1. INTRODUCTION TO PHENYLPROPANOIDS
Phenylpropanoids represent a large conglomerate of naturally occurring phenolic compounds essentially derived from the aromatic amino acids phenylalanine and tyrosine or in certain specific instances the intermediates obtained from Shikimic Acid Biosynthetic Pathway. In other words, these compounds comprise of a phenylring to which is attached a 3C-side chain; and may also contain one or more C6—C3 residues.
Interestingly, the unique combination of the phenyl-propane side chain (i.e., 3C-atom) evidently present in ‘phenylpropanoids’ are absolutely devoid of nitrogen atom, which is observed to be in contradiction to such other vital class of natural products, namely: alkaloids, cyanogenic glycosides, and glucosinolates. Obviously, the phenylpropanoids are distinctly phenolic in character by virtue of the presence of one or several hydroxyl groups attached to the aromatic ring (C6H6), they are more often known among the phytochemists as ‘plant phenolics’.