In this book, the authors present current research in the study of the occurrence, medicinal uses and physiological importance of quinones. Topics discussed in this compilation include the biological implications of benzoquinones; dihydropyrimidinone derivates and their redox reactivity and pharmacological relevance; quinone monoacetal compounds in the application of controlled reactions with nucleophiles; quinone oxidoreductase 2 in the brain and retina; and plasma membrane CoQ, porin, and redox control of autism.