This concise text provides a straightforward introduction to the chemistry involved in the biosynthesis of natural products. The first chapter explains the connections between primary and secondary metabolites, outlines the chemistry mediated by the major enzyme cofactors, and describes the methods for the elucidation of biosynthetic pathways. The different classes of secondary metabolites are then discussed, with emphasis placed on the pharmacological and toxiocological significance of the various compounds. The final chapter offers an insight into the ecological significance of a wide variety of natural products. Suggestions for further reading are provided.