Chemical elicitation of secondary metabolism

Secondary metabolites produced by environmental microorganisms or their derivatives make up most of the drugs in current use. Genome sequencing has revealed that the full complement of secondary metabolites in nature, the parvome, includes many compounds that are not expressed well in the laboratory. It is agreed that these low-yield compounds, sometimes referred to as ‘cryptic secondary metabolites’, include candidates of interest for therapeutic development. The low production levels of these compounds in the laboratory has impeded their discovery. We have explored the use of chemical elicitors to drive the discovery of these low abundance metabolites. Using this approach we have identified biologically active compounds that act on eukaryotic cells. Our results call into question the meaning of the term ‘cryptic’ as applied to secondary metabolites.