Secondary natural products

Bell EA. 1981. The physiological role(s) of secondary (natural) products. In Conn EE, editor. The Biochemistry of Plants. Volume 7, Secondary Plant Products. New York Academic Press, pp. 1-19. 

As in the other -omics, analyses may be directed at a specific metabolite, at all metabolites in a given system in a shot-gun approach, or at accessible groups of molecules in profiling experiments. In that also the technology varies. In addition, the chemistry of different metabolites is very heterogeneous since it involves hydrophobic lipids, hydrophilic carbohydrates, ionic inorganic species, and other secondary natural products and already the choice of solvent in metabolite extraction dictates which types of molecules will be present (Fig. 10.8). Therefore, total metabolome profiling is not possible, because no analytical method will be able to accommodate all the different molecule classes at once. 

The carbohydrates, amino acids, proteins, and nucleic acids discussed in Chapters 25, 26, and 27 are sometimes called primary natural products because they are found in all types of organisms and are the products of primary metabolism. Secondary natural products are usually produced from primary natural product precursors, such as amino acids or acetate ion, and, in general, are less widespread in occurrence. Today, natural product chemistry usually refers to the structure, reactions, and synthesis of these secondary natural products. 

Secondary natural products (Chapter 28) Natural products that are usually produced from primary natural product precursors, such as amino acids or acetate ion, and, in general, are less widespread in occurrence than primary natural products. 

This is parsimony which would not be in the sense of a synthetic chemist synthesizing a new drug molecule It is not directed towards specificity but serves rather the opposite to obtain a broad-band chemical mace as efficacious as possible against as many targets as possible. This section has shown the enormous versatility of STL structure and the major determinants of their structural diversity. In this light on the outstanding success of STLs as secondary natural products in evolution the next section will focus in more detail on reactivity as the basis of this success, and on particular structure-activity relationships associated therewith. 

Natural products. General term for substances from animals, plants, or microorganisms, generally arising from their secondary metabolism but also in the wider sense from the primary metabolism. The primary substances are ubiquitous in nature, the occurrence of secondary substances is mostly limited to specific oigan-isms. The classification into primary and secondary natural products was introduced by the physiologist A. Kessel. 

Barz, W. and J. Koster, Turnover and degradation of secondary (natural) products, in Secondary Plant Products, (E. E. Conn, ed.), of Biochemistry of Plants (P. K. Stumpf and E. E. Conn, eds.), 35-84, Academic Press, New York, 1981. 

Table 2. Biological functions of secondary natural products...

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