This book focuses on the different compounds (polyphenols, sterols, alkaloids terpenes) that arise from the secondary metabolism of plants and fungi and their importance for research and industry. These compounds have been the backbone and inspiration of various industries like the food, pharmaceutical and others to produce synthetic counterparts. Furthermore, many of these compounds are still widely used to carry out specific functions in all these industries. This book offers a compilation of different texts from world leading scientists in the areas of chemistry, biochemistry, plant science, biotechnology which compile information on each group of secondary metabolism compounds, and their most important applications in the food, pharmaceutical, cosmetic and textile industry. By showcasing the best uses of these compounds, the chemistry behind their production in plants and fungi, this book is a valuable resource and a "go to" artifact for various audiences. The new approach this book offers, by linking research and the application of these compounds, makes it interesting as an inspiration for new research or as a hallmark of what has been done in the secondary metabolism of plants and fungi in recent years. Although this book may be technical, it is also enjoyable as an integral reading experience due to a structured and integrated flow, from the origins of secondary metabolism in organisms, to the discovery of their effects, their high intensity research in recent years and translation into various industries. Beyond learning more on their chemistry, synthesis, metabolic pathway, readers will understand their importance to different research and industry.