Antibacterial Activity of 2-(3',5'-Dibromo-2'-methoxyphenoxy)-3,5- dibromophenol Isolated from Phyllospongia papyracea.

A principal active antimicrobial compound, 2-(3',5'-dibromo-2'-methoxyphenoxy)-3,5-dibromophenol, was isolated from the methanol extract of Phyllospongiapapyracea via bioassay-guided fractionation and isolation. The crude extract and the purified compound were assayed to determine the minimal - inhibitory concentration and minimal bactericidal concentration (MBC) using the broth. microdilution method. The purified compound was found to be highly active against Bacillus subtilis and Staphylococcus aureus at MIC=1 μg/mL, Campylobacter jejuni at MIC=2 gg/mL, Pseudomonas aeruginosa at MIC=4 μg/mL; and Streptococcus pneumoniae and Listeria monocytogenes at MIC = 8 μg/mL. The activity of this compound was found to be comparable with antibiotics commonly used to control these species of bacteria. The results establish 2-(3',5'-dibromo-2'-methoxyphenoxy)-3,5-dibromopheno as a potential lead molecule for the development of antibacterial agents.