ABSTRACT
Not long ago, the large num ber of organic com pounds occurring in nature, other than the p rim ary m etabolites and the sem antides, were dism issed as waste products of metabolism. However, this description was never fully accepted and there have been, from tim e to tim e, suggestions that these com pounds do have well-defined biological functions. However, convincing experim ental evidences in support of such suggestions have become available only during the past few years. As a result of such studies, the secondary metabolites, particularly of plant origin, have ceased to be merely chemical curiosities; biologists are increasingly taking an interest in them as they help us understand several nuances in physiological functions. It is now generally accepted that while they may not be needed for the prim ary, prim itive and fundam ental m olecular phenom ena inseparable from any form of life, the secondary m etabolites endow the species in which they occur w ith some of their unique and species-specific characteristics. These include the ability to interact in a specific m anner w ith other forms of life in any given environm ent; in other words, the capacity to ‘articulate’ in a unique and distinctive m anner.
