Drugs are usually derived from natural sources, such as plant-derived natural products, microbial metabolites, marine invertebrate derived compounds, etc. Drug discovery is an interdisciplinary field of medicine, pharmacology and biotechnology, which is concerned with the process of discovery of potential new medications. Modern drug discovery is a complex process, which involves a number of technical procedures such as identification of screening hits and their optimization to increase the selectivity, potency, affinity, metabolic stability and oral bioavailability of the hits. When a compound fulfills all of these requirements, it proceeds towards drug development and clinical trials. This book elucidates the concepts and innovative models around prospective developments with respect to drug discovery. It provides significant information of this domain to help develop a good understanding of drug discovery and related fields. With state-of-the-art inputs by acclaimed experts of this field, this book targets students and professionals.