Antifungal activity of some mono, bis and quaternary Mannich bases derivedfrom acetophenone

The development of resistance to current antifungal therapeutics drives sea rch for new effective agents. Some Mannich bases have antifungal activity, but no information is available regarding the antifungal activity of acetop henone derived Mannich bases. Mono Mannich bases of acetophenone 1-3 were s ynthesized and converted into their corresponding bis derivatives, 5-7. Rep resentative quaternary derivatives 4 and 8 were also synthesized. Antifunga l activities of the compounds were evaluated using some yeasts and dermatop hytes in vitro. Mono Mannich base 3 and quaternary compounds 4 and 8 were f ound to be 2-16 times more potent than the reference compound amphotericin B against dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum canis. Compounds 4 and 8 were also found to be 2 times more effective compared with amphotericin B against the yeast Saccharomyces cer evisiae. Quaternization procedure Improved the biological activity dramatic ally, whereas conversion of mono Mannich bases to corresponding bis derivat ives generally did not affect antifungal activity. Our results suggest that acetophenone derived mono Mannich base 3 and quaternary derivatives 4 and 8 may serve as leading compounds for further studies to develop new antifun gal agents with their highly potent antifungal activity.