"' Polyporic acid "'is a terphenyl benzoquinone compound first identified by German chemist Stahlschmidt from a inhibits the enzyme dihydroorotate dehydrogenase.
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In his 1966 publication, Allen and coworkers investigated the effects that different substituents on the benzoquinone starting material had on the arrangement of the final product.
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In 2006, a chemical study was carried out on the rhizomes of " Iris kemanonensis ", it found several compounds including a benzoquinone.
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The reaction conditions and purifications could be easily simplified by just using excess of palladium ( II ) acetate without benzoquinone, while at a much higher cost.
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The prototypical member of the class is 1, 4-benzoquinone or cyclohexadienedione, often called simply'quinone'( thus the name of the class ).
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Although not generally considered dangerous to humans, many millipedes produce noxious secretions ( often containing benzoquinones ) which in rare cases can cause temporary blistering and discolouration of the skin.
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It can also be prepared in high yield and selectivity at room temperature from glycerol using cationic palladium-based catalysts with oxygen, air or benzoquinone acting as co-oxidants.
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In the new study, the researchers were able to demonstrate that the millipede secretion consists of only two chemicals, both in the benzoquinone family and both known to be potent insect repellents.
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It is formed by the reaction of 1, 4-benzoquinone with hydrogen peroxide and is a byproduct of the metabolism of phenols, such as 1, 2, 4-benzenetriol.
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Thus, tissue damage facilitates the interaction of catechol oxidase with its substrate to produce o-benzoquinone, which can polymerize non-enzymatically to yield melanins that form an insoluble barrier for wound protection.
