Natural product libraries from plants

The study of natural products, or Nature s Combinatorial Library , has had a long history as a source of drugs, and plants have historically been at the forefront of natural product drug discovery. In the anticancer area, for example, vinblastine and vincristine, etoposide, paclitaxel (Taxol), docetaxel, topotecan, and irinotecan, among others, are all plant-derived natural products or modified versions of plant compounds, while antimalarial therapy would be much poorer without quinine and artemisinin and the drugs derived from these plant products. This chapter provides an overview of the major medicinal agents that are themselves natural products isolated from plants or are chemical modifications of such lead compounds. It covers the therapeutic areas of cancer, HIV, malaria, cardiovascular, and central nervous system (CNS) diseases. Natural plant products have also made contributions in areas such as immunomodulatory and antibiotic activities," and the reader is referred to the cited reviews for information on these areas. 

Several of the most useful small-molecule probes are complex natural products isolated from marine, fungal, or plant sources. As natural products have built-in biologic properties efforts in the synthesis of compound libraries increasingly use natural product scaffolds as a starting material because they promise higher hit rates in biologic screens (23). 

Products/technologies The company has diverse libraries of natural compounds prepared from plant, fungal, and microbial sources and proprietary... 

A library of pure natural products will always be less chemically diverse compared to a library of extracts and will not generally benefit from the bioactivity clues that the ethnopharmacological selection of the starting plant material can afford. 

TimTech Natural compound library Purified natural products. 480 Structures retrievable from website. Mainly plant derived, 16% flavonoids. 17... 

The term opium alkaloids has been used rather loosely to cover all narcotic analgesics, whether they be synthetic compounds, partially synthetic, or extracted from plant material. To be precise, we should really only use the term for those natural compounds which have been extracted from opium—the sticky exudate obtained from the poppy (Papaver somniferum). The term alkaloid refers to a natural product which contains a nitrogen atom and is therefore basic in character. There are, in fact, several thousand alkaloids which have been extracted and identified from various plant sources and examples of some of the better known alkaloids are shown in Fig. 12.1. These compounds provide a vast library of biologically active compounds which can be used as lead compounds into many possible fields of medicinal chemistry. However, we are only interested at present in the alkaloids derived from opium. 

Fig. 7 Gene suppression. Gene fragments are used to silence genes in plant cell culture. If a fragment from a biosynthetic gene is used for silencing, then natural product production will be suppressed. The fragment can be used to identify the full length clone in a cDNA library...

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