Synergistic Inhibitions of Gram‐Negative Bacteria by Combination Treatment with Ciprofloxacin and a Novel Glucolipid

Abstract

AbstractPsychrophilic fungus Pseudogymnoascus sp. OUCMDZ‐4032 derived from Antarctica was cultivated under 16 °C to produce a new glucolipid compound (1). Its structure was elucidated by analysis of detailed spectroscopic data, acid hydrolysis and 1‐phenyl‐3‐methyl‐5‐pyrazolone precolumn derivatization, and 13C NMR quantum chemical calculations. Though compound 1 did not show inhibitory activity against bacteria, it can reduce the minimum inhibitory concentration (MIC) of ciprofloxacin against Gram‐negative bacteria Pseudomonas aeruginosa, Escherichia coli, and Salmonella paratyphi by 1024, 256 and 256‐fold. Compound 1 showed potential as a synergistically inhibiting adjuvant in co‐administration with antibiotic to enhance antibacterial activities.