Natural product libraries require collection of samples of biota and extraction of compounds for screening against a biological target. Although this is a simple task, the establishment of a quality natural product–based library requires a good understanding of the modern drug discovery paradigm. A quality natural product library will allow both the discovery of natural products that may be able to be developed into therapeutic agents as they occur in nature and the identification of starting points for medicinal chemistry optimization. The process of establishing a natural product screening library for use in high-throughput screening (HTS) is illustrated in Figure 7.1. The collected sample may be plant material, marine organisms, or terrestrial or marine microorganisms. Once collected, the samples need to be processed to provide the compounds contained in the samples in a soluble form to allow HTS. Extraction with organic and aqueous solvents provides the soluble constituents that may be processed further into fractions or pure compounds.

Requirements prior to collecting natural products

In recent years, it has been recognized that genetic material is a sovereign right of the country of origin. Collection of biota samples must be undertaken according to the United Nations Convention on Biological Diversity (CBD). The CBD opened for signature on June 5, 1992, at the United Nations Conference on Environment and Development (UNCED), also known as the Earth Summit, in Rio de Janeiro, Brazil. The text of the CBD is available on the Web site of the Convention of Biological Diversity at www.cbd.int/convention/convention.shtml.