depsides
TRANSCRIPT
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• These are yellow pigments which occurs in plant kingdome either in the free state or as a glycosides or accociated with tanins
• These are also known as the anthoxanthins
• Flavones (flavus = yellow), are a class of flavonoids based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one)
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• Isoflavones comprise a class of organic compounds, often naturally occurring, related to the isoflavonoids.
• Many act as phytoestrogens in mammals.
• Some are termed antioxidants because of their ability to trap singlet oxygen.
• Isoflavones are produced almost exclusively by the members of the Fabaceae
• (i.e., Leguminosae, or bean) family.
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Isoflavones are produced via a branch of the general phenylpropanoid pathway that produces flavonoid
compounds in higher plants
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•Determination of structure of isoflavone
•(1) Number of –OH gp. and –OCH3 gp. are determined by Zerewitinoff’s and Zeisel’smethod.
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• (2) On reaction with KOH it gives following :
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(3) On oxidation with alkaline H2O2 , degradation of isoflavon occurs .
•These method provide usefull information of the substituents in the 3-phenyl nucleus.
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Synthesis :-
• Spath synthesis
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• Baker – ollis synthesis
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• Wessley synthesis
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• A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an esterbond.
• Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, Lamiaceae, Papaveraceae and Myrtaceae
• Depsides have antibiotic, anti-HIV, antioxidant, and anti-proliferative activity.
• As inhibitors of prostaglandin synthesis and leukotriene B4biosynthesis, depsides are potent non-steroidal anti-inflammatories
• A depsidase is a type of enzyme that cuts depside bonds,Onesuch enzyme is tannase.
• Gyrophoric acid, found in the lichen Cryptothecia rubrocincta, is a depside.