Natural products as a resource for new drugs.

Natural products have served as a major source of drugs for centuries, and about half of the pharmaceuticals in use today are derived from natural products. The aim of this review is to provide an overview of the continuing central role of natural products in the discovery and development of new pharmaceuticals. In this context, selected examples of important natural product-derived drugs are cited, focusing on some of the most recent introductions to the clinical setting, and a brief overview of some of the important recent developments and remaining challenges in the process of discovering and developing bioactive natural products is provided. Interest in natural products research is strong and can be attributed to several factors, including unmet therapeutic needs, the remarkable diversity of both chemical structures and biological activities of naturally occurring secondary metabolites, the utility of bioactive natural products as biochemical and molecular probes, the development of novel and sensitive techniques to detect biologically active natural products, improved techniques to isolate, purify, and structurally characterize these active constituents, and advances in solving the demand for supply of complex natural products. Opportunities for multidisciplinary research that joins the forces of natural products chemistry, molecular and cellular biology, synthetic and analytical chemistry, biochemistry, and pharmacology to exploit the vast diversity of chemical structures and biological activities of natural products are discussed.