What is unique about this book? This book is intended for undergraduates, graduates and scientists in general. It introduces certain topics of natural products which are only taught in institutes of higher learning. Despite the fact that there exists a vast literature devoted principally or entirely to naturally occurring compounds, there are very few books or monographs of moderate length that provide an overall view of the field. There are many aspects of natural products that deserve a special emphasis that is unlikely to be encountered in a conventional course of organic chemistry. Among them are biosynthesis; metabolic transformations; and physiological and biological properties of some of the natural products. The field of the chemistry of natural products is so immense that it embraces an almost limitless scope of the compound types. This book contains specialized work that describes the chemistry of separate classes of compounds such as steroids, terpenes, alkaloids, sugars, carotenoids, fatty acids and so on. It also includes data on compounds isolated from various classes of organisms such as, lichens, bacteria, fungi are treated in special monographs. The topics in this book are unlikely to be found in general chemistry courses. The book covers the following topics of natural products: cannabinoids, toxic constituents from marine sources, natural sweeteners, generation of wines, biological markers, pheromones of insects and mammals, pest management and secondary natural chemicals formed by microorganisms. Among the authors of the reviews is Professor Raphael Mechoulam who received the Israel Prize for his work on active constituents (cannabinoids) of the Cannabis plant and Professor Douglas Kinghorn from University of Chicago who is the chief editor of "Journal of Natural Products."