Letter	Planta Med 2004; 70: 1087-1090 DOI: 10.1055/s-2004-832653
© Georg Thieme Verlag KG Stuttgart · New York
Potent Antibacterial Activity of Halogenated Compounds against Antibiotic-Resistant Bacteria
Charles Santhanaraju Vairappan1, Tomotake Kawamoto2,4, Hideaki Miwa3, Minoru Suzuki2,5
1 Laboratory of Marine Natural Product Chemistry, Borneo Marine Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia 2 Division of Material Science, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan 3 Discovery Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan 4 Present address: Tama Laboratory, Japan Food Research Laboratories, Tama, Japan 5 Present address: Borneo Marine Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia

Abstract

Common Gram-positive clinical pathogens are showing an increasing trend for resistance to conventional antimicrobial agents. New drugs with potent antibacterial activities are urgently needed to remediate this problem. Halogenated compounds isolated from several species of the red algae genus Laurencia were examined for their antibacterial activity against 22 strains of human pathogenic bacteria, 7 strains of which were antibiotic-resistant bacteria. Four phenolic sesquiterpenes and a polybrominated indole showed wide spectra of antibacterial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae, and vancomycin-resistant Enterococcus faecalis and E. faecium (VRE). In addition, laurinterol and allolaurinterol displayed potent bactericidal activity against three strains of MRSA at 3.13 μg mL^-1, and three strains of vancomycin-susceptible Enterococcus, at 3.13 μg mL^-1 and 6.25 μg mL^-1, respectively.