Quinolactacins A, B and C:: Novel quinolone compounds from Penicillium sp EPF-6 II.: Physico-chemical properties and structure elucidation

Three novel quinolone compounds, quinolactacins A (1), B (2) and C (3), have been found from the fermentation broth of Penicillium sp. EPF-6, a fungus isolated from the larvae of mulberry pyralid (Margaronia pyloalis Welker). The molecular formulas of 1, 2 and 3 were determined to be C16H18N2O2, C15H16N2O2 and C16H18N2O3, respectively by FAB-MS and NMR spectral analyses. The structures of these compounds have a novel quinolone skeleton with a gamma -lactam ring consisting of C12H8N2O2 as the common chromophore.