Symmetrical Acyclic Aryl Aldazines with Antibacterial and Antifungal Activity

A series of 22 symmetrical acyclic aromatic aldazines were obtained and their qualitative antimicrobial activities were evaluated against 10 bacterial and 3 fungal species. The results demonstrated that the bi- and polycyclic aromatics studied are remarkably more active than benzaldazines. The latter possess antibacterial activities only, which were dramatically reduced by the introduction of substituents. The tests showed that the activities are strongly dependent on the type and position of the substituents and that the effects on antibacterial and antifungal activities are the opposite. 2-Naphtaldazine was significantly more active than its position isomer 1-naphthaldazine against Saccharomyces cerevisiae and Penicillium chrysogenum, whereas both compounds possess commensurable activities towards Candida tropicalis and the bacterial strains. From the other side, the presence of 4-hydroxy substituent in 1-naphthaldazine reduced the antibacterial and increased the antifungal activities, while the influence of 2-hydroxy group led to reversed results.