8-Hydroxyquinolines with the potential for long-term anticaries activity: design, synthesis, and in vitro evaluation

8-Hydroxyquinolyl benzoate and 8-hydroxyquinolyl para-(fluorosulfonyl)benzoate have been synthesized and evaluated in vitro as antimicrobial and antiplaque agents. Both compounds inhibited the growth of cultures of the following genera: Streptococcus, Staphylococcus, Actinomyces, Lactobacillus, Veillonella, and Candida. Minimum inhibitory concentrations ranged from 0.98 to 62 microgram/ml. Extracted human teeth pretreated with 1% solutions of either compound and rinsed with distilled water exhibited reduced in vitro plaque formation for 48 hours. These results indicate that the in vitro antiplaque activity of 8-hydroxyquinolines can be enhanced by attaching the appropriate side chain in the 8-position.