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Exploratory Chemometrics and Analytical Chemistry – Looking for the Needle in the Haystack. Nikoline Juul Nielsen, Post Doc Soil and Environmental Chemistry (present) Bioorganic Chemistry (previous). PhD in Natural Product Research.
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Exploratory Chemometrics and Analytical Chemistry – Looking for the Needle in the Haystack Nikoline Juul Nielsen, Post Doc Soil and Environmental Chemistry (present) Bioorganic Chemistry (previous)
PhD in Natural Product Research • Developing analytical tools (ways of measuring) and data processing tools (ways of interpreting data) for discovery of novel natural products
Natural Products I - Drugs Small molecule drugs approved 1981-2006 sorted by origin Newman and Cragg (2007): Journal of Natural Products, 70, 461-
Natural Products II – Establishing biosynthetic pathways OxidoR FMO Gip1 AurJ Compound C Enz. 1 Enz. 2 Enz. 3 Compound A Compound C Compound B Aurofusarin Frandsen et al. (2006): Molecular Microbiology, vol. 61(4), pp. 1069-
Natural Products III – Insect resistance factors in plants Shinoda et al. (2002): J. Chem Ecol., 28(3), 587- Agerbirk et al. (2003): J. Chem Ecol., 29(6), 1417- Kuzina et al. (2009): Plant Phys., 151, 1977- Nielsen et al. (in press): J. Agric. Food. Chem.
Natural Products IV – Small molecule endpoints from genes of unknown function m/z 683.5 rt 8.9 min CMycelia CLiquid media m/z 774.5 rt 14.1 min Overexpression Overexpression Intensity Transporter deletion Wildtype Wildtype Transporter deletion Nielsen et al. (in press): Metabolomics Deletion Deletion rt 9.4 min.
Natural Products V – Plant biomarkers of environmental contamination
How? • Meauring the organisms fingerprint i.e. as many analyte signal as possible and ideally all metabolites • Relating the fingerprints to a target vector i.e. • expected level of gene expression • plant resistance to herbivores • contaminant exposure level
Measuring the organism metabolite fingerprints - Instrumentation ESI-TOF-MS UPLC DAD FLR Mass-to-charge spectrum UV spectrum Chromatogram
Measuring the organism metabolite fingerprints - Data > 104 m/z values samples Spectrum 1000 scans Chromatogram
Relating the metabolite fingerprints to the target vector Multivariate models can visualize the major variations in data e.g. Principal Component Analysis (PCA)
Relating the metabolite fingerprints to the target vector Artefacts in the chromatographic dimension Noise Baseline Retention time shifts Varying detector sensitivity
My prime areas of interest • How to measure the entire set of metabolites i.e. increasing the information content of the data sets • How to fix up messy data i.e. for subsequent multivariate modelling • And this applies to a wide range of applications... • To characterize and identify targeted analytes from each application using e.g. NMR Basically what we can do is finding out what metabolites from an organism are related to a treatment or an effect
Acknowledgements:The Research School of Environmental Chemistry, Microbiology and ToxicologyAny Questions?TYFYA