cursory perusal of the recent literature provides a small sampling of the wide variety of compounds that have not been developed but have significant indications of efficacy (Table 4). Estimates of the number of existing compounds that are undeveloped is in the low hundreds (J. Faulkner, personal communication). One of the major stumbling blocks to the development of many of these compounds is that there is nothing currently known that allows us to distinguish them from the plethora of nonspecific toxins produced by a wide variety of organisms. This situation results from a lack of knowledge of their pharmacological mechanisms of action. A second major reason for their lack of development is their limited supply (Faulkner, 2000). Undertaking preclinical characterization and clinical testing of novel compounds requires hundreds of grams of compound, depending on its potency. Most of these compounds come from marine invertebrates or algae that are in relatively short supply. Thus, the choice is between culturing the organism in large quantities, developing a genetically manipulated culture system to produce the compound by means of modern molecular biological techniques, or chemically synthesizing the compound. Each of these production methods is costly and time-consuming. Sufficient scientific validation and information about the mechanism of the compound must be discovered first to develop significant advocacy and sufficient industrial interest for development.

One of the best examples of how this advocacy and interest-raising process occurs is the recent development of a number of antimitotic anti-cancer drugs, including Taxol and several vinca alkaloid-like drugs. Taxol and the vinca alkaloids are widely used and effective drugs that work by actions on microtubules. Microtubules are long proteinaceous tubules that form a dynamic and ever-changing skeleton or structural framework in the cell. They are central to many cellular functions, including cell movement, cell growth and reproduction, and cell signaling. It has been argued that microtubules are among the most important and most successful targets for anticancer drugs (Giannakakou et al., 2000). Although Taxol and vinca alkaloids are both derived from terrestrial plants, their development is a prime example of how the advocacy and developmental process works.

The history of Taxol in modern medicine starts over 30 years ago with the collection of samples of the Pacific yew tree by the U.S. Department of Agriculture (USDA) and the National Cancer Institute (NCI). Taxol’s path from that point to its current status as one of the most successful new cancer drugs is the result of the perseverance of a cadre of chemists, pharmacologists, and oncologists (Horwitz, 1994), including seminal work on