During 2003 and 2004, marine antitumor pharmacology research directed towards the discovery and development of novel antitumour agents was published in 163 peer-reviewed articles. The purpose of this review  is to present a structured assessment of the antitumour and cytotoxic properties of 150 marine natural products, many of which are novel compounds that belong to diverse structural classes, including polyketides, terpenes, steroids and peptides. The organisms yielding these bioactive marine compounds include invertebrate animals, algae, fungi and bacteria. Antitumour pharmacological studies were conducted with 31 structurally defined marine natural products in a number of experimental and clinical models which further defined their mechanisms of action. Particularly potent in vitro cytotoxicity data generated with murine and human tumour cell lines was reported for 119 novel marine chemicals with as yet undetermined mechanisms of action. Noteworthy is the fact that marine anticancer research was sustained by a global collaborative effort, involving researchers from Australia, Austria, Canada, China, Egypt, France, Germany, Italy, Japan, Mexico, the Netherlands, New Zealand, Papua New Guinea, the Phillipines, South Africa, South Korea, Spain, Switzerland, Taiwan, Thailand and the United States. Finally, this 2003-4 overview of the marine pharmacology literature highlights the fact that the discovery of novel marine antitumour agents continued at the same pace as during 1998-2002. Mayer, A.M.S. and K.R.Gustafson. Marine Pharmacology in 2003-4: Antitumor and Cytotoxic Compounds. European Journal of Cancer 42: 2241-2270, 2006

During 2003-4, research on the pharmacology of marine chemicals involved investigators from Argentina, Australia, Brazil, Belgium, Canada, China, France, Germany, India, Indonesia, Israel, Italy, Japan, Mexico, Morocco, the Netherlands, New Zealand, Norway, Panama, the Phillipines, Portugal, Russia,  Slovenia, South Korea, Spain, Thailand, Turkey, United Kingdom, and the United States. This current article, a sequel to the authors’ 1998-2002 reviews, classifies 163 marine chemicals derived from a diverse group of marine animals, algae, fungi and bacteria, on the basis of peer-reviewed preclinical pharmacology. Anthelminthic, antibacterial, anticoagulant, antifungal, antimalarial, antiplatelet, antiprotozoal, antituberculosis or antiviral activities were reported for 64 marine chemicals. Additionally 45 marine compounds were shown to have significant effects on the cardiovascular, immune and nervous system as well as possessing anti-inflammatory and antidiabetic effects. Finally, 54 marine compounds were reported to act on a variety of molecular targets and thus may potentially contribute to several pharmacological classes.  Thus, during 2003-2004 the pharmacology of marine chemicals contributed numerous chemical leads for the continued global search for novel therapeutic agents with broad spectrum activity. (Mayer, A.M.S., Rodriguez, A.D., Berlinck, R.,and M. T. Hamann.  Marine pharmacology  in 2003-4:  Marine Compounds with Anthelminthic, Antibacterial, Anticoagulant, Antifungal, Anti-inflammatory, Antimalarial, Antiplatelet, Antiprotozoal, Antituberculosis, and Antiviral Activities;  affecting the Cardiovascular and Nervous Systems, and other Miscellaneous Mechanisms of Action. Comparative Biochemistry and Physiology Part C: 145: 553-581, 2007