid. It is related to resorcinol, 1,3-C6H4(OH)2. Synthesis and reactions Orcinol was first prepared by dehydroacetic acid, a conversion that involved ring-opening of the pyrone to a triketone. This early experiment helped establish the rich condensation chemistry of polyketides. It can be obtained by fusing extract of aloes with potash, followed by acidification. It undergoes O-methylation with dimethylsulfate. It is used in the production of the dye orcein and as a reagent in some chemical tests for pentoses, such as Bial's Test. It may be synthesized from toluene; more interesting is its production when acetone dicarboxylic ester is condensed with the aid of sodium. It crystallizes in colorless prisms with one molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thamnolic Acid
Thamnolic acid is a β-orcinol depside with the molecular formula C19H16O11. Thamnolic acid was first isolated from the lichen '' Thamnolia vermicularis'', but it also occur in ''Cladonia ''Cladonia'' is a genus of moss-like lichens in the family Cladoniaceae. They are the primary food source for reindeer/caribou. ''Cladonia'' species are of economic importance to reindeer-herders, such as the Sami in Scandinavia or the Nenets ...'' spezies. References Further reading * * * Lichen products Polyphenols Carboxylic acids Methoxy compounds {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atranorin
Atranorin is a chemical substance produced by some species of lichen. It is a secondary metabolite belonging to a group of compounds known as depsides. Atranorin has analgesic, anti-inflammatory, antibacterial, antifungal, cytotoxic, antioxidant, antiviral, and immunomodulatory properties. In rare cases, people can react allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ... to atranorin. References Further reading * * * * Polyphenols Lichen products {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
