ABSTRACT
All research programs that aim to discover novel bioactive compounds from natural sources rely to some degree on the assumption that a carefully reasoned philosophy guiding the selection of species to be sampled can improve the rate of discovery. Plants are probably the most common source of samples for evaluation in high-throughput screens of natural products. They have yielded many useful compounds, and plant-derived ingredients are an important component of modern pharmaceuticals.1-3 Nevertheless, the vast majority of the world’s quarter of a million plant species have not been evaluated in pharmaceutical screens, and the small percentage that has been tested has generally been screened for activity against only a few therapeutic targets. The geographic and taxonomic distribution of the approximately 250,000 species of higher plants is not random, the chemistry of various plant families is known to differ significantly, and our present state of knowledge of the chemistry of plants remains uneven. For these reasons, many collecting schemes have been proposed to yield novel bioactive compounds at a rate above that predicted by chance.
