Book excerpt: This book is principally concerned with the relatively complex small molecules produced by plants, which are important as drugs, fine chemicals, fragrances, flavours and biologically-active dietary constituents. In a wide-ranging series of thematic essays, it covers key aspects of their role in plant ecology, their metabolism in the plant, their discovery, characterisation and use and their significance in the diet. Biotechnology, including prospects for the genetic engineering of metabolic pathways, for biotransformations and also for the production of biologically-active proteins, is the focus of the final section of the book. The overall aim of the volume is to provide, in each of the selected subject areas, a personal critique which is readily accessible to the advanced undergraduate student and to the non-specialist research worker alike.