Chemistry and Pharmacology of Flavonoids- A Review

‘Flavonoid’ word was initially derived from ‘flavous’, a latin word which means yellow, resembling flavonoid’s colour in nature.1-3 Despite of its meaning, plentiful of other flavonoids are white and the chief flavonoid-related anthocyanins are purple, red or blue in colour as well.3 Flavonoids or bioflavonoids, are a category of secondary metabolites of plants and fungal origin.4-9 They are a class of natural compounds having variable phenolic structures.6 A new substance was screened out from oranges in 1930 which was thought to be a member of a new class of vitamins and was designated as vitamin P.7,10,11 Later on, that substance was confirmed to be a flavonoid, called rutin.11 The term “flavonoid” is basically used to describe a broad assemblage of natural compounds that contain a C6-C3-C6 carbon framework or more accurately a phenylbenzopyran functionality.12 The position at which the aromatic ring links with the benzopyrano functionality helps to determine the three classes into which this group of natural compounds can be divided: the flavonoids (2-phenylbenzopyrans) Figure 1, isoflavonoids (3-phenylbenzopyrans) Figure 2 and the neoflavonoids (4-phenylbenzopyrans) Figure 3 and (Chalcone) Figure 4. These groups generally share a common precursor (chalcone) and are therefore structurally and biogenetically related.13-17 Flavonoids possess different pharmacological activities and act through several mechanisms. All the healthy information regarding flavonoids will be discussed in this paper. ABSTRACT