Ligiamycins A and B, Decalin-Amino-Maleimides from the Co-Culture of sp. and sp. Isolated from the Marine Wharf Roach, .

sp. GET02.ST and sp. GET02.AC were isolated together from the gut of the wharf roach,  , inhabiting the intertidal zone of the west coast of Korea. The co-cultivation of these two strains significantly induced the production of two new metabolites, ligiamycins A () and B (), which were barely detected in the single culture of sp. GET02.ST. The planar structures of ligiamycins A () and B () were elucidated as new decalins coupled with amino-maleimides by the analysis of various spectroscopic data, including nuclear magnetic resonance (NMR), ultraviolet (UV), and mass (MS) data. The assignment of two nitrogen atoms in amino-maleimide in was accomplished based on H-N heteroatom single quantum coherence spectroscopy (HSQC) NMR experiments. The relative configurations of the ligiamycins were determined using rotating frame Overhauser effect spectroscopy (ROESY) NMR data, and their absolute configurations were deduced by comparing their experimental and calculated optical rotations. Ligiamycin A () displayed antibacterial effects against and , while ligiamycin B () exhibited mild cell cytotoxicity against human colorectal cancer cells.