5-N-Acetylardeemin, A Novel Heterocyclic Compound which Reverses Multiple Drug Resistance in Tumor Cells: II. Isolation and Elucidation of the Structure of 5-N-Acetylardeemin and Two Congeners

Abstract

A family of novel compounds has been detected and isolated following an assay for the attenuation of multiple drug resistance in tumor cells from the fermentation broth and mycelia of a strain of Aspergillus fischeri which we have designated var. brasiliensis. The structures of three components were determined employing 1-D and 2-D homonuclear and heteronuclear NMR spectroscopy and mass spectrometry. The structure of 5-N-acetylardeemin was confirmed by single crystal X-ray diffraction. These compounds are most closely structurally related to asnerlicin E1). © 1993, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.