This book is intended to be a presentation of alkaloids from chemical, biological and ecological points of view. It is a text for chemists, biologists and ecologists alike. However, the intended audience of this work is not limited to scientists, teachers and other present and future specialists. In fact, I wrote this book because I felt the need for it as a university educator and as a scientific enthusiast on the subject. My purpose was to compose a beneficial text for an academic and professional audience that could also serve as a source of knowledge for anyone who is interested in the fascinating subject of alkaloids. As.