Authored by leading experts in the enzymology of natural product biosynthesis, this textbook provides a thorough description of the types of natural products, the biosynthetic pathways that enable the production of these molecules, and an update on the discovery of novel products in the post-genomic era. Although some 500-600,000 natural products have been isolated and characterized over the past two centuries, there may be a 10-fold greater inventory awaiting immediate exploration based on biosynthetic gene cluster predictions. The approach of this book is to codify the chemical logic that underlies each natural product structural class as they are assembled from building blocks of primary metabolism. This text will serve as a reference point for chemists of every subdiscipline, including synthetic organic chemists and medicinal chemists. It will also be valuable to bioinformatic and computational biologists, to pharmacognocists and chemical ecologists, to bioengineers and synthetic biologists.