Characterization and detection of major micromolecular constituents from species of Brazilian Cerrado and Atlantic rainforest using in silico and hyphenated techniques

Aiming to accelerate the screening of potential antimalarial and antioxidant crude extracts from several Brazilian plant species and endophytic fungi, we incorporated the development of dereplication processes using the HPLC/microtiter-plate approach (to construct DPPH-reduction and heme polymerization inhibition bioactivity profiles) plus HPLC/DAD-HRMS [1]. Further analysis combining in silico techniques of homemade/public databases [2], we were able to construct a micromolecular profile useful to decide if the matrix is worthwhile for further specific studies such as isolation and elucidation. Strychnos brasiliensis, S. pseudoquina, Citrus limetta and the ethyl acetate extracts from the edophytic fungi Phomopsis stipata, were selected for this study. Combining the chromatographic profile plus the total ion current (TIC) with the high resolution masses from the databases, allowed us to detect the major antimalarial and antioxidant compounds accumulated by those species. Final molecules were proposed using HRMS-ESI-MS-MS through the establishment of rational fragmentation patterns. From the Strychnos species we were able to detect bisamides of the grandamide family, diamide-aminopirrolidine and indole alkaloids. P. stipata accumulated mainly anthraquinone derivates, diterpenes and norsesquiterpenes and C. limetta bears mainly flavones and coumarins such as: salvigenine, pilosine and 7-methoxy-6-(1,2,3-trihidroxy-3-methylbutyl)-coumarin, biacangelicine, clausarine and O-(3-methylbutanoyl)-sesinol.

Acknowledgements: FAPESP, CAPES and CNPq for financial support.

References: 1. Wolfender, J-L. et al. (2006) Exp. Op. Drug Disc. 3:237–260.

2. Kerber, A. et al. (2004)J. Comp. Chem. 3:85–96.