The anticandidal properties of chlorinated 8-quinolinols

The in vitro anticandidal properties of six chlorinated 8-quinolinols (3-chloro-, 5-chloro-, 6-chloro-, 7-chloro-, 3,6-dichloro-, and 5,7-dichloro-8-quinolinols) were evaluated. Various concentrations of these compounds were added to cultures of Candida albicans and C. tropicalis grown in Sabouraud dextrose broth with and without bovine serum. The 5-chloro- and 6-chloro-8-quinolinols proved to be most effective at inhibiting the growth of C. albicans while 3,6-dichloro-8-quinolinol was most effective at controlling the growth of C. tropicalis. Cytotoxicity tests on baby hamster kidney (BHK) cells, however, demonstrated that the compounds tested were cytotoxic at their minimum inhibitory concentrations except for 3,6-dichloro-8-quinolinol which proved effective at inhibiting the growth of C. tropicalis at about one half the cytotoxic dose. Because this compound showed antifungal properties at concentrations that do not suppress mammalian cell growth, it merits further investigation as a possible topical or systemic anticandidal agent.