title: Antifungal activity of substituted 8-quinolinol-5- and 7-sulfonic acids: a mechanism of action is suggested based on intramolecular synergism.
abstract: 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.
authors.affiliation: Harding Laboratory, The New York Botanical Garden, Bronx, New York 10458, USA.
authors.forename: Herman
authors.initials: H
authors.lastname: Gershon
authors.forename: Muriel
authors.initials: M
authors.lastname: Gershon
authors.forename: Donald D
authors.initials: DD
authors.lastname: Clarke
mesh_terms: 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
chemical_list: D000935:Antifungal Agents; D011804:Quinolines; D013451:Sulfonic Acids