Strategies in the Analysis of Plant Flavonoids

Abstract

Flavonoids are one of the largest groups of plant secondary metabolites. They comprise several thousand compounds that share a phenylchromane skeleton and can be classified into different classes, namely flavones, flavonols, flavanones, flavanols, anthocyanins, dihydroflavonols, isoflavones, and chalcones. Flavonoids occur in their natural sources as aglycones or glycosylated forms and as monomers or constituting polymerized structures and can be found both as free and matrix‐bound compounds. This structural diversity affects their physicochemical behavior, and different flavonoid classes and compounds may have different requisites for their extraction and analysis, so that there is not a unique analytical strategy that applies in all situations. In this chapter, the main methodological approaches to the analysis of flavonoids in plant materials are revised paying particular attention to more recent extraction techniques and high performance liquid chromatography‐based methodologies that currently dominate the field of flavonoid analysis.