In the present investigation, a series of dihydrotriazine derivatives-bearing 5-aryloxypyrazole moieties were synthesized and their structures were confirmed by different spectral tools. The biological evaluation in vitro revealed that some of the target compounds exerted good antibacterial and antifungal activity in comparison with the reference drugs. Among these novel hybrids, compound 10d showed the most potent activity with minimum inhibitory concentration values (MIC) of 0.5 µg/mL against S. aureus 4220, MRSA 3506 and E. coli 1924 strain. The cytotoxic activity of the compounds 6d, 6m, 10d and 10g was assessed in MCF-7 and HeLa cells. Growth kinetics study showed significant inhibition of bacterial growth when treated with different conc. of 10d. In vitro enzyme study implied that compound 10d exerted its antibacterial activity through DHFR inhibition. Moreover, significant inhibition of biofilm formation was observed in bacterial cells treated with MIC conc. of 10d as visualized by SEM micrographs. Twenty-nine target compounds were designed, synthesized and evaluated in terms of their antibacterial and antifungal activities.
Keywords: 5-Aryloxypyrazole; Antibacterial activity; DHFR inhibition; Dihydrotriazine; Growth kinetics.