Antifungal activity of substituted 8-quinolinol-5- and 7-sulfonic acids: a mechanism of action is suggested based on intramolecular synergism.
8-Quinolinol-5-sulfonic acid was nearly devoid of antimicrobial activity, due to what was believed to be an unfavorable partition coefficient. Since twenty six 8-quinolinol-5- and 7-sulfonic acids were available from our previous work, they were tested against six fungi. The 7-chloro and 7-bromo-5-sulfonic acids and the 5-chloro and 5-bromo-7-sulfonic acids showed fungal inhibition within one order of magnitude of that of 8-quinolinol. It is suggested that a nonchelating mechanism is in part responsible for this fungitoxicity. Five additional 5-sulfonic acids with chlorine in positions 3-, 6-, 3,6-, 3,7-, and 6,7- that were suitable for studies in synergism became available more recently. The enhanced activities of the dichlorosulfonic acids over the correspondingly substituted monochlorosulfonic acids is attributed to intramolecular synergism.
Gershon
Herman
H
Harding Laboratory, The New York Botanical Garden, Bronx, New York 10458, USA.
Gershon
Muriel
M
Clarke
Donald D
DD
D000935:Antifungal Agents / Q000494:pharmacology*; D001234:Aspergillus niger / Q000187:drug effects / Q000378:metabolism; D001236:Aspergillus oryzae / Q000187:drug effects / Q000378:metabolism; D004357:Drug Synergism; D008826:Microbial Sensitivity Tests; D009089:Mucor / Q000187:drug effects / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013451:Sulfonic Acids / Q000494:pharmacology*; D014242:Trichoderma / Q000187:drug effects / Q000378:metabolism; D014249:Trichophyton / Q000187:drug effects / Q000378:metabolism
D000935:Antifungal Agents; D011804:Quinolines; D013451:Sulfonic Acids