ABSTRACT:
Phenolic compounds form one of the main class of secondary metabolites. They display a large range of structures and are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structure, biosynthesis, chemical synthetic methodologies and various biological activities appears essential to make them as potential therapeutic agents and also to predict and control food quality. The purpose of this work is an overview of structural diversities, synthetic methodologies and shed a light on biological activities. The first part of this review concerns the structural aspects, biosynthetic and synthetic schemes for different classes of flavonoids. Regarding the synthesis of flavonoids various schemes have been highlighted to obtain variety of higher potent flavonoid derivatives. These schemes can be applicable at regular laboratory levels. The second part of this review concerns the various biological properties of flavonoids on plant as well as on mammalian cells. Recently this group of natural products has gained much interest as bioactive compounds. Because of the variety of pharmacological activities on mammalian body flavonoids are more correctly referred as “Nutraceutical”.