Highly Brominated Antimicrobial Metabolites from a Marine Pseudoalteromonas sp.

Extracts of a marine Pseudoalteromonas sp. (CMMED 290) isolated from the surface of a nudibranch collected in Kaneohe Bay, Oahu, displayed significant antimicrobial activity against methicillin-resistant Staphylococcus aureus. Bioassay-guided fractionation of the lipophilic extract led to the isolation and structure elucidation of two new highly brominated compounds, 2,3,.5,7-tetrabromobenzofuro[3,2-b]pyrrole (1) and 4,4',6-tribromo-2,2'-biphenol (2). In addition, we have identified the known compounds pentabromopseudilin and bromophene. We describe the isolation and structure elucidation of the compounds 1 and 2 together with their antimicrobial activities against methicillin-resistant Staphylococcus aureus.