A natural product is a chemical compound or substance produced by a living organism - found in nature that usually has a pharmacological or biological activity for use in pharmaceutical drug discovery and drug design. A natural product can be considered as such even if it can be prepared by total synthesis. In this book, the authors present current research in the study of the structure, bioactivity and applications of natural products. Topics discussed include the in-vitro assessment of chromones and alkaloids from Caribbean plants as potential anti-tuberculars and chemopreventors; natural products as inhibitors of ubiquitin and ubiquitin-like protein-proteasome pathways; the biological activities of red propolis; nanoencapsulation of natural products; and natural products as a source of potential drugs for the treatment of fungal infections.