Lodopyridones D - G from a marine-derived bacterium Saccharomonospora sp.

The intensive investigation of chemical components from the culture broth of the bacterium Saccharomonospora sp. CNQ-490 has yielded four new natural products, lodopyridones D - G ( 1 - 4 ) along with the previously reported compounds, lodopyridones A - C ( 5 - 7 ) and cotteslosin A ( 8 ). The planar structures of the lodopyridones D - G ( 1 - 4 ) were elucidated by interpreting the mass spectrometry, ultraviolet (UV) spectroscopy, and 1D and 2D nuclear magnetic spectroscopy (NMR) data, as well as comparing NMR data with those of the lodopyridones A - C ( 5 - 7 ).