Absolute Configurations of Globosuxanthone A and Secondary Metabolites from Microdiplodia sp. – A Novel Solid‐State CD/TDDFT Approach

The absolute configuration of a potent new antitumor dihydroxanthenone, globosuxanthone A (1), active against human solid tumor cell lines and isolated by Gunatilaka et al. from Chaetomium globosum Ames1 and in this study from the endophytic fungus Microdiplodia sp., was established by a new methodology. In this new approach, the Cartesian coordinates of the X-ray data serve as input geometry for quantum mechanical calculation of the theoretical CD spectrum. Comparison with the solid-state CD spectrum gives a very good match, since the calculated and the experimentally acquired data are derived from the very same single conformation. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)