Chemography and phylogeny – navigating chemical and evolutionary space

Natural products are, in one respect, forming a mirror image of evolutionary processes, as pointed out already by Abbot [1]. In recent years approaches have been made resulting in e.g. consistent mapping devices for the drug-related chemical space, such as ChemGPS [2, 3]. Observations made employing this device [3] triggered the development of a device tuned for the biologically relevant sectors of chemical space, ChemGPS-NP [4].

In a similar way the result of evolutionary processes can be regarded as forming an evolutionary space, populated by extant and extinct organisms. This space has for the last 50 years been the subject of extensive mapping, lately as phylogenetic studies, aimed at elucidating evolutionary relationships providing robust results for various groups of organisms.

In this study we apply ChemGPS-NP to predict chemical traits of natural products with a limited distribution in the phylogeny of living organisms, aiming to cross-validating maps of chemical and evolutionary space. The key findings to be presented include a clearer understanding of the evolutionary driven changes in physical-chemical properties of sets of iridoids, sesquiterpene lactones, and Strychnos-alkaloids. Comparisons will be made to previously presented hypotheses of chemosystematic relatedness, and how this tool will aid in a systematic exploration of natural products chemical space.

References: 1. Abbot, H. (1887), The chemical basis of plant forms, Franklin Institute lecture. 2. Oprea, T.I., Gottfries, J. (2001), J. Comb. Chem. 3: 157–166. 3. Larsson, J. et al. (2005), J. Nat. Prod. 68: 985–991. 4. Larsson, J. et al. (2006), submitted manuscript.