Two Diketopiperazines and One Halogenated Phenol from Cultures of the Marine Bacterium,Pseudoalteromonas luteoviolacea

Abstract
Two diketopiperazines, cyclo-(L-prolyl-L-glycine) and cyclo-(L-phenylalanyl-4R-hydroxy-L-proline), and 2,4-dibromo-6-chlorophenol were isolated from cultures of the marine bacterium, Pseudoalteromonas luteoviolacea. Cyclo-(L-prolyl-L-glycine) and cyclo-(L-phenylalanyl-4R-hydroxy-L-proline) stimulated antibiotic production in this strain. 2,4-Dibromo-6-chlorophenol showed antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) and the cystic fibrosis associated pathogen Burkholderia cepacia.