Preface [Hot Topic;Marine Natural Products (Guest Editor: Raymond Andersen)]

Infectious diseases continue to represent a significant challenge to human medicine. Antibiotic resistance has made treatment of the common Gram-positive human pathogens Staphylococus aureus, Enterococcus faecalis, and Enterococcus faecium a serious medical problem. HIV and several newly emerging viral diseases such as SARS lack adequate treatments and patients who are HIV-positive are susceptible to opportunistic fungal infections involving the pathogens Candida sp., Cryptococcus neoformans, and Aspergillus sp. It has been estimated that approximately one third of the world's population is infected with Mycobacterium tuberculosis, the causative agent of tuberculosis, and that 2 million people will die of the disease each year. Clearly, there is an urgent need for new and better drugs to treat these lifethreatening infections. A large proportion of the drugs currently used to treat infectious diseases are natural products or synthetic analogs of natural products, and an analysis of the sources of recently approved drugs and pre-NDA candidates showed that more than 60% were of natural origin. The plants, animals and microorganisms living in the world's oceans represent a rich and relatively unexplored resource of new antibacterial, antifungal, and antiviral natural products. The current issue of CMC-Anti-Infective Agents features four articles written by experts in the field that review the recent literature describing marine natural products with anti-infective activities. Bernan, Greenstein, and Carter from Wyeth Research examine marine microorganisms as an important emerging source of new antibacterial and antifungal agents. Molinski from the Department of Chemistry at UC Davis describes recent research, much of it from his own laboratory, on antifungal metabolites isolated from marine invertebrates. Nicholas and Bewley from NIH illustrate the use of a marine natural product extract library as an important resource to find lead structures in a screen for inhibitors of enzymes involved in mycothiol biosynthesis and degradation. These enzymes are unique to actinomycetes, including medically important mycobacteria such as M. tuberculosis, making them potentially interesting selective targets for treating TB. Finally, Gustafson, Oku, and Milanowski from the National Cancer Institute provide a comprehensive review of the recent literature on antiviral marine natural products. I would like to thank the authors for contributing these stimulating articles that illustrate the important role that marine natural products can play in the critical search for new anti-infective drugs.