ABSTRACT
Plants have been used as sources of food, beverages, fibers, or building materials, and also as sources of poisons, drugs, colorants, flavors, fragrances, and insecticides. Many natural products are now produced as specialty chemicals for applications in the food, pharmaceutical, and flavor and fragrance industries. Synthesis is usually directed at certain compounds, which will only lead to improved drugs for already known receptors, whereas natural compounds are much more probable to show totally new modes of action in broad screens. The screening methods for antibiotic and antiviral activities are rather straightforward. The use of isolated organs for studying certain biological activities is decreasing because of the wish to reduce the number of animal experiments. In plants, a large number of compounds is present, encompassing a broad spectrum of polarities. Screening of plant cell cultures for new biologically active compounds is feasible.
