Biologically active metabolites from fungi, 9. New palmarumycins CP4a and CP5 from Coniothyrium palmarum: Structure elucidation, crystal structure analysis and determination of the absolute configuration by CD calculations

Abstract Two new palmarumycins CP 4a ( 2 ) and CP 5 ( 3 ) with an unusual bridged structure were isolated from Coniothyrium palmarum . The structure and relative configuration was elucidated by NMR and X-ray studies; the absolute configuration was determined by CD calculations.