This book deals with different Oxygenases enzymes. Due to their inherent regioselectivity and stereoselectivity, oxygenases have attracted attention as potential biocatalysts for various biotechnological processes. They are also involved in numerous catabolic as well as anabolic transformations in higher organisms. Keeping in view the studies of biotransformations and their synthetic relevance, attempt has been made to search new methods for stereoselective organic synthesis and biologically catalytic synthesis. Medicinal Chemistry, Heterocyclic Chemistry, and exploration of the interface between chemistry and biology through target oriented approach for making biologically significant molecules have been studied.The chemistry of different oxygenases and their detailed mechanism of action have been studied extensively in this book.