Reisolation and Configurational Reinvestigation of Cottoquinazolines E-G from an Arthropod-Derived Strain of the Fungus .

The reported fumiquinazoline-related alkaloids cottoquinazolines E-G (-) were reisolated from solid cultures of the fungus , which was isolated from the medicinal arthropod . The unresolved issues regarding the absolute configurations (for cottoquinazolines E and F) prompted a reinvestigation of the configurations for all three compounds, as enabled by extensive spectroscopic methods, comparisons of experimental electronic circular dichroism data, and X-ray crystallography. In addition, cottoquinazoline F () showed significant antibacterial activity against ESBL-producing , , , and with MIC values of 8, 32, 32, and 16 μg/mL, respectively.