2. • 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)
3.
4.
5. • 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.
6. Isoflavones are produced via a branch of the general
phenylpropanoid pathway that produces flavonoid
compounds in higher plants
7. •Determination of structure of
isoflavone
•(1) Number of –OH gp. and –OCH3 gp. are
determined by Zerewitinoff’s and Zeisel’s
method.
8. • (2) On reaction with KOH it gives following :
9. (3) On oxidation with alkaline H2O2 , degradation
of isoflavon occurs .
•These method provide usefull information of
the substituents in the 3-phenyl nucleus.
14. • A depside is a type of polyphenolic compound composed of
two or more monocyclic aromatic units linked by an ester
bond.
• 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 B4
biosynthesis, depsides are potent non-steroidal anti-inflammatories
• A depsidase is a type of enzyme that cuts depside bonds,One
such enzyme is tannase.
• Gyrophoric acid, found in the lichen Cryptothecia rubrocincta,
is a depside.
