Modification of Biphenolic Anti-Bacterial to Achieve Broad-Spectrum Activity.

The Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria, Acinetobacter baumannii, are pathogens responsible for millions of nosocomial infections worldwide. Due to the threat of bacteria evolving resistance to antibiotics, scientists are constantly looking for new classes of compounds to treat infectious diseases. The biphenolic analogs of honokiol that were most potent against oral bacteria had similar bioactivity against MRSA. However, all the compounds proved ineffective against A. baumannii. The inability to inhibit A. baumannii is due to the difficult-to-penetrate lipopolysaccharide-coated outer membrane that makes it challenging for antibiotics to enter Gram-negative bacteria. The C 2 scaffold was optimized from the inhibition of Gram-positive bacteria to broad-spectrum antibacterial compounds that inhibit the dangerous Gram-negative pathogen A. baumannii.