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 Ames 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)