Submitted to: Angewandte Chemie
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/6/2006
Publication Date: 1/29/2007
Citation: Schroeder, F.C., Gibson, D.M., Churchill, A.C., Punchapat, S., Wursthorn, E.J., Krasnoff, S.B., Clardy, J. 2007. Differential Analysis of 2D NMR Spectra: New Natural Products from a Pilot-Scale Fungal Extract Library. Angewandte Chemie International Edition. 46:901-904. Interpretive Summary: Fungi are prolific producers of natural products, but it is clear from recent analysis of full genomes that only a fraction of the productive capabilities of these organisms have been discovered. In order to establish a more systematic means of evaluating the factors that might affect natural product metabolism, we used a novel two dimensional comparison of spectra obtained by nuclear magnetic resonance spectroscopy. In this pilot study, we characterized a small library of fungal extracts derived from a Tolypocladium cylindrosporum strain cultured on a variety of different media formulation, which quickly revealed two new terpenoid indole alkaloids under one set of conditions. This method may be useful for quickly evaluating crude fungal extracts for any unique chemical signatures prior to any chemical purification methods.
Technical Abstract: Using a newly developed protocol for the differential analysis of arrays of 2D NMR spectra, we were able to rapidly identify two previously unreported indole alkaloids from a library of unfractionated fungal extracts. Differential analyses of NMR spectra thus constitute an effective tool for the non-discriminatory characterization of secondary product mixtures.