The Mode of the Antifungal Activity of Gemini-Pyridinium Salt against Yeast

摘要

The gemlni quaternary salt (gemini-QUAT) containing two pyrldinlum residues per molecule, 3,3'-(2,7-dioxaoctane)bls(1-decylpyridinlum bromide) (3DOBP-4,10), exerted funglcldal activity against Saccharomyces cerevisiae accompanied by respiration Inhibition and the cytoplasmic material leakage of ATP, magnesium, and potassium Ions. We previously found that geminl-QUAT exerted bacterloclastic action against Escherichia coll by causing the rapid and abundant leakage of turbid materials from the cells. In addition, the first stage of the bacterloclastic action was the leakage of magnesium ions, outer membrane protein E, ATP, and llpopolysaccharides. Here, we Investigated how the gemini-QUAT 3DOBP-4,10 exerts fungicidal action against S. cerevisiae. The results showed that that greater than or equal to 0.4 mu M 3DOBP-4,10 stopped respiration and that greater than or equal to 3.0, 1.0 and 1.0 mu M caused the leakage of cytoplasmic components ATP, magnesium and potassium Ions, respectively. Scanning and transmission electron micrographs showed a preserved cell wall structure, whereas intracellular organelles were destroyed In cells Incubated with 3DOBP-4.10. We postulated that 3DOBP-4,10 exerts Its fungicidal action against S. cerevisiae not through cell wall destruction and protein leakage, but rather by penetrating the cell wall and disrupting the membranes of organelles.